Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
PLoS One. 2013;8(2):e57657. doi: 10.1371/journal.pone.0057657. Epub 2013 Feb 28.
Plants are sessile organisms, and they can not move away under abiotic or biotic stresses. Thus plants have evolved a set of genes that response to adverse environment to modulate gene expression. In this study, we characterized and functionally studied an ERF transcription factor from Artemisia annua, AaERF1, which plays an important role in biotic stress responses. The AaERF1 promoter had been cloned and GUS staining results of AaERF1 promoter-GUS transgenic A. annua showed that AaERF1 is expressed ubiquitiously in all organs. Several putative cis-acting elements such as W-box, TGA-box and Py-rich element, which are involved in defense responsiveness, are present in the promoter. The expression of AaERF1 can be induced vigorously by methyl jasmonate as well as by ethephon and wounding, implying that AaERF1 may activate some of the defense genes via the jasmonic acid and ethylene signaling pathways of A. annua. The results of electrophoretic mobility shift assay (EMSA) and yeast one-hybrid experiments showed that AaERF1 was able to bind to the GCC box cis-acting element in vitro and in yeast. Ectopic expression of AaERF1 could enhance the expression levels of the defense marker genes PLANT DEFENSIN1.2 (PDF1.2) and BASIC CHITINASE (ChiB), and increase the resistance to Botrytis cinerea in the 35S::AaERF1 transgenic Arabidopsis. The down-regulated expression level of AaERF1 evidently reduced the resistance to B. cinerea in A. annua. The overall results showed that AaERF1 positively regulated the resistance to B. cinerea in A. annua.
植物是固定不动的生物，它们不能在非生物或生物胁迫下移动。因此，植物进化出了一套基因，以响应不利环境来调节基因表达。在这项研究中，我们从黄花蒿中鉴定并研究了一个 ERF 转录因子，即 AaERF1，它在生物胁迫反应中起着重要作用。已经克隆了 AaERF1 启动子，并且 AaERF1 启动子-GUS 转基因黄花蒿的 GUS 染色结果表明，AaERF1 在所有器官中广泛表达。该启动子中存在几个假定的顺式作用元件，如参与防御反应的 W-盒、TGA-盒和富含吡咯的元件。AaERF1 的表达可以被茉莉酸甲酯以及乙烯利和损伤强烈诱导，这表明 AaERF1 可能通过黄花蒿的茉莉酸和乙烯信号通路激活一些防御基因。电泳迁移率变动分析（EMSA）和酵母单杂交实验的结果表明，AaERF1 能够在体外和酵母中结合 GCC 框顺式作用元件。AaERF1 的异位表达可以增强防御标记基因 PLANT DEFENSIN1.2 (PDF1.2) 和 BASIC CHITINASE (ChiB) 的表达水平，并增加 35S::AaERF1 转基因拟南芥对灰葡萄孢的抗性。AaERF1 的下调表达水平明显降低了黄花蒿对灰葡萄孢的抗性。总的来说，这些结果表明 AaERF1 正向调节黄花蒿对灰葡萄孢的抗性。
