植物中DREBs类转录因子及其在非生物胁迫中的作用

低温、干旱、高盐等非生物胁迫能够严重影响植物的生长及作物的产量。最近发现了许多调控多种与逆境相关基因表达的转录因子, 其中DREBs类转录因子能够通过与含有DRE/CRT顺式作用元件的抗逆相关基因启动子区相互作用, 进而调控一系列抗逆基因的表达, 使植物品质得到综合改良从而提高植物对非生物胁迫耐受力。文章通过对DREBs的结构、表达调控、作用方式及机理进行总结, 并结合其在植物胁迫信号通路中的作用以及提高转基因植株胁迫耐受性的最新研究成果加以综述, 并对其在农业生产中的应用前景进行展望。     

ERF类转录因子OPBP1基因的超表达提高烟草的耐盐能力

ERF是植物中的一类重要的转录因子,参与调节植物的生长,发育以及抗胁迫等过程,对一烟草OPBP1基因（属于ERF类基因）的烟草转化,获得了该基因超表达的植株,转基因植株明显地增加了耐盐能力,Northern杂交结果表明,OPBP1基因有不同程度的表达,而且表达丰度与其耐盐性有一定的正相关性,凝胶阻滞实验结果证明OPBP1融合蛋白能特异地与含GCC盒的DNA序列结合,这些结果说明OPBP1基因可能作为一转录因子来调节烟草耐盐相关的基因。     

NAC转录因子在植物抗病和抗非生物胁迫反应中的作用

NAC转录因子是植物特有的一类转录因子,其共同特点是在N端含有一段高度保守、由约150个氨基酸组成的NAC结构域,而C端为高度变异的转录调控区。研究表明,NAC转录因子不仅参与植物生长发育的调控,而且在植物抗逆反应中具有重要的调控作用。文章着重介绍NAC转录因子在植物抗逆反应中的作用及其调控机制,并简要讨论NAC转录因子生物学功能的研究方向。     

Methylglyoxal detoxification by a DJ-1 family protein provides dual abiotic and biotic stress tolerance in transgenic plants

Methylglyoxal (MG) is a key signaling molecule resulting from glycolysis and other metabolic pathways. During abiotic stress, MG levels accumulate to toxic levels in affected cells. However, MG is routinely detoxified through the action of DJ1/PARK7/Hsp31 proteins that are highly conserved across kingdoms and mutations in such genes are associated with neurodegenerative diseases. Here, we report for the first time that, similar to abiotic stresses, MG levels increase during biotic stresses in plants, likely contributing to enhanced susceptibility to a wide range of stresses. We show that overexpression of yeast Heat shock protein 31 (Hsp31), a DJ-1 homolog with robust MG detoxifying capabilities, confers dual biotic and abiotic stress tolerance in model plant Nicotiana tabacum. Strikingly, overexpression of Hsp31 in tobacco imparts robust stress tolerance against diverse biotic stress inducers such as viruses, bacteria and fungi, in addition to tolerance against a range of abiotic stress inducers. During stress, Hsp31 was targeted to mitochondria and induced expression of key stress-related genes. These results indicate that Hsp31 is a novel attractive tool to engineer plants against both biotic and abiotic stresses.     

Enhancement of abiotic stress tolerance in poplar by overexpression of key Arabidopsis stress response genes, <Emphasis Type="Italic">AtSRK2C</Emphasis> and <Emphasis Type="Italic">AtGolS2</Emphasis>

Recent environmental issues have increased the demand for woody biomass as a renewable resource for industry and energy. For a stable supply of woody biomass, it is critical to decrease the effects of abiotic stresses, such as drought and salinity, which hinder plant growth. For the goal to develop practical stress-tolerant trees, we generated transgenic poplar plants (P. tremula × tremuloides), in which a key Arabidopsis regulatory factor involved in stress responses, SNF1-related protein kinase 2C (AtSRK2C), or galactinol synthase 2 (AtGolS2), was overexpressed. Both types of transgenic poplar plants displayed higher tolerance to abiotic stresses, in comparison with nontransgenic plants, indicating that AtSRK2C and AtGolS2 can function in the abiotic stress response pathway of poplar. We also examined the expression profiles of ten poplar genes putatively homologous to well-known Arabidopsis stress response genes and found that several of the poplar genes showed different responses to abiotic stress from their Arabidopsis counterparts. Whereas the overexpression of AtSRK2C in transgenic Arabidopsis plants was reported to upregulate the expression of endogenous genes, the overexpression of AtSRK2C or AtGolS2 in transgenic poplar did not. Taken together, our findings suggest that the details of the underlying molecular mechanisms of the abiotic stress response may differ, but that the key regulatory factors in Arabidopsis and poplar have common features and are effective molecular targets for further breeding to enhance abiotic stress tolerance in poplar.     

非生物胁迫相关NAC转录因子的结构及功能

NAC是植物特有的一类转录因子,参与植物多个生长发育过程,还参与植物对逆境胁迫的响应。本文对非生物胁迫相关NAC转录因子的结构特征、功能预测、表达特性、在转基因植物中的作用及调控路径进行综述。非生物胁迫相关NAC转录因子具有典型的NAc胁迫亚家族结构特征,根据这些结构特征可以预测其功能;非生物胁迫相关NAc转录因子能响应多种非生物胁迫,其转基因过表达大多能使转基因植物提高一种或几种胁迫耐受性;非生物胁迫相关NAc转录因子有着复杂的调控路径。这些NAc转录因子可用于提高转基因植物的逆境耐受性。