State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 310006, China.
State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 310006, China.
Plant Sci. 2021 Jun;307:110907. doi: 10.1016/j.plantsci.2021.110907. Epub 2021 Apr 7.
Chloroplasts are closely associated with the growth and development of higher plants. Accumulating evidence has revealed that the multiple organellar RNA editing factors (MORF) family of proteins influences plastidic and mitochondrial development through post-transcriptional regulation. However, the role of MORFs in regulating the development of chloroplasts in rice is still unclear. The OsMORF9 gene belongs to a small family of 7 genes in rice and is highly expressed in young leaves. We used the CRISPR/Cas9 system to mutate OsMORF9. The resulting knockout lines osmorf9-1 and osmorf9-2 exhibited an albino seedling lethal phenotype. Besides, the expression of many plastid-encoded genes involved in photosynthesis, the biogenesis of plastidic ribosomes and the editing and splicing of specific plastidic RNA molecules were severely affected in these two OsMORF9 mutants. Furthermore, yeast two-hybrid analysis revealed that OsMORF9 could interact with OsSLA4 and DUA1 which are members of the pentatricopeptide repeat (PPR) family of proteins. Analysis of subcellular localization of OsMORF9 also suggested that it might function in chloroplasts. The findings from the present study demonstrated the critical role of OsMORF9 in the biogenesis of chloroplast ribosomes, chloroplast development and seedling survival. This therefore provides new insights on the function of MORF proteins in rice.
叶绿体与高等植物的生长和发育密切相关。越来越多的证据表明，多细胞器 RNA 编辑因子（MORF）家族的蛋白质通过转录后调控影响质体和线粒体的发育。然而，MORFs 在调节水稻叶绿体发育中的作用尚不清楚。OsMORF9 基因属于水稻中一个由 7 个基因组成的小家族，在嫩叶中高度表达。我们使用 CRISPR/Cas9 系统对 OsMORF9 进行突变。由此产生的敲除系 osmorf9-1 和 osmorf9-2 表现出白化苗致死表型。此外，这两个 OsMORF9 突变体中涉及光合作用、质体核糖体生物发生以及特定质体 RNA 分子编辑和剪接的许多质体编码基因的表达受到严重影响。此外，酵母双杂交分析表明，OsMORF9 可以与 OsSLA4 和 DUA1 相互作用，它们是五肽重复（PPR）家族蛋白的成员。对 OsMORF9 亚细胞定位的分析也表明它可能在叶绿体中发挥作用。本研究的结果表明，OsMORF9 在叶绿体核糖体的生物发生、叶绿体发育和幼苗存活中起着关键作用。这为 MORF 蛋白在水稻中的功能提供了新的见解。
