title: A wheat 1-FEH w3 variant underlies enzyme activity for stem WSC remobilization to grain under drought.
abstract: 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.
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Zhang
authors.forename: Yunji
authors.initials: Y
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Bernard
authors.initials: B
authors.lastname: Dell
authors.forename: Rudy
authors.initials: R
authors.lastname: Vergauwen
authors.forename: Ben
authors.initials: B
authors.lastname: Biddulph
authors.forename: Nusrat
authors.initials: N
authors.lastname: Khan
authors.forename: Hao
authors.initials: H
authors.lastname: Luo
authors.forename: Rudi
authors.initials: R
authors.lastname: Appels
authors.forename: Wim
authors.initials: W
authors.lastname: Van den Ende
mesh_terms: D057914:Agricultural Irrigation; D000483:Alleles; D018533:Biomass; D002241:Carbohydrates / Q000032:analysis*; D055864:Droughts; D005630:Fructans / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D006238:Haploidy; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism*; D012995:Solubility; D014908:Triticum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000737:chemistry; D014904:Western Australia
chemical_list: D002241:Carbohydrates; D005630:Fructans; D005819:Genetic Markers; D010940:Plant Proteins; D014867:Water; D005632:Fructose
keywords: fructan degradation; gene expression; grain filling; single nucleotide polymorphism (SNP); stem water-soluble carbohydrate (WSC) remobilization; terminal drought