Pan-genomic evolutionary analysis of MsPR10 gene family reveals MsPR10.SC10 plays a positive role in alfalfa salt tolerance
TL;DR
The pan-genomic architecture of the PR10 gene family members in alfalfa is revealed, and provides valuable candidate gene for breeding of salt tolerant alfalfa cultivar and may also other crops.
Abstract
The PR10 gene family plays a critical role in plant stress responses. Phylogenetic analysis across species indicated that the PR10 gene first appeared during plant terrestrialization and underwent significant expansion. And, PR10 is conserved in leguminous plants, yet its genomic architecture and functional mechanisms in alfalfa (Medicago sativa L.) remains unclear. In this study, a pan-genomic analysis of 28 alfalfa accessions identified a total of 1657 MsPR10 genes, with tandem duplication accounting for the majority of gene expansion (61.19%). These MsPR10 genes were clustered into 81 Orthologous Gene Groups (OGGs) based on conservative levels, ranging from core to cloud genes. Significant expansion of PR10 genes in Zhongmu No.1 alfalfa (ZMNO) was associated with elevated transposon activity and selective pressure. Transcriptomic analysis indicated MsPR10.SC10 may be a key gene in alfalfa salt-tolerance. Transgenic alfalfa plants overexpressing MsPR10.SC10 were generated by Agrobacterium-mediated transformation. Detailed physiological tests suggested overexpression of MsPR10.SC10 enhanced salt tolerance of alfalfa by maintaining ion homeostasis (reducing Na+/K+ ratio), boosting antioxidant capacity by increasing SOD/ POD activity and reducing H2O2/ MDA accumulation, and regulates the expression of salt stress responsive genes. This study reveals the pan-genomic architecture of the PR10 gene family members in alfalfa, and provides valuable candidate gene for breeding of salt tolerant alfalfa cultivar and may also other crops.