ES7, encoding a ferredoxin-dependent glutamate synthase, functions in nitrogen metabolism and impacts leaf senescence in rice
ES7, encoding a ferredoxin-dependent glutamate synthase, functions in nitrogen metabolism and impacts leaf senescence in rice
复制标题
ES7 编码铁氧还蛋白依赖性谷氨酸合酶，在氮代谢中发挥作用并影响水稻叶片衰老
DOI：
10.1016/j.plantsci.2017.03.003
复制
发表时间：
2017-06-01
期刊：
影响因子：
5.2
通讯作者：
Cao, Liyong
中科院分区：
文献类型：
--
作者：
Bi, Zhenzhen;Zhang, Yingxin;Cao, Liyong
谷氨酸合成酶（GOGAT）是植物氮代谢和铵同化的关键酶。在这项研究中，早期衰老7（es 7）突变体的鉴定和表征。es 7突变体的叶片在播种后约60天的分蘖期开始衰老，并且在抽穗期随着植株的发育而变得越来越衰老。当es 7植物生长在光呼吸抑制条件下（高CO2），衰老表型和叶绿素含量被拯救。qRT-PCR分析显示，衰老相关基因在es 7中表达显著上调。基于图位的克隆策略用于鉴定编码铁氧还蛋白依赖性谷氨酸合酶（Fd-GOGAT）的ES 7。ES 7蛋白在叶绿体中表达，并且ES 7蛋白定位于叶绿体中。qRT-PCR分析表明，与氮代谢相关的多个基因在es 7中差异表达。此外，我们还表明，叶绿素合成相关基因显着下调es 7。另外，当氮浓度（NR 4 NO 3）增加15 d时，es 7的叶绿素a、叶绿素B和总叶绿素含量显著降低。研究结果表明，ES 7基因参与水稻氮代谢，影响叶绿素合成，可能与光呼吸作用有关，影响叶片衰老。(C)2017爱思唯尔B. V.保留所有权利。
Glutamate synthase (GOGAT) is a key enzyme for nitrogen metabolism and ammonium assimilation in plants. In this study, an early senescence 7 (es7) mutant was identified and characterized. The leaves of the es7 mutant begin to senesce at the tillering stage about 60 day after sowing, and become increasingly senescent as the plants develop at the heading stage. When es7 plants are grown under photorespiration-suppressed conditions (high CO2), the senescence phenotype and chlorophyll content are rescued. qRT-PCR analysis showed that senescence-associated genes were up-regulated significantly in es7. A map-based cloning strategy was used to identify ES7, which encodes a ferredoxin-dependent glutamate synthase (Fd-GOGAT). ES7 was expressed constitutively, and the ES7 protein was localized in chloroplast. qRT-PCR analysis indicated that several genes related to nitrogen metabolism were differentially expressed in es7. Further, we also demonstrated that chlorophyll synthesis-associated genes were significantly down-regulated in es7. In addition, when seedlings are grown under increasing nitrogen concentrations (NR4NO3) for 15 days, the contents of chlorophyll a, chlorophyll b and total chlorophyll were significantly lower in es7. Our results demonstrated that ES7 is involved in nitrogen metabolism, effects chlorophyll synthesis, and may also associated with photorespiration, impacting leaf senescence in rice. (C) 2017 Elsevier B.V. All rights reserved.