A cytosolic pentatricopeptide repeat protein is essential for tapetal plastid development by regulating OsGLK1 transcript levels in rice
A cytosolic pentatricopeptide repeat protein is essential for tapetal plastid development by regulating OsGLK1 transcript levels in rice
复制标题
胞质五肽重复蛋白通过调节水稻中的 OsGLK1 转录水平对于绒毡质体发育至关重要
DOI：
10.1111/nph.18105
复制
发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Zhuang Chuxiong
中科院分区：
文献类型：
--
作者：
Zheng Shaoyan;Dong Jingfang;Lu Jingqin;Li Jing;Jiang Dagang;Yu Haopeng;Ye Simiao;Bu Wenli;Liu Zhenlan;Zhou Hai;Ding Yiliang;Zhuang Chuxiong
大多数植物五肽重复序列（PPR）蛋白定位于质体和线粒体并在其中发挥作用。然而，仅定位于细胞质的PPR的功能仍然未知。在这里，我们证明了水稻（Oryza sativa）PPR蛋白质细胞质定位PPR 1（OsCPPR 1）有助于花粉发育和定位于细胞质。OsCPPR 1基因的敲除导致绒毡层细胞中质体发育异常，绒毡层细胞程序性死亡（PCD）和绒毡层降解时间延长，花粉育性显著降低。转录组分析显示，OsGOLDEN-LIKE 1（OsGLK 1）的转录水平，其编码调节质体发育和维持的转录因子，在OsCPPR 1敲除植物中比野生型植物显著更高。我们进一步确定OsCPPR 1通过直接结合OsGLK 1 mRNA的单链区域来下调OsGLK 1的转录。OsGLK 1的过表达导致绒毡层和质体发育异常，类似于OsCPPR 1敲除植物中所见，并且OsGLK 1的抑制部分恢复OsCPPR 1敲除植物中的花粉育性。因此，我们得出结论，OsCPPR 1抑制OsGLK 1在调节质体发育和PCD的绒毡层。我们的工作揭示了细胞质PPR的新功能，证明了PPR在植物中的不同作用，并确定了调节水稻花粉发育的新调节机制。
Most plant pentatricopeptide repeat (PPR) proteins localize to and function inside plastids and mitochondria. However, the function of PPRs that only localize to the cytoplasm remains unknown. Here, we demonstrated that the rice (Oryza sativa) PPR protein CYTOPLASM-LOCALIZED PPR1 (OsCPPR1) contributes to pollen development and localizes to the cytoplasm. Knocking down OsCPPR1 led to abnormal plastid development in tapetal cells, prolonged tapetal programmed cell death (PCD) and tapetum degradation, and significantly reduced pollen fertility. Transcriptome analysis revealed that the transcript level of OsGOLDEN-LIKE1 (OsGLK1), which encodes a transcription factor that regulates plastid development and maintenance, was significantly higher in the OsCPPR1 knockdown plants compared to wild-type plants. We further determined that OsCPPR1 downregulates OsGLK1 transcription by directly binding to the single-stranded regions of OsGLK1 mRNAs. Overexpression of OsGLK1 resulted in abnormal tapetum and plastid development, similar to that seen in OsCPPR1 knockdown plants, and suppression of OsGLK1 partially restored pollen fertility in the OsCPPR1 knockdown plants. We therefore conclude that OsCPPR1 suppresses OsGLK1 in the regulation of plastid development and PCD in the tapetum. Our work revealed novel functions for a cytosolic PPR, demonstrating the diverse roles of PPRs in plants and identifying a new regulatory mechanism for regulating pollen development in rice.