Dickeya dadantii pectic enzymes necessary for virulence are also responsible for activation of the Arabidopsis thaliana innate immune systemстатья из журнала
Аннотация: Soft-rot diseases of plants attributed to Dickeya dadantii result from lysis of the plant cell wall caused by pectic enzymes released by the bacterial cell by a type II secretion system (T2SS). Arabidopsis thaliana can express several lines of defence against this bacterium. We employed bacterial mutants with defective envelope structures or secreted proteins to examine early plant defence reactions. We focused on the production of AtrbohD-dependent reactive oxygen species (ROS), callose deposition and cell death as indicators of these reactions. We observed a significant reduction in ROS and callose formation with a bacterial mutant in which genes encoding five pectate lyases (Pels) were disrupted. Treatment of plant leaves with bacterial culture filtrates containing Pels resulted in ROS and callose production, and both reactions were dependent on a functional AtrbohD gene. ROS and callose were produced in response to treatment with a cellular fraction of a T2SS-negative mutant grown in a Pels-inducing medium. Finally, ROS and callose were produced in leaves treated with purified Pels that had also been shown to induce the expression of jasmonic acid-dependent defence genes. Pel catalytic activity is required for the induction of ROS accumulation. In contrast, cell death observed in leaves infected with the wild-type strain appeared to be independent of a functional AtrbohD gene. It was also independent of the bacterial production of pectic enzymes and the type III secretion system (T3SS). In conclusion, the work presented here shows that D. dadantii is recognized by the A. thaliana innate immune system through the action of pectic enzymes secreted by bacteria at the site of infection. This recognition leads to AtrbohD-dependent ROS and callose accumulation, but not cell death.
Год издания: 2016
Авторы: Dominique Expert, Oriane Patrit, Vladimir E. Shevchik, Claude Périno, Virginie Boucher, Christophe Crézé, Estelle Wénès, Mathilde Fagard
Издательство: Wiley
Источник: Molecular Plant Pathology
Ключевые слова: Plant Pathogenic Bacteria Studies, Plant-Microbe Interactions and Immunity, Legume Nitrogen Fixing Symbiosis
Другие ссылки: Molecular Plant Pathology (PDF)
Molecular Plant Pathology (HTML)
HAL (Le Centre pour la Communication Scientifique Directe) (HTML)
hal.science (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
Molecular Plant Pathology (HTML)
HAL (Le Centre pour la Communication Scientifique Directe) (HTML)
hal.science (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
Открытый доступ: bronze
Том: 19
Выпуск: 2
Страницы: 313–327