文献类型： 外文期刊

作者： Wang, Lina ¹ ; Cui, Jing ¹ ; Zhang, Ning ¹ ; Wang, Xueqin ¹ ; Su, Jingping ³ ; Valles, Maria Pilar ⁴ ; Wu, Shian ¹ ; Yao, Wei ¹ ; Chen, Xiwen ² ; Chen, Defu ¹ ;

作者机构： 1.Nankai Univ, Coll Life Sci, Dept Genet & Cell Biol, Tianjin 300071, Peoples R China

2.Nankai Univ, Coll Life Sci, Dept Biochem & Mol Biol, Tianjin 300071, Peoples R China

3.Tianjin Acad Agr Sci, Crop Res Inst, Tianjin Key Lab Crop Genet & Breeding, Tianjin 300384, Peoples R China

4.Spanish Natl Res Council EEAD CSIC, Dept Genet & Plant Breeding, Aula Expt Stn, Zaragoza 50059, Spain

5.Southwest United Grad Sch, Kunming 650092, Peoples R China

关键词： OsIPK1; Phytic acid; Homozygous lethality; Starch synthesis; Rice

期刊名称：PLANT MOLECULAR BIOLOGY （ 影响因子：3.9； 五年影响因子：4.6 ）

ISSN： 0167-4412

年卷期： 2024 年 114 卷 5 期

页码：

收录情况： SCI

摘要： Inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IPK1) catalyzes the final step in phytic acid (InsP(6)) synthesis. In this study, the effects of OsIPK1 mutations on InsP(6) synthesis, grain filling and their underlying mechanisms were investigated. Seven gRNAs were designed to disrupt the OsIPK1 gene via CRISPR/CAS9 system. Only 4 of them generated 29 individual insertion or deletion T-0 plants, in which nine biallelic or heterozygous genotypes were identified. Segregation analysis revealed that OsIPK1 frameshift mutants are homozygous lethality. The biallelic and heterozygous frameshift mutants exhibited significant reduction in yield-related traits, particularly in the seed-setting rate and yield per plant. Despite a notable decline in pollen viability, the male and female gametes had comparable transmission rates to their progenies in the mutants. A significant number of the filling-aborted (FA) grains was observed in mature grains of these heterozygous frameshift mutants. These grains exhibited a nearly complete blockage of InsP(6) synthesis, resulting in a pronounced increase in Pi content. In contrast, a slight decline in InsP(6) content was observed in the plump grains. During the filling stage, owing to the excessive accumulation of Pi, starch synthesis was significantly impaired, and the endosperm development-specific gene expression was nearly abolished. Consistently, the activity of whereas AGPase, a key enzyme in starch synthesis, was significantly decreased and Pi transporter gene expression was upregulated in the FA grains. Taken together, these results demonstrate that OsIPK1 frameshift mutations result in excessive Pi accumulation, decreased starch synthesis, and ultimately leading to lower yields in rice.