College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
College of Food Science and Biological Engineering, Tianjin Agricultural University, Tianjin 300384, China.
Plant Physiol. 2017 Dec;175(4):1690-1702. doi: 10.1104/pp.17.01265. Epub 2017 Oct 23.
RNA editing plays a key posttranscriptional role in gene expression. Existing studies on cytidine-to-uridine RNA editing in plants have focused on maize (), rice (), and Arabidopsis (). However, the importance and regulation of RNA editing in several critical agronomic processes are not well understood, a notable example of which is fruit ripening. Here, we analyzed the expression profile of 33 RNA editing factors and identified 11 putative tomato () fruit ripening-related factors. A rapid virus-induced gene silencing assay indicated that the organelle RNA recognition motif-containing protein SlORRM4 affected tomato fruit ripening. Knocking out SlORRM4 expression using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 genome editing strategy delayed tomato fruit ripening by lowering respiratory rate and ethylene production. Additionally, the expression of numerous genes associated with fruit ripening and mitochondrial functions changed significantly when was knocked out. Moreover, the loss of function significantly reduced RNA editing of many mitochondrial transcripts, leading to low-level expression of some core subunits that are critical for mitochondrial complex assembly (i.e. Nad3, Cytc1, and COX II). Taken together, these results indicate that SlORRM4 is involved in RNA editing of transcripts in ripening fruit that influence mitochondrial function and key aspects of fruit ripening.
RNA 编辑在基因表达中发挥着关键的转录后作用。现有的植物胞嘧啶向尿嘧啶 RNA 编辑研究主要集中在玉米（）、水稻（）和拟南芥（）上。然而，RNA 编辑在几个关键农业过程中的重要性和调控机制还不是很清楚，一个显著的例子就是果实成熟。在这里，我们分析了 33 个 RNA 编辑因子的表达谱，并鉴定了 11 个可能与番茄（）果实成熟相关的因子。快速病毒诱导基因沉默试验表明，含有细胞器 RNA 识别模体的蛋白 SlORRM4 影响番茄果实成熟。使用成簇规则间隔短回文重复（CRISPR）/CRISPR 相关蛋白 9 基因组编辑策略敲除 SlORRM4 表达会降低呼吸速率和乙烯生成，从而延缓番茄果实成熟。此外，当 被敲除时，与果实成熟和线粒体功能相关的许多基因的表达显著变化。此外，功能丧失显著降低了许多线粒体转录本的 RNA 编辑，导致一些对于线粒体复合物组装至关重要的核心亚基表达水平降低（即 Nad3、Cytc1 和 COX II）。总之，这些结果表明 SlORRM4 参与了影响线粒体功能和果实成熟关键方面的成熟果实中转录本的 RNA 编辑。
