Salicylic Acid Activates DNA Damage Responses to Potentiate Plant Immunity

• Published in: Molecular cell Vol. 52; no. 4; pp. 602 - 610
• Main Authors: Yan, Shunping, Wang, Wei, Marqués, Jorge, Mohan, Rajinikanth, Saleh, Abdelaty, Durrant, Wendy E, Song, Junqi, Dong, Xinnian
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 21.11.2013
• Subjects: Arabidopsis - genetics; Arabidopsis - immunology; Arabidopsis - metabolism; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - metabolism; Ataxia Telangiectasia Mutated Proteins - metabolism; Cell Cycle Proteins - metabolism; chromosomes; DNA Damage; DNA Repair; DNA, Plant - genetics; gene expression; genotoxicity; immune response; Models, Molecular; Multiprotein Complexes - metabolism; mutation; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Plant Growth Regulators - metabolism; Plant Immunity; Protein Structure, Secondary; Protein Subunits - metabolism; proteins; salicylic acid; Salicylic Acid - metabolism; Structural Homology, Protein
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/j.molcel.2013.09.019

DNA damage is normally detrimental to living organisms. Here we show that it can also serve as a signal to promote immune responses in plants. We found that the plant immune hormone salicylic acid (SA) can trigger DNA damage in the absence of a genotoxic agent. The DNA damage sensor proteins RAD17 and ATR are required for effective immune responses. These sensor proteins are negatively regulated by a key immune regulator, SNI1 (suppressor of npr1-1, inducible 1), which we found is a subunit of the structural maintenance of chromosome (SMC) 5/6 complex required for controlling DNA damage. Elevated DNA damage caused by the sni1 mutation or treatment with a DNA-damaging agent markedly enhances SA-mediated defense gene expression. Our study suggests that activation of DNA damage responses is an intrinsic component of the plant immune responses.