AUTHOR=Yang Bowen , Xu Shunju , Xu Liang , You Hui , Xiang Xunchao 

TITLE=Effects of Wx and Its Interaction With SSIII-2 on Rice Eating and Cooking Qualities

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00456

DOI=10.3389/fpls.2018.00456

ISSN=1664-462X

ABSTRACT=<p>The <italic>Wx</italic> gene encodes a granule-bound starch synthase (GBSS) and plays a key role in determining rice eating and cooking qualities (ECQs). SSIII-2 (SSIIIa), a member of the soluble starch synthases, is responsible for the synthesis of long chains of amylopectin. To investigate the effects of <italic>Wx</italic> and its interaction with <italic>SSIII-2</italic> on grain ECQs, a population from a hybrid combination was established as a research material. The genotypes of <italic>SSIII-2</italic> and the single nucleotide polymorphisms (SNPs) on intron1, exon6, and exon10 of <italic>Wx</italic>, and the physicochemical indicators and rapid visco analyzer (RVA) profile characteristics were analyzed. The results revealed various effects of <italic>SSIII-2</italic> on rice quality under different backgrounds of <italic>Wx</italic> alleles. There was no obvious difference between different <italic>SSIII-2</italic> alleles under the same background of <italic>Wx</italic><sup><italic>a</italic></sup>, whereas there was a significant diversity under the same background of <italic>Wx</italic><sup><italic>b</italic></sup>. <italic>Wx</italic><sup><italic>a</italic></sup> had a dominant epistasis to <italic>SSIII-2</italic> because the effect of <italic>SSIII-2</italic> was masked by the massive synthesis of GBSS under <italic>Wx</italic><sup><italic>a</italic></sup>. The apparent amylose content (AAC) was mainly controlled by the In1G/T SNP, and rice gel consistency (GC) was regulated by the Ex10C/T SNP. The combined effects of three SNPs had a significant influence on all ECQs and RVA profile parameters, except for gelatinization temperature. In1T-Ex6A-Ex10C and In1T-Ex6A-Ex10T were classified as being low AAC type. TT-AA-CC and TT-AA-TT had a low AAC and a soft GC. The combined effects of different SNPs of <italic>Wx</italic> are very important for rice quality breeding.</p>