Characterization of Arabidopsis mur3 mutations that result in constitutive activation of defence in petioles, but not leaves.

TEDMAN-JONES JENNIFER D; LEI RITA; JAY FLORENCE; FABRO GEORGINA; LI XUEMEI; REITER WOLF-DIETER; BREARLEY CHARLES; JONESJONATHAN D.G.

WILEY-BLACKWELL PUBLISHING, INC

Año: 2008 vol. 56 p. 691 - 691

screen was established for mutants in which the plant defence response is de-repressed. The pathogen-inducible isochorismate synthase (ICS1) promoter was fused to firefly luciferase (luc) and a homozygous transgenic line generated in which the ICS1:luc fusion is co-regulated with ICS1. This line was mutagenized and M(2) seedlings screened for constitutive ICS1:luc expression (cie). The cie mutants fall into distinct phenotypic classes based on tissue-specific localization of luciferase activity. One mutant, cie1, that shows constitutive luciferase activity specifically in petioles, was chosen for further analysis. In addition to ICS1, PR and other defence-related genes are constitutively expressed in cie1 plants. The cie1 mutant is also characterized by an increased production of conjugated salicylic acid and reactive oxygen intermediates, as well as spontaneous lesion formation, all confined to petiole tissue. Significantly, defences activated in cie1 are sufficient to prevent infec