文献类型： 外文期刊

作者： Yu, Xinyi ¹ ; Hou, Yingjun ¹ ; Chen, Weiping ³ ; Wang, Sanhong ¹ ; Wang, Peihong ¹ ; Qu, Shenchun ¹ ;

作者机构： 1.Nanjing Agr Univ, Coll Hort, Nanjing 210095, Jiangsu, Peoples R China

2.Jiangsu Acad Agr Sci, Jiangsu Key Lab Hort Crop Genet Improvement, Nanjing 210014, Jiangsu, Peoples R China

3.Nanjing Agr Univ, Coll Agr, Nanjing 210095, Jiangsu, Peoples R China

关键词： ARGONAUTE1;Botryosphaeria dothidea;Defense responses;Malus hupehensis;miR168

期刊名称：PLANT AND CELL PHYSIOLOGY （ 影响因子：4.927； 五年影响因子：5.516 ）

ISSN： 0032-0781

年卷期： 2017 年 58 卷 9 期

页码：

收录情况： SCI

摘要： MicroRNA (miRNA)-mediated post-transcriptional regulation plays a fundamental role in various plant physiological processes, including responses to pathogens. MicroRNA168 has been implicated as an essential factor of miRNA pathways by targeting ARGONAUTE1 (AGO1), the core component of the RNA-induced silencing complex (RISC). A fluctuation in AGO1 expression influences various plant-pathogen interactions, and the homeostasis of AGO1 and miR168 accumulation is maintained by a complicated feedback regulatory loop. In this study, the connection between miR168 and the resistance of Malus hupehensis to Botryosphaeria dothidea is revealed. The induction of both thematuremiR168 and its precursor in plants subjected to B. dothidea infection indicate the transcriptional activation of MIR168a. MIR168a promoter analysis demonstrates that the promoter can be activated by B. dothidea and salicylic acid (SA). However, the direct target of miR168, M. hupehensis ARGONAUTE1 (MhAGO1), is shown to be induced under the infection. Expression and transcription activity analysis demonstrate the transcriptional activation and the post-transcriptional suppression of MhAGO1 in response to B. dothidea infection. By inhibiting reactive oxygen species (ROS) production and enhancing SA-mediated defense responses, miR168a delays the symptom development of leaves inoculated with B. dothidea and impedes the pathogen growth, while MhAGO1 is found to have the opposite effects. Collectively, these findings suggest that the expression of miR168 and MhAGO1 in M. hupehensis in response to B. dothidea infection is regulated by a complicated mechanism. Targeting to MhAGO1, a negative regulator, miR168 plays a positive role in the resistance by alterations in diverse defense responses.