Toxicity of effector Pi16275 of Phytophthora infestans

Abstract:

[Objective] Our aim was to analyze the effect of overexpressing the effector Pi16275 on the pathogenicity of Phytophthora infestans, and to clarify the subcellular localization of Pi16275. We screened the plant proteins that interacted with Pi16275 and explored their role in plant disease resistance, and finally revealed the role of Pi16275 in the process of pathogen infecting plants.[Methods] We used the Agrobacterium-mediated method to transiently overexpress Pi16275 in the epidermal cells of tobacco leaves, and then observed the subcellular location of Pi16275 under a fluorescence microscope. After inoculating the zoospores of P. infestans at the transient expression site, we measured the area of the diseased spot. The yeast nuclear cDNA library and yeast two-hybrid assay were used to mine and verify the target protein of Pi16275 in potato. In order to explore whether gene silencing affects the plant resistance to pathogens, we used virus-mediated gene silencing technology to silence the homologous gene of the target protein gene in tobacco and inoculated the tobacco leaves with zoospores of P. infestans.[Results] The transient expression of Pi16275 in tobacco leaves significantly promoted the infection of P. infestans, and Pi16275 was located in plant cell nucleus, cytoplasm, and cell membrane. Three target proteins of potato interacted with Pi16275, including 40S ribosomal protein S5 (StRPS5), mucin 2 (StMUC2), and V-type proton ATPase subunit E-like protein (StVAEL). Silencing the homologous gene of StRPS5 significantly weakened the resistance of tobacco to P. infestans.[Conclusion] Pi16275 plays a role in the infection of P. infestans in plants.