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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Crop Improvement and Genetics Research » Research » Publications at this Location » Publication #323129
Title: RNA interference targeting rye secalins alters flour protein composition in a wheat variety carrying a 1Bl.1RS translocation

Author
item Blechl, Ann
item Beecher, Brian
item Vensel, William
item Tanaka, Charlene
item Altenbach, Susan

Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2016
Publication Date: 1/25/2016
Citation: Blechl, A.E., Beecher, B.S., Vensel, W.H., Tanaka, C.K., Altenbach, S.B. 2016. RNA interference targeting rye secalins alters flour protein composition in a wheat variety carrying a 1Bl.1RS translocation. Journal of Cereal Science. 68:172-180.

Interpretive Summary: Wheat varieties carrying chromosome segments from rye (wheat/rye translocation lines) are used by wheat breeders worldwide because the rye genes confer resistance to some types of fungi and improve yield in drought conditions and some other growth environments. However, wheat/rye translocation lines often yield bread doughs that are weak, sticky and have low tolerance for over-mixing. In this report, a biotechnology approach known as RNA interference (RNAi) was used to decrease the levels of seed storage proteins encoded by rye genes in one wheat/rye translocation line. The introduced RNAi gene also reduced the levels of wheat seed proteins whose genes are related to those that code the rye proteins. Doughs derived from flour from two different lines of RNAi plants had improved mixing tolerance. We conclude that the changes in protein composition engineered by introducing the RNAi construct into the wheat/rye translocation line improved dough mixing properties.

Technical Abstract: Wheat varieties carrying chromosome translocations from rye are part of the international wheat breeding pool, despite being associated with defects in dough processing quality. Among the proposed causes for the quality defects of flours from such wheats is the presence of the secalins, encoded by the Sec1 locus on the short arm of rye chromosome 1. In this report, we decrease the levels of these and related proteins by RNA interference (RNAi). A construction designed to down-regulate secalin levels was introduced by biolistics into ‘Bobwhite’, which carries a 1BL.1RS translocation. The flour proteins of two independent transformants were analyzed by 2-dimensional gel electrophoresis and tandem mass spectrometry. Compared to the parent, the transformants exhibited up to 5.5-fold decreases in the levels of individual secalins, up to 7-fold decreases in the closely related omega gliadins, and lesser decreases in many gamma gliadins, low-molecular-weight (LMW)-glutenins, and farinins. Increased levels were found for nearly all identified alpha gliadins, triticins, and y-type HMW-glutenins. Flours from the transgenic wheats exhibited longer development times and reduced declines in resistance after peak in the 2-gram mixograph. We conclude that the changes in protein composition engineered by introducing the RNAi construct into ‘Bobwhite’ improved dough mixing tolerance.