Objective Identification and analysis of the gene family members, its structures and expression patterns of DNA methyltransferase (IbC5-MTase) and demethylase (IbdMTase) will provide theoretical support for in-depth exploration of the molecular basis and biological functions of DNA methylation in sweetpotato. Method The physicochemical properties, sequences, evolution and structures of the IbC5-MTase and IbdMTase gene family members were analyzed by bioinformatic methods. The expressions of IbC5-MTase and IbdMTase in different sweetpotato tissues, and under abiotic and biotic stress conditions were analyzed by integrating transcriptome data with RT-qPCR. Result A total of seven IbC5-MTase genes and four IbdMTase genes were identified in the whole genome of sweetpotato, distributed across 8 linkage groups. The IbC5-MTase and IbdMTase proteins contain 355-1 305 amino acids (aa), with theoretical isoelectric points (pI) ranging from 4.81 to 9.81. Subcellular localization predictions indicate that nine proteins are in the nucleus. Phylogenetic analysis showed the IbC5-MTase and IbdMTase proteins are classified into four and three subfamilies, respectively. Conserved motif analysis demonstrated distinct motif compositions between two protein types. Promoter regions of both gene families were enriched with cis-regulatory elements associated with light responsiveness, hormonal regulation, and stress adaptation. Tissue-specific expression profiling revealed relatively high expression levels of IbDRM2 and IbCMT3b, with overall higher expression of both gene families in aerial tissues as compared to roots, particularly in young tissues. Transcriptome analysis under abiotic stresses demonstrated widespread expression reprogramming of these genes during salt, drought, and cold adaptation. Stem nematode infection triggered distinct transcriptional responses, IbCMT3a and IbDRM2 were significantly downregulated, whereas IbCMT3b and IbROS1 were upregulated, as validated by RT-qPCR. Conclusion The IbC5-MTase and IbdMTase genes of sweetpotato have potential functions under biotic and abiotic stresses.

Objective MYB transcription factors are primarily participate in the biosynthesis of flavonoids and anthocyanins. To explore MYB transcription factors in regulating anthocyanin biosynthesis in cassava leaves and verify its biological function would provide a theoretical basis for elucidating the molecular mechanisms of anthocyanin synthesis and leaves color improvement in cassava (Manihot esculenta Crantz). Method The coding sequence of MeMYB106 was cloned using cDNA from South China 9 (SC9) leaves as a template. Transient expression in tobacco was performed to determine its subcellular localization. RT-qPCR was applied to analyze the expression patterns of MeMYB106 in different tissues and differently colored leaves. Virus-induced gene silencing (VIGS) was employed to investigate the gene function in anthocyanin synthesis. Yeast one-hybrid assays and dual luciferase reporter assay were used to examine the regulatory relationship between MeMYB106 and anthocyanidin reductase (MeANR) gene. Result A MeMYB106 gene was cloned from SC9 leaves, with a coding region of 1 194 bp encoding 398 amino acids. The subcellular localization revealed that MeMYB106 was localized in the nucleus. Tissue-specific expression analysis showed that MeMYB106 was highly expressed in SC9 leaves, axillary buds, and stems, with significantly higher expression in green-leaves varieties compared with purple-leaves varieties. Silencing MeMYB106 in SC9 resulted in purple pigmentation in newly emerged leaves, with varying degrees of purple pigmentation depending on silencing efficiency. The anthocyanin content in the leaves of silenced plants was significantly higher than that in empty vector control. Further analysis demonstrated that MeMYB106 bound to the promoter region of MeANR to enhance its expression, thereby influencing anthocyanin biosynthesis in cassava leaves. Conclusion MeMYB106 transcription factor in cassava negatively regulate the biosynthesis of anthocyanins, and MeMYB106 positively regulate the expression of MeANR. Silencing MeMYB106 promotes anthocyanin accumulation in cassava leaves.

Objective To identify key genes regulating anthocyanin accumulation in the tubers of colored potatoes (Solanum tuberosum L.), provide genetic resources and technical references for potato molecular breeding. Method GARP transcription factors were screened based on transcriptome sequencing data of purple potato tubers at different developmental stages. Bioinformatics analysis was conducted, and functional verification of StARR14-X1 gene related to anthocyanin regulation was performed. Result The 12 GARP transcription factors were screened through transcriptome data. The amino acid sequence lengths of 12 GARP transcription factors were concentrated between 148-686 aa, the molecular weight ranged from 16.66 to 75.44 kD, the pI value ranged from 5.13 to 8.05, the fatty index ranged from 71.36 to 97.36, and the instability coefficient ranged from 35.59 to 75.94, all of which belonged to hydrophilic proteins. Subcellular localization prediction showed that 12 GARP transcription factors were distributed in the nucleus, cytoplasm and chloroplasts. The StARR14-X1 gene was successfully transformed into tetraploid tobacco using the Agrobacterium-mediated leaf disc method, and transgenic tobacco plants overexpressing StARR14-X1 were obtained. The anthocyanin contents in the stems and petals of StARR14-X1-overexpressing transgenic lines increased significantly. Conclusion StARR14-X1 gene has a positive regulatory function in anthocyanin accumulation and promotes anthocyanin accumulation.

Objective To study the function of the MeSWEET2b gene in cassava (Manihot esculenta Crantz) under low-temperature stress, and to provide theoretical basis for exploring the molecular mechanism of cassava tolerance to cold and breeding new varieties with low-temperature tolerance. Method Bioinformatics method was used to analyze the sequence characteristics, phylogenetic relationships of the MeSWEET2b gene. Transient expression of the MeSWEET2b protein in tobacco was to determine its subcellular localization. RT-qPCR was adapted to analyze the expressions of the MeSWEET2b gene at different growth stages, under darkness treatments of different sugar and low-temperature stress. Virus induced gene silencing (VIGS) technology was applied to study the function of this gene under low-temperature stress. Result The MeSWEET2b protein had 7 transmembrane domains, and phylogenetic tree analysis indicated that it belonged to the SWEETs Clade I subfamily and had the closest homology with Arabidopsis AtSWEET2. The subcellular localization results showed that MeSWEET2b was located on the cell plasma membrane. The RT-qPCR analysis showed that MeSWEET2b had the highest expression in the leaves during the expansion period (7 months). For the water culture seedlings of cassava treated with different sugars, the expression trends of MeSWEET2b in glucose and fructose were consistent. As the temperature of cold stress decreased and the time extended, the expression of MeSWEET2b in cassava showed a significantly increased. Using VIGS technology to silence MeSWEET2b, under 4 ℃ low-temperature stress, the wilting of the leaves in the MeSWEET2b silenced plants were significantly more severe than that of the control, and the contents of glucose and fructose significantly reduced. Conclusion The silencing of MeSWEET2b gene led to the intolerance of cassava to low temperatures. It is speculated that this gene plays an important role in the cold tolerance of cassava.

