The Impact on Resistant-starch Content for Base Mutations Near the 3' Splice Site of the Fourth Intron of the Waxy Gene in Rice (Oryza sativa)
LUO Xi1,2,*, FAN Jia-Xing1,2,3,*, WEI Yi-Dong1,2, WEI Lin-Yan1,2, ZHU Yong-Sheng1,2, HE Wei1,2, WU Fang-Xi1,2, CAI Qiu-Hua1,2, XIE Hua-An1,2, ZHANG Jian-Fu1,2,**
1 Rice Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350019 China; 2 Key Laboratory of Germplasm Innovation and Molecular Breeding of Hybrid Rice for South China, Ministry of Agriculture and Rural Affairs/Fuzhou Branch, National Rice Improvement Center of China/Fujian Engineering Laboratory of Crop Molecular Breeding/Fujian Key Laboratory of Rice Molecular Breeding /Incubator of National key Laboratory of Fujian Germplasm Innovation and Molecular Breeding between Fujian and Ministry of Sciences &Technology, China/South China Bases of National Key Laboratory of Hybrid Rice for China/National Rice Engineering Center of China, Fuzhou 350003 China; 3 College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Abstract：In recent years, with the rising incidence of typeⅡ diabetes, resistant starch (RS) has gained significant attention as a low-glycemic index food component. Resistant starch offers important physiological benefits, such as reducing postprandial blood glucose levels in diabetic patients and decreasing the risk of intestinal dysfunction and colon cancer. The content of resistant starch in rice (Oryza sativa) is positively correlated with amylose content, and the synthesis of amylose is controlled by the Waxy (Wx) gene. In this study, CRISPR/Cas9 gene editing technology was employed to edit the bases near the 3' splice site AG of the fourth intron of the Wx gene in rice, resulting in 4 different types of mutant lines. By analyzing the expression levels of the Wx gene, the activity of granule-bound starch synthase (GBSS), and the contents of amylose and resistant starch in these mutant lines, it was found that mutations near the 3' splice site AG significantly affected the expression of the Wx gene, thereby regulating the contents of amylose and resistant starch in rice. Correlation analysis revealed a significant positive correlation between Wx gene expression and resistant starch content. This study identified intron mutation genotypes that can effectively regulate the expression level of the Wx gene (either increasing or decreasing it), providing new insights for future improvements in the resistant starch content of rice.
罗曦, 樊佳星, 魏毅东, 魏林艳, 朱永生, 何炜, 吴方喜, 蔡秋华, 谢华安, 张建福. 水稻Waxy基因第四内含子3'剪接位点邻近碱基突变影响水稻抗性淀粉含量[J]. 农业生物技术学报, 2025, 33(9): 1873-1882.
LUO Xi, FAN Jia-Xing, WEI Yi-Dong, WEI Lin-Yan, ZHU Yong-Sheng, HE Wei, WU Fang-Xi, CAI Qiu-Hua, XIE Hua-An, ZHANG Jian-Fu. The Impact on Resistant-starch Content for Base Mutations Near the 3' Splice Site of the Fourth Intron of the Waxy Gene in Rice (Oryza sativa). 农业生物技术学报, 2025, 33(9): 1873-1882.
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