State Key Laboratory of Molecular Developmental Biology, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2012;7(4):e33595. doi: 10.1371/journal.pone.0033595. Epub 2012 Apr 11.
RNA biogenesis, including biosynthesis and maturation of rRNA, tRNA and mRNA, is a fundamental process that is critical for cell growth, division and differentiation. Previous studies showed that mutations in components involved in RNA biogenesis resulted in abnormalities in gametophyte and leaf development in Arabidopsis. In eukaryotes, RNases P/MRP (RNase mitochondrial RNA processing) are important ribonucleases that are responsible for processing of tRNA, and transcription of small non-coding RNAs. Here we report that Gametophyte Defective 1 (GAF1), a gene encoding a predicted protein subunit of RNases P/MRP, AtRPP30, plays a role in female gametophyte development and male competence. Embryo sacs were arrested at stages ranging from FG1 to FG7 in gaf1 mutant, suggesting that the progression of the gametophytic division during female gametogenesis was impaired in gaf1 mutant. In contrast, pollen development was not affected in gaf1. However, the fitness of the mutant pollen tube was weaker than that of the wild-type, leading to reduced transmission through the male gametes. GAF1 is featured as a typical RPP30 domain protein and interacts physically with AtPOP5, a homologue of RNases P/MRP subunit POP5 of yeast. Together, our data suggest that components of the RNases P/MRP family, such as RPP30, play important roles in gametophyte development and function in plants.
RNA 生物发生，包括 rRNA、tRNA 和 mRNA 的生物合成和成熟，是细胞生长、分裂和分化的关键基本过程。先前的研究表明，涉及 RNA 生物发生的成分的突变导致拟南芥配子体和叶片发育异常。在真核生物中，RNase P/MRP（RNase 线粒体 RNA 加工）是重要的核糖核酸酶，负责 tRNA 的加工和小非编码 RNA 的转录。在这里，我们报道 Gametophyte Defective 1（GAF1），一个编码 RNase P/MRP 的预测蛋白亚基 AtRPP30 的基因，在雌性配子体发育和雄性育性中发挥作用。gaf1 突变体的胚囊停滞在 FG1 到 FG7 阶段，这表明雌性配子体发生过程中的配子体分裂进展在 gaf1 突变体中受到了损害。相比之下，gaf1 突变体的花粉发育不受影响。然而，突变体花粉管的适应性比野生型弱，导致雄性配子传递减少。GAF1 是一种典型的 RPP30 结构域蛋白，与 AtPOP5 相互作用，AtPOP5 是酵母 RNase P/MRP 亚基 POP5 的同源物。总之，我们的数据表明，RNase P/MRP 家族的成分，如 RPP30，在植物配子体发育和功能中发挥重要作用。
