Expression of PR-protein genes and induction of defense-related enzymes by Bacillus subtilis CBR05 in tomato (Solanum lycopersicum) plants challenged with Erwinia carotovora subsp. carotovora

Abstract

The present study was aimed to evaluate the effectiveness of a biocontrol agent Bacillus subtilis CBR05 for control of soft rot disease (Erwinia carotovora subsp. carotovora) in tomato, and the possible mechanisms of its resistance induction have been investigated under pot conditions. Results showed that plants inoculated with B. subtilis CBR05 had lower disease incidence (36%). A significant increase in superoxide dismutase, catalase, peroxidase, and polyphenol oxidase activities was observed in plants inoculated with B. subtilis between 48 and 72 hpi. Also, the transcript profiles of Glu and Phenyl ammonia lyase (PAL) showed a significant up-regulation following inoculation. The most significant up-regulation was observed in transcript profile of PAL that showed 0.49 Fold Expression, at 72 hpi as compared to its expression at 12 hpi. These results suggest that systemic induction of defense-related genes expression and antioxidant enzyme activity by B. subtilis could play a pivotal role in disease resistance against soft rot disease.

miR825 and miR825* function as negative regulators in Bacillus cereus AR156-elicited systemic resistance to Botrytis cinerea in Arabidopsis thaliana

“…Carotovora [48], and in Arabidopsis plants pretreated by B. cereus AR156 and infected by B. cinerea B1301 [28]. In line with this, it has been documented that enhanced PR gene expression promotes defense responses to necrotrophic and hemibiotrophic pathogens [47,48]. In this study, the transcriptional levels of PR1, PR2, PR5, and PDF1.2 in plants with different genotypes were analysed by two-way ANOVA.…”

“…The induced defense-related gene expression has also been observed in ISR to some necrotrophic and hemibiotrophic pathogens; for example, the expression of defense genes was induced in rice plants primed by Harpophora oryzae and infected by Magnaporthe oryzae [47], in tomato plants primed by Bacillus subtilis CBR05 and infected by Erwinia carotovora subsp. Carotovora [48], and in Arabidopsis plants pretreated by B. cereus AR156 and infected by B. cinerea B1301 [28]. In line with this, it has been documented that enhanced PR gene expression promotes defense responses to necrotrophic and hemibiotrophic pathogens [47,48].…”

Induced resistance in peach fruit as treated by Pichia guilliermondii and their possible mechanism

“…Once exogenous pathogens invade the fruit, they begin to resist the disease. [38] GLU belongs to PR protein, which can inhibit pathogen growth by degrading the cell wall of pathogenic fungi or indirectly activate defense responses by releasing excitons from the cell wall. [39] A similar study also found that GLU inhibits the oxidative damage and enhances the tolerance of plant toward pathogen infection.…”

Antimicrobial Activity Screening of Rhizosphere Soil Bacteria from Tomato and Genome-Based Analysis of their Antimicrobial Biosynthetic Potential

“…In this study, We found 34 Bacillus strains (out of 351 strains) have antagonistic activity against six major tomato plant pathogens (E. carotovora, P. syringae, R. solani, B. cinerea, V. dahliae, and P. infestans). E. carotovora and P. syringae are Gram-negative phytopathogens that cause bacterial soft rot disease and bacterial speck disease in tomato, respectively [50,51]. R. solani, B. cinerea and V. dahliae are fungal pathogens that cause damping-off, gray mold and verticillium wilt diseases of tomato [3,52,53].…”