USDA/ARS - Western Wheat Quality Laboratory
E-202 Food Science & Human Nutrition Facility East
P.O. Box 646394, Washington State University
Pullman, WA 99164-6394
Voice: 509.335.4062
Facsimile: 509.335.8573

Beecher,B., Bettge,A., Smidansky E. and Giroux, M.J. 2002. Expression of wild-type pinB sequence in transgenic wheat complements a hard phenotype Theoretical and Applied Genetics 105:870-877.
Dept. Of Plant Sciences and Plant Pathology, Ag. BioSci. Fac., Montana State Univ., Bozeman, MT 59717 Dept. Of Agronomy and Horticulture, Univ. of Nebraska, Lincoln, NB 68583 USDA-ARS Western Wheat Quality Lab, FSHN East, Washington State Univ., Pullman
Wheat grain hardness is a major factor in wheat end-product quality. Grain hardness in wheat affects such parameters as milling yield, starch damage and baking properties. A single locus determines whether wheat is hard or soft textured. This locus, termed Hardness (Ha), resides on the short arm of chromosome 5D. Sequence alterations in the tryptophan-rich proteins puroindoline a and b (PINA and PINB) are inseparably linked to hard textured grain, but their role in endosperm texture has been controversial. Here, we show that the pinB-D1b alteration, common in hard textured wheats, and be complemented by the expression of wild-type pinB-D1a in transformed plants. Transgenic wheat seeds expressing wild-type pinB were soft in phenotype, having greatly increased friabilin levels, and greatly decreased kernel hardness and damaged starch. These results indicate that the pinB-D1b alteration is most likely the causative Ha mutation in the majority of hard wheats.