Overexpression of the Brassica rapa transcription factor WRKY12 results in reduced soft rot symptoms caused by Pectobacterium carotovorum in Arabidopsis and Chinese cabbage. (19th February 2014)

• Record Type: Journal Article
• Authors: Kim, H. S.; Park, Y. H.; Nam, H.; Lee, Y. M.; Song, K.; Choi, C.; Ahn, I.; Park, S. R.; Lee, Y. H.; Hwang, D. J.; van Wees, S.
• Is Part Of: Plant biology. Volume 16:Number 5(2014:Sep.)
• Page Start: 973
• Page End: 981
• Publication Date: 2014-02-19
• Subjects: Botany -- Periodicals; Plants -- genetics -- Periodicals; Plants -- growth & development -- Periodicals; Plant Proteins -- Periodicals; Gene Expression Regulation, Plant -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1111/plb.12149
• Languages: English
• ISSNs: 1435-8603

Abstract

<abstract abstract-type="main" id="plb12149-abs-0001"> <title>Abstract</title> <p>Chinese cabbage (<italic>Brassica rapa </italic>L. ssp<italic>. pekinensis</italic>), an important vegetable crop, can succumb to diseases such as bacterial soft rot, resulting in significant loss of crop productivity and quality. <italic>Pectobacterium carotovorum</italic> ssp. <italic>carotovorum</italic> (<italic>Pcc</italic>) causes soft rot disease in various plants, including Chinese cabbage. To overcome crop loss caused by bacterial soft rot, a gene from Chinese cabbage was isolated and characterised in this study. We isolated the <italic>BrWRKY12</italic> gene from Chinese cabbage, which is a group II member of the WRKY transcription factor superfamily. The 645‐bp coding sequence of <italic>BrWRKY12</italic> translates to a protein with a molecular mass of approximately 24.4 kDa, and <italic>Br</italic>WRKY12 was exclusively localised in the nucleus. Transcripts of <italic>BrWRKY12</italic> were induced by <italic>Pcc</italic> infection in <italic>Brassica</italic>. Heterologous expression of <italic>BrWRKY12</italic> resulted in reduced susceptibility to <italic>Pcc</italic> but not to <italic>Pseudomonas syringae</italic> pv. <italic>tomato</italic> in <italic>Arabidopsis</italic>. Defence‐associated genes, such as <italic>AtPDF1.2</italic> and <italic>AtPGIP2</italic>, were constitutively expressed in transgenic lines overexpressing <italic>BrWRKY12</italic>. The expression of <italic>AtWKRY12</italic>, which is the closest orthologue of <italic>BrWRKY12</italic>, was down‐regulated by <italic>Pcc</italic> in <italic>Arabidopsis</italic>. However, the <italic>Atwrky12‐2</italic> mutants did not show any difference in response to <italic>Pcc</italic>, pointing to a difference in function of WRKY12 in <italic>Brassica</italic> and <italic>Arabidopsis</italic>. Furthermore, <italic>Br</italic>WRKY12 in Chinese cabbage also exhibited enhanced resistance to bacterial soft rot and increased the expression of defence‐associated genes. In summary, <italic>Br</italic>WRKY12 confers enhanced resistance to <italic>Pcc</italic> through transcriptional activation of defence‐related genes.</p> </abstract>