Objective Late embryogenesis abundant proteins (LEA) are important genes that regulate plant growth and development as well as responses to abiotic stress. This study aimed to investigate the biological function of StLEA_2 genes, so as to provide a theoretical basis and genetic resources for improving potato tolerance to cold. Method Members of the LEA_2 gene family were identified from the potato genome, and their physicochemical properties, subcellular localization, gene structure, evolutionary features and cis-acting elements were analyzed. Transcriptome and RT-qPCR analyses were employed to examine the expression patterns of StLEA_2 under cold stress, jasmonic acid (JA) and gibberellic acid (GA) treatments. The function of StLEA37 in cold stress response was analyzed through Agrobacterium-mediated transient overexpression in tobacco. Result A total of 45 StLEA_2 genes were identified in cultivated potato (Solanum tuberosum L.), while 42 ScLEA_2 genes were identified in the cold-tolerant wild species (Solanum commersonii), all of them were classified into nine subgroups. Subcellular localization prediction indicates that members of the LEA_2 gene family are mainly localized in the cytoplasm and chloroplasts. Collinearity analysis revealed that there are 10 and 11 pairs of homologous genes in the LEA family of cultivated and wild potatoes, respectively. The promoters of StLEA_2 genes contain numerous light-, stress-, and hormone-responsive elements. Expression analysis indicated that 44 StLEA_2 genes are involved in responses to low-temperature stress. Under GA and JA treatments, the expressions of 39 and 43 genes, respectively, changed significantly. StLEA37 is localized on the plasma membrane, and its transient overexpression contributes to the regulation of plant cold stress tolerance by activating the COR-CBF regulatory pathway and reactive oxygen species scavenging mechanisms. Conclusion A total of 45 StLEA_2 genes were identified in the potato genome. StLEA37 is localized on the plasma membrane and may participate in plant responses to cold stress by affecting the COR-CBF pathway and ROS scavenging mechanisms, as well as by mediating GA and JA signaling pathways.

Objective Studying the relationship between the CBF/DREB1 family members and the salt tolerance and drought tolerance may provide scientific references for breeding new potato germplasms with excellent stress resistance. Method The expression patterns of potato CBF/DREB1 family members under salt and drought stresses were detected by RT-qPCR technology, and the key gene was screened. Potato transgenic lines with overexpression and knockdown expression were constructed to detect the function of the key gene in response to salt and drought stresses. Meanwhile, the action mechanism of the key gene was analyzed by detecting subcellular localization and screening the interaction proteins. Result Based on the RT-qPCR detection results, the StDREB4 gene was selected as the research object for functional analysis. The results of growth phenotype and physicochemical index detection showed that the overexpressing lines had more obvious phenotypic and index changes. Under salt stress, the overexpression of StDREB4 reduced the root length, fresh weight, root activity, photosynthetic capacity, antioxidant capacity and osmotic regulatory substance content of plants, as well as increased MDA content, thereby reducing the tolerance of potatoes to salt. However, under drought stress, the relevant indicators of plants overexpressing StDREB4 were superior to those of wild-type lines, which enhanced the tolerance of potatoes to drought. In addition, StDREB4 was located in the nucleus and had transcriptional activation activity. Three important interacting proteins, including EBF protein, DSK2A protein and PSMB3 protein, were screened out using yeast two hybrid technology. Conclusion The overexpression of StDREB4 may be involved in the ethylene signaling process through the ubiquitin degradation pathway, regulating multiple physicochemical index parameters, thereby reducing the tolerance of potatoes to salt and enhancing its tolerance to drought.

Objective The MADS-box transcription factor family is widely involved in plant growth, development, and floral organ formation. This study systematically analyzes the function of core MADS-box transcription factors across 51 potato genomes, aiming to provide a theoretical basis and genetic resources for molecular breeding in potato (Solanum tuberosum L.). Method Based on whole-genome data from 33 wild and 18 cultivated diploid potatoes, core MADS-box genes were identified. Bioinformatics analysis was conducted to investigate their physicochemical properties, phylogenetic relationships, chromosomal distribution, and conserved domains. Expression patterns were analyzed by integrating transcriptome data and RT-qPCR. Their biological functions were inferred through GO enrichment analysis, exogenous hormone treatment, and comparison with functionally characterized homologous genes from major crops. Collinearity analysis was also performed on closely related species. Result A total of 95 common MADS-box genes, referred to as core genes, were identified across 51 diploid potatoes, classified into two major subfamilies: Type I (Mα, Mβ, Mγ) and Type II (MIKC*, MIKCc). Physicochemical analysis indicated that these proteins are generally hydrophilic and unstable. Phylogenetic and structural analyses revealed that each subfamily possesses characteristic motifs and domains. Chromosomal mapping showed that the genes are clustered on chromosomes Chr01, Chr04, Chr05, and Chr12. Expression pattern analysis indicated that several MIKC^c-type genes are specifically expressed in floral buds, stolons, and other tissues. GO enrichment analysis demonstrated that this family is involved in floral organ development and hormone response processes. Hormone response analysis revealed that the expressions of key candidate genes are suppressed by GA₃ and induced by ABA. Phylogenetic comparison with functional genes such as OsMADS29 from rice suggested that some genes may participate in tuber development and yield formation. Collinearity analysis revealed 37 conserved MADS-box genes between potato and its close relatives, with some genes exhibiting translocation variations. Conclusion The MADS-box gene family in potatoes retains conserved functions in regulating floral and tuber development during evolution. Candidate genes such as DM8C02G24490.1 and DM8C03G29590.1, which are associated with seed development and tuber formation, provide important targets for subsequent functional validation and breeding improvement.

Objective Chromosome ploidy identification is an important step in evaluating sweetpotato germplasm resources. To overcome the limitations of traditional methods in sweetpotato sampling, this study optimized the application of flow cytometry for ploidy identification, established an efficient method, and provided a foundation for subsequent large-scale identification of sweetpotato materials with different ploidy levels. Method Using ‘Xuzishu 8’ as the experimental material, this study systematically compared the effects of the liquid nitrogen-ground leaf method and the blade-chopped root tip method in preparing cell nucleus suspensions. The comparison focused on nucleus yield, sample preparation time, and the quality of flow cytometry profiles. To address the difficulty of sampling precious materials, we explored the feasibility of ploidy identification using fully expanded mature sweetpotato leaves by adjusting the concentrations of MgSO₄·7H₂O, DTT, and Triton X-100 in the lysis buffer. The method was validated by individual and mixed detection of materials with different ploidy levels. Result The liquid nitrogen-ground leaf method significantly improved preparation efficiency while maintaining detection accuracy, and both the crushing step and the on-machine detection time per sample were markedly reduced. For mature leaf identification, doubling the concentrations of DTT and Triton X-100 in the lysis buffer remarkably increased the release of intact nuclei, successfully overcoming the difficulty of detecting mature leaves. This method showed excellent resolution in both individual and mixed detection of diploid, tetraploid, and hexaploid materials, and the observed fluorescence intensity ratio was highly consistent with the theoretical ploidy ratio (1:2:3), confirming its stability and universality. Conclusion For sweetpotato ploidy identification, the flow cytometry method improved by the liquid nitrogen-ground leaf approach is not restricted by sampling limitations such as root tip dependence, and can rapidly and accurately determine the ploidy of sweetpotato materials and facilitate material screening.

