Overexpression of the Medicago falcata NAC transcription factor MfNAC3 enhances cold tolerance in Medicago truncatula
Overexpression of the Medicago falcata NAC transcription factor MfNAC3 enhances cold tolerance in Medicago truncatula
复制标题
苜蓿 NAC 转录因子 MfNAC3 的过表达增强了蒺藜苜蓿的耐寒性
DOI：
10.1016/j.envexpbot.2015.12.012
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发表时间：
2016-09-01
影响因子：
5.7
通讯作者：
Wang, Tao
中科院分区：
文献类型：
--
作者：
Qu, Yueting;Duan, Mei;Wang, Tao
冷胁迫是苜蓿生产力下降的主要原因。黄花苜蓿（Medicago falcata）和蒺藜苜蓿（Medicago truncatula）是苜蓿属（Medicago）的两个亚种，其地理适应性受水分、盐度和温度的限制。然而，苜蓿属植物在低温胁迫下的调控信号通路尚不清楚。在这项研究中，我们确定了一个基因，MfNAC3，诱导盐，干旱和低温胁迫。通过产生MfNAC 3的过表达系，我们观察到在冷驯化和非驯化条件下的典型的抗寒表型，其特征在于存活率增加以及冷响应基因MtCBFs和MtCAS的显著更高的表达水平。进一步的研究表明，该基因编码一个NAC型转录因子，该因子定位于细胞核中并具有转录活性。通过电泳迁移率变动分析，我们发现MINA可以与MtCBF4启动子区的CATGTG和CACG基序结合。综上所述，我们的研究结果表明，MfNAC3在冷反应中发挥积极作用，并提供证据表明MfNAC3是MtCBF4的正调节剂。(C)2016爱思唯尔B.V.保留所有权利。
Cold stress is the main factor underlying the reduction in productivity of Medicago. Medicago falcata and Medicago truncatula are two subspecies of Medicago, whose geographic adaption is limited by Water, salinity and temperature. However, the regulatory signaling pathway under cold stress in Medicago is unclear. In this study, we identified a gene, MfNAC3, induced under salt, drought and cold stress. By generating the overexpression lines of MfNAC3, we observed a typical cold-resistant phenotype under both cold-acclimated and non-acclimated conditions, featured by an increased survival rate and significantly higher expression levels of the cold-responsive genes MtCBFs and MtCASs. Further investigations revealed that this gene encodes a NAC-type transcriptional factor that is localized in the nucleus and exhibits transcription activity. By performing an electrophoretic mobility shift assay, we found that MINA could bind to the CATGTG and CACG motifs in the promoter region of MtCBF4. Taken together, our results demonstrate that MfNAC3 exerts a positive role in cold response and provide evidence that MfNAC3 is a positive regulator of MtCBF4. (C) 2016 Elsevier B.V. All rights reserved.