Three stress-responsive NAC transcription factors from Populus euphratica differentially regulate salt and drought tolerance in transgenic plants
Three stress-responsive NAC transcription factors from Populus euphratica differentially regulate salt and drought tolerance in transgenic plants
复制标题
胡杨的三种胁迫响应 NAC 转录因子差异调节转基因植物的耐盐性和耐旱性
DOI：
10.1111/ppl.12613
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发表时间：
2018-01-01
影响因子：
6.4
通讯作者：
Xia, Xinli
中科院分区：
文献类型：
--
作者：
Lu, Xin;Zhang, Xiaofei;Xia, Xinli
逆境反应基因NAM、拟南芥转录激活因子1/2(ATAF1/2)和CUC2(SNAC)基因正被用来通过基因工程改变拟南芥或禾本科植物的逆境耐性。然而，有关SNAC在树木中的功能特性的报道却很有限。在本研究中，从胡杨中鉴定了三个可能的NAC蛋白。PeNAC034和PeNAC045属于ATAF亚组，PeNAC036属于ANAC072亚组。这三种SNAC转录因子均定位于细胞核内，其C端含有转录激活结构域。在干旱和盐胁迫下，PeNAC036在整个植株中被强烈诱导，而PeNAC034在根和茎中受到显著抑制，PeNAC045在根中受到抑制。突变体anac072(anac072/PeNAC036)的PeNAC036过表达和突变体anac072(anac072/PeNAC036)的PeNAC036互补增强了对盐和干旱的耐性，而野生型(OEPeNAC034)和突变体ataf1(ataf1/PeNAC034)的PeNAC034过表达和PeNAC034的互补增强了对盐分和干旱的敏感性。干旱和盐处理后，COR47、RD29B、ERD11、RD22和DREB2A在OEPeNAC036和Anac072/PeNAC036中表达上调，而在OEPeNAC034和ataf1/PeNAC034中表达下调。与WT和载体株系相比，在盐分和干旱条件下，过表达PeNAC045的杨树WT(OEPeNAC045)的净光合速率、气孔导度和蒸腾速率显著降低。这些结果表明，胡杨能够适应高盐度和干旱的环境，这可能与SNAC基因的差异表达模式有关。
Stress-responsive NAM, Arabidopsis transcription activation factor 1/2 (ATAF1/2) and CUC2 (SNAC) genes are being used to alter stress tolerance in Arabidopsis or grasses through genetic engineering. However, limited reports are available about the functional characteristics of SNAC in trees. In this study, three putative NAC proteins were identified from Populus euphratica. PeNAC034 and PeNAC045 were classified into the ATAF subgroup and PeNAC036 into the ANAC072 subgroup. These three SNAC transcription factors were localized in the nucleus and contained the transcription activation domain in their C-terminal. Under drought and salt stresses, PeNAC036 was strongly induced in the whole plant, but PeNAC034 was significantly suppressed in the roots and stems, and PeNAC045 was inhibited in the roots. PeNAC036 overexpression in Arabidopsis wild-type (WT) (OEPeNAC036) and PeNAC036 complementation in mutant anac072 (anac072/PeNAC036) lines increased tolerance to salt and drought, whereas PeNAC034 overexpression in WT (OEPeNAC034) and PeNAC034 complementation in mutant ataf1 (ataf1/PeNAC034) lines enhanced salt and drought sensitivity. After drought and salt treatments, the expression levels of COR47, RD29B, ERD11, RD22 and DREB2A were upregulated in OEPeNAC036 and anac072/PeNAC036 lines, but were downregulated in OEPeNAC034 and ataf1/PeNAC034 plants. Compared with WT and Vector lines, PeNAC045 overexpression in poplar WT (OEPeNAC045) led to a significant decrease in the net photosynthesis rate, stomatal conductance and transpiration rate under salinity and drought conditions. These results suggest that P. euphratica can adapt to the environment of high salinity and drought, which may be related to the differential expression patterns of SNAC genes.