Objective To establish an efficient regeneration and genetic transformation system for potatoes (Solanum tuberosum L.) variety ‘Xinjiang No. 2’, and to provide technical support for virus-resistant breeding. Method Using ‘Xinjiang No. 2’ potato as the experimental material, Agrobacterium-mediated transformation was employed to introduce the plant interference vector plasmid pCAMBIA2300-CP-RNAi into potato stem explants. The effects of pre-culture duration, plant hormone combinations, and types and concentrations of antibiotics on callus induction and shoot differentiation were investigated. By real-time quantitative PCR (RT-qPCR) technology, with the Actin gene as an internal reference, the mRNA expression of the CP gene was detected. The actual content of PVY virus in plants was quantitatively measured using enzyme-linked immunosorbent assay (ELISA) to validate the RNAi silencing effect and virus suppression. Result The optimal hormone and antibiotic combination for callus induction was 2.0 mg/L 6-BA + 0.8 mg/L 2,4-D + 50 mg/L Kan + 200 mg/L TMT when pre-culture and co-culture durations were both 2 days, achieving an induction rate of 85%. The callus showed a compact morphology, fresh green color, and a dumbbell-shaped swelling at both ends of the stem segments. For shoot differentiation, the optimal hormone and antibiotic ratio was 2 mg/L 6-BA + 2 mg/L ZT + 0.5 mg/L GA₃ + 50 mg/L Kan + 200 mg/L TMT, resulting in the highest germination and transformation rates, with well-developed seedlings. Transgenic seedlings regenerated into plants on 1/2 MS medium supplemented with 0.6 mg/L IAA + 75 mg/L Kan + 200 mg/L TMT, demonstrating robust root systems. Compared to non-transformed control plants, the relative expression of the CP gene in transgenic plants was significantly downregulated, and PVY virus content was markedly reduced, confirming that the constructed RNAi vector successfully triggered specific gene silencing and effectively inhibited virus accumulation in plants. Conclusion This study successfully establishes a stable and efficient genetic transformation system for the potato variety ‘Xinjiang No. 2’. The constructed RNAi interference vector effectively suppresses Y virus accumulation in plants.

Objective Cassava (Manihot esculenta Crantz) is one of the most important economic and food crops in the world. The problem of postharvest physiological deterioration (PPD) causes a serious impact on the storage period and economic benefits. As a member of the glyoxalaseⅠ (GLYⅠ) family, the expressionof MeGLYI-13 was positively correlated with the PPD tolerance of cassava. In-depth analysis of the molecular mechanism of upstream regulation of MeGLYI-13 involved in cassava PPD tolerance may provide a new idea for exploring the molecular mechanism of cassava postharvest physiological deterioration process, and PPD-tolerant cassava germplasm innovation. Method The promoter region sequence of MeGLYI-13 was cloned and analyzed. The proMeGLYI-13-pAbAi bait vector was constructed and transformed into yeast cells to obtain the bait strain. The expression pattern analysis and interaction verification of candidate transcription factors were carried out by yeast one-hybrid screening library experiment using cassava cDNA library. Result The 2 000 bp upstream promoter sequence of MeGLYI-13 was successfully cloned. The sequence contained cis-acting elements responding to low temperature, drought, auxin, gibberellin, light, defense and stress. Through yeast one-hybrid screening, four candidate transcription factors were screened from cassava cDNA library, which were ethylene-responsive transcription factor ERF1 and AT-hook motif nuclear localization proteins AHL17, AHL29 and AHL31. The rotary verification test and dual luciferase test further confirmed that MeAHL17 played a negative regulatory role in the promoter activity of MeGLYI-13. Gene expression analysis showed that the expression trend of MeAHL17 was negatively correlated with PPD tolerance of cassava. Conclusion The combination of MeAHL17 and MeGLYI-13 promoter regulate gene expression, which may play a role in the physiological deterioration of cassava after harvest.

Objective Melatonin (MT) acts as a crucial signaling molecule in plant responses to biotic and abiotic stresses, its physiological effects exhibit a significant dose-response relationship. To investigate the impact and underlying mechanism of exogenous MT on potato late blight, and to identify the optimal concentration for suppressing Phytophthora infestans (P. infestans) infection, this study provides a theoretical foundation for the potential field application of MT. Methods Using the potato cultivar ‘Qingshu 9’ as material, different concentrations of MT (0, 300, 650, 1 300, 1 650, and 2 000 μmol/L) were sprayed on leaves continuously for three days (morning, noon, and evening) before inoculation with P. infestans. After pathogen infection, the control efficacy, antioxidant system, defense enzyme activities, and defense-related gene expression in potato plants were analyzed. Results Exogenous MT effectively inhibited the mycelial growth of P. infestans. MT concentrations ranging from 300 to 2 000 μmol/L enhanced the resistance of potato to late blight, with 1 300 μmol/L was identified as the optimal concentration based on DAB and trypan blue staining. Compared to the control, pretreatment with 1 300 μmol/L MT increased the activities of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), while reducing the accumulation of reactive oxygen species and malondialdehyde (MDA). Additionally, it enhanced the activities of defense-related enzymes such as chitinase (CHT), polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia-lyase (PAL), and significantly induced the expression of defense genes (StPR1, StPR5, StPOD, and StPPO). Conclusion Under P. infestans stress, MT treatment enhances potato resistance to late blight by inhibiting pathogen mycelial growth, improving the plant antioxidant capacity, activating defense enzyme activities, and inducing the expression of defense genes.

Objective To identify the AP2/ERF transcription factor family genes in the whole genome of potato (Solanum tuberosum) and analyze their expression patterns in different tissues and under Phytophthora infestans stress, this study aimed to provide a basis for elucidating the involvement of AP2/ERF family genes in potato responses to P. infestans infection. Method Bioinformatics approaches were used to systematically identify AP2/ERF family members in potato, followed by analyses of their phylogeny, chromosomal localization, gene structure, conserved motifs, and collinearity relationships. Combined with previously published transcriptome data, tissue-specific expression profiles and P. infestans-responsive expression patterns of these genes were characterized. Potato plants were inoculated with P. infestans at 0, 24, 48, and 72 h, and RT-qPCR was performed to detect differential expression of selected family members. Result A total of 179 AP2/ERF genes were identified in potato, which were clustered into 5 subfamilies and unevenly distributed across 12 chromosomes. Significant differences in motif, intron, and exon distributions were observed among subfamilies. Intraspecific collinearity analysis revealed 57 pairs of collinear AP2/ERF genes, while interspecific collinearity analysis identified 69 and 164 homologous gene pairs with rice (Oryza sativa) and Arabidopsis respectively. Tissue expression analysis indicated that AP2/ERF genes were involved in both vegetative and reproductive growth, with some showing tissue-specific high expression. Under P. infestans stress, most AP2/ERF genes were induced to varying degrees. Conclusion The AP2/ERF transcription factor family plays roles in potato growth and development, and rapidly responds to P. infestans stress.

Objective Phenacoccus manihoti is a major pest of cassava, and its cuticular wax layer serves as a critical barrier against external stresses. Identifying key genes involved in wax biosynthesis in P. manihoti and elucidating their expression patterns under the stress of insect-resistant versus insect-susceptible cassava varieties will provide a theoretical basis for pest control strategies targeting wax synthesis disruption. Method Based on annotations from the NR database and established knowledge of the insect wax biosynthesis pathway, wax synthesis candidate genes were initially screened from lipid metabolism-related genes. The expression profiles of these candidate genes were systematically analyzed by RT-qPCR in P. manihoti reared on a highly resistant cassava variety (C1115) versus a highly susceptible one (KU50). Subsequently, for those candidate genes whose expression peaks closely coincided with the critical wax secretion period of the mealybug and exhibited significant differential expression between insect-resistant and insect-susceptible hosts, their expression dynamics were further examined in insects reared on six cassava varieties with varying levels of resistance. The correlation between their expression levels and host resistance was assessed to identify key candidate genes. Finally, enzyme activity assays were performed focusing on these key candidates, and their association with host resistance was analyzed. Result A total of nine wax biosynthesis candidate genes were identified (FAR1/2, FAD1/2, ACC, FAS1/2, and ELO1/2). Among them, the expression peaks of FAR2, FAD1, ACC, and FAS1 closely coincided with the key wax secretion period of P. manihoti, and their expressions were significantly higher in insects reared on insect-susceptible cassava varieties than in those reared on insect-resistant ones. Furthermore, the expressions of FAR2, FAD1, and ACC showed significant negative correlations with host resistance. However, only total FAR enzyme activity showed a significant negative correlation with cassava resistance. Conclusion FAR2, FAD1, and ACC are three key genes that respond to host resistance and regulate wax biosynthesis. The suppression of FAR2 expression and total FAR enzyme activity in insects feeding on resistant cassava varieties likely represents a crucial mechanism limiting the adaptability of P. manihoti.

