PhERF2, an ethylene-responsive element binding factor, plays an essential role in waterlogging tolerance of petunia
PhERF2, an ethylene-responsive element binding factor, plays an essential role in waterlogging tolerance of petunia
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PhERF2是一种乙烯响应元件结合因子，在矮牵牛的耐涝性中发挥重要作用
DOI：
10.1038/s41438-019-0165-z
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发表时间：
2019-07-01
影响因子：
8.7
通讯作者：
Jiang, Cai-Zhong
中科院分区：
文献类型：
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作者：
Yin, Dongmei;Sun, Daoyang;Jiang, Cai-Zhong
乙烯反应元件结合因子(ERF)参与植物各种逆境反应的调节，但其在内涝胁迫中的生物学功能尚不清楚。在本研究中，我们鉴定了一个矮牵牛(矮牵牛×杂交种)ERF基因PhERF2，该基因在野生型(WT)受涝诱导下显著诱导。为了研究PhERF2在受涝反应中的调控作用，获得了RNAi沉默和高表达PhERF2的转基因矮牵牛植株。与WT植株相比，PhERF2沉默降低了矮牵牛幼苗的耐涝能力，在受涝4d和恢复14d后死亡率为96%，而过表达PhERF2提高了幼苗在受涝条件下的存活率。与WT相比，PhERF2-RNAi品系表现出更早、更严重的叶片黄化和坏死，而高表达PhERF2的植株在渍水条件下表现出促进生长的活力。PhERF2沉默植株的叶绿素含量显著低于WT或过度表达植株。典型的细胞程序性死亡(PCD)、DNA凝聚和月形核的特征仅在PhERF2过表达系中观察到，而在PhERF2-RNAi或对照系中未观察到。此外，在PhERF2沉默的植株中，酒精发酵相关基因ADH1-1、ADH1-2、ADH1-3、PDC1和PDC2的转录丰度在受涝12h后降低，而在PhERF2过度表达的植株中转录丰度增加。相反，乳酸发酵相关基因LDH的表达在PhERF2沉默的植物中上调，但在其过度表达的植物中下调。此外，观察到PhERF2直接与带有ATCTA基序的ADH1-2启动子结合。我们的结果表明，PhERF2通过调节PCD和酒精发酵系统来提高矮牵牛的耐湿性。
Ethylene-responsive element binding factors (ERFs) are involved in regulation of various stress responses in plants, but their biological functions in waterlogging stress are largely unclear. In this study, we identified a petunia (Petunia× hybrida) ERF gene, PhERF2, that was significantly induced by waterlogging in wild-type (WT). To study the regulatory role of PhERF2 in waterlogging responses, transgenic petunia plants with RNAi silencing and overexpression of PhERF2 were generated. Compared with WT plants, PhERF2 silencing compromised the tolerance of petunia seedlings to waterlogging, shown as 96% mortality after 4 days waterlogging and 14 days recovery, while overexpression of PhERF2 improved the survival of seedlings subjected to waterlogging. PhERF2-RNAi lines exhibited earlier and more severe leaf chlorosis and necrosis than WT, whereas plants overexpressing PhERF2 showed promoted growth vigor under waterlogging. Chlorophyll content was dramatically lower in PhERF2-silenced plants than WT or overexpression plants. Typical characteristics of programmed cell death (PCD), DNA condensation, and moon-shaped nuclei were only observed in PhERF2-overexpressing lines but not in PhERF2-RNAi or control lines. Furthermore, transcript abundances of the alcoholic fermentation-related genes ADH1-1, ADH1-2, ADH1-3, PDC1, and PDC2 were reduced in PhERF2-silenced plants, but increased in PhERF2-overexpressing plants following exposure to 12-h waterlogging. In contrast, expression of the lactate fermentation-related gene LDH was up-regulated in PhERF2-silenced plants, but down-regulated in its overexpressing plants. Moreover, PhERF2 was observed to directly bind to the ADH1-2 promoter bearing ATCTA motifs. Our results demonstrate that PhERF2 contributes to petunia waterlogging tolerance through modulation of PCD and alcoholic fermentation system.