ARS | Publication request: Transcriptomic analysis of starch biosynthesis in the developing grain of hexaploid wheat

Submitted to: International Journal of Plant Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 19, 2009
Publication Date: March 8, 2010
Citation: Stamova, B., Chingcuanco, D.L., Beckles, D. 2010. Transcriptomic analysis of starch biosynthesis in the developing grain of hexaploid wheat. International Journal of Plant Genomics. Available at: http://www.hindawi com/journals/ijpg/2009/407426/. doi:10.1155/2009/407426.

Interpretive Summary: Starch from cereals is the major source of calories in the human diet. In this report we examined how this important compound is made in wheat. We looked at the expression of the genes that are critical in starch synthesis in developing wheat grain using DNA microarrays. We found that starch synthesis genes exhibit different patterns of expression suggesting their relative importance at the different stages of grain development. We also identified metabolic and regulatory genes which expression pattern is similar to the accumulation profiles of starch and starch granules which could suggest involvement in starch synthesis. Understanding how starch is made could help us develop research tools and new varieties of wheat with better starch quality and yield.

Technical Abstract: The expression of genes involved in starch synthesis in wheat was analyzed together with the accumulation profiles of soluble sugars, starch, protein, and starch granule distribution in developing caryopses obtained from the same biological materials used for profiling of gene expression using DNA microarrays. Multiple expression patterns were detected for the different starch biosynthetic gene isoforms, suggesting their relative importance through caryopsis development. Members of the ADP-glucose pyrophosphorylase, starch synthase, starch branching enzyme and sucrose synthase gene families showed different expression profiles; expression of some members of these gene families coincided with a period of high accumulation of starch while others did not. A biphasic pattern was observed in the rates of starch and protein accumulation which paralleled changes in global gene expression. Metabolic and regulatory genes that show a pattern of expression similar to starch accumulation and granule size distribution were identified, suggesting their co-involvement in these biological processes. -