Objective To elucidate the biological functions and host target proteins of the effector Pi07555 from Phytophthora infestans. Methods The secretory activity of the signal peptide of effector Pi07555 was verified using the SignalP 6.0 online server and the yeast invertase secretion system. The virulence function of the Pi07555 gene was analyzed via combined assays including quantitative real-time PCR (RT-qPCR), Agrobacterium-mediated transient gene expression, and in vitro leaf inoculation. The host target protein of Pi07555 and the function of its encoding gene were identified through yeast two-hybrid (Y2H) assay, luciferase complementation imaging (LCI) assay, and virus-induced gene silencing (VIGS) technology. Results The Pi07555 gene encodes 170 amino acids, and the N-terminal signal peptide has secretory activity. The Pi07555 gene is upregulated at the early stage of pathogenic Phytophthora infection and is localized to the plant nucleus, cytoplasm, and cell membrane. The transient expression of Pi07555 promotes pathogenic Phytophthora infection but does not inhibit BAX and INF1-mediated hypersensitive cell death. The yeast two-hybrid and luciferase complementation imaging assays demonstrated that potato hypersensitive-induced reaction 1 (StHIR1) interacts with Pi07555. The StHIR1 gene is upregulated 48 hours after pathogenic Phytophthora infection, and silencing its homolog significantly increased the resistance of Nicotiana benthamiana to pathogenic Phytophthora. Conclusion Pi07555 is a secreted virulence effector that localizes to the plant nucleus, cytoplasm, and plasma membrane.

Shade avoidance syndrome (SAS) encompasses a series of morphological and physiological adaptive responses initiated by plants to cope with competitive shade environments. This is triggered by perceiving light signals such as a decreased red to far-red light ratio (R:FR) and reduced light intensity. SAS significantly impacts the light utilization efficiency of crop populations and their yield potential under high-density planting conditions. Plants perceive changes in environmental light quality primarily through a photoreceptor network centered on phytochromes (PHYs) and cryptochromes (CRYs). Under shade, the reduced activity of these two main photoreceptors cooperatively relieve inhibition on phytochrome-interacting factors (PIFs), leading to large PIF accumulation and the activation of downstream SAS-related gene transcription. As the core hub of signal integration, PIFs positively regulate the synthesis and signal transduction of growth-promoting hormones like auxins and gibberellins, driving cell elongation, while simultaneously suppressing defense signaling, reflecting the adaptive trade-off strategies of plants when competing for light resources. Furthermore, PIFs also mediate the close integration of SAS with signals such as circadian rhythm, carbon and nitrogen metabolism, temperature and salt stress, with its regulatory modules exhibiting both conservation and species-specificity across different crops. This review summarizes advances in SAS molecular mechanisms, systematically elucidating how PHYs and CRYs perceive light quality, and the complex regulatory networks where PIFs act as central hubs integrating hormonal, epigenetic, and circadian clock signals. It specifically compares differences in photosensory system evolution and signal transduction between C₃ and C₄ crops, and thoroughly discusses molecular breeding strategies, including genome and promoter editing. In addition, the review discusses the balance mechanism between SAS regulation, carbon-nitrogen metabolism, and abiotic stress responses. Future research can leverage single-cell multi-omics technologies to precisely dissect the spatiotemporally specific regulatory networks of SAS signals. This will facilitate the intelligent design of dense planting-tolerant ideotypes, providing robust theoretical guidance and technical support for high-yield crop breeding.

Seeds are recognized as the “chips” of agricultural production, and their germination, as the starting point of a crop’s life cycle, directly determines seedling emergence quality as well as crop yield and quality. Nitric oxide (NO), a key gaseous signaling molecule, has emerged as a research frontier in plant biology due to its central role in regulating seed dormancy and germination. This review systematically summarizes the current progress in this field, elucidating the primary synthesis and metabolic pathways of NO in plants and their homeostatic regulation. It focuses on dissecting the signal transduction mechanisms of NO, particularly its molecular basis for coordinately regulating key nodes of seed dormancy and germination through crosstalk with hormonal and reactive oxygen species (ROS) signaling networks as well as through post-translational modifications. Although significant progress has been achieved, several important scientific issues in this area still remain to be deeply explored. At the basic research level, future efforts should further be on resolving the spatiotemporal specificity of NO synthesis and signaling within different seed tissues and germination stages, utilizing multi-omics technologies to systematically identify downstream modification targets of NO and clarify their functions. Additionally, elucidating the molecular mechanisms underlying the integration of NO signaling with environmental signals such as light and temperature is essential. At the applied level, novel green seed treatment technologies based on NO can be developed to enhance seed germination performance and seedling resistance to stress under adverse conditions. Furthermore, exploring genetic or biotechnological approaches to modulate endogenous NO synthesis and metabolism pathways in seeds could improve crop germination traits, offering new strategies for breeding crop varieties with uniform emergence and enhanced stress resistance. By systematically synthesizing the regulatory mechanisms of NO in seed dormancy and germination, this review aims to provide a theoretical foundation for a deeper understanding of the molecular regulatory network governing the initiation of seed life, while also offering new insights for the development of key technologies to enhance crop seed quality and innovate stress-resilient cultivation models.

High-temperature stress is one of the main abiotic stresses leading to stunted growth, sharp yield reduction, and deterioration of fruit quality of strawberries in South China. Understanding the research status of the molecular response mechanisms of strawberry to high-temperature tolerance not only provides precise gene targets and theoretical support for the breeding of high-temperature-tolerant strawberry varieties, but also can guide the formulation of targeted cultivation and management measures such as sunshade cooling and spraying of stress-resistant regulators. These measures can effectively enhance the high-temperature resistance of strawberry plants, ensuring the stable annual output of the strawberry industry in South China and the improvement of the rate of high-quality fruits. This article reviews the latest research progress on the molecular response mechanisms of strawberry to high-temperature tolerance. Starting from the physiological effects of high-temperature stress on strawberries, the article systematically expounds on key molecular response pathways such as heat shock proteins, antioxidant systems, osmotic adjustment substances, and hormone signal transduction. Among them, the heat shock protein family can protect cell structures by maintaining protein homeostasis under high-temperature induction; in the antioxidant system, the activities of enzymes such as superoxide dismutase (SOD) and catalase (CAT) increase significantly, which work together to scavenge excessive reactive oxygen species (ROS) and reduce the damage of cell membrane lipid peroxidation. Osmotic adjustment substances enhance water retention capacity by increasing cell osmotic pressure. In hormone signal transduction, abscisic acid (ABA) and salicylic acid (SA) construct a multi-level heat tolerance regulatory network by regulating the expression of downstream stress-resistant genes. In addition, it also introduces the application of transcriptomics, proteomics, and metabolomics in the research on plant high-temperature tolerance, providing technical support for the analysis of the strawberry heat tolerance mechanism. These research results provide a theoretical basis for in-depth understanding of the molecular mechanisms underlying strawberry heat tolerance and stress-resistant cultivation, and also offer resources for accelerating molecular design breeding of high-temperature-tolerant strawberries.

