State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China.
State Key Laboratory of Hybrid Rice, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
Int J Mol Sci. 2020 Mar 16;21(6):2018. doi: 10.3390/ijms21062018.
Pollen development plays crucial roles in the life cycle of higher plants. Here we characterized a rice mutant with complete male-sterile phenotype, (). exhibited smaller anthers with arrested pollen development, absent Ubisch bodies, necrosis-like tapetal hypertrophy, and smooth anther cuticular surface. Molecular mapping revealed a synonymous mutation in the fourth exon of co-segregated with the mutant phenotype. This mutation disrupts the exon-intron splice junction in , generating aberrant mRNA species and truncated proteins. is highly expressed in the tapetal cells of developing anther, and its protein is co-localized with plasma membrane (PM) and endoplasmic reticulum (ER) signal. encodes an integrin-α FG-GAP repeat-containing protein, which has seven β-sheets and putative Ca-binding motifs and is broadly conserved in terrestrial plants. Our findings therefore provide insights into both the role of integrin-α FG-GAP repeat-containing protein in rice male fertility and the influence of exonic mutation on intronic splice donor site selection.
花粉发育在高等植物的生命周期中起着至关重要的作用。在这里，我们描述了一个水稻雄性不育突变体（）。该突变体的花粉发育停滞，花粉粒小，绒毡层小体缺失，绒毡层出现坏死样肥大，花粉外壁光滑。分子作图表明，突变与一个第四外显子同义突变（）共分离，该突变破坏了 的内含子-外显子拼接接头，导致异常的 mRNA 种类和截短的蛋白质。在花药发育过程中绒毡层细胞中高度表达，其蛋白与质膜（PM）和内质网（ER）信号共定位。编码一个整合素-α FG-GAP 重复蛋白，它具有七个β片层和推定的 Ca 结合基序，在陆生植物中广泛保守。因此，我们的研究结果为整合素-α FG-GAP 重复蛋白在水稻雄性育性中的作用以及外显子突变对内含子剪接供体位点选择的影响提供了新的见解。
