Absence of endo-1,4-beta-glucanase KOR1 alters the Jasmonate-dependent defence response to Pseudomonas syringae in Arabidopsis

作者：Lopez Cruz Jaime; Finiti Ivan; Fernandez Crespo Emma; Crespo Salvador Oscar; Garcia Agustin Pilar; Gonzalez Bosch Carmen^*

来源：Journal of Plant Physiology, 2014, 171(16): 1524-1532.

DOI：10.1016/j.jplph.2014.07.006

• Arabidopsis
• Cell wall
• Endo-glucanases
• Plant response
• Pseudomonas syringae

During plant-pathogen interactions, the plant cell wall forms part of active defence against invaders. In recent years, cell wall-editing enzymes, associated with growth and development, have been related to plant susceptibility or resistance. Our previous work identified a role for several tomato and Arabidopsis endo-1,4-beta-glucanases (EGs) in plant-pathogen interactions. Here we studied the response of the Arabidopsis thaliana T-DNA insertion mutant lacking EG Korriganl (KOR1) infected with Pseudomonas syringae. KOR1 is predicted to be an EG which is thought to participate in cellulose biosynthesis. We found that kor1-1 plants were more susceptible to P. syringae, and displayed severe disease symptoms and enhanced bacterial growth if compared to Wassilewskija (Ws) wild-type plants. Hormonal and gene expression analyses revealed that the jasmonic acid (JA) pathway was activated more in kor1-1 plants with an increase in the JA-biosynthesis gene LOX3 and a greater accumulation of JA. Upon infection the accumulation of JA and JA-isoleucine (JA-Ile) was higher than in wild-type plants and increased the induction of LOX3 and the JA-responsive PDF1.2 gene. In addition, the increase of salicylic acid (SA) in healthy and infected kor1-1 may reflect the complex interaction between JA and SA, which results in the more susceptible phenotype displayed by the infected mutant plants. Callose deposition was enhanced in infected kor1-1 and an increase in pathogen-induced hydrogen peroxide took place. The susceptible phenotype displayed by KOR1-deficient plants was coronatine-independent. No significant changes were detected in the hormonal profile of the kor1-1 plants infected by coronatine-deficient P. syringae cmaA, which supports that absence of EG KOR1 alters per se the plant response to infection. We previously reported increased resistance of kor1-1 to B. cinerea, hence, the lack of this EG alters cell wall properties and plant responses in such a way that benefits P. syringae colonisation but restricts B. cinerea invasion.

• 出版日期2014-10-15