Li Peng-Cheng, Ma Jun-Jie, Zhou Xi-Meng, Li Guang-Hui, Zhao Chuan-Zhi, Xia Han, Fan Shou-Jin, Wang Xing-Jun
Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, China.
College of Life Science, Shandong University, Qingdao, China.
Front Plant Sci. 2019 Sep 10;10:1118. doi: 10.3389/fpls.2019.01118. eCollection 2019.
Seed germination and formation are the beginning and ending, respectively, of a plant life cycle. These two processes are under fine regulation by the internal genetic information. Previously, we demonstrated that MIDASIN 1 (MDN1) is required for ribosome biogenesis, and its dysfunction leads to pleiotropic developmental phenotypes, including impaired embryogenesis and slow seed germination. In this study, we further found that the weak mutant of , , exhibits an increased seed size phenotype. Seed proteomic analysis reveals that a number of proteins involved in seed development and response to external environments are mis-regulated by the MDN1 dysfunction. Many 2S seed storage proteins (SSPs) and late embryogenesis abundant (LEA) proteins are over-accumulated in the dry seeds of . Further, some genes encoding seed storage reserves are also upregulated in seedlings. More interestingly, abscisic acid-insensitive 5 (ABI5) is over-accumulated in seeds, and the loss of its function partially rescues the low seed germination rate of . Together, this study further demonstrates that MDN1 is essential for establishing a normal seed proteome, and its mutation triggers ABI5-mediated repression of seed germination.
种子萌发和形成分别是植物生命周期的起点和终点。这两个过程受到内部遗传信息的精细调控。此前，我们证明了核糖体生物发生需要MIDASIN 1（MDN1），其功能障碍会导致多效性发育表型，包括胚胎发生受损和种子萌发缓慢。在本研究中，我们进一步发现，MDN1的弱突变体表现出种子大小增加的表型。种子蛋白质组学分析表明，许多参与种子发育和对外部环境响应的蛋白质因MDN1功能障碍而调控异常。许多2S种子贮藏蛋白（SSP）和胚胎后期丰富蛋白（LEA）在MDN1弱突变体的干种子中过度积累。此外，一些编码种子贮藏储备的基因在MDN1弱突变体幼苗中也上调。更有趣的是，脱落酸不敏感5（ABI5）在MDN1弱突变体种子中过度积累，其功能丧失部分挽救了MDN1弱突变体种子的低萌发率。总之，本研究进一步证明MDN1对于建立正常的种子蛋白质组至关重要，其突变触发了ABI5介导的种子萌发抑制。
