1. POLLEN STERILITY, a novel suppressor of cell division, is required for timely tapetal programmed cell death in rice
- Author
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Che, Ronghui, Hu, Bin, Wang, Wei, Xiao, Yunhua, Liu, Dapu, Yin, Wenchao, Tong, Hongning, and Chu, Chengcai
- Abstract
Timely programmed cell death (PCD) of the tapetum supplying nutrients to microspores is a prerequisite for normal pollen development. Here we identified a unique mutant of rice (Oryza sativaL.), pollen sterility(post), which showed aborted pollens accompanied with extra-large husks. Due to failure of timely PCD of tapetal cells, postexhibited abnormal pollen wall patterning and defective pollen grains. By map-based cloning, we identified a causal gene, POST, encoding a novel protein which is ubiquitously localized in cells. RNA in situhybridization showed that POSTis highly detected in the tapetum and microspores at stages 8 and 9. Transcriptome analysis indicated that POSTcould function as an important regulator of the metabolic process involved in tapetal PCD. Compared with wild-type rice, postmutant has an increased cell number resulting from elevated expression of cell cycle associated genes in grain husks. Overexpression of POSTinhibits grain size in wild type, while appropriate expression of POSTin postmutant can recover the seed fertility but has little effect on the large grains, illustrating that fine-tuning of POSTexpression could be a potential strategy for rice yield improvement. The connection between cell division and cell death conferred by POST provides novel insights into the understanding of the tapetal PCD process.
- Published
- 2022
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