Functional characterization of tomato membrane-bound NAC transcription factors
Functional characterization of tomato membrane-bound NAC transcription factors
复制标题
DOI：
10.1007/s11103-016-0579-z
复制
发表时间：
2017-03-01
影响因子：
5.1
通讯作者：
Kundu, Pallob
中科院分区：
文献类型：
--
作者：
Bhattacharjee, Payel;Das, Rohit;Kundu, Pallob
利用全基因组分析技术对番茄膜结合NAC转录因子（SlNACMTF）在逆境胁迫下的差异表达进行了鉴定和分析。两个与生物胁迫相关的SlNACMTF已被鉴定以阐明其调控功能。NAC转录因子是已知的胁迫相关基因表达的调节因子。由于胁迫是通过膜结合蛋白来感知和传递的，番茄中膜相关NAC转录因子的功能表征可以揭示关于膜介导的胁迫信号传导的有价值的见解。番茄基因组编码13个NAC基因，它们具有预测的跨膜结构域（SlNACMTF）。12个SlNACMTF的mRNA在多个组织中容易地检测到，并且还在从叶分离的多核糖体中检测到，证实这些基因的活性转录和翻译在正常生理条件下发生。此外，大多数的SlNACMTF的差异调节过程中的压力和压力相关的转录因子结合位点是普遍存在于其启动子。SlNACMTF 3和8主要受生物和非生物胁迫的调控。与其他MTF一样，SlNACMTF 3易位至质膜，而C-末端截短（Δ C）形式定位于细胞质和细胞核中。因此，Δ C形式显著影响含有NAC结合位点（NACbs）的启动子的活性。此外，这些转录因子的NAC结构域可以直接与NACbs相互作用，并且这些蛋白质不能调节缺乏关键NACbs的启动子。有趣的是，对含有NACbs的启动子的影响类型取决于NACbs的背景，因为相同的SlNACMTF在不同的启动子上显示出替代的调节模式，并且相同的启动子活性由两种不同的SlNACMTF相反地调节。最后，这两个SlNACMTF表现出不同的调控效果上的几个压力相关基因的表达，通过相互作用与推定的NACbs在其启动子区域，这表明它们在植物胁迫反应中的直接作用。
Genome-wide analysis was carried out to identify and analyze differential expression pattern of tomato membrane bound NAC transcription factors (SlNACMTFs) during stresses. Two biotic-stress-related SlNACMTFs have been characterized to elucidate their regulatory function.NAC transcription factors are known regulators of stress-related gene expression. As Stresses are perceived and transmitted by membrane-bound proteins, functional characterization of membrane-associated NAC transcription factors in tomato can reveal valuable insight about membrane-mediated stress-signalling. Tomato genome encodes 13 NAC genes which have predicted transmembrane domain(s) (SlNACMTFs). mRNA of 12 SlNACMTFs were readily detected in multiple tissues, and also in polysome isolated from leaf, confirming active transcription and translation from these genes occur under normal physiological condition. Additionally, most of the SlNACMTFs were differentially regulated during stresses and stress-related transcription factor binding sites are prevalent in their promoters. SlNACMTF3 and 8 were majorly regulated in biotic and abiotic stresses. Like other MTFs, SlNACMTF3 was translocated to the plasma membrane, whereas the C-terminus truncated (Delta C) form localized in the cytoplasm and the nucleus. Accordingly, the Delta C forms significantly influenced the activity of promoters harbouring NAC binding sites (NACbs). Furthermore, the NAC domain of these transcription factors could directly interact with an NACbs, and the proteins failed to regulate a promoter lacking a crucial NACbs. Interestingly, the type of influence to an NACbs containing promoter was dependent on the context of the NACbs, as the same SlNACMTF showed an alternative mode of regulation on different promoters, as well as the same promoter activity was oppositely regulated by two different SlNACMTF. Finally, both SlNACMTFs demonstrated the differential regulatory effect on the expression of several stress-related genes by interacting with the putative NACbs in their promoter region, suggesting their direct role in plant stress response.