Genetic Dissection of Starch Quality Traits in Wheat and Evaluation of its Health Benefits

Abstract

The present work is based on starch processing and nutritional quality that affect the food newlinequality. During the processing of starchy food, hydration of starch molecules occurs in the newlinepresence of water and heat, which undergoes gelatinization. Thus gelatinization is an important newlinephysicochemical property, affecting the cooking and nutritional quality of its food products. No newlineattempt has been reported about the genetic basis of starch gelatinization in wheat. Thus, newlinegenomic loci controlling gelatinization properties of starch and amylose-lipid complex newline(resistant starch type 5) is still not reported in wheat. This study evaluated different newlinegelatinization parameters in a large set of 226 wheat genotypes using Differential Scanning newlineCalorimetry (DSC). The five parameters (onset, peak, conclusive, range temperature, and newlineenthalpy) of both starch and amylose-lipid complex (ALc) gelatinization showed wide variation newlineamong the genotypes. Genome-wide association studies (GWAS) using the multiple markers newlinegenotyping data of 258 SSRs and high quality 3,696 SNPs identified twenty-four and six SSRs newlinemarkers and eight and twenty SNPs marker associated for starch and amylose-lipid complex newlinegelatinization properties respectively on false discovery rate (FDR). Using wheat reference newlinegenome sequence and LD decay information, 12 starch biosynthesis pathway genes (SBP) were newlineidentified, which were co-located within 50Mb of the associated SSRs marker. Four out of 12 newlinegenes (starch synthase IV, Starch Branching Enzyme IIb, Phosphorylase, and Pullulanase) newlinewere co-located within 5.2 Mb. On the other hand, in SNPs panel 28 genes were co-located newlinewithin the range of 60 Kb to 15 Mb. Out of 28, based on literature four genes (RING-type newlinedomain-containing protein, Tetratricopeptide repeat protein, Hexosyltransferase, and newlineGalactosyltransferase) were involved in starch biosynthesis pathway. In nutritional aspect, newlinehigh resistant starch (HRS) wheat mutant lines were selected that was previously generated by newlineviii newlineethyl mathanesulfonate m