Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/30/2009
Publication Date: 6/2/2010
Citation: Hurkman Ii, W.J., Williams, T.G., Wood, D.F. 2010. Starch granule formation and protein deposition in wheat (Triticum aestivum L.) starchy endosperm cells are altered by high temperature during grain fill. SPIE Scanning Microscopy, 2010, May 17-19, 2010, Monterey, CA.
Technical Abstract: High temperatures during wheat grain fill decrease starch and protein levels, adversely affecting wheat yield and flour quality. To determine the effect of high temperature on starchy endosperm cell development, grain (Triticum aestivum L. ‘Butte 86’) was produced under a 24/17°C or 37/28°C day/night regimen imposed from flowering to maturity and starch and protein deposition examined using fluorescence and scanning electron microscopy. The high temperature regimen shortened the duration of grain fill from 40 to 18 days and substantially reduced fresh weight and protein amount per grain. Under the 37/28° C regimen, A-type starch granules increased in number and decreased in size and B-type granules decreased in both number and size. A-type starch granules in mature grain exhibited pitting, suggesting enhanced action of starch degradative enzymes. Under both temperature regimens, protein bodies originated early in development and coalesced during mid to late development to form a continuous protein matrix surrounding the starch granules. Under the 37/28° C regimen, the proportion of protein matrix increased in endosperm cells of mature grain. Taken together, the changes in starch granule number and size and in protein matrix amount provide clues for understanding how high temperature during grain fill can affect end use properties of wheat flour.