Genoud, Thierry Buchala, Antony J. Chua, Nam-Hai Métraux, Jean-Pierre 2002-06-01 The interaction of phytochrome signalling with the SA signal transduction pathway has been investigated in <i>Arabidopsis</i> using single and multiple mutants affected in light perception (phyA and phyB deficient) and light-signal processing (<i>psi2</i>, phytochrome signalling). The induction of <i>PR1</i> by SA and functional analogues has been found to strictly correlate with the activity of the signalling pathway controlled by both phyA and phyB photoreceptors. In darkness as well as dim light, and independently of a carbohydrate source, SA-induced <i>PR</i> gene expression as well as the hypersensitive response to pathogens (HR) are strongly reduced. Moreover, the initiation of HR also exhibits a strict dependence upon both the presence and the amplitude of a phytochrome-elicited signal. The growth of an incompatible strain of bacterial a pathogen (<i>Pseudomonas syringae</i> pv. <i>tomato</i>) was enhanced in <i>phyA-phyB</i> and decreased in <i>psi2</i> mutants. While functional chloroplasts were found necessary for the development of an HR, the induction of <i>PR</i>s was strictly dependent on light, but independent of functional chloroplasts. Taken together, these data demonstrate that the light-induced signalling pathway interacts with the pathogen/SA-mediated signal transduction route. These results are summarized in a formalism that allows qualitative computer simulation. application/pdf https://folia.unifr.ch/global/documents/300136 https://folia.unifr.ch/documents/300136/files/1_metraux_psm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1046/j.1365-313X.2002.01338.x info:eu-repo/semantics/openAccess License undefined The Plant Journal. - 2002, vol. 31, no. 1, p. 87-95 Phytochrome Salicylic acid Cross-talk PR1 HR info:eu-repo/classification/udc/57 Phytochrome signalling modulates the SA-perceptive pathway in Arabidopsis http://purl.org/coar/resource_type/c_6501