A 13-lipoxygenase is expressed early in the hypersensitive reaction of cotton plants to Xanthomonas campestris pv. malvacearum

Sanier Christine, Sayegh-Alhamdia Majd, Jalloul Aida, Clerivet Alain, Nicole Michel, Marmey Philippe. 2012. A 13-lipoxygenase is expressed early in the hypersensitive reaction of cotton plants to Xanthomonas campestris pv. malvacearum. Journal of Phytopathology, 160 (6) : 286-293.

Quartile : Q3, Sujet : PLANT SCIENCES

Résumé : Lipoxygenases (LOXs) are enzymes responsible for lipid peroxidation processes during plant defence responses to pathogen infection. Jasmonates are lipidderived signals that mediate plant stress responses with chloroplastic LOXs implicated in the biosynthesis of oxylipins like jasmonic acid (JA). Hypersensitive reaction (HR) cell death of cotton to the incompatible race 18 of Xanthomonas campestris pathovar malvacearum (Xcm) is associated with 9S-lipoxygenase activity and expression of a 9-LOX GhLOX1. Here, we report the cloning of cotton (Gossypium hirsutum L.) LOX gene GhLOX2. Sequence analysis showed that GhLOX2 is a putative 13-LOX with a chloroplast-transit peptide in the amino acid terminus. GhLOX2 was found to be significantly expressed in the first hour of Xcm-induced HR. Investigation into LOX signalization on cotyledons incubated with methyl-jasmonate (MeJA) or infiltrated with salicylic acid (SA) or ethylene (ET) revealed that the first two treatments induced GhLOX2 gene expression. Our results show that GhLOX2 gene expression occurred at the stage of the HR prior biochemical events previously highlighted. The role that GhLOX2 may have in the defence strategy of cotton to Xcm is discussed regarding the HR.

Mots-clés Agrovoc : Xanthomonas campestris malvacearum, Gossypium hirsutum, lipoxygénase, acide jasmonique, acide salicylique, mécanisme de défense, éthylène, expression des gènes, réaction biochimique

Classification Agris : H20 - Maladies des plantes
F30 - Génétique et amélioration des plantes

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Sanier Christine, CIRAD-BIOS-UMR AGAP (FRA)
• Sayegh-Alhamdia Majd, IRD (FRA)
• Jalloul Aida, University of Damascus (SYR)
• Clerivet Alain, IRD (FRA)
• Nicole Michel, IRD (FRA)
• Marmey Philippe, IRD (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/564084/)

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