Effects of single and double infections with Potato virus X and Tobacco mosaic virus on disease development, plant growth, and virus accumulation in tomato

Abstract

The tomato cv. Fukuju nº. 2 was used for studying the effect of single and double infections with Potato virus X (PVX) and Tobacco mosaic virus (TMV). Mixed infection resulted in a synergistic increase of disease severity, where more growth reduction was seen with simultaneous inoculations than with sequential inoculations at four-day intervals. At five and 12 days post-inoculation, the increased severity of the disease coincided with enhancement of virus accumulation in the rapidly expanding upper leaves. The PVX concentration in leaves nº 5 to 7 of doubly infected plants was three to six fold that of singly infected ones, as determined by DAS-ELISA. Mixed infection with the L strain led to higher enhancement of PVX than with the TMV-L11A strain. The concentration of TMV-L was lower in double infection and significantly higher than TMV-L11A in both singly and doubly infected plants. Analyses of the PVX ORF2 by Western blot and Northern hybridization revealed the pattern of accumulation of the 25 kDa protein and the RNAs, respectively, following those of the virion and coat protein. The strain TMV-L11A overcame the resistance gene in cv. GCR 237 (Tm-1). In the upper leaf nº. 8, the concentration of PVX was three times higher in plants with mixed infection than with L11A. The concentrations of the L and OM (TMV strains) in both singly and doubly infected plants were at very low levels, and the synergistic effect on PVX concentration and disease severity was not observed.

Current status of viral diseases of potato and their ecofriendly management -A critical review

“…Balogun, et al reported that the concentration of PVX in upper 5 to 7 leaves of doubly infected plants was three to six-fold than those of singly infected plants as determined by DAS-ELISA in tomato cv [79]. Fukujo No.…”

“…Tripathi reported that PVM disease is most popular in different parts of the world especially in Europe and North America [38]. Xu et al reported PVM in Canada [79].…”

“…Singh reported that PVM cause mosaic symptom on potato plants [42]. PVMcause mottle, mosaic, crinkling and rolling of leaves and stunting of shoots [79].…”

“…Flakten develop a full length cDNA clone of potato virus M (PVM) from total RNA extracted from infected Nicotiana hesperis plant by using RT-PCR and inoculated in different hosts plant to study the symptoms undistinguished from those caused by wild type PVM [165]. Xu, et al reported that currently enzyme-linked immunosorbent assay (ELISA) is the predominant method employed for the detection of PVM in potato sample on large scale [79]. They also told that reverse transcription polymerase chain reaction (RT-PCR) have been developed and employed successfully for the specific detection of several potato viruses including various strain of groups of viruses including PVM.…”

“…Slight or distinct mottle and sometimes faint vein banding was observed by Kumar, et al [35] due to PVS infection in potato cultivars. Potato virus S (PVS) belongs to carlavirus group and cause very mild symptom of mosaic on hosts [11,38,39,42,79].…”