A wheat 1- FEH w3 variant underlies enzyme activity for stem WSC remobilization to grain under drought.

In wheat stems, the levels of fructan-dominated water-soluble carbohydrates ( WSC) do not always correlate well with grain yield., Field drought experiments were carried out to further explain this lack of correlation. Wheat ( Triticum aestivum) varieties, Westonia, Kauz and c. 20 genetically diverse double haploid ( DH) lines derived from them were investigated., Substantial genotypic differences in fructan remobilization were found and the 1- FEH w3 gene was shown to be the major contributor in the stem fructan remobilization process based on enzyme activity and gene expression results. A single nucleotide polymorphism ( SNP) was detected in an auxin response element in the 1- FEH w3 promoter region, therefore we speculated that the mutated Westonia allele might affect gene expression and enzyme activity levels. A cleaved amplified polymorphic ( CAP) marker was generated from the SNP. The harvested results showed that the mutated Westonia 1- FEH w3 allele was associated with a higher thousand grain weight ( TGW) under drought conditions in 2011 and 2012., These results indicated that higher gene expression of 1- FEH w3 and 1- FEH w3 mediated enzyme activities that favoured stem WSC remobilization to the grains. The CAP marker residing in the 1- FEH w3 promoter region may facilitate wheat breeding by selecting lines with high stem fructan remobilization capacity under terminal drought. [ABSTRACT FROM AUTHOR]