Genes coding for starch branching enzymes are major contributors to starch viscosity characteristics in waxy rice (Oryza sativa L.)

作者：Han YP; Xu ML; Liu XY; Yan CJ; Korban SS; Chen XL; Gu MH^*

来源：Plant Science, 2004, 166(2): 357-364.

DOI：10.1016/j.plantsci.2003.09.023

• Rice (Oryza sativa L.)
• starch branching enzyme
• (CT)(n) repeats
• starch paste viscosity
• rapid viscosity analyzer

Granule-bound starch synthase (GBSS) encoded by the Waxy (Wx) gene determines the synthesis of amylose; while, starch branching enzymes encoded by Sbe genes are involved in the formation of amylopectin. Both amylose and amylopectin form starch in the endosperm of seeds. Here, we report on the effects of the wx gene and the two Sbe genes, Sbe1 and Sbe3, on starch paste viscosity in waxy rice. Molecular markers for both Sbe1 and Sbe3 have been developed based on sequence diversity between the rice subspecies indica and japonica. All Sbe- and Wx- linked markers have been used to investigate 40 waxy rice cultivars. For the wx locus (null Wx locus in waxy rice), four classes of (CT)(n) repeats, including (CT)(16), (CT)(17), (CT)(18), and (CT)(19), were detected in the putative leader sequence. Moreover, a unique sequence, AGTTATA, is also present at the 5' splice junction site of the putative leader intron. Overall, the wx locus has no effect on starch paste viscosity characteristics. Among all 40 waxy rice cultivars, five genotypes are observed at the Sbe1 and Sbe3 loci. Polymorphisms in both Sbe1 and Sbe3 loci account for similar to70% of the observed variations in both hot and cool viscosities, and for 40% of the observed variations in both peak viscosity and consistency.

• 出版日期2004-2
• 单位扬州大学