Arabidopsis BRCA2 and RAD51 proteins are specifically involved in defense gene transcription during plant immune responses.

Published

Journal Article

Systemic acquired resistance (SAR) is a plant immune response associated with both transcriptional reprogramming and increased homologous DNA recombination (HR). SNI1 is a negative regulator of SAR and HR, as indicated by the increased basal expression of defense genes and HR in sni1. We found that the sni1 phenotypes are rescued by mutations in BREAST CANCER 2 (BRCA2). In humans, BRCA2 is a mediator of RAD51 in pairing of homologous DNA. Mutations in BRCA2 cause predisposition to breast/ovarian cancers; however, the role of the BRCA2-RAD51 complex in transcriptional regulation remains unclear. In Arabidopsis, both brca2 and rad51 were found to be hypersusceptible not only to genotoxic substances, but also to pathogen infections. A whole-genome microarray analysis showed that downstream of NPR1, BRCA2A is a major regulator of defense-related gene transcription. ChIP demonstrated that RAD51 is specifically recruited to the promoters of defense genes during SAR. This recruitment is dependent on the SAR signal salicylic acid (SA) and on the function of BRCA2. This study provides the molecular evidence showing that the BRCA2-RAD51 complex, known for its function in HR, also plays a direct and specific role in transcription regulation during plant immune responses.

Full Text

Duke Authors

Cited Authors

  • Wang, S; Durrant, WE; Song, J; Spivey, NW; Dong, X

Published Date

  • December 13, 2010

Published In

Volume / Issue

  • 107 / 52

Start / End Page

  • 22716 - 22721

PubMed ID

  • 21149701

Pubmed Central ID

  • 21149701

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1005978107

Language

  • eng