Systemic Resistance Induced by Stenotrophomonas maltophilia Sg3 against Cucumber Mosaic Virus in Tobacco Plant

Cucumber mosaic virus (CMV) is one of the plant viruses that greatly interfere with the growth, quantity and quality of tobacco leaves. It is difficult to control the CMV, since it has a high genetic diversity, wide host range, and transmitted by insect vector. It is necessary to develop an alternative control method through induced systemic resistance (ISR) using rhizobacteria. This study was done to evaluate the potential of a rhizobacterium, Stenotrophomonas maltophilia Sg3 to induce antiviral activity against CMV in tobacco plant. Presences of CMV in the tobacco plant was detected based on double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) method, while the detection of compounds produced in the leaves of tobacco was done using gas chromatography mass spectrophotometer (GC-MS). Results of this study showed that treatment with S. maltophilia Sg3 significantly (P < 0.05) reduced the accumulation of CMV virus in the leaves of tobacco when compared to untreated leaves. In addition, this treatment significantly increased the leaves wet and dry weight, plant height, number of leaves per plant, and leaves chlorophyll content when compared to the leaves of control. These results suggested that S. maltophilia Sg3 was able to suppress the accumulation of CMV in the leaves, suppressed the symptom resulted from CMV infection as well as promoted the growth of tobacco plant. A compound, 2-naphthalene-sulfonic acid was detected in the leaves of plants treated with S. maltophilia Sg3, while no such compound was detected in the leaves of control plant. This compound might be responsible for the antiviral activity against CMV in tobacco. Results of this study suggested that S. maltophilia Sg3 can be considered as one of potential bio-agents for inducing antiviral activity against CMV in tobacco and promoted the growth of tobacco plant © 2020 Friends Science Publishers