UV-Induced DNA Damage Promotes Resistance to the Biotrophic Pathogen Hyaloperonospora parasitica in Arabidopsis

Abstract

Plant innate immunity to pathogenic microorganisms is activated in response to recognition of extracellular or intracellular pathogen molecules by transmembrane receptors or resistance proteins, respectively. The defense signaling pathways share components with those involved in plant responses to UV radiation, which can induce expression of plant genes important for pathogen resistance. Such intriguing links suggest that UV treatment might activate resistance to pathogens in normally susceptible host plants. Here, we demonstrate that pre-inoculative UV (254 nm) irradiation of Arabidopsis (Arabidopsis thaliana) susceptible to infection by the biotrophic oomycete Hyaloperonospora parasitica, the causative agent of downy mildew, induces dose-and timedependent resistance to the pathogen detectable up to 7 d after UVexposure. Limiting repair of UV photoproducts by postirradiation incubation in the dark, or mutational inactivation of cyclobutane pyrimidine dimer photolyase, (6-4) photoproduct photolyase, or nucleotide excision repair increased the magnitude of UV-induced pathogen resistance. In the absence of treatment with 254-nm UV, plant nucleotide excision repair mutants also defective for cyclobutane pyrimidine dimer or (6-4) photoproduct photolyase displayed resistance to H. parasitica, partially attributable to short wavelength UV-B (280-320 nm) radiation emitted by incubator lights. These results indicate UV irradiation can initiate the development of resistance to H. parasitica in plants normally susceptible to the pathogen and point to a key role for UV-induced DNA damage. They also suggest UV treatment can circumvent the requirement for recognition of H. parasitica molecules by Arabidopsis proteins to activate an immune response.

Canopy Light and Plant Health

“…1). UV-B radiation has also been reported to increase plant resistance to microbial pathogens (Gunasekera et al, 1997;Wargent et al, 2006;Gunasekera and Paul, 2007;Kunz et al, 2008;Demkura and Ballaré, 2012) and can interact with the plant to modify the composition of microbial communities in the phyllosphere (Kadivar and Stapleton, 2003;Balint-Kurti et al, 2010). Treatment with unnaturally high doses of UV-B radiation, or with UV wavelengths not present in the daylight spectrum (UV-C, l , 280 nm), has also been reported to activate defense-related pathways in several species (Bridge and Klarman, 1973;Brederode et al, 1991;Conconi et al, 1996;Mert-Turk et al, 2003;Glawischnig, 2007); however, the ecological significance of these responses is not clear.…”

Tobacco Mosaic Virus Infection Results in an Increase in Recombination Frequency and Resistance to Viral, Bacterial, and Fungal Pathogens in the Progeny of Infected Tobacco Plants

“…It is common knowledge that plants with certain mycorrhizal associations are less sensitive to cadmium stress than nonmycorrhizal plants (Schutzendubel and Polle, 2002). Several recent reports have shown that plants exposed to UV-C light acquire protection against pathogen infection (Kunz et al, 2006(Kunz et al, , 2008. Moreover, one of the reports proved that plants treated with salicylic acid exhibited higher tolerance to UV-B and UV-C light (Mahdavian et al, 2007).…”

Effects of copper-oxide nanoparticles, dissolved copper and ultraviolet radiation on copper bioaccumulation, photosynthesis and oxidative stress in the aquatic macrophyte Elodea nuttallii

“…What is more, it has been proposed that the general response induced by UV treatment can be advantageous to resist to other environmental factors (e.g. biocides) (Kunz et al, 2008). However, there are only a few studies on higher plants that addressed the combined effects of enhanced UV-radiation with metals and nothing is known about the interactions of UV with NPs.…”