Plant Biotechnol J：GT-1顺式元件参与水稻生物及非生物胁迫响应

最近，山东农业大学的储昭辉教授研究团队在Plant Biotechnol J（2017 IF=7.443）发表了一篇水稻抗病基因OsASR2通过调控Os2H16启动子顺式元件GT-1参与抗病或干旱胁迫等调控的文章。

GT-1顺式元件广泛存在于植物基因启动子上。然而GT-1顺式元件对于生物及非生物胁迫响应的潜在分子机制还有很多未解之谜。作者之前已经报道了一个水稻短链肽编码基因Os2H16参与水稻疾病抗性及干旱耐性。本文，作者进行了Os2H16的启动子试验，结果发现GT-1作为一个重要的顺式作用元件介导Os2H16在病原侵染及渗透胁迫响应的表达。利用重复的GT-1作为bait，通过酵母单杂试验作者鉴定了一个ASR2蛋白。序列比对显示OsASR2的C末端结构域存在一段80–138的残基是DNA结合结构域。此外，作者鉴定OsASR2特异性地结合到GT-1上，并激活其靶基因Os2H16的表达，正如由两个GT-1与35S一起驱动的GFP表达。另外，OsASR2的的表达在病原侵染和渗透胁迫后得到提升。过表达OsASR2基因会增强水稻对白叶枯病和立枯丝核菌的抗性，以及对干旱的耐性。以上的试验结果表明OsASR2和GT-1之间的互作在水稻应对生物及非生物胁迫的过程中起到重要作用。

OsASR2 regulates the expression of a defence-relatedgene, Os2H16, by targeting the GT-1 cis-element

Firstauthor:Ning Li; Affiliations: ShandongAgricultural University (山东农业大学): Shandong, China

Correspondingauthor:Zhaohui Chu (储昭辉)

The GT-1 cis-element widely exists in many plant gene promoters.However, the molecular mechanism that underlies the response of the GT-1 cis-element to abiotic and biotic stresses remains elusive in rice. Wepreviously isolated a rice short-chain peptide-encoding gene (短链肽编码基因), Os2H16, and demonstrated that it plays important roles inboth disease resistance and drought tolerance. Here, we conducted a promoterassay of Os2H16and identified GT-1 as an important cis-element that mediates Os2H16expressionin response to pathogen attack and osmotic stress (渗透胁迫). Using therepeated GT-1 as bait, we characterized an abscisic acid, stress and ripening 2(ASR2) protein from yeast-one hybridization screening. Sequence alignmentsshowed that the carboxy-terminal domain (C末端结构域) of OsASR2 containing residues 80–138 was theDNA-binding domain. Furthermore, we identified that OsASR2 was specificallybound to GT-1 and activated the expression of the target gene Os2H16, as well as GFPdriven by thechimeric promoter (嵌合启动子) of 2 × GT-1-35Smini construct.Additionally, the expression of OsASR2was elevatedby pathogens and osmotic stress challenges. Overexpression of OsASR2enhanced the resistance against Xanthomonas oryzaepv. oryzae(水稻白叶枯病) and Rhizoctonia solani(立枯丝核菌), and tolerance to drought in rice. These resultssuggest that the interaction between OsASR2 and GT-1 plays an important role inthe crosstalk of the response of rice to biotic and abiotic stresses.