Expression and Functional Analysis of Gene LoSAUR10 from Lilium Oriental Hybrids

doi:10.13560/j.cnki.biotech.bull.1985.2024-0502

Abstract

Abstract:

【Objective】LoSAUR10 was cloned and its expression patterns were analyzed, and then the function of LoSAUR10 was identified using over-expressed transgenic plants in Arabidopsis thaliana, which may provide reference for the developmental mechanism of lily bulbs.【Method】According to the effect of exogenous auxin treatment on the occurrence of bulblets, lily cultivar ‘Siberian’ cDNA was used as template to clone LoSAUR10 for bioinformatics analysis. Real-time quantitative PCR and over-expressed transgenic Arabidopsis plants were used to analyze the expression characteristics of LoSAUR10 and its function in leaf development.【Result】The exogenous IAA treatment significantly promoted the occurrence and enlargement of bulblets. The occurrence rate of lily bulblets increased by 69.04% compared to the control treatment at a treatment with concentration of 0.05 g/L IAA. In the early stage of bulblets formation, the expression of LoSAUR10 gene was induced by exogenous auxin. As the bulblets enter the enlargement stage, the expressions of LoSAUR10 gene gradually decreased under IAA treatment. Results of gene sequencing indicated that the length pf coding region of the LoSAUR10 gene was 297 bp without introns, encoding 98 amino acids and containing an auxin-inducible domain. The phylogenetic tree analysis showed that the LoSAUR10 protein sequence had high similarity with Tulipa gesneriana TgSAUR10 and A. thaliana AtSAUR9 and AtSAUR10. Real-time RT-qPCR indicated that LoSAUR10 was induced by auxin treatment at the transcriptional level and expressed in most detected tissues with high expression in lily scales. Compared to wild-type plants, transgenic Arabidopsis plants overexpressing LoSAUR10 had the phenotypes of enlarged rosette leaves, increased leaf cell area, as well as early bolting.【Conclusion】LoSAUR10 is involved in the regulation of plant leaf growth and flowering processes, and the results lay a foundation for revealing the mechanism of lily bulbs development.

Key words: Lilium, LoSAUR10, bulblet, tissue-specific expression, transgenic Arabidopsis

TIAN Xu-rui, HUO Xin-yi, GUO Yun-han, XIANG Lin, CHAN Zhu-long, WANG Yan-ping. Expression and Functional Analysis of Gene LoSAUR10 from Lilium Oriental Hybrids[J]. Biotechnology Bulletin, 2025, 41(1): 221-229.

Figures/Tables 7

Table 1 Information of primers

引物名称 Primer name	引物序列 Primer sequence（5'-3'）
LoSAUR10-cloning-F	CTCCGTCTACTTCATTCTTTC
LoSAUR10-cloning-R	GTATCAGTGGTGGGTCTTCT
pCAMBIA1307-LoSAUR10-F	ACCGTCGACGAGCTCTCTAGAATGGCAGCAAGGAGGTTGAA
pCAMBIA1307-LoSAUR10-R	TTTGCGGAGTACCCGGGTACCGCAGAGACTGGAGGTGAGAGATCG
qRT-LoActin-F	TGCTGACCGTATGAGCAAGG
qRT-LoActin-R	GACGATGGCTGGACCAGATT
qRT-LoSAUR10-F	CATCGTCCCCATCTCTCTACTTG
qRT-LoSAUR10-R	AGGTGAGAGATCGGAAGACAGTA
qRT-AtActin-F	TGAGAGATTCAGATGCCCAGA
qRT-AtActin-R	TGGATTCCAGCAGCTTCCAT
qRT-At-LoSAUR10-F	GCTTCATCGTCCCCATCTC
qRT-At-LoSAUR10-R	GAAGACAGTATCCTCGCATGG

Fig. 1 Effects of auxin application on the development of lily bulblets A: IAA treatment enhanced bulblets enlargement in lily; bar=0.5 cm. B: Reproduction rates were induced by IAA treatment. C: Comparison of the proportion of bulblets. * P<0.05, *** P<0.001. The same below

Fig. 2 Effects of IAA treatment on the bulblets occurrence and relative expressions of LoSAUR10 in lily A: Comparison of the bulblets at different time courses after IAA treatment; bar=0.5 cm. B: Relative expressions of LoSAUR1 gene after IAA treatment

Fig. 3 Relative expressions of LoSAUR10 in different treatment time (A) and different tissues with (B) IAA treatment Different letters indicate P<0.05

Fig. 4 Protein sequence and phylogenetic tree construction of LoSAUR10 in lily A: Alignment of conserved sequence of LoSAUR10 protein; the red box indicates SAUR domain. B: Phylogenetic tree of LoSAUR10 and other homologous proteins from Arabidopsis thaliana and Tulipa gesneriana

Fig. 5 Bioinformatics analysis of LoSAUR10 protein A: Transmembrane domain analysis of LoSAUR10. B: Hydrophilicity analysis of LoSAUR10 protein. C: Conserved domain analysis of LoSAUR10. D: Secondary structure of LoSAUR10 protein

Fig. 6 Phenotype analysis of transgenic plants with over-expressed LoSAUR10 gene A: Comparison of leaves sizes after 3 weeks growing; bar=1.0 cm. B: Relative expression of LoSAUR10 analyzed by RT-qPCR; M: marker; WT: wild-type; P: plasmid. C: Length comparison of the 6th-7th rosette leaves. D: Width comparison of the 6th-7th rosette leaves. E: Area comparison of epidermal cells. F: Comparison of numbers of rosette leaves.G: Plant width comparison. H: Bolting time comparison

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