Identification of the Pseudo-response Regulator PRR Gene Family in Broomcorn Millet and Its Response to Photoperiod

doi:10.13560/j.cnki.biotech.bull.1985.2025-1113

Abstract

Abstract:

Objective Pseudo-response regulators (PRRs) play crucial roles in regulating circadian rhythms and flowering time in plants. This study aimed to systematically identify the PRR gene family in broomcorn millet (Panicum miliaceum L.) at the whole-genome level, providing a theoretical basis for understanding their biological functions. Method Bioinformatics methods were employed to analyze the physicochemical properties, conserved motifs, gene structures, collinearity, and phylogenetic relationships of the PRR gene family in broomcorn millet. The expression patterns of PRR genes under different photoperiod treatments were investigated using real-time quantitative PCR (RT-qPCR). Result A total of seven PRR genes were identified from the broomcorn millet genome, designated as PmPRR1 to PmPRR7, which were unevenly distributed across five chromosomes. Phylogenetic analysis revealed that the PmPRR genes belong to Group 1 to Group 3 subfamilies. Analysis of conserved protein motifs showed that six genes contained Motif1, Motif2, and Motif3, indicating high conservation among them. Promoter cis-acting element analysis suggested that PmPRR genes are associated with light response, plant growth and development, stress responses, and hormone regulation. RT-qPCR results demonstrated significant differences in the expressions of PmPRR genes under different photoperiod treatments (short-day, 8 h; intermediate-day, 14 h; long-day, 16 h). Conclusion This study identified seven PmPRR genes. The expression patterns of genes from different subfamilies vary under different photoperiods, indicating that PmPRRs play an important regulatory role in the response of broomcorn millet to photoperiod changes.

Key words: broomcorn millet, pseudo-response regulators, photoperiod, bioinformatics, RT-qPCR

CUI Xiu-yan, DAI Chun-yang, ZHANG Yi-ting, TIAN Xiang, CHEN Ling, QIAO Zhi-jun, WANG Hai-gang, WANG Jun-jie. Identification of the Pseudo-response Regulator PRR Gene Family in Broomcorn Millet and Its Response to Photoperiod[J]. Biotechnology Bulletin, 2026, 42(8): 133-141.

Figures/Tables 8

Table 1 Physicochemical properties of broomcorn millet PmPRR gene family

基因 Gene	基因号 Gene number	氨基酸数量 Number of amino acids （aa）	分子量 Molecular weight （Da）	理论等电点 Theoretical pI	不稳定指数 Instability index	脂肪指数 Aliphatic index	总平均亲水性 Grand average of hydropathicity	亚细胞定位 Subcellular localization
PmPRR1	RLN16623.1	632	68 998.91	8.78	53.12	62.14	-0.761	细胞核 Nucleus
PmPRR2	RLM78629.1	522	58 010.95	6.07	52.84	65.31	-0.608	细胞核 Nucleus
PmPRR3	RLN39167.1	761	83 134.48	6.31	49.50	57.91	-0.910	细胞核 Nucleus
PmPRR4	RLM80225.1	522	57 978.79	5.75	51.39	65.69	-0.630	细胞核 Nucleus
PmPRR5	RLM69356.1	613	67 065.69	8.60	50.83	64.83	-0.744	细胞核 Nucleus
PmPRR6	RLM85946.1	623	69 412.30	6.36	52.53	67.48	-0.827	细胞核 Nucleus
PmPRR7	RLM86309.1	766	82 342.57	6.41	41.35	56.58	-0.851	细胞核Nucleus

Fig. 1 Chromosome distribution of PmPRR gene family in broomcorn millet

Fig. 2 Phylogenetic tree of the PRR protein in Panicum miliaceum (Pm), Arabidopsis thaliana (At), Oryza sativa (Os), Zea mays (Zm), and Setaria italica (Si)

Fig. 3 Conserved motifs (A) and structure (B) of PmPRR genes in broomcorn millet

Fig. 4 Cis-acting elements of broomcorn millet PmPRR gene promoters

Fig. 5 Intra-species synteny analysis of the PmPRR gene family in broomcorn millet

Fig. 6 Synteny analysis between PmPRR genes in Panicum miliaceum L.(broomcorn millet) and PRR genes in Arabidopsis thaliana, Oryza sativa, Setaria italica, and Zea mays

Fig. 7 Expressions of the PmPRR genes in broomcorn millet under different light conditions

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