Scientists from Wisconsin University published in Applied and Environmental Microbiology an article entitled “Time of arrival during plant disease progression and humidity additively influence Salmonella enterica colonization of lettuce.” Salmonella enterica has been known to take advantage of phytobacterial infection to increase its success in plants. Still, there is little knowledge of additional factors that may influence the relationship between enteric pathogens and plant disease. The study investigated the role of humidity and the extent of plant disease progression on S. enterica colonization of plants. High humidity was necessary for the replication of S. enterica on diseased lettuce but not required for S. enterica ingress into the UV-protected apoplast. The Xanthomonas hortorum pv. vitians ( X. vitians) infected lettuce host was found to be a relatively hostile environment for S. enterica when it arrived before the development of water soaking or following necrosis onset. In vitro growth studies in sucrose media suggest that X. vitians may allow S. enterica to benefit from cross-feeding during plant infection. The study emphasizes the role of phytobacterial disease as a driver of S. enterica success in the phyllosphere, demonstrates how the time of arrival during disease progress can influence S. enterica’s fate in the apoplast, and highlights the potential for humidity to transform an infected apoplast into a growth-promoting environment for bacterial colonizers. Increased humidity did not enhance plant disease; high humidity substantially facilitated Salmonella enterica growth in Xanthomonas-infected plants. High humidity climates may directly contribute to the survival of human enteric pathogens in crop fields or indirectly affect bacterial survival via changes to the phyllosphere brought on by phytopathogen disease @ https://journals.asm.org/doi/10.1128/aem.01311-24
