Bacillus amyloliquefaciens strain MBI600 induces salicylic acid dependent resistance in tomato plants against Tomato spotted wilt virus and Potato virus Y

Abstract

Plant growth promoting rhizobacteria have been proposed as effective biocontrol agents against several fungal and bacterial plant pathogens. However, there is limited knowledge regarding their effect against viruses. In this study, Bacillus amyloliquefaciens strain MBI600 (MBI600), active ingredient of the biological fungicide Serifel® (BASF SE), was tested for its antiviral action in tomato plants. Drench, foliar or soil amendment applications of MBI600 reduced up to 80% the incidence of Tomato spotted wilt virus under two different sets of environmental conditions. In addition, drench application of MBI600 delayed Potato virus Y systemic accumulation. Transcriptional analysis of a range of genes associated with salicylic acid (SA)- or jasmonic acid - related defense, priming or basal defense against viruses, revealed the induction of the SA signaling pathway in tomato after MBI600 treatment, and discrete gene expression patterns in plant response to TSWV and PVY infection.

Mechanisms of Plant Tolerance to RNA Viruses Induced by Plant-Growth-Promoting Microorganisms

“…Genes of both salicylate-(NbPR1a and NbPR5) and jasmonate-mediated (NbPR3 and NbPDF1.2) signaling pathways were activated after the treatment with this strain [54]. This is somewhat contrary to the data showing that the treatment of tomato with the B. amyloliquefaciens MBI600 strain induced plant resistance to TSWV and PVY accompanied by gene expression of only the SA-induced signaling pathway [24].…”

“…Beris et al [24] explained the development of PGRB-induced tomato resistance to the spotted wilt virus and PVY by simultaneous expression of defense genes predominantly of SA-, and to a lesser degree, of JA-signaling cascades. Thus, it should be noted that the treatment of plants with benzothiadiazole, which is used as a reference in many studies of plant resistance to viruses, despite a decrease in the incidence of viral particles in plants, in some cases, suppressed growth and reduced the weight of plants during viral infection compared with bacterial cultures [54,55].…”

Induced Systemic Resistance by a Plant Growth-Promoting Rhizobacterium Impacts Development and Feeding Behavior of Aphids

“…Bacillus amyloliquefaciens induced an ISR in broad beans, because the highest contents of JA were measured in aphid-colonized plants [9]. Interestingly, SA contents were similarly enhanced by PGPR treatment, as mentioned in previous studies [37,38]. Phytohormone contents were not increased by PGPR treatment in aphid-free plants, a cost−Effective phenomenon called "plant defenses priming" that makes plants more reactive when attacked by a pest or a pathogen.…”

Bacillus licheniformis strain POT1 mediated polyphenol biosynthetic pathways genes activation and systemic resistance in potato plants against Alfalfa mosaic virus

“…Biological control using PGPR (one or more strains) is being www.nature.com/scientificreports/ considered as an alternative or a supplemental way of handling of plant diseases better than the chemical control in agriculture [31][32][33][34] . Consequently, searching and discovering new environmental eco-friendly biocontrol agents capable to control plant viral diseases are demand 8 . In the current study, the antiviral activity of Bacillus licheniformis strain POT1 against AMV on potato (Solanum tuberosum L.) plant was evaluated.…”