Allelic variations and differential expressions detected at quantitative trait loci for salt stress tolerance in wheat. (7th March 2017)

• Record Type: Journal Article
• Authors: Oyiga, Benedict C.; Sharma, Ram C.; Baum, Michael; Ogbonnaya, Francis C.; Léon, Jens; Ballvora, Agim
• Is Part Of: Plant, cell and environment. Volume 41:Number 5(2018)
• Page Start: 919
• Page End: 935
• Publication Date: 2017-03-07
• Subjects: developmental growth stages -- genome‐wide association study (GWAS) -- salt tolerance -- transcription regulation; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12898
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: The increasing salinization of agricultural lands is a threat to global wheat production. Understanding of the mechanistic basis of salt tolerance (ST) is essential for developing breeding and selection strategies that would allow for increased wheat production under saline conditions to meet the increasing global demand. We used a set that consists of 150 internationally derived winter and facultative wheat cultivars genotyped with a 90K SNP chip and phenotyped for ST across three growth stages and for ionic (leaf K + and Na + contents) traits to dissect the genetic architecture regulating ST in wheat. Genome‐wide association mapping revealed 187 Single Nucleotide Polymorphism (SNPs) ( R 2 = 3.00–30.67%), representing 37 quantitative trait loci (QTL), significantly associated with the ST traits. Of these, four QTL on 1BS, 2AL, 2BS and 3AL were associated with ST across the three growth stages and with the ionic traits. Novel QTL were also detected on 1BS and 1DL. Candidate genes linked to these polymorphisms were uncovered, and expression analyses were performed and validated on them under saline and non‐saline conditions using transcriptomics and qRT‐PCR data. Expressed sequence comparisons in contrasting ST wheat genotypes identified several non‐synonymous/missense mutation sites that are contributory to the ST trait variations, indicating the biological relevance of these polymorphisms that can be exploited in breeding for ST in wheat. Brief Summary/Summary Statement: This study provides additional genetic and molecular insights into the salt tolerance mechanisms and thus would aid efforts geared towards improving wheat adaptation to salinity. A genome‐wide association study was used to identify major loci regulating K + and Na + uptake, and several agronomic related traits across multiple growth stages under saline conditions in a 150 diversity wheat panel. The analysis of the underlying candidate genes revealed that some of them are differentially expressed and contain several functional polymorphic sites at the associated gene coding regions when wheat genotypes with contrasting response to salt stress were compared.