山新杨PdPapWRKY51基因在胁迫条件下的组织表达模式

Tissue Expression Patterns of PdPapWRKY51 in Shanxin Poplar(Populus davidiana×P.alba var.pyramidlis)under Stress Conditions

为了筛选和验证提高杨树抗逆性的基因,基于受木霉菌或链格孢菌诱导后的山新杨叶片转录组文库,克隆得到1个关键的响应基因,命名为PdPapWRKY51。该基因编码蛋白为WRKY家族Ⅱc类转录因子。其编码蛋白PdPapWRKY51为非跨膜亲水性蛋白,定位于细胞核。利用实时定量聚合酶链式反应(RT-qPCR)技术研究了PdPapWRKY51在山新杨幼苗不同组织中的表达水平,发现其在植株中广泛表达,根中表达最高。研究了PdPapWRKY51在盐、碱、PEG、5种植物病原真菌、植物激素分别诱导48 h后的表达变化,发现其表达水平受碱胁迫影响较大;尖孢镰刀菌(Fo)、核盘菌(Cc)和细链格孢菌(Aa)使其茎尖表达显著上调;Fo使其叶表达显著上调;金黄壳囊孢菌和Aa使其根内表达显著上调。PdPapWRKY51的表达广泛受水杨酸诱导;茉莉酸或脱落酸诱导仅使其茎尖表达上调,而根中表达下调。本研究揭示了PdPapWRKY51基因响应多种诱导的组织特异性表达谱,为进一步研究其功能及培育相关高抗杨树品种提供依据。

In order to identify and verify crucial genes that regulate the stress resistance of poplar,based on the RNA-seq data of poplar(Populus davidiana × P. alba var. Pyramidlis,cv’Shanxin’)leaves induced by Trichoderma asperellumon or Alternaria alternata,a key responding gene was cloned and named as PdPapWRKY51. In silico analysis showed that the coded protein of PdpapWRKY51 was a Ⅱc class transcription factor of the WRKY family and a non-transmembrane hydrophilic protein localized in the nucleus. The tissuespecific expression profile of PdPapWRKY51 in poplar seedlings was investigated through real-time quantitative polymerase chain reaction(RT-qPCR). The results showed that PdPapWRKY51 was broadly expressed in plants and the highest expression was found in roots. The expression of PdPapWRKY51 was investigated after 48 hours of induction by salt, alkali, PEG(Polyethylene glycol), five soil-borne plant fungal pathogens or phytohormones respectively. The results showed that the PdPapWRKY51 expression level was greatly affected by alkali stress. Fusarium oxysporum,Cytospora chrysosperma or A. alternata induction significantly up-regulated PdPapWRKY51 expression in the apex respectively. F. oxysporum induction significantly up-regulated PdPapWRKY51 in the leaf. C. chrysosperma and A. alternata induced significantly higher PdPapWRKY51 expression in the root. PdPapWRKY51 expression could be broadly induced by SA(salicylic acid)in plants.When induced by JA(jasmonic acid)or ABA(abscisic acid),the PdPapWRKY51 expression was up-regulated in the apex but down-regulated in the root. The results revealed the tissue-specific expression patterns of PdPapWRKY51 gene in respond to multiple induction,and would provide a basis for further elucidating the function of PdPapWRKY51 and insights into breeding novel stress-resistant poplar cultivars through modifying PdPapWRKY51 expression.