Genome-wide identification of PYL-PP2C-SnRK2 gene family members in Medicago sativa ‘Xinjiangdaye’ and their transcript profiles under drought stress

doi:10.11686/cyxb2025161

Abstract

Abstract:

Global climate change has led to the intensification of drought， which has had a serious impact on the sustainability of the forage industry. Among the various physiological and molecular mechanisms that plants employ to adapt to drought， the PYL-PP2C-SnRK2 module stands out because it constitutes the core components of the abscisic acid （ABA） signaling pathway， which plays an essential role in mediating plant adaptation to drought. In this study， genome-wide identification of PYL-PP2C-SnRK2 gene family members in Medicago sativa ‘Xinjiangdaye’ and analysis of their regulatory patterns under drought stress were conducted using bioinformatics and molecular biological methods. Searches of the M. sativa ‘Xinjiangdaye’ genome revealed 40 MsPYL， 216 MsPP2C， and 36 MsSnRK2 genes. The members of these three gene families were distributed across different chromosomes： MsPYLs across 22 chromosomes； MsPP2Cs across 21 chromosomes； and MsSnRK2s across 24 chromosomes. Domain architecture analysis of the putative proteins encoded by these genes confirmed the presence of the PYR-PYL-RCAR-like structural domain inall of the MsPYLs； the PP2Cc structural domain in most of the MsPP2Cs； and the STKc structural domainin all the MsSnRK2s. Analyses of gene promoter regions identified multiple stress-responsive and growth-related cis-regulatory elements. Under progressive drought stress， the MsPYL-PP2C-SnRK2 genes exhibited significantly divergent transcript profiles. A weighted gene co-expression network analysis established robust correlations between endogenous ABA accumulation and the transcript levels of specific genes， which allowed us to identify candidate core regulatory factors involved in the drought adaptation process. Molecular docking analyses demonstrated that MsSnRK2-14.1/14.2/1.2 and MsPP2C88.4 had functional predominance as key positive regulators during the drought adaptation of M. sativa ‘Xinjiangdaye’. The results of this study provide a foundational theoretical framework for further studies on the functional mechanisms of the MsPYL-PP2C-SnRK2 module and its components in the response to drought stress. Furthermore， it offers an excellent set of genetic resources for breeding new varieties of drought-resistant pasture grasses.

Key words: drought stress, PYL-PP2C-SnRK2, abscisic acid, weighted gene co-expression network analysis, Medicago sativa ‘Xinjiangdaye’

Xiao-tong ZHOU, Yong-zhong LUO, Jian-wei QI, Ying-de QIU, Chao MA. Genome-wide identification of PYL-PP2C-SnRK2 gene family members in Medicago sativa ‘Xinjiangdaye’ and their transcript profiles under drought stress[J]. Acta Prataculturae Sinica, 2026, 35(4): 169-196.

Figures/Tables 19

References 41

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基因 Gene	正向引物 Forward primer （5′-3′）	反向引物 Reverse primer （5′-3′）
MsPP2C10.1	GATGGCTTGTGGGGTGTAATGT	GCAGCTTCAGCAGCACGACTAC
MsPP2C25	TGAAACGCCTATCCTCAAAGCT	TGATTGCTCAAGTGCTCCCATA
MsPP2C66.3	ATGTCTGATACTTGCGAGTGATGG	TCGCCAATGCCAACTTCGT
MsPP2C66.4	TTACAACTGGGCTGCAACGAG	TCACAAATGGCGTCCAGAATAG
MsActin	GCCAATGATGCTTAGCTGGTCTT	CCCTTCTTCACTCACGCGATAT

基因 Gene	正向引物 Forward primer （5′-3′）	反向引物 Reverse primer （5′-3′）
MsPP2C10.1	GATGGCTTGTGGGGTGTAATGT	GCAGCTTCAGCAGCACGACTAC
MsPP2C25	TGAAACGCCTATCCTCAAAGCT	TGATTGCTCAAGTGCTCCCATA
MsPP2C66.3	ATGTCTGATACTTGCGAGTGATGG	TCGCCAATGCCAACTTCGT
MsPP2C66.4	TTACAACTGGGCTGCAACGAG	TCACAAATGGCGTCCAGAATAG
MsActin	GCCAATGATGCTTAGCTGGTCTT	CCCTTCTTCACTCACGCGATAT