Ma Liufeng, Hu Longxing, Fan Jibiao, Amombo Erick, Khaldun A B M, Zheng Yong, Chen Liang
College of Biology and Geography Sciences, Kashgal University, Xinjiang, 844000, China.
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China.
Ecotoxicology. 2017 Aug;26(6):841-854. doi: 10.1007/s10646-017-1815-2. Epub 2017 May 23.
ERF (ethylene-responsive factor) transcription factors play important roles in plant stress signaling transduction pathways. However, their specific roles during diverse abiotic stresses tolerance in Gossypium hirsutum are largely unknown. Here, a novel ERF transcription factor, designated GhERF38, homologous to AtERF38 in Arabidopsis, was isolated from cotton (Gossypium hirsutum L). GhERF38 expression was up-regulated by salt, drought and ABA treatments. Subcellular localization results indicated that GhERF38 was localized in the cell nucleus. Over-expression of GhERF38 in Arabidopsis reduced plant tolerance to salt and drought stress as indicated by a decline of seed germination, plant greenness frequency, primary roots length and the survival rate in transgenic plants compared to those of wild type plants under salt or drought treatment. Besides, stress tolerance related physiological parameters such as proline content, relative water content, soluble sugar and chlorophyll content were all significantly lower in transgenic plants than those of wild type plants under salt or drought treatment. Furthermore, over-expression of GhERF38 in Arabidopsis resulted in ABA sensitivity in transgenic plants during both seed germination and seedling growth. Interestingly, the stomatal aperture of guard cells in the transgenic plants was larger than that in transgenic plant after ABA treatment, suggesting that GhERF38-overexpressing plants were insensitive to ABA in terms of stomatal closure. Furthermore, expressions of the stress-related genes were altered in the GhERF38 transgenic plants under high salinity, drought or ABA treatment. Together, our results revealed that GhERF38 functions as a novel regulator that is involved in response to salt/drought stress and ABA signaling during plant development.
乙烯响应因子（ERF）转录因子在植物胁迫信号转导途径中发挥着重要作用。然而，它们在陆地棉多种非生物胁迫耐受性中的具体作用尚不清楚。在此，从棉花（陆地棉）中分离出一种与拟南芥AtERF38同源的新型ERF转录因子，命名为GhERF38。GhERF38的表达在盐、干旱和脱落酸（ABA）处理下上调。亚细胞定位结果表明，GhERF38定位于细胞核。与野生型植株相比，在盐或干旱处理下，拟南芥中GhERF38的过表达导致种子萌发率、植株绿化频率、主根长度和转基因植株成活率下降，从而降低了植株对盐和干旱胁迫的耐受性。此外，在盐或干旱处理下，转基因植株中脯氨酸含量、相对含水量、可溶性糖和叶绿素含量等与胁迫耐受性相关的生理参数均显著低于野生型植株。此外，拟南芥中GhERF38的过表达导致转基因植株在种子萌发和幼苗生长过程中对ABA敏感。有趣的是，ABA处理后转基因植株保卫细胞的气孔孔径大于野生型植株，这表明过表达GhERF38的植株在气孔关闭方面对ABA不敏感。此外，在高盐、干旱或ABA处理下，GhERF38转基因植株中胁迫相关基因的表达发生了改变。总之，我们的结果表明，GhERF38作为一种新型调节因子，参与了植物发育过程中对盐/干旱胁迫和ABA信号的响应。
