Wxlv, the Ancestral Allele of Rice Waxy Gene

Abstract

In rice endosperms, the Waxy (Wx) gene is important for amylose synthesis, and various Wx alleles control the amylose content and affect the taste of cooked rice. Herein, we report the cloning of the ancestral allele Wxlv of the Wx locus, which affects the mouthfeel of rice grains by modulating the size of amylose molecules. Using evolutionary analysis, we demonstrated that Wxlv originated directly from wild rice, and the three major Wx alleles in cultivated rice (Wxb, Wxa, and Wxin) differentiated after the substitution of one base pair at the functional sites. These data indicate that the Wxlv allele played an important role in artificial selection and domestication. The findings also shed light on the evolution of various Wx alleles, which have greatly contributed to improving the eating and cooking quality of rice.

Keywords

• Oryza sativa
• Waxy
• eating and cooking quality
• allelic variation