Over-Expression of a Wheat Late Maturity Alpha-Amylase Type 1 Impact on Starch Properties During Grain Development and Germination.

The hydrolysis of starch is a complex process that requires synergistic action of multiple hydrolytic enzymes, including α-amylases. Wheat over-expression of , driven by seed specific promoter, resulted in a 20- to 230-fold total α-amylase activity in mature grains. Ectopic expression of showed a significant elevated α-amylase activity in stem and leaf without consequences on transitory starch.

Overexpression of a wheat α-amylase type 2 impact on starch metabolism and abscisic acid sensitivity during grain germination.

Despite being of vital importance for seed establishment and grain quality, starch degradation remains poorly understood in organs such as cereal or legume seeds. In cereals, starch degradation requires the synergetic action of different isoforms of α-amylases. Ubiquitous overexpression of TaAmy2 resulted in a 2.

Evaluation of the impact of heat on wheat dormancy, late maturity α-amylase and grain size under controlled conditions in diverse germplasm.

In the Australian wheat belts, short episodes of high temperatures or hot spells during grain filling are becoming increasingly common and have an enormous impact on yield and quality, bringing multi-billion losses annually. This problem will become recurrent under the climate change scenario that forecast increasing extreme temperatures, but so far, no systematic analysis of the resistance to hot spells has yet been performed in a diverse genetic background. We developed a protocol to study the effects of heat on three important traits: grain size, grain dormancy and the presence of Late Maturity α-Amylase (LMA), and we validated it by analysing the phenotypes of 28 genetically diverse wheat landraces and exploring the potential variability existing in the responses to hot spells.

Does Late Maturity Alpha-Amylase Impact Wheat Baking Quality?

Late maturity α-amylase (LMA) and pre-harvest sprouting (PHS) are both recognized as environmentally induced grain quality defects resulting from abnormally high levels of α-amylase. LMA is a more recently identified quality issue that is now receiving increasing attention worldwide and whose prevalence is now seen as impeding the development of superior quality wheat varieties. LMA is a genetic defect present in specific wheat genotypes and is characterized by elevated levels of the high pI TaAMY1 α-amylase, triggered by environmental stress during wheat grain development.

Fast and Efficient Screening for Wheat Loss-of-Gene Mutants Using Multiplexed Melt Curve Analyses.

This study describes a new approach in the screening for loss-of-gene mutants in Heavy Ion Bombardment (HIB) mutant populations of genetically complex organisms such as hexaploid bread wheat using multiplexed single-color (SYBR Green) melt curve analyses. The assay was set up for three target genes to test its validity and applicability. For each gene, three genome-specific primer pairs (one for each genome) with distinct melt curves were developed and multiplexed.

GrainScan: a low cost, fast method for grain size and colour measurements.

Background: Measuring grain characteristics is an integral component of cereal breeding and research into genetic control of seed development. Measures such as thousand grain weight are fast, but do not give an indication of variation within a sample. Other methods exist for detailed analysis of grain size, but are generally costly and very low throughput.