title: How Does Host Carbon Concentration Modulate the Lifestyle of Postharvest Pathogens during Colonization?
abstract: Postharvest pathogens can penetrate fruit by breaching the cuticle or directly through wounds, and they show disease symptoms only long after infection. During ripening and senescence, the fruit undergo physiological processes accompanied by a decline in antifungal compounds, which allows the pathogen to activate a mechanism of secretion of small effector molecules that modulate host environmental pH. These result in the activation of genes under their optimal pH conditions, enabling the fungus to use a specific group of pathogenicity factors at each particular pH. New research suggests that carbon availability in the environment is a key factor triggering the production and secretion of small pH-modulating molecules: ammonia and organic acids. Ammonia is secreted under limited carbon and gluconic acid under excess carbon. This mini review describes our most recent knowledge of the mechanism of activation of pH-secreted molecules and their contribution to colonization by postharvest pathogens to facilitate the transition from quiescence to necrotrophic lifestyle.
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center Beit Dagan, Israel.
authors.forename: Dov B
authors.initials: DB
authors.lastname: Prusky
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture Guangzhou, China.
authors.forename: Fangcheng
authors.initials: F
authors.lastname: Bi
authors.affiliation: Departamento de Agronomía, Universidad de Córdoba Córdoba, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Moral
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center Beit Dagan, Israel.
authors.forename: Shiri
authors.initials: S
authors.lastname: Barad
keywords: colletotrichum; pH regulation; pathogenicity; penicillium; postharvest susceptibility; small effector molecules