Chloroplast Translation Initiation Factors Regulate Leaf Variegation and Development
Chloroplast Translation Initiation Factors Regulate Leaf Variegation and Development
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叶绿体翻译起始因子调节叶片杂色和发育。
DOI：
10.1104/pp.15.02040
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发表时间：
2016
期刊：
影响因子：
7.4
通讯作者：
Yu Fei
中科院分区：
文献类型：
--
作者：
Zheng Mengdi;Liu Xiayan;Liang Shuang;Fu Shiying;Qi Yafei;Zhao Jun;Shao Jingxia;An Lijun;Yu Fei
叶绿体的发育需要核和叶绿体基因组的协调表达，顺行和逆行信号都存在并共同促进这种协调。我们利用拟南芥黄色杂色突变体(Var2)作为工具来剖析叶绿体发育的遗传调控网络。在这里，我们报道了一个新的(据我们所知)VARIEGATION9(VARIEGATION9)基因抑制基因座的分离。SVR9编码一个叶绿体定位的原核型翻译起始因子3(IF3)。svr9-1突变体可以被大肠杆菌IF3完全拯救，这表明SVR9在叶绿体中起着真正的IF3的作用。遗传和分子证据表明，SVR9及其同源基因SVR9-like 1(SVR9L1)在功能上是可以互换的，它们的结合活性对叶绿体的发育和植物的生存是必不可少的。有趣的是，我们发现SVR9和SVR9L1也参与了叶片的正常发育。在vr9-1和svr9-1纯合子突变体(svr9-1)和杂合子突变体(svr9-1 svr9l1-1/+)中发现了叶片解剖、子叶脉型和叶缘发育的异常。同时，生长素应答报告DR5：GUS表明，生长素的动态平衡在vr9-1、svr9-1 svr911-1/+和叶绿体翻译抑制剂处理的植物中被破坏。遗传分析表明，SVR9/SVR9L1介导的叶缘发育依赖于CUP-COTYLEDON2活性，与它们在叶绿体发育中的作用无关。总之，我们的发现提供了直接证据，表明叶绿体IF3对叶绿体发育是必不可少的，也可以调节叶片的发育。
Chloroplast development requires the coordinated expressions of nuclear and chloroplast genomes, and both anterograde and retrograde signals exist and work together to facilitate this coordination. We have utilized theArabidopsis yellow variegated(var2) mutant as a tool to dissect the genetic regulatory network of chloroplast development. Here, we report the isolation of a new (to our knowledge)var2genetic suppressor locus,SUPPRESSOR OF VARIEGATION9(SVR9).SVR9encodes a chloroplast-localized prokaryotic type translation initiation factor 3 (IF3).svr9-1mutant can be fully rescued by theEscherichia coliIF3 infC, suggesting that SVR9 functions as a bona fide IF3 in the chloroplast. Genetic and molecular evidence indicate that SVR9 and its close homolog SVR9-LIKE1 (SVR9L1) are functionally interchangeable and their combined activities are essential for chloroplast development and plant survival. Interestingly, we found that SVR9 and SVR9L1 are also involved in normal leaf development. Abnormalities in leaf anatomy, cotyledon venation patterns, and leaf margin development were identified insvr9-1and mutants that are homozygous forsvr9-1and heterozygous forsvr9l1-1(svr9-1 svr9l1-1/+). Meanwhile, as indicated by the auxin response reporterDR5:GUS, auxin homeostasis was disturbed insvr9-1,svr9-1 svr9l1-1/+, and plants treated with inhibitors of chloroplast translation. Genetic analysis established thatSVR9/SVR9L1-mediated leaf margin development is dependent onCUP-SHAPED COTYLEDON2activities and is independent of their roles in chloroplast development. Together, our findings provide direct evidence that chloroplast IF3s are essential for chloroplast development and can also regulate leaf development.