CaWRKY58, encoding a group I WRKY transcription factor of Capsicum annuum, negatively regulates resistance to Ralstonia solanacearum infection. (11th October 2012)

• Record Type: Journal Article
• Authors: Wang, Yuna; Dang, Fengfeng; Liu, Zhiqin; Wang, Xu; Eulgem, Thomas; Lai, Yan; Yu, Lu; She, Jianju; Shi, Youliang; Lin, Jinhui; Chen, Chengcong; Guan, Deyi; Qiu, Ailian; He, Shuilin
• Is Part Of: Molecular plant pathology. Volume 14:Number 2(2013:Feb.)
• Page Start: 131
• Page End: 144
• Publication Date: 2012-10-11
• Subjects: Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/j.1364-3703.2012.00836.x
• Languages: English
• ISSNs: 1464-6722

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>WRKY transcription factors are encoded by large gene families across the plant kingdom. So far, their biological and molecular functions in nonmodel plants, including pepper (<italic>Capsicum annuum</italic>) and other Solanaceae, remain poorly understood. Here, we report on the functional characterization of a new group I WRKY protein from pepper, termed CaWRKY58. Our data indicate that CaWRKY58 can be localized to the nucleus and can activate the transcription of the reporter <italic>β‐glucuronidase</italic> (<italic>GUS</italic>) gene driven by the <italic>35S</italic> core promoter with two copies of the W‐box in its proximal upstream region. In pepper plants infected with the bacterial pathogen <italic>Ralstonia solanacearum</italic>, <italic>CaWRKY58</italic> transcript levels showed a biphasic response, manifested in an early/transient down‐regulation and late up‐regulation. <italic>CaWRKY58</italic> transcripts were suppressed by treatment with methyl jasmonate and abscisic acid. Tobacco plants overexpressing <italic>CaWRKY58</italic> did not show any obvious morphological phenotypes, but exhibited disease symptoms of greater severity than did wild‐type plants. The enhanced susceptibility of <italic>CaWRKY58</italic>‐overexpressing tobacco plants correlated with the decreased expression of hypersensitive response marker genes, as well as various defence‐associated genes. Consistently, <italic>CaWRKY58</italic> pepper plants silenced by virus‐induced gene silencing (VIGS) displayed enhanced resistance to the highly virulent <italic>R. solanacearum</italic> strain FJC100301, and this was correlated with enhanced transcripts of defence‐related pepper genes. Our results suggest that <italic>CaWRKY58</italic> acts as a transcriptional activator of negative regulators in the resistance of pepper to <italic>R. solanacearum</italic> infection.</p> </abstract>