Chinese herbal medicine derived extracellular vesicles-like particles (CHM-EVLPs) are a collective term for nanoscale vesicles secreted by various cells of medicinal plants. These vesicles are composed of a lipid bilayer membrane and encapsulate a variety of bioactive components, including nucleic acids, proteins, lipids, and small active molecules. Numerous studies have demonstrated that CHM-EVLPs possess cross-kingdom regulatory functions, such as excellent biocompatibility, high stability, skin penetration capability, potent targeting capabilities, and high safety, making them highly promising for applications in drug delivery systems and disease therapy. This review systematically summarizes the diverse extraction and purification techniques for CHM-EVLPs, compares their advantages and disadvantages, along with their characterization and identification methods. It provides a detailed analysis of the composition and functions of their internal cargo, including nucleic acids (such as miRNAs with gene regulatory functions), proteins, lipids, and small bioactive molecules. Furthermore, the review synthesizes the multiple biological activities of CHM-EVLPs, encompassing their roles in plant growth, development, metabolism, stress responses, material information transfer, and multiple bioactivities in mammalian systems, various bioactive effects and mechanisms including anti-inflammatory, anti-tumor and anti-cancer, antioxidant, and anti-osteoporosis activities. This review also discusses the potential applications of CHM-EVLPs as novel therapeutic agents and nanoscale drug carriers in fields including cancer therapy, inflammatory diseases, medical aesthetics, and skincare products. Despite the remarkable progress in CHM-EVLP research, challenges remain, including low extraction efficiency, the lack of standardized methods and biomarkers, unclear mechanisms of action, and difficulties in long-term storage. Future research should focus on developing efficient and scalable preparation processes, establishing a unified quality evaluation system, and deeply revealing the molecular mechanisms of their cross-kingdom regulation. Continuous exploration is needed to promote their practical application and industrialization in clinical treatment and health products, thereby facilitating the in-depth development and utilization of new medicinal plant resources.

Objective This study aims to efficiently utilize the Sorghum sudanense germplasm resources, and clarify the genetic relationships among the germplasms. Method Twenty-one pairs of highly polymorphic primers with clear electrophoresis bands were screened from 56 pairs of SSR primers. Polyacrylamide gel electrophoresis technology was used to detect the polymorphism of 29 S. sudanense germplasm materials. Genetic diversity analysis and cluster analysis were conducted based on molecular marker sites, and a fingerprint was constructed using the digital assignment method. Result A total of 258 polymorphic bands were detected, with each primer combination detected 6 to 29 bands, and the polymorphism ratio was 85.15%. Shannon’s information index ranged from 0.509 8 to 0.692 6, with an average of 0.659 7. The polymorphism information content was between 0.712 2 and 0.836 4, with an average of 0.775 4. Nei’s genetic diversity index ranged from 0.328 2 to 0.499 4, with an average of 0.467 5. European clustering analysis showed that when the genetic distance was 22.5 the 29 germplasms could be clustered into 4 major groups, and most of them were clustered by color and panicle shape. A fingerprint of S. sudanense containing 20 SSR marker loci was constructed, which can be used for the identification of germplasm materials. Conclusion The genetic diversity among 29 germplasm materials is relatively high. The construction of a fingerprint for S. sudanense using SSR molecular markers is simple and feasible to operate.

Objective To address the limitations of traditional methods for detecting starch granule size in mature maize kernels (such as laser diffraction particle size analysis), including cumbersome sample preparation, low efficiency, and poor accuracy, this study aimed to develop an efficient and accurate automatic analysis tool. This tool is intended to meet the demand for starch granule size measurement in maize yield and quality improvement, as well as in the production of specialty maize starch. Method Based on the YOLOv10 object detection algorithm, an automatic detection model for maize kernel starch granules was established and trained. A granule size analysis system was developed using the Django framework. Mature kernels from six representative maize inbred lines (B73, B104, KN5585, MO17, RP125, W22) were selected. Scanning electron microscopy (SEM) images of their endosperms were acquired. Starch granule size of the six inbred lines endosperms was analyzed using the developed system. Result Model evaluation indicates that the constructed starch granule detection model has an accuracy rate of 0.812, a recall rate of 0.843, and an average precision (AP) of 0.895. The developed system supports batch uploading of kernel endosperm SEM images by users. It utilizes the trained model to automatically identify starch granules within the images, analyzes and calculates the size data for each detected granule, and ultimately outputs the results in an Excel file. Analysis of starch granules from the six maize inbred lines revealed significant differences in mean granule diameter among them. MO17 showed the largest mean starch granule diameter (15.46 µm), while RP125 presented the smallest (10.61 µm). Compared with manual starch granule size measurements from SEM images, the system-generated granule size data demonstrates reliability, offering significant advantages in labor-saving and time-efficiency, with a substantial improvement in work productivity. Conclusion This study developed a maize kernel starch granule size analysis system based on the YOLOv10 object detection algorithm and the Django framework. The system enables the rapid, batch, and accurate automatic identification of starch granules in maize endosperm SEM images and analysis of their size. It effectively overcomes the limitations of traditional methods, providing a convenient, efficient, and accurate granule size analysis tool.

Objective Dongnong Winter Wheat 1 (Dn1) is the first highly cold-tolerant winter wheat (Triticum aestivum) variety suitable for large-scale cultivation in high-latitude cold regions, with an overwintering survival rate exceeding 85% after winter. This study was conducted to investigate the function of the TaMYBS1-like gene in winter wheat and its expression responses to low-temperature and drought stress. Methods The cDNA sequence of the TaMYBS1-like gene from winter wheat (Dn1) was cloned using RT-PCR and subjected to bioinformatic analysis. Samples of leaves and tiller nodes were collected under low-temperature treatments at 4, 0, -10, and -25 ℃. At the three-leaf stage, seedlings were treated with 20% PEG-6000, and leaf and tiller node samples were taken at 0, 3, 6, 12, and 24 h. RT-qPCR was used to analyze the gene expression patterns in leaves and tiller nodes under different low-temperature and drought treatments. An expression vector was constructed, and subcellular localization was performed to determine the protein localization. The TaMYBS1-like gene was transferred into Arabidopsis thaliana via Agrobacterium-mediated transformation for low-temperature and drought stress assays to validate its function. Results TaMYBS1-like belongs to the MYB transcription factor family. The full-length cDNA of TaMYBS1-like is 903 bp, encoding 300 amino acids. The encoded protein is an unstable hydrophilic protein primarily localized in the nucleus. Expression pattern analysis revealed that under low-temperature stress, TaMYBS1-like expression levels at 0, -10, and -25 ℃ were significantly higher compared to those at 4 ℃. In leaves, TaMYBS1-like expression was significantly higher at 3, 6, 12, and 24 h of drought stress compared to the control. Overexpression of TaMYBS1-like enhanced basic physiological metabolism, cell activity, and antioxidant enzyme system activity, while reducing cell membrane damage. Conclusion Overexpression of the winter wheat TaMYBS1-like gene improves plant cold and drought tolerance.

