Resistance genes expression pattern analysis of Piriformospora indica - colonized sour orange plants in challenging with citrus bacterial blast (Pseudomonas viridiflava)

Document Type : Research Paper


1 Department of Plant Protection, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

2 Genetics and Agricultural biotechnology Institute of Tabarestan, Sari Agricultural Sciences and Natural Resources University, Mazandaran, Iran


Citrus bacterial blast disease is one of the prevalent diseases in most citrus-growing regions in the world. Plants use a wide range of mechanisms to defend against pathogens, and the plant-pathogen interaction induces the expression of genes involved in the plant resistance. Furthermore, symbiotic association between plant and mycorrhizal fungi could effectively promote growth and protect the plant against adverse environmental conditions. In the present study, Piriformospora indica- root colonized Sour orange seedlings were infected by Pseudomonas viridiflava. Shoot samples of treated plants were taken 24, 48, and 72 h after inoculation and the expression patterns of PR1, PR2, PR3, PR4, PR5, PAL, POX, and LOX genes in the early stages of citrus blast disease were investigated using the qRT-PCR. According to the results, the expression levels of PR1, PR4, PAL, POX, PR3, and PR5 genes increased at 48 h after inoculation of sour orange plants in symbiosis with P. indica, but the expression levels of PR2 and LOX genes increased at 72 h after infection compared to the control. It seems that the symbiotic fungus can induce systemic effects and prepare the host plant to increase the expression of defense genes more rapidly once it receives a signal for the presence of the pathogen.


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