title: Arabidopsis thaliana cdd1 mutant uncouples the constitutive activation of salicylic acid signalling from growth defects.
abstract: Arabidopsis genotypes with a hyperactive salicylic acid-mediated signalling pathway exhibit enhanced disease resistance, which is often coupled with growth and developmental defects, such as dwarfing and spontaneous necrotic lesions on the leaves, resulting in reduced biomass yield. In this article, we report a novel recessive mutant of Arabidopsis, cdd1 (constitutive defence without defect in growth and development1), that exhibits enhanced disease resistance associated with constitutive salicylic acid signalling, but without any observable pleiotropic phenotype. Both NPR1 (NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1)-dependent and NPR1-independent salicylic acid-regulated defence pathways are hyperactivated in cdd1 mutant plants, conferring enhanced resistance against bacterial pathogens. However, a functional NPR1 allele is required for the cdd1-conferred heightened resistance against the oomycete pathogen Hyaloperonospora arabidopsidis. Salicylic acid accumulates at elevated levels in cdd1 and cdd1 npr1 mutant plants and is necessary for cdd1-mediated PR1 expression and disease resistance phenotypes. In addition, we provide data which indicate that the cdd1 mutation negatively regulates the npr1 mutation-induced hyperactivation of ethylene/jasmonic acid signalling.
authors: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
authors: Swadhin
authors: S
authors: Swain
authors: Shweta
authors: S
authors: Roy
authors: Jyoti
authors: J
authors: Shah
authors: Saskia
authors: S
authors: Van Wees
authors: Corné M
authors: CM
authors: Pieterse
authors: Ashis K
authors: AK
authors: Nandi
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D020156:Salicylic Acid