Objective This study aimed to investigate the xenia effects on fruit traits in late-maturing citrus and to efficiently identify true hybrids using SCoT molecular markers, thereby providing a theoretical basis and high-quality germplasm resources for breeding new late-maturing citrus varieties with desirable maturity and improved fruit quality. Method Twelve hybrid combinations were constructed using ‘Kiyomi tangor’, ‘Ehime Kashi 38’, and ‘Orah’ as female parents crossed with nine male parents. Fruit set rate, seedling rate, and fruit traits including single fruit weight, longitudinal and transverse diameters, fruit shape index, and soluble solids content (TSS) were measured to evaluate xenia effects. SCoT molecular markers were employed for hybrid authenticity identification and genetic diversity analysis of the progeny. Result The total fruit set rates for ‘Kiyomi tangor’, ‘Ehime Kashi 38’, and ‘Orah’ as female parents were 19.78%, 12.31%, and 5.4%, respectively. Significant xenia effects were observed on fruit traits with different male parents. Pollination with ‘Tarocco’ most significantly increased single fruit weight and TSS in ‘Kiyomi tangor’ fruits. SCoT analysis identified 891 true hybrids from nine cross combinations, with an average hybridity rate of 99.78%. Genetic diversity analysis revealed that the polymorphism ratio among hybrid progenies ranged from 42.11% to 94.59%, with the ‘Kiyomi tangor’ × ‘Asumi’ combination showing the highest genetic diversity. Conclusion Xenia effects show significant parental dependency. ‘Asumi’, ‘Hongyun Xianggan’ and ‘Huangguogan’ are identified as the optimal male parents for ‘Kiyomi tangor’, ‘Ehime Kashi 38’, and ‘Orah’, respectively. The hybrid progenies possess high genetic diversity, primarily attributes to parental genetic background differences and gene recombination during hybridization. The novel hybrid germplasm created in this study provides core breeding materials for late-maturing citrus improvement, and SCoT molecular markers proved to be an efficient tool for hybrid identification.

Objective We investigated the structural characteristics and expression patterns of CmoNAC genes in Cucurbita moschata,which provides insights into the biological functions of CmoNAC genes and facilitates the breeding of stress-resistant rootstock and hull-less seeded C. moschata. Method Based on the whole genome information of C. moschata, CmoNAC gene family members were identified using bioinformatic approaches. Systematic analyses were conducted on the physicochemical properties, subcellular localization, chromosomal localization, gene structure, and conserved motifs of its members. By integrating transcriptome data and quantitative real-time PCR (RT-qPCR), the tissue-specific expression patterns of CmoNAC genes, as well as their responses to stress and their roles in seed coat development, were investigated. Result The CmoNAC gene family comprises 133 members, all of which encode proteins predominantly localized in the nucleus and contain a typical NAM domain. These members are unevenly distributed across 20 chromosomes, with chromosome 4 harboring the highest number. Phylogenetic analysis classified them into 15 subfamilies, among which the NAM subfamily is the largest. Conserved Motif and gene structure analyses revealed that members within the same subfamily share similar motif compositions and exon-intron structures. Motifs 2/3/4 were widely present across most members, while some Motifs presented subfamily-specific distribution. Cis-acting element analysis indicated that the promoter regions of CmoNACs contain various regulatory elements related to light responsiveness, hormone signaling, stress response, and developmental processes. Tissue-specific expression analysis revealed that CmoNAC family members had the highest expressions in the roots. Among the CmoNAC genes in C. moschata, 100 ones were significantly upregulated under salt stress. Furthermore, 64 members showed differential expression between hull and hull-less seeded C. moschata. RT-qPCR showed the expression patterns of CmoNAC genes under salt stress and during seed coat development were consistent with the transcriptome data. Conclusion A total of 133 CmoNAC genes are identified in the C. moschata genome, which could be classified into 15 subfamilies. The gene structure and conserved motifs are highly conserved within each subfamily. CmoNAC108, CmoNAC102, and CmoNAC013 are respectively closely associated with root, stem development and stress responses while CmoNAC026, CmoNAC062 and CmoNAC121 are specifically upregulated in hull-less seeds, suggesting their potential roles in the formation of the seed coat.

Objective This study investigates the expression characteristics of the thioredoxin (TRX) gene HbTRXh2 in rubber tree (Hevea brasiliensis) and its function in responding to low-temperature stress, aiming to provide valuable gene resources for improving the tolerance to cold in rubber tree. Method RT-PCR technology was adapted to clone the HbTRXh2 gene from rubber tree. Bioinformatics methods were employed to analyze its sequence characteristics and phylogenetic relationships. Quantitative real-time PCR (RT-qPCR) was used to examine the expression patterns of HbTRXh2 in various rubber tree tissues, as well as under different abiotic stresses and hormone treatments. Furthermore, the yeast expression system was used to evaluate the function of HbTRXh2 in responding to low-temperature, salt, drought and oxidative stresses. Result The open reading frame (ORF) of rubber tree HbTRXh2 was 405 bp in length, encoding 134 amino acids. The predicted molecular weight of the HbTRXh2 protein was 14.64 kD, with a theoretical isoelectric point (pI) of 5.78. HbTRXh2 contained a conserved TRX domain, and phylogenetic tree analysis indicated that it belonged to the h-type TRX. RT-qPCR analysis revealed that HbTRXh2 had the highest expression in mature leaves. Abiotic stresses (low temperature, drought, salt and oxidative stress) and plant hormones (abscisic acid, salicylic acid, ethylene and jasmonic acid) treatments significantly up-regulated the expression of HbTRXh2. Survival assays after low-temperature, salt, drought and oxidative stresses revealed significantly higher viability in HbTRXh2-expressing yeasts compared to controls carrying the empty pYES2 vector. The results showed that, compared with the control yeast, the yeast transformed with pYES2-HbTRXh2 had a significantly higher survival rate after low-temperature, salt, and oxidative stress treatments, while its survival rate was significantly lower after sorbitol-induced drought stress treatment. HbTRXh2 expression in yeast improved the tolerance to low-temperature, salt, and oxidative stress, but reduced the tolerance to drought stress. Conclusion HbTRXh2 is involved in the rubber tree responses to abiotic stresses and phytohormones. Heterologous expression of HbTRXh2 in yeast enhances the tolerance to low temperature, salt and oxidative stresses, but reduces the tolerance to drought stress.

Objective TCP (teosinte branched 1/cincinnata/proliferating cell factor) is a plant-specific transcription factor that plays a significant role in the growth and development of plants. By identifying the TCP gene family in Quercus fabri, this study aims to investigate the expression patterns of QfTCP genes in the branching development, validate the function of the key gene QfTCP22, and provide a molecular basis for the improvement of plant architecture in Q. fabri. Method Bioinformatics methods were used to identify the TCP gene family based on the genomic data of Q. fabri, and to analyze the physicochemical properties, chromosomal distribution, phylogenetic relationships, gene structures, cis-acting elements, and gene collinearity of the family members. RT-qPCR combined with transcriptome data was to examine the expression patterns of QfTCP gene family members during axillary bud development, while the function of QfTCP22 was verified through heterologous overexpression in Arabidopsis. Result A total of 23 TCP genes were identified in Q. fabri, classified into three subfamilies: PCE, CIN, and CYC/TB1. These genes were unevenly distributed across 10 chromosomes, with chromosome 10 containing the highest number of members. All QfTCP members possessed a common conserved motif Motif 1, and presented relatively simple gene structures. Collinearity analysis revealed that 10 pairs of QfTCP genes had collinear relationships. Analysis of cis-acting elements indicated that the functions of QfTCP genes were relatively complex, involving light signal response, hormone regulation, and stress adversity. Transcriptomic data of axillary bud development and RT-qPCR results showed that QfTCP1 and QfTCP22 of the CYC/TB1 subfamily showed a significant downregulation trend during axillary bud development. Furthermore, the overexpression of the QfTCP22 gene in the Arabidopsis brc1 mutant significantly reduced the number of branches. Conclusion Members of the Q. fabriTCP gene family was identified, revealing that QfTCP22 acts as a suppressor in plant branch development.

