Wang Wang, Feng Liu, Haodong Shen, Tiancheng Hao, Xiaoyun Tan, Kun Chen, Tianqi Duan, Jingyi Li, Liyan Bu, Shiqi Song, Nan Wang, Huiting Yang, Yifeng Xu, Huadong Zhan, Yiqun Bao
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引用次数: 0
Abstract
Proper timing of programmed cell death (PCD) in the tapetum and the deposition of pollen wall are crucial for gametophyte development. Although several genes involved in these processes have been identified, the regulatory mechanisms remain poorly understood. We isolated and characterized a rice male-sterile mutant, exine abnormal 1 (exa1), which exhibits pale anthers and aborted pollen. The exa1 mutant displays delayed tapetal PCD and defective pollen wall patterning, including thinner sexine and thicker nexine. EXA1 (Exine Abnormal 1), preferentially expressed in the tapetum and microspores, encodes a novel Zf-HIT (Zinc finger-High Temperature) family protein, OsZNHIT3. Nucleus and cytoplasm dual-localized EXA1 functions as a transcriptional activator via its previously undefined C-terminal domain. Phenotypic similarities in rice expressing EXA1-SRDX (SUPERMAN Repressive Domain X) fusion proteins further support its role as a transcriptional activator. PTC1 (Persistent Tapetal Cell 1), EAT1 (Eternal Tapetum 1), and their downstream genes were significantly downregulated in exa1 mutant anthers. Introducing pEXA1:PTC1 or pEXA1:EAT1 into the exa1 mutant partially rescued anther appearance, pollen morphology, and sexine-nexine ratio. This suggests that EXA1 acts genetically upstream of PTC1 and EAT1 in the regulatory pathway. Our study reveals a novel and essential role for EXA1 as a transcriptional activator in rice anther development.
期刊介绍:
New Phytologist is a leading publication that showcases exceptional and groundbreaking research in plant science and its practical applications. With a focus on five distinct sections - Physiology & Development, Environment, Interaction, Evolution, and Transformative Plant Biotechnology - the journal covers a wide array of topics ranging from cellular processes to the impact of global environmental changes. We encourage the use of interdisciplinary approaches, and our content is structured to reflect this. Our journal acknowledges the diverse techniques employed in plant science, including molecular and cell biology, functional genomics, modeling, and system-based approaches, across various subfields.