Buckwheat plants with increased urea disintegration ability

Abstract

This product provides buckwheat plants with altered starch properties. [Solution] Starch synthase (SSIIa) activity is deficient in buckwheat plants. Buckwheat flour obtained from such buckwheat plants has urea disintegration properties that are 1.5 times higher than those of the wild type, and its gelatinization peak temperature is 95% or less than that of the wild type.

Claims

1. The following are mutant SSIIa genes of the starch synthase SSIIa gene in which its function is suppressed or lost: (i) Starch synthase SSIIa2 gene having the nucleotide sequence shown in SEQ ID NOs: 1, 3, 5, or 7, (ii) The starch synthase SSIIa1 gene having the nucleotide sequence shown in SEQ ID NOs: 24, 25, 6, or 8.

2. The mutant SSIIa gene according to claim 1, wherein the suppression or deletion of the SSIIa gene function is caused by any mutation selected from the group consisting of splicing mutations, stop codon insertion mutations, and mutations involving amino acid substitutions.

3. A variant SSIIa2 gene having the nucleotide sequence shown in Sequence ID No. 2 or 4.

4. A buckwheat plant strain having the mutant SSIIa gene described in any one of claims 1 to 3, and exhibiting increased urea disintegration compared to the wild type.

5. A buckwheat-containing food product comprising buckwheat flour milled from a buckwheat plant strain described in claim 4, or buckwheat grains obtained from a buckwheat plant strain described in claim 4, as a raw material.

6. A method to increase the urea disintegration properties of buckwheat plants by suppressing the activity of any of the following proteins or the expression of polynucleotides: (A) A protein consisting of one of the amino acid sequences of sequence numbers 11, 13, and 15; (B) A protein having an amino acid sequence that is 90% or more identical to any one of the amino acid sequences of Sequence ID Nos. 11, 13, and 15, and that has the function of reducing the urea disintegration of buckwheat plants; (C) A polynucleotide that encodes an amino acid sequence in which 1 to 60 amino acids are deleted, substituted, or added in any one of the amino acid sequences of Sequence ID Nos. 11, 13, and 15, and has the function of reducing the urea disintegration of buckwheat plants.

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