Objective To analyze the characteristics of the Dof transcription factor family in elephant grass (Cenchrus purpureus), and its response mechanism to cold stress, and conduct genome-wide identification of CpDof genes, and providing support for mining cold-tolerant candidate genes in elephant grass. Method Based on the elephant grass genome data, CpDof genes were identified through conserved domain search. Bioinformatics methods were used to analyze their physicochemical properties, chromosome localization, phylogeny, and cis-acting element characteristics. Taking ‘Chuanxu 4’ elephant grass as the material, after the treatment by 4 ℃ cold stress, transcriptome sequencing and quantitative real-time PCR were used to analyze gene expression characteristics. Key genes were cloned to construct yeast expression vectors, and heterologous expression experiments were conducted to verify cold tolerance function. Result A total of 68 CpDof genes were identified in the elephant grass genome, unevenly distributed on 14 chromosomes. Collinearity analysis revealed 51 pairs of segmental duplications and 2 pairs of tandem duplications among CpDof genes. Subcellular localization prediction showed that almost all CpDof family members were localized in the nucleus. Under cold stress induction, 28 CpDof genes were significantly upregulated, among which CpDof17 and CpDof28 had relatively prominent expressions. They were highly expressed in the roots and stems, respectively, and cold stress enhanced their expression in the roots and leaves. Yeast heterologous expression experiments showed that the overexpression of CpDof28 significantly improved the cold tolerance of Saccharomyces cerevisiae, while CpDof17 had no obvious effect. Conclusion CpDof28 may act as a key regulatory factor playing a core role in the response of elephant grass to cold stress. This study clarifies the core characteristics of the Dof gene family in elephant grass and screenes the cold-tolerant candidate gene CpDof28, providing important genetic resources and theoretical basis for cold-resistant molecular breeding and variety improvement of elephant grass.

Objective This study elucidated the functional differentiation mechanism across Paphiopedilum purpuratum tissues and systematically revealed its metabolite distribution characteristics, gene expression patterns, and metabolism-gene co-regulation network through multi-omics strategies, which may provide a molecular basis for understanding species environmental adaptability. Method Non-targeted metabolomic analysis (UHPLC-MS/MS) were used to compare metabolites differences in leaves (SL), flowers (SF), and roots (SR) of P. purpuratum. Transcriptome sequencing was used to identify differentially expressed genes, followed by metabolite-gene co-expression network construction. Result The 2 164 metabolites (1 471 positive ion mode, 693 negative ion mode) were identified in metabolomics, with significant inter-group differences: SL vs. SF (499 positive and 193 negative ion mode metabolites), SL vs. SR (534 and 243), SF vs. SR (433 and 187). KEGG enrichment analysis showed differential metabolite enrichment in phenylpropanoid biosynthesis, flavonoid biosynthesis, and linoleic acid metabolism pathways. Transcriptomic analysis revealed profound tissue-specific gene expression: Photosynthetic genes (e.g., sqdB, DVR) were significantly upregulated in the leaves; second, fragrance/pigment synthesis genes (e.g., FAH, crtZ) were highly expressed in the flowers; and third, stress-responsive genes (e.g., CCR, GPAT) were upregulated in the roots. Key regulators were identified via co-expression network analysis: such as INO80B (regulating flavonoid synthesis), CCT1 (regulating terpene metabolism), and CCR (involved in root defense), revealing core metabolite synthesis regulatory mechanisms. Conclusion Integrated metabolomic and transcriptomic analysis demonstrates that P. purpuratum forms its ecological adaptability molecular mechanism through three tissue-specific “metabolism-gene” coordinated regulatory networks: The synergy of photosynthesis and stress resistance in its leaves, the attraction of pollination in its flowers, and the stress defense in its roots.

Objective There are numerous MYB transcription factor family members in plants. They play a crucial role in regulating the growth and development of plants as well as in enabling plants to adapt to external environmental stress. Industrial hemp (Cannabis sativa L.), as an economic crop, has a wide range of applications and holds great potential for development and utilization. Revealing the drought resistance function of the transcription factor gene CsMYB12 in industrial hemp may lay a foundation for improving the drought resistance and yield of industrial hemp varieties. Method The expression of CsMYB12 under drought stress was detected by real-time fluorescent quantitative PCR. CsMYB12 was cloned and subjected to bioinformatics analysis. The transcriptional activation activity of CsMYB12 was detected through yeast transcriptional activation test. The CsMYB12 plant expression vector was constructed and transformed into tobacco. The resistance of CsMYB12 transgenic tobacco to drought was identified. Result The expressions of CsMYB12 were significantly induced by drought stress. The open reading frame of CsMYB12 was 1 560 bp and encoded 519 amino acids. The molecular weight of the CsMYB12 protein was 5.81 kD and its isoelectric point was 4.94. The CsMYB12 protein contained two SANT domains and it was a typical R2R3-MYB transcription factor. CsMYB12 had transcriptional activation activity in yeast cells. Six CsMYB12 transgenic tobacco plants were identified. After drought stress and rehydration treatment, the performance of CsMYB12 transgenic tobacco was superior to that of wild-type tobacco. After drought stress, the content of osmotic regulatory substances, relative water content and antioxidant enzyme activities in CsMYB12 transgenic tobacco increased, while the electrolyte leakage rate and malondialdehyde content decreased compared with the wild-type tobacco. The expressions of stress-related genes (NtLTP, NtOsmotin, NtLEA5, NtERD10B and NtCSD) in CsMYB12 transgenic tobacco significantly increased. Conclusion The heterologous overexpression of CsMYB12 in tobacco enhances the resistance of transgenic tobacco to drought.

Objective To clarify the mechanism of exogenous selenium (Se) pretreatment alleviating cadmium (Cd) toxicity in Brassica juncea var. tumida Tsen et Lee seedlings, and to provide a theoretical basis for the rational application of Se to ensure the safe cultivation of Brassica juncea var. tumida Tsen et Lee in Cd-contaminated soils. Method The dominant cultivar ‘Yonganxiaoye’ which is sensitive to Cd stress was used as the experimental material, and a hydroponic experiment was conducted with four treatments: CK, CK+Se, Cd, and Cd+Se, thus to study the effects of exogenous selenium on Cd accumulation and distribution, photosynthetic assimilation capacity, and antioxidant capacity of B. juncea var. tumida Tsen et Lee seedlings under Cd stress. Results Compared with CK, Cd stress treatment markedly inhibited the growth of B. juncea var. tumida Tsen et Lee seedlings, reduced the chlorophyll content and photosynthetic efficiency of the plants, decreased the antioxidant enzymes activities, and increased the Cd content in both root and leaf tissues to 45.06 and 72.30 times that of CK, respectively. Compared with Cd stress alone, exogenous Se pretreatment significantly promoted the growth of B. juncea var. tumida Tsen et Lee seedlings under Cd stress, increased the chlorophyll content, Pn, Fv/Fm, ΦPSII, ETR, and qP values of the plants, enhanced the activities of SOD and CAT, and increased the contents of ASA, GSH, total phenol, phytochelatin, and cysteine content, down-regulated the expression levels of Cd uptake and transport-related genes (IRT1, Nramp1, HMA2, and HMA3) to 46.85%‒70.33% of those treated by Cd stress alone, reduced Cd accumulation in both root and leaf tissues and increased the proportion of Cd content in the cytoderm. Conclusion Exogenous Se alleviates Cd toxicity in B. juncea var. tumida Tsen et Lee seedlings under Cd stress, mainly by improving the conversion efficiency of photosynthetic system, enhancing the antioxidant capacity,^{strengthening the Cd chelating capacity and compartmentalization, and down-regulating the Cd uptake and transport-related genes expression levels.}

