Liu Derui, Xu Lina, Wang Wei, Jia Shuwen, Jin Sukui, Gao Jiping
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Crop Genomics and Molecular Breeding of Jiangsu Province, Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, College of Agriculture, Yangzhou University, Yangzhou, China.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Front Plant Sci. 2020 Dec 8;11:605276. doi: 10.3389/fpls.2020.605276. eCollection 2020.
Sugar allocation between vegetative and reproductive tissues is vital to plant development, and sugar transporters play fundamental roles in this process. Although several transcription factors have been identified that control their transcription levels, the way in which the expression of sugar transporter genes is controlled at the posttranscriptional level is unknown. In this study, we showed that OsRRM, an RNA-binding protein, modulates sugar allocation in tissues on the source-to-sink route. The expression pattern partly resembles that of several sugar transporter and transcription factor genes that specifically affect sugar transporter gene expression. The messenger RNA levels of almost all of the sugar transporter genes are severely reduced in the mutant, and this alters sugar metabolism and sugar signaling, which further affects plant height, flowering time, seed size, and starch synthesis. We further showed that OsRRM binds directly to messenger RNAs encoded by sugar transporter genes and thus may stabilize their transcripts. Therefore, we have uncovered the physiological function of OsRRM, which sheds new light on sugar metabolism and sugar signaling.
营养组织和生殖组织之间的糖分分配对植物发育至关重要，而糖转运蛋白在此过程中发挥着重要作用。尽管已经鉴定出几种控制其转录水平的转录因子，但糖转运蛋白基因在转录后水平的表达调控方式尚不清楚。在本研究中，我们表明，一种RNA结合蛋白OsRRM可调节源库途径中各组织的糖分分配。其表达模式部分类似于几种特异性影响糖转运蛋白基因表达的糖转运蛋白和转录因子基因的表达模式。在突变体中，几乎所有糖转运蛋白基因的信使RNA水平都大幅降低，这改变了糖代谢和糖信号传导，进而影响株高、开花时间、种子大小和淀粉合成。我们进一步表明，OsRRM直接与糖转运蛋白基因编码的信使RNA结合，因此可能会稳定其转录本。因此，我们揭示了OsRRM的生理功能，这为糖代谢和糖信号传导提供了新的线索。
