title: Isolation and characterization of a subgroup IIa WRKY transcription factor PtrWRKY40 from Populus trichocarpa.
abstract: Salicylic acid (SA) is a defense-related key signaling molecule involved in plant immunity. In this study, a subgroup IIa WRKY gene PtrWRKY40 was isolated from Populus trichocarpa, which displayed amino acid sequence similar to Arabidopsis AtWRKY40, AtWRKY18 and AtWRKY60. PtrWRKY40 transcripts accumulated significantly in response to SA, methyl jasmonate and hemibiotrophic fungus Dothiorella gregaria Sacc. Overexpression of PtrWRKY40 in transgenic poplar conferred higher susceptibility to D. gregaria infection. This susceptibility was coupled with reduced expression of SA-associated genes (PR1.1, PR2.1, PR5.9, CPR5 and SID2) and jasmonic acid (JA)-related gene JAZ8. Decreased accumulation of endogenous SA was observed in transgenic lines overexpressing PtrWRKY40 when compared with wild-type plants. However, constitutive expression of PtrWRKY40 in Arabidopsis thaliana displayed resistance to necrotrophic fungus Botrytis cinerea, and the expression of JA-defense-related genes such as PDF1.2, VSP2 and PR3 was remarkably increased in transgenic plants upon infection with fugal pathogens. Together, our findings indicate that PtrWRKY40 plays a negative role in resistance to hemibiotrophic fungi in poplar but functions as a positive regulator of resistance toward the necrotrophic fungi in Arabidopsis.
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Abdul
authors.initials: A
authors.lastname: Karim
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Yuanzhong
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Ling
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Shenglong
authors.initials: S
authors.lastname: Ye
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Yanjiao
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 810008 Xining, China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 810008 Xining, China kemingl@swu.edu.cn.
authors.forename: Keming
authors.initials: K
authors.lastname: Luo
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D001203:Ascomycota / Q000502:physiology*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D010935:Plant Diseases / Q000382:microbiology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D032107:Populus / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D014157:Transcription Factors
keywords: Populus; jasmonate; pathogen resistance; salicylic acid