Biological Control of n Severe Viral Strain Using a Benign Viral Satellite RNA Associated with Cucumber mosaic virus

Application of plant growth-promoting rhizobacteria (PGPR) in combination with a mild strain ofCucumber mosaic virus(CMV) associated with viral satellite RNAs to enhance growth and protection against a virulent strain of CMV in tomato

“…The use of viral satellite RNA (CMV-KU1) and PGPRs individually for plant protection against viruses and promoting growth has been previously reported by a number of scientists (Murphy et al, 2003;Montasser et al, 2006b). The PGPR treatments, when applied to seeds of tomato and cucumber, significantly reduced the AUDPC values of CMV-inoculated plants compared with CMVinoculated controls without any bacterial inoculations (Murphy et al, 2003).…”

“…Cucumber mosaic viral strain associated with a benign viral satellite RNA (CMV-KU1) was isolated in Kuwait (Montasser et al, 2006b). This virus is symptomless in tomato.…”

“…Some strains of CMV contain viral satellite RNAs while others, such as CMV-16, is a satellite RNA-free strain which causes severe stunting, chlorosis, and malformation of fruits in tomato plants (Sayama et al, 1993;Gallitelli et al, 1991). Viral disease management strategies employed can include the use of nonpathogenic microorganisms or naturally occurring viral satellites (Montasser et al, , 2006b) that can be used as a biological control agent against such viral infections. These control agents act by enhancing the systemic resistance or acquired resistance of the plants against viruses (Murphy et al, 2000).…”

“…In tobacco plants, strain KU1 induced mild mosaic on very young leaves but later the plants were symptomless. It is symptomless on tomato and its presence in these plants can be detected only by a slight decrease in vegetative growth and a significant yield loss of about 15-20% (Montasser et al, , 2006b.…”

“…This viral satellite RNA parasitizes the viral genome at the molecular level by competing with the virulent virus for the host plant enzymatic machinery and replicative enzymes which are essential for virus multiplication and causing infection. This serves as the conceptual basis for experiments on biological control of CMV (Montasser et al, 2006b). Strain KU1 is a mild strain associated with a benign satellite RNA (345 bp long) that induces mosaic symptoms on squash leaves.…”