title: Influence of single-nucleotide polymorphisms in the gene encoding granule-bound starch synthase I on amylose content in Vietnamese rice cultivars.
abstract: Amylose content is one of the most important factors influencing the physical and chemical properties of starch in rice. Analysis of 352 Vietnamese rice cultivars revealed a wide range of variation in apparent amylose content and the expression level of granule-bound starch synthase. On the basis of single-nucleotide polymorphisms (SNP) at the splicing donor site of the first intron and in the coding region of the granule-bound starch synthase I gene, Waxy gene, alleles can be classified into seven groups that reflect differences in apparent amylose content. The very low and low apparent amylose content levels were tightly associated with a G to T in the first intron whereas intermediate and high amylose was associated with a T genotype at SNP in exon 10. The correlation between the combination of T genotype at SNP in the first intron, C in exon 6, or C in exon 10 was predominant among low amylose rice varieties. Our analysis confirmed the existence of Wx (op) allele in Vietnamese rice germplasm. The results of this study suggest that the low amylose properties of Vietnamese local rice germplasm are attributable to spontaneous mutations at exons, and not at the splicing donor site.
authors.affiliation: Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka 812-8581 , Japan ; Plant Resources Center, Vietnamese Academy of Agricultural Science , Ankhanh, Hoaiduc, Hanoi , Vietnam.
authors.forename: Tran Thi Thu
authors.initials: TT
authors.lastname: Hoai
authors.affiliation: Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka 812-8581 , Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsusaka
authors.affiliation: Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka 812-8581 , Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Toyosawa
authors.affiliation: Plant Resources Center, Vietnamese Academy of Agricultural Science , Ankhanh, Hoaiduc, Hanoi , Vietnam.
authors.forename: Tran Danh
authors.initials: TD
authors.lastname: Suu
authors.affiliation: Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka 812-8581 , Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Satoh
authors.affiliation: Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka 812-8581 , Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kumamaru
keywords: Waxy gene; amylose; granule-bound starch synthase I; rice germplasm; single-nucleotide polymorphism