山海关杨PdERF-18转录因子的表达特征分析

Expression patterns for a PdERF-18 response to different stresses in Populus deltoides ‘Shanhaiguan'

对一个溃疡病菌Botryosphaeria dothidea胁迫相关的山海关杨Populus deltoides‘Shanghaiguan’乙烯反应因子(ethylene responsive factors,ERFs)基因——PdERF-18基因的系统发育、编码产物结构以及多种胁迫下的表达模式进行了分析。结果表明:PdERF-18基因编码产物属于ERF转录因子家族B-6类群,具有植物ERF转录因子的典型结构,但它与转录调控功能密切相关的AP2/ERF结构域第19位氨基酸位点发生替换,推测PdERF-18基因可能具有不同于其他典型ERF转录因子的功能;实时定量分析表明:溃疡病菌、根癌农杆菌Agrobacterium tumefaciens(Rhizobium radiobacter),脱水、机械胁迫、盐胁迫和高温处理、茉莉酸以及水杨酸处理均可诱导PdERF-18基因的上调表达。其中溃疡病菌与茉莉酸处理以及根癌农杆菌与水杨酸处理下,杨树PdERF-18基因分别具有相似的表达特征,显示溃疡病菌、根癌农杆菌侵染的信号转导可能分别与茉莉酸/乙烯途径、水杨酸信号传导途径有关。PdERF-18基因可以对多种非生物、生物胁迫产生响应,PdERF-18基因有可能作为一种新的遗传资源而应用于杨树抗性遗传改良。

Ethylene responsive factors （ERFs）, one kind of APETALA2（AP2）/ERF transcriptional factor that responds to environmental stimuli, especially to pathogen attacks, play an important role in plant-pathogen in- teractions. Recently, we noticed that one ERF-18 gene involved in the pathogenesis processes of the poplar stern canker disease of some poplar hybrid clones. However, the expression patterns of this gene response to other environmental stimuli are unclear. In this study, the phylogenesis, structure, and expression patterns of one Populus cleltoicles ERF gene （PdERF-18） were reported. Treatments including salicylic acid and jasmonic acid （JA） induction, Botryosphaeria dothiclea and A grobacterium tumefaciens （ Rhizobium radiobacter ） inocu- lation, mechanical stress, high temperature, salt stress, and dehydration stress were tested with real-time reverse transcription polymerase chain reaction （RT-qPCR）. Results revealed a PdERF-18 coding for a B-6 member in the ERF family B. The 14th alanine and 19th aspartate residues in the AP2/ERF domain, typically characteris- tie of plant ERFs, were altered with an aspartate site substituted by a glutamate （an amino acid residue with stronger eleetronegativity than aspartate） in the coding product for the PdERF-18 gene implying that PdERF-18 might have some additional functions besides its resistance to a pathogen. RT-qPCR data of the diverse stresses revealed up-regulated expressed patterns in P. deltoides. Also, similar expression pattern responses for both B. dothidea and JA as well as responses to A. tumefaciens and salicylic acid were found. Thus, it was inferred that the JA/ethylene （ET） transduction pathway regulated gene expression in poplar canker pathogen attacks, but the SA pathway was involved in the responsiveness to poplar crown gall disease; therefore, it was deduced that PdERF-18 was a muhi-functional transcriptional factor involved in many biotic and abiotic stresses. [Ch, 4 fig. 30 ref, ]