Objective To explore the basic characteristics, evolution and potential functions of the terpene synthases (TPS) gene family in Morinda officinalis. Method Based on the whole genome and transcriptome data of M. officinalis, the gene structure, evolution and expression pattern of MoTPS were systematically analyzed through screening of gene family members, examination of structural features, construction of evolutionary relationships, gene expression analysis, and protein-protein interaction (PPI) prediction. Result A total of 33 MoTPS genes were identified in M. officinalis, unevenly distributed on 7 chromosomes, all of which were hydrophilic proteins located in chloroplasts. Phylogenetic analysis showed that the MoTPS gene family was divided into six subfamilies, among which the TPS-b and TPS-a subfamilies contained the most genes. There were six pairs of tandem replication genes and two pairs of segmental replication genes in MoTPS gene family. PPI prediction indicated that MoTPS1, MoTPS32, and MoTPS33 participated in the synthesis of gibberellins precursors by interacting with ent-KOD proteins, whileMoTPS18, MoTPS19, MoTPS20, and MotPS21 interacted with CYP450 proteins synthesized by terpenoid modification. Cis-acting element analysis showed that the MoTPS gene family was widely involved in light, hormone and abiotic stress responses. The correlation analysis of gene expression showed that 19 MoTPS family genes were significantly positively correlated with upstream genes in terpenoid biosynthesis pathway. Among them, the expression of MoTPS31, which encoded geraniol synthase, a key gene involved in the biosynthesis of iridoid components, was positively correlated with DXS1 in the MEP pathway. Conclusion Tandem duplication and segmental duplication events are the main driving forces for the evolution and expansion of MoTPS family genes. The MoTPS family genes are widely involved in light, hormone signal transduction and abiotic stress responses by regulating the biosynthesis of terpenoids.

Objective To investigate the effects and underlying mechanisms of a bio-nursery substrate prepared from PGPR co-fermented broth on the growth of pepper seedlings under tray-based seedling cultivation conditions, which may provide a basis for the research and development of biological nursery substrate. Method Co-fermented strains were selected through compatibility analysis of four PGPR strains, IAA (indoleacetic acid) content determination of different strain combination's culture, and pepper seed soaking experiments. The optimal strain combination was determined by analyzing the effects of co-fermented broth on pepper seed germination and seedling growth using tray seedling cultivation. The optimal addition ratio was determined by assessing the effects of different proportions co-fermented broth on the seedlings growth during the seedling tray stage. The seedling growth-promoting mechanism was elucidated by analyzing the effects of co-fermented liquids on nutrient content and microbial diversity in the nursery substrate. Result The co-fermented broth of Burkholderia pyrrocinia P10 and Bacillus flexus HGD12 contained 60.84 mg/L IAA, significantly higher than the single-strain culture, which significantly promoted seed germination and seedling growth of peppers under both soaked-seed and tray-seedling cultivation conditions. Adding 15% co-fermented broth to the seedling substrate provided optimal growth promotion for seedlings in the seedling tray stage, significantly increasing pepper seedling height, stem diameter, fresh weight, dry weight, number of leaves, leaf area, and chlorophyll SPAD value by 29.17%, 17.67%, 64.68%, 94.44%, 22.30%, 49.45%, and 17.83%, respectively. The organic matter, alkali-hydrolyzed nitrogen, and available phosphorus content of the substrate increased by 11.31%, 20.39%, and 14.14%, respectively. Moreover, the co-fermented broth significantly increased bacterial species richness while reducing fungal community diversity in the substrate. The abundance of Bacteroidota, Gemmatimonadota, Chloroflexi, Halobacterota, Rozellomycota, and Basidiomycota, had significantly positively correlation with substrate nutrient content, all increased; whereas the abundance of Proteobacteria, Ascomycota, and Glomeromycota demonstrated a negative correlation with nutrient content, showing a decline. Conclusion Co-fermented broth from P10 and HGD12 strains added to seedling substrates increased nutrient content and altered microbial community structure, thereby significantly promoting pepper seed germination and seedling growth during the tray stage.

Objective This study aimed to investigate the effects of dietary probiotic supplementation on growth performance, cecal microbiota diversity, short-chain fatty acid (SCFA) content, and predictive analysis of microbial functional differences in Yimeng chicken crossbred lines. Method A two-factor experimental design was adopted. Healthy one-day-old male chicks of purebred Yimeng chickens, two-way crosses, and three-way crosses were selected as the main research subjects. The three populations were divided into six groups, with each population further assigned to a control group (C group) and a probiotic group (T group). Specifically, the groups were as follows: control group of Yimeng chickens (Group C1), two-way cross (Group C2), and three-way cross (Group C3); probiotic group of Yimeng chickens (Group T1), two-way cross (Group T2), and three-way cross (Group T3). Each group had three replicates, with 15 chicks per replicate, totaling 270 chicks. The trial lasted for 7 weeks. Result 1) Probiotics significantly improved the growth performance of Yimeng chicken crossbred lines from 1 to 42 days of age (P0.05). For ADG (average daily gain) and F/G (feed/gain), the T3 group showed the best performance, while for ADFI (average daily feed intake), the C2 group was the highest. Furthermore, significant interaction effects between P (Probiotic) and B (Breed) were observed on ADFI and F/G. 2) At the phylum level, the abundance of Actinobacteria in Group C1 was significantly higher than in Groups C2 and C3 (P0.05). The abundances of Actinobacteria and Deferribacteres in Group T2 were significantly higher than in Group C2 (P0.05). At the genus level, the abundance of Bacteroides in Group T3 was significantly higher than in Group T1 (P0.05). The abundance of Phascolarctobacterium in Group T1 was significantly higher than in Group C1 (P0.05). The abundance of Methanobrevibacter in Group T2 was significantly higher than in Group C2 (P0.05). 3) The contents of acetate, propionate, and butyrate in the T group were significantly higher than in the C group (P0.05). Furthermore, significant interaction effects (P0.05) between Probiotic and Breed (P and B) were observed for acetate, propionate, valerate, isovalerate, butyrate, and isobutyrate in the C and T groups. 4) KEGG functional prediction revealed that the metabolic pathways significantly enriched in the C group included cofactor and vitamin metabolism, as well as fructose and mannose metabolism. In the T group, significantly enriched metabolic pathways included arginine and proline metabolism, niacin and nicotinamide metabolism, protein digestion and absorption, and pentose and glucuronate interconversions. Conclusion Dietary probiotic supplementation and crossbreeding can improve the growth performance and short-chain fatty acid production in Yimeng chickens, with interactive effects observed. They can also alter the structural diversity of the cecal microbiota and influence microbial functional metabolic pathways.