| Plants possess a highly sophisticated defense system to fight against pathogen infection. One of the components of this system, stomatal immunity, was studied here. Stomata, formed by a pair of epidermal guard cells, are tiny apertures on leaf surfaces that regulate exchange of gases and water loss in the plant. Apart from this function, stomata actively close in response to pathogens, thereby preventing entry of the pathogen in the plant. This constitutes stomatal immunity. However, in this study it was seen that stomatal immunity in Arabidopsis thaliana is suppressed when infection occurs in high relative humidity (RH). Now, opening and closing of stomata relies on a complex network of signaling in guard cells. Regulation of some components of this signaling was assessed in high relative humidity, to explain suppression of stomatal immunity and higher incidence of disease in high RH. Arabidopsis immunity was also studied when the plant encounters a human pathogen. It was observed that infection with the enteric pathogen Salmonella enterica compromises stomatal immunity and some components of apoplastic defense in Arabidopsis. These studies will be beneficial in the advancement of the fundamental knowledge of early events in plant-pathogen interactions, thus leading to solutions for reduction in occurrence of plant diseases and food-borne illnesses. |
