Role of Stomatal Opening and Frequency on Infection ofLycopersiconspp. byXanthomonas campestrispv.vesicatoria

Stomatal Defense a Decade Later

“…Earlier observations provided some clues that stomatal closure might diminish bacterial disease severity in a biologically relevant context. For instance, reduced number of lesions developed on dark-or abscisic acid (ABA)-treated tomato (Solanum lycopersicum) plants after inoculation with X. campestris pv vesicatoria (Ramos and Volin, 1987). Furthermore, direct comparison of disease severity after surface-inoculation and apoplastic-infiltration in this pathosystem revealed that bacterium penetration through stomata may be a control point for disease progression (Ramos and Volin, 1987).…”

“…For instance, reduced number of lesions developed on dark-or abscisic acid (ABA)-treated tomato (Solanum lycopersicum) plants after inoculation with X. campestris pv vesicatoria (Ramos and Volin, 1987). Furthermore, direct comparison of disease severity after surface-inoculation and apoplastic-infiltration in this pathosystem revealed that bacterium penetration through stomata may be a control point for disease progression (Ramos and Volin, 1987). Characterization of either bacterial or plant mutants also provided indications for possible stomatal control of bacterial infection.…”

Response of wheat fungal diseases to elevated atmospheric CO2level

“…Greater plant biomass may increase the amount of residues in the soil, which could favour necrotrophic organisms and promote the over-wintering of pathogens and pests; (ii) The greater assimilation of carbon may result in a change in the carbon to nitrogen ratio in plant tissues, and lower N content may influence the extent of damage caused by certain plant pathogens (McElrone et al 2005). Higher carbohydrate concentration within the host tissue promotes the development of certain biotrophic pathogens such as rusts (Gassner and Straib 1930), although increased silicon accumulation may inhibit others, such as mildews, due either to the higher proportion of conidia being arrested at the appressorial stage or to the slower development of the fungus (Hibberd et al 1996a); (iii) Partial stomatal closure due to high CO 2 concentration may hinder the entry of pathogens that germinate through the stomata and enter with the air flow (Royle and Thomas 1971;Ramos and Violin 1987), while lower humidity on the leaf surface may also delay pathogen invasion (Eastburn et al 2011); (iv) Infection by powdery mildew accelerated the decline in the net photosynthesis of leaves (Hibberd et al 1996b). A faster rate of phenological development and earlier maturation might favour necrotrophic over biotrophic organisms.…”

Host and Non-Host Disease Resistances of Kimchi Cabbage Against Different Xanthomonas campestris Pathovars

“…These indicated kimchi cabbage is a non-host plant for these two Xcv strains without showing any significant symptomatic appearance mediated by natural infection through hydathodes and veins. Although differential disease responses distinctly occurred by host and non-host X. campestris infections, we could not conclude this was due to suppression of non-host Xcv proliferation within plant tissues by non-host disease resistance of kimchi cabbage leaves or only the inability of this organism to enter the vascular structures of the leaves, because Xcv naturally invades plant tissues through stomata and/or mechanical wounds (Ramos and Volin, 1987;Vakili, 1967).…”