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Single-nucleotide polymorphisms and association analysis of drought-resistance gene TaSnRK2.8 in common wheat

Zhang, Hongying, Mao, Xinguo, Zhang, Jianan, Chang, Xiaoping, Jing, Ruilian
Plant physiology and biochemistry 2013 v.70 pp. 174-181
alleles, analysis of variance, biomass, breeding, carbohydrate content, carbohydrate metabolism, drought, drought tolerance, exons, genotype, introns, leaves, protein kinases, seedlings, sequence analysis, single nucleotide polymorphism, stress tolerance, sucrose, wheat
TaSnRK2.8, an SnRK2 (sucrose non-fermenting1-related protein kinase 2) member of wheat, confers enhanced multi-stress tolerances in carbohydrate metabolism. In the study, two types of genomic sequences of TaSnRK2.8 were detected in common wheat. Sequencing analysis showed that there was a variation-enriched region, designated TaSnRK2.8-A-C, covering the eighth intron, the ninth exon and the 3′-flanking region of TaSnRK2.8-A, and no divergence occurred in TaSnRK2.8-B. Single nucleotide polymorphisms in the TaSnRK2.8-A-C region were investigated in 165 wheat accessions. Three of 751 sequenced nucleotide sites were polymorphic. Nucleotide diversity (π) in the region was 0.00068. Sliding-window analysis demonstrated that the nucleotide diversity was highest in the 3′-flanking sequence. As predicted, the highly frequent SNP was significantly associated with seedling biomass under normal conditions, plant height, flag leaf width and water-soluble carbohydrate content under drought conditions. Analysis of variance of correlated traits between accessions with the A and G genotypes indicated that the A variant was the more favorable allele associated with significantly increased seedling biomass and water-soluble carbohydrates. Based on the SNP, we developed a functional marker of TaSnRK2.8-A-C, that could be utilized in wheat breeding programs aimed at improving seedling biomass and water-soluble carbohydrates, and consequently to enhance stress resistance in wheat.