Zhang Biyao, Wu Shaohuan, Zhang Yu'e, Xu Ting, Guo Feifei, Tang Huashan, Li Xiang, Wang Pengfei, Qian Wenfeng, Xue Yongbiao
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences and National Center for Plant Gene Research, Beijing, the People's Republic of China.
University of Chinese Academy of Sciences, Beijing, the People's Republic of China.
PLoS Genet. 2016 Jul 1;12(7):e1006152. doi: 10.1371/journal.pgen.1006152. eCollection 2016 Jul.
The sessile plants have evolved diverse intrinsic mechanisms to control their proper development under variable environments. In contrast to plastic vegetative development, reproductive traits like floral identity often show phenotypic robustness against environmental variations. However, it remains obscure about the molecular basis of this phenotypic robustness. In this study, we found that eg1 (extra glume1) mutants of rice (Oryza savita L.) showed floral phenotypic variations in different growth locations resulting in a breakdown of floral identity robustness. Physiological and biochemical analyses showed that EG1 encodes a predominantly mitochondria-localized functional lipase and functions in a high temperature-dependent manner. Furthermore, we found that numerous environmentally responsive genes including many floral identity genes are transcriptionally repressed in eg1 mutants and OsMADS1, OsMADS6 and OsG1 genetically act downstream of EG1 to maintain floral robustness. Collectively, our results demonstrate that EG1 promotes floral robustness against temperature fluctuation by safeguarding the expression of floral identify genes through a high temperature-dependent mitochondrial lipid pathway and uncovers a novel mechanistic insight into floral developmental control.
固着植物已经进化出多种内在机制，以在多变的环境中控制其正常发育。与可塑性营养发育不同，花身份等生殖性状通常表现出对环境变化的表型稳健性。然而，这种表型稳健性的分子基础仍不清楚。在本研究中，我们发现水稻（Oryza savita L.）的eg1（extra glume1）突变体在不同生长地点表现出花表型变异，导致花身份稳健性的破坏。生理和生化分析表明，EG1编码一种主要定位于线粒体的功能性脂肪酶，并以高温依赖的方式发挥作用。此外，我们发现包括许多花身份基因在内的众多环境响应基因在eg1突变体中被转录抑制，并且OsMADS1、OsMADS6和OsG1在遗传上作用于EG1下游以维持花的稳健性。总体而言，我们的结果表明，EG1通过高温依赖的线粒体脂质途径保护花身份基因的表达，从而促进花对温度波动的稳健性，并揭示了花发育控制的一种新的机制性见解。
