文献类型： 外文期刊

作者： Li, Ning ¹ ; Zheng, Hongliang ¹ ; Cui, Jingnan ¹ ; Wang, Jingguo ¹ ; Liu, Hualong ¹ ; Sun, Jian ¹ ; Liu, Tongtong ¹ ; Zha ¹ ;

作者机构： 1.Northeast Agr Univ, Key Lab Germplasm Enhancement Physiol & Ecol Food, Minist Educ, Harbin 150030, Heilongjiang, Peoples R China

2.Heilongjiang Acad Agr Sci, Postdoctoral Programme, Harbin 150030, Heilongjiang, Peoples R China

关键词： Japonica rice; Alkalinity tolerance; Gene; Genome-wide association study (GWAS)

期刊名称：RICE （ 影响因子：4.783； 五年影响因子：5.23 ）

ISSN： 1939-8425

年卷期： 2019 年 12 卷

页码：

收录情况： SCI

摘要： Background: Salinity-alkalinity stress is one of the major factors limiting rice production. The damage caused by alkaline salt stress to rice growth is more severe than that caused by neutral salt stress. At present, the genetic resources (quantitative trait loci (QTLs) and genes) that can be used by rice breeders to improve alkalinity tolerance are limited. Here, we assessed the alkalinity tolerance of rice at the seedling stage and performed a genome-wide association study (GWAS) based on genotypic data including 788,396 single-nucleotide polymorphisms (SNPs) developed by re-sequencing 295 japonica rice varieties. Results: We used the score of alkalinity tolerance (SAT), the concentrations of Na+ and K+ in the shoots (SNC and SKC, respectively) and the Na+/K+ ratio of shoots (SNK) as indices to assess alkalinity tolerance at the seedling stage in rice. Based on population structure analysis, the japonica rice panel was divided into three subgroups. Linkage disequilibrium (LD) analysis showed that LD decay occurred at 109.77 kb for the whole genome and varied between 13.79 kb and 415.77 kb across the 12 chromosomes, at which point the pairwise squared correlation coefficient (r(2)) decreased to half of its maximum value. A total of eight QTLs significantly associated with the SAT, SNC and SNK were identified by genome-wide association mapping. A common QTL associated with the SAT, SNC and SNK on chromosome 3 at the position of 15.0 Mb, which explaining 13.36 similar to 13.64% of phenotypic variation, was selected for further analysis. The candidate genes were filtered based on LD decay, Gene Ontology (GO) enrichment, RNA sequencing data, and quantitative real-time PCR (qRT-PCR) analysis. Moreover, sequence analysis revealed one 7-bp insertion/deletion (indel) difference in LOC_Os03g26210 (OsIRO3) between the alkalinity-tolerant and alkalinity-sensitive rice varieties. OsIRO3 encodes a bHLH-type transcription factor and has been shown to be a negative regulator of the Fe-deficiency response in rice. Conclusion: Based on these results, OsIRO3 maybe a novel functional gene associated with alkalinity tolerance in japonica rice. This study provides resources for improving alkalinity tolerance in rice, and the functional molecular marker could be verified to breed new rice varieties with alkalinity tolerance via marker-assisted selection (MAS).