Genome-wide Association Study Of Maize Salt Tolerance At Seedling Stage

Salinity stress is one of major abiotic stresses threading crop performance.To engineer salt-tolerant maize it is crucial to unravel the genetic basis of the maize salt tolerance.High salt tolerance variations and genetic variations in maize give us opportunity to uncover the genetic architecture of the maize salt tolerance.In order to uncover loci controlling salinity tolerance,we performed genome-wide association study(GWAS)using 1.24 million SNPs characterized in 445 maize inbred lines.We identified 196 SNPs significantly associated with salt tolerance.Those SNPs were resolved to 112 candidate genes,among which,21 genes involved in stress,include salt stress,drought stress,and so on;10 genes contributed to hormone signal transduction,include ABA,ethylene,auxin and so on;12 genes functioned in the metabolic process.More than half of candidate genes' expression pattern changed dramatically under salt stress,among which more genes enrich in stress response,hormone signaling,metabolic processes and development processes.We found 6 genes located in 6 QTL which reported by previous linkage mapping study.Our results provide insights into the genetic basis of salt tolerance at maize seedling stage and the genes identified in this study will provide genetic resources for further basic and application study of maize salt-tolerant.