Arabidopsis Elongator subunit 2 positively contributes to resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. (17th August 2015)

• Record Type: Journal Article
• Authors: Wang, Chenggang; Ding, Yezhang; Yao, Jin; Zhang, Yanping; Sun, Yijun; Colee, James; Mou, Zhonglin
• Is Part Of: Plant journal. Volume 83:Number 6(2015:Sep.)
• Page Start: 1019
• Page End: 1033
• Publication Date: 2015-08-17
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12946
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12946-abs-0001"> <title>Summary</title> <p>The evolutionarily conserved Elongator complex functions in diverse biological processes including salicylic acid‐mediated immune response. However, how Elongator functions in jasmonic acid (JA)/ethylene (ET)‐mediated defense is unknown. Here, we show that Elongator is required for full induction of the JA/ET defense pathway marker gene <italic>PLANT DEFENSIN1.2</italic> (<italic>PDF1.2</italic>) and for resistance to the necrotrophic fungal pathogens <italic>Botrytis cinerea</italic> and <italic>Alternaria brassicicola</italic>. A loss‐of‐function mutation in the Arabidopsis Elongator subunit 2 (ELP2) alters <italic>B. cinerea</italic>‐induced transcriptome reprogramming. Interestingly, in <italic>elp2</italic>, expression of <italic>WRKY33</italic>, <italic> OCTADECANOID‐RESPONSIVE ARABIDOPSIS AP2</italic>/<italic>ERF59</italic> (<italic>ORA59</italic>), and <italic>PDF1.2</italic> is inhibited, whereas transcription of <italic>MYC2</italic> and its target genes is enhanced. However, overexpression of <italic>WRKY33</italic> or <italic>ORA59</italic> and mutation of <italic>MYC2</italic> fail to restore <italic>PDF1.2</italic> expression and <italic>B. cinerea</italic> resistance in <italic>elp2</italic>, suggesting that <italic>ELP2</italic> is required for induction of not only <italic>WRKY33</italic> and <italic>ORA59</italic> but also <italic>PDF1.2</italic>. Moreover, <italic>elp2</italic> is as susceptible as <italic>coronatine‐insensitive1</italic> (<italic>coi1</italic>) and <italic>ethylene‐insensitive2</italic> (<italic>ein2</italic>) to <italic>B. cinerea</italic>, indicating that <italic>ELP2</italic> is an important player in <italic>B. cinerea</italic> resistance. Further analysis of the lesion sizes on the double mutants <italic>elp2 coi1</italic> and <italic>elp2 ein2</italic> and the corresponding single mutants revealed that the function of <italic>ELP2</italic> overlaps with <italic>COI1</italic> and is additive to <italic>EIN2</italic> for <italic>B. cinerea</italic> resistance. Finally, basal histone acetylation levels in the coding regions of <italic>WRKY33</italic>, <italic> ORA59</italic>, and <italic>PDF1.2</italic> are reduced in <italic>elp2</italic> and a functional ELP2‐GFP fusion protein binds to the chromatin of these genes, suggesting that constitutive ELP2‐mediated histone acetylation may be required for full activation of the <italic>WRKY33</italic>/<italic>ORA59</italic>/<italic>PDF1.2</italic> transcriptional cascade.</p> </abstract>