高粱SAR基因负调控耐盐碱性的功能解析OA

Saline-alkaline land represents an important potential resource for agricultural development,and cultivating salt-alkali tolerant crops is of great significance for ensuring food security.Sorghum(Sorghum bicolor L.)possesses strong salt-alkali tolerance and as a pioneer crop on marginal lands.Through combined genome-wide association analysis(GWAS)and transcriptomic analysis,we previously identified a key major quantitative trait locus(QTL)regulating salt-alkali tolerance in sorghum,designated qSAR-1(Salt Alkali Related),located at approximately 59.48 Mb on chromosome 1,with the candidate gene SAR(Sobic.001G309500).In this study,using sorghum inbred line Tx430,we generated T2 stable lines with SAR overex-pression and CRISPR/Cas9-mediated knockout via Agrobacterium-mediated genetic transformation.Phenotypic analysis re-vealed that SAR overexpression lines exhibited significant salt-alkali sensitive phenotype under salt-alkali stress,whereas knockout lines showed significantly enhanced salt-alkali tolerance with a 36%increase in survival rate.Physiological and biochemical analyses demonstrated that SAR knockout improved photosynthetic performance,reduced reactive oxygen species(ROS)accumulation and membrane lipid peroxidation,and increased antioxidant enzyme activities and osmoregulatory substance contents.Endogenous abscisic acid(ABA)measurements and inhibitor treatment experiments confirmed that SAR negatively regulates salt-alkali tolerance in sorghum primarily through the ABA pathway.This research provides valuable genetic resources and theoretical basis for molecular breeding of salt-alkali tolerant sorghum,aligning with recent breakthroughs in crop salt-alkali tolerance research.