High amylose wheat

摘要

Provided is a Wheat grain (Triticum aestivum) comprising an embryo, starch and one, two or three SBEIIa proteins, said embryo comprising two identical alleles of an SBEIIa-A gene, two identical alleles of an SBEIIa-B gene and two identical alleles of an SBEIIa-D gene, wherein the starch has an amylose content of at least 50% (w/w) as a proportion of the extractable starch of the grain, and wherein at least one of the SBEIIa proteins is produced in the developing wheat endosperm and has starch branching enzyme activity.

主权项

1. Wheat grain (Triticum aestivum) comprising an embryo, an endosperm, starch and a reduced level or activity of total SBEII protein, wherein the embryo comprises a loss of function mutation in alleles of endogenous genes of SBEIIa-A, SBEIIa-B, SBEIIa-D, SBEIIb-A, SBEIIb-B or SBEIIb-D, such that the level or activity of total SBEII protein in the grain is between 2% and 30% of the level or activity of total SBEII protein in a wild-type wheat grain, wherein
i) said alleles include 2, 4 or 6 SBEIIb alleles which are null alleles and 5 or 6 SBEIIa alleles which each comprise a loss of function mutation, wherein at least one of the 5 or 6 SBEIIa alleles which comprises a loss of function mutation comprises a loss of function point mutation; ii) the grain has a germination rate of between about 70% and about 100% relative to the germination rate of a wild-type grain, and iii) the starch of the grain has an amylose content of at least 50% (w/w) as determined by an iodometric method.