The transcription factor ZmNAC126 accelerates leaf senescence downstream of the ethylene signaling pathway in maize.
The transcription factor ZmNAC126 accelerates leaf senescence downstream of the ethylene signaling pathway in maize.
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转录因子ZmNAC126在玉米乙烯信号传导途径下游加速叶片衰老。
DOI：
10.1111/pce.13803
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Zhen Yang;Chaoqiuyu Wang;Kai Qiu;Huiru Chen;Zhongpeng Li;Xin Li;Jiang-bo Song;Xiaolei Wang;Jiong Gao;B. Kuai;Xin Zhou
中科院分区：
文献类型：
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作者：
Zhen Yang;Chaoqiuyu Wang;Kai Qiu;Huiru Chen;Zhongpeng Li;Xin Li;Jiang-bo Song;Xiaolei Wang;Jiong Gao;B. Kuai;Xin Zhou
叶片衰老是植物生长发育过程中的一个重要环节，在此过程中，营养物质从衰老的叶片向快速生长的器官转移。因此，叶片衰老的启动和进展动态不仅对同化物的最大积累，而且对养分的有效再动员至关重要。衰老是一个精细调节的过程，涉及大量转录因子（TF）的作用。NAC转录因子在拟南芥、小麦、水稻和番茄的叶片衰老过程中起着重要的调控作用。在此，我们鉴定了响应玉米叶片衰老的NAC TF，ZmNAC 126。ZmNAC126在拟南芥和玉米中的异位过表达增强了叶绿素降解，促进了叶片衰老。电泳迁移率改变和染色质免疫沉淀分析表明，ZmNAC 126可以直接结合到玉米主要叶绿素分解代谢基因的启动子。玉米原生质体双荧光素酶分析表明，ZmNAC 126正调控这些玉米叶绿素分解代谢基因。此外，ZmNAC 126可以被乙烯诱导，并且ZmEIN 3，乙烯信号的主要TF，可以结合到其启动子，反式激活其表达。综上所述，ZmNAC 126可能在调节玉米的自然和乙烯触发的叶片衰老中发挥关键作用。
Leaf senescence is an integral part of plant development, during which, nutrients are remobilized from senescent leaves to fast-growing organs. The initiation and progression dynamics of leaf senescence is therefore vital not only to the maximal accumulation of assimilates but also to the efficient remobilization of nutrients. Senescence is a finely tuned process that involves the action of a large number of transcription factors (TFs). The NAC TFs play critical roles in regulating leaf senescence in Arabidopsis, wheat, rice, and tomato. Here, we identified a NAC TF, ZmNAC126 that is responsive to leaf senescence in maize. Ectopic overexpression of ZmNAC126 in Arabidopsis and maize enhanced chlorophyll degradation and promoted leaf senescence. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed that ZmNAC126 could directly bind to the promoters of major chlorophyll catabolic genes in maize. Dual-luciferase assay in maize protoplasts indicated that ZmNAC126 positively regulates these chlorophyll catabolic genes in maize. Moreover, ZmNAC126 could be induced by ethylene, and ZmEIN3, a major TF of ethylene signaling, could bind to its promoter to transactivate its expression. Taken together, ZmNAC126 may play a pivotal role in regulating natural and ethylene-triggered leaf senescence in maize.