The Arabidopsis immune adaptor SRFR1 interacts with TCP transcription factors that redundantly contribute to effector‐triggered immunity. (23rd May 2014)

• Record Type: Journal Article
• Authors: Kim, Sang Hee; Son, Geon Hui; Bhattacharjee, Saikat; Kim, Hye Jin; Nam, Ji Chul; Nguyen, Phuong Dung T.; Hong, Jong Chan; Gassmann, Walter
• Is Part Of: Plant journal. Volume 78:Number 6(2014:Jun.)
• Page Start: 978
• Page End: 989
• Publication Date: 2014-05-23
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12527
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12527-abs-0001"> <title>Summary</title> <p>The plant immune system must be tightly controlled both positively and negatively to maintain normal plant growth and health. We previously identified <italic>SUPPRESSOR OF rps4</italic>‐<italic>RLD1</italic> (<italic>SRFR1</italic>) as a negative regulator specifically of effector‐triggered immunity. SRFR1 is localized in both a cytoplasmic microsomal compartment and in the nucleus. Its TPR domain has sequence similarity to TPR domains of transcriptional repressors in other organisms, suggesting that SRFR1 may negatively regulate effector‐triggered immunity via transcriptional control. We show here that excluding SRFR1 from the nucleus prevented complementation of the <italic>srfr1</italic> phenotype. To identify transcription factors that interact with SRFR1, we screened an Arabidopsis transcription factor prey library by yeast two‐hybrid assay and isolated six class I members of the TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factor family. Specific interactions were verified <italic>in planta</italic>. Although single or double T‐DNA mutant <italic>tcp8</italic>, <italic> tcp14</italic> or <italic>tcp15</italic> lines were not more susceptible to bacteria expressing AvrRps4, the triple <italic>tcp8 tcp14 tcp15</italic> mutant displayed decreased effector‐triggered immunity mediated by the resistance genes <italic>RPS2</italic>, <italic> RPS4</italic>, <italic> RPS6</italic> and <italic>RPM1</italic>. In addition, expression of PATHOGENESIS‐RELATED PROTEIN2 was attenuated in <italic>srfr1</italic>‐<italic>4 tcp8</italic>‐<italic>1 tcp14</italic>‐<italic>5 tcp15</italic>‐<italic>3</italic> plants compared to <italic>srfr1</italic>‐<italic>4</italic> plants. To date, TCP transcription factors have been implicated mostly in developmental processes. Our data indicate that one function of a subset of TCP proteins is to regulate defense gene expression in antagonism to SRFR1, and suggest a mechanism for an intimate connection between plant development and immunity.</p> </abstract>