Investigating the expression pattern of PR1, FLS2, and RAR1 genes in lime in response to the citrus bacterial canker pathogen (Xanthomonas citri subsp. citri )

Document Type : Research Article

Authors

1 Department of Plant Pathology, Faculty of Agriculture, Lorestan University

2 Department of Plant Production and Genetic Engineering, Faculty of Agriculture, Lorestan University, Khorramabad, Iran

3 Ph.D. candidate, Plant Protection Department, Faculty of Agriculture, Lorestan university, Khorram Abad, Iran

10.22034/ijpp.2024.2021791.446

Abstract

Citrus canker is one of the most destructive citrus diseases caused by Xanthomonas citri subsp. citri (Xcc) Following the pathogen's attack on the plant, plant hormones and the induction of resistance genes play crucial roles in plant defense. This study explored the antibacterial effects of linalool and citral components against Xcc bacteria. Subsequently, we examined the expression patterns of the FLS2, RAR1, and PR1 genes in C. aurantifolia seedlings under different treatments, including citral, linalool, citral+Xcc bacteria (strain KVXCC1), and linalool+Xcc bacteria (strain KVXCC1), at 0-, 1-, and 4-days post-inoculation with Xcc bacteria using real-time PCR. The antimicrobial activity of linalool and citral essential oils revealed significant inhibitory effects on Xcc bacterial growth (P < 0.01). The minimum inhibitory concentration results showed that citral essential oil, with a concentration of 0.37 μg/ml, exhibited relatively high inhibitory power on this pathogen. Gene expression results indicated that the expression of FLS2, RAR1, and PR1 genes increased in response to citral, linalool, bacterial citral, and bacterial linalool treatments within one day after inoculation. However, the expression levels of these genes differed four days after inoculation. The findings of this study demonstrated that the linalool+bacteria treatment effectively enhanced the expression of defense genes and induced disease resistance in C. aurantifolia seedlings, thereby significantly reducing the pathogenic damage caused by citrus canker.

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