title: Overexpression of Arabidopsis NIMIN1 results in salicylate intolerance.
abstract: The transcriptional regulator NPR1 mediates salicylic acid (SA)-induced plant immunity. NPR1 is also required for tolerance to high concentrations of SA. NPR1-interacting protein, NIMIN1, represses immune response by interacting with and negating NPR1. We tested the salicylic acid tolerance of transgenic plants overexpressing NIMIN1 and found that these plants displayed SA intolerance, similar to the npr1 mutant, due to sequestration of NPR1 by NIMIN1. Plants overexpressing mutated NIMIN1 that cannot interact with NPR1 showed no SA tolerance defect. Gene expression analysis showed that NPR1 is required for SA-stress induced as well as pathogen-induced NIMIN1 expression. These results indicate that over-accumulation of a negative regulator renders plants hypersensitive to SA by limiting NPR1 function. Furthermore, NPR1 activates negative regulators such as NIMIN1 for feedback inhibition of SA signaling to maintain immune homeostasis.
authors.affiliation: a Department of Biology , Hamilton College , Clinton , NY , USA.
authors.forename: Rajinikanth
authors.initials: R
authors.lastname: Mohan
authors.affiliation: a Department of Biology , Hamilton College , Clinton , NY , USA.
authors.forename: Thomson
authors.initials: T
authors.lastname: Tai
authors.affiliation: a Department of Biology , Hamilton College , Clinton , NY , USA.
authors.forename: Andy
authors.initials: A
authors.lastname: Chen
authors.affiliation: a Department of Biology , Hamilton College , Clinton , NY , USA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Arnoff
authors.affiliation: b Department of Biological Sciences , University of South Carolina , Columbia , SC , USA.
authors.forename: Zheng-Qing
authors.initials: ZQ
authors.lastname: Fu
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014157:Transcription Factors
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C507154:NIMIN1 protein, Arabidopsis; D014157:Transcription Factors; D020156:Salicylic Acid
keywords: NIMIN1; NPR1; feedback inhibition; negative regulator of immunity; salicylic acid intolerance; salicylic acid sensitivity; transcriptional regulator