Genome-wide association study dissects the genetic bases of salt tolerance in maize seedlings  

作　　者：Xi Luo Bingcai Wang Shan Gao Fei Zhang William Terzaghi Mingqiu Dai 

机构地区：[1]National Key Laboratory of Crop Genetic Improvement,Huazhong Agricultural University,Wuhan 430070,China [2]College of Plant Science,Tarim University,Alaer 843300,China [3]Department of Biology,Wilkes University,Wilkes-Barre,Pennsylvania 18766,USA

出　　处：《Journal of Integrative Plant Biology》2019年第6期658-674,共17页植物学报（英文版）

基　　金：supported by the Ministry of Science and Technology of China (2015 BAD02B01)

摘　　要：Excess salinity is a natural stress that causes crop yield losses worldwide. The genetic bases of maize salt tolerance remain largely unknown. Here we investigated the survival rates of 445 maize natural accessions after salt treatments. A skewed distribution of the salttolerant phenotypes was observed in this population.Genome-wide association studies(GWAS) revealed 57 loci significantly associated with salt tolerance. Forty-nine candidate genes were detected from these loci. About10% of these genes were co-localized with loci from QTL mapping. Forty four percent of the candidate genes were involved in stress responses, ABA signaling,stomata division, DNA binding/transcription regulation and auxin signaling, suggesting that they are key genetic mechanisms of maize salt tolerance. Transgenic studies showed that two genes, the salt-tolerance-associatedgene 4(SAG4, GRMZM2 G077295) and SAG6(GRMZM2 G106056), which encode a protein transport protein and the double-strand break repair protein MRE11,respectively, had positive roles in plant salt tolerance,and their salt-tolerant haplotypes were revealed. The genes we identified in this study provide a list of candidate targets for further study of maize salt tolerance, and of genetic markers and materials that may be used for breeding salt-tolerance in maize.Excess salinity is a natural stress that causes crop yield losses worldwide. The genetic bases of maize salt tolerance remain largely unknown. Here we investigated the survival rates of 445 maize natural accessions after salt treatments. A skewed distribution of the salttolerant phenotypes was observed in this population.Genome-wide association studies(GWAS) revealed 57 loci significantly associated with salt tolerance. Forty-nine candidate genes were detected from these loci. About10% of these genes were co-localized with loci from QTL mapping. Forty four percent of the candidate genes were involved in stress responses, ABA signaling,stomata division, DNA binding/transcription regulation and auxin signaling, suggesting that they are key genetic mechanisms of maize salt tolerance. Transgenic studies showed that two genes, the salt-tolerance-associatedgene 4(SAG4, GRMZM2 G077295) and SAG6(GRMZM2 G106056), which encode a protein transport protein and the double-strand break repair protein MRE11,respectively, had positive roles in plant salt tolerance,and their salt-tolerant haplotypes were revealed. The genes we identified in this study provide a list of candidate targets for further study of maize salt tolerance, and of genetic markers and materials that may be used for breeding salt-tolerance in maize.

关 键 词：GENOME-WIDE ASSOCIATION dissects TOLERANCE 

分 类 号：Q[生物学]