title: Genetic, hormonal, and physiological analysis of late maturity α-amylase in wheat.
abstract: Late maturity α-amylase (LMA) is a genetic defect that is commonly found in bread wheat (Triticum aestivum) cultivars and can result in commercially unacceptably high levels of α-amylase in harvest-ripe grain in the absence of rain or preharvest sprouting. This defect represents a serious problem for wheat farmers, and apart from the circumstantial evidence that gibberellins are somehow involved in the expression of LMA, the mechanisms or genes underlying LMA are unknown. In this work, we use a doubled haploid population segregating for constitutive LMA to physiologically analyze the appearance of LMA during grain development and to profile the transcriptomic and hormonal changes associated with this phenomenon. Our results show that LMA is a consequence of a very narrow and transitory peak of expression of genes encoding high-isoelectric point α-amylase during grain development and that the LMA phenotype seems to be a partial or incomplete gibberellin response emerging from a strongly altered hormonal environment.
authors: Commonwealth Scientific and Industrial Research Organization Plant Industry, Canberra, Australian Capital Territory 2601, Australia.
authors: Jose M
authors: JM
authors: Barrero
authors: Kolumbina
authors: K
authors: Mrva
authors: Mark J
authors: MJ
authors: Talbot
authors: Rosemary G
authors: RG
authors: White
authors: Jennifer
authors: J
authors: Taylor
authors: Frank
authors: F
authors: Gubler
authors: Daryl J
authors: DJ
authors: Mares
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D056625:Endosperm / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D005838:Genotype; D005875:Gibberellins / Q000494:pharmacology; D007526:Isoelectric Point; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000494:pharmacology*; D019655:Quantitative Trait, Heritable; D012639:Seeds / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D014908:Triticum / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D000516:alpha-Amylases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D000040:Abscisic Acid; D000516:alpha-Amylases