Cucumber Mosaic Virus Infection Research Articles

Qualitative changes in cucumber gibberellins following cucumber mosaic virus infection

Extracts from cucumber seedlings infected with cucumber mosaic virus, assayed biologically when virus-induced stunt was perceptible, exhibited reduced gibberellin-like activity when compared with extracts of healthy seedlings. No differences could be detected when comparisons were made prior to symptom appearance. Different spots appeared when extracts from healthy and infected plants were compared by thin layer chromatography for gibberellin-like substances, both before and after stunting could be detected. When 3 H-GA 3 was applied to shoots, different peaks, representing different breakdown products of the original 3 H-GA 3 , appeared on radiochromatograms of extracts from healthy seedlings as compared with those from virus-infected seedlings which were found to be less active biologically. These results might indicate that cucumber mosaic virus-infected cucumber plants have different metabolic pathways for their gibberellins, converting them to less or non-active forms. This may explain the reduced response of infected plants to exogenous gibberellin treatments, sustaining the possibility that gibberellin turnover might be involved with virus-induced stunt.

Inheritance of Resistance to Cucumber Mosaic Virus Infection in Mungbean1

The resistant reaction to cucumber mosaic virus, CMV‐M, infection in mungbean (Vigna radiata (L.) Wilczek) strain PI 271401, in crosses with susceptible strains PI 201868 and PI 368307, was conditioned by a single dominant gene designated Cmm. The Cmm locus was not linked with loci controlling color of seed texture layer or color of seed coat. Seed yields of CMV‐M susceptible F2 plants in the field were reduced by more than 50% compared to resistant plants.

Response of susceptible and resistant cantaloupes (Cucumis Melo) to cucumber mosaic Virus under field conditions

A green-fleshed cucumber mosaic virus (CMV)-resistant cantaloupe line, ‘Xy 140’, resembling the recurrent parent, was obtained after five cycles of backcrossing followed by selfing from a cross between the cultivars ‘Noy Yizre’el’ (susceptible) and ‘Freeman Cucumber’ (resistant). Compared with the respective non-infected cultivars, CMV infection in an early stage of growth reduced the yield of Noy Yizre’el by 73% and of Xvl40 by 31%. Yield reduction in Noy Yizre’el was due to fewer fruits and lower fruit weight, whereas in Xvl40 fruit weight was not affected although the number of fruits per plant was reduced.

Cucumber mosaic virus RNA 5 Partial characterization and evidence for no large sequence homologies with genomic RNAs

Cucumber mosaic virus (CMV) contains four major RNA species (RNAs 1,2,3 and 4) the largest three of which are necessary for infectivity [ 1,2] . RNA 4 serves as a messenger for synthesis of coat protein in a wheat embryo cell-free system [3] . The nucleotide sequence of RNA 4 must also be present in RNA 3 since it is known that RNA 3 carries the information for coat protein synthesis in vivo [4,5] . In addition to the genome RNAs and RNA 4, a fifth RNA component (RNA 5) of low molecular weight (100 000) has been detected in CMV preparations [ 1,6] . Interest in RNA 5 was enhanced by the finding that, even though the small RNA is apparently dependent upon the CMV genome RNAs for replication [7] , the relative proportions of RNA 5 and RNA l-4 is tied to the nature of the plant host of viral propagation and, furthermore, the presence of RNA 5 can dramatically alter the response of certain hosts to CMV infection [8,9]. The above findings make it unlikely that RNA 5 is a host RNA normally present in the plant which is entrapped during virus assembly, but they do not in themselves permit us to distinguish between two further possibilities: (1) RNA 5 originates from the CMV RNA but is nonessential for infectivity, i.e., a deletion fragment or partial transcription product of one of the genome RNAs, or (2) RNA 5 is a ‘satellite’ RNA, that is, a parasite RNA with little or no sequence homology with the helper genome. As a prelude to a more detailed sequence analysis, we have determined some of the properties of RNA 5. In particular, the 5’ and 3’ extremities of the RNA

Effect of Cucumber Mosaic Virus Infection on the Amino Acids and Amides in Vegetable Marrow Leaves

Effect of Cucumber Mosaic Virus Infection on the Amino Acids and Amides in Vegetable Marrow Leaves

Serological demonstration of virus-specified proteins associated with cucumber mosaic virus infection of cucumber cotyledons

Antisera were raised in rabbits to the W strain of cucumber mosaic virus (CMV), to virus coat protein and to cucumber extracts (from both healthy and infected tissue) by the footpad route of immunization, a procedure which yielded good antisera at the expense of little antigen. Removal of fraction 1 protein from the soluble fraction of plant extracts with ammonium sulphate permitted the production of precipitating antibodies against more components of the extracts than were formed in its presence. Absorption of antisera raised against soluble protein extracts from tissue infected with either the W or N strain of CMV with soluble protein extracts from healthy tissue revealed the presence of one or possibly two antigens specific to extracts from infected tissue. Observations made with both strains of CMV were qualitatively identical. Soluble protein extracts from infected tissue did not react with antiserum raised against purified CMV, but did react with antiserum to SDS-disrupted virus. This antiserum revealed the presence of possibly two coat protein-related soluble antigens associated with infection.

The influence of actinomycin D on cucumber mosaic virus (strain W) multiplication in cucumber cultivars

Actinomycin D was demonstrated, by its effect on the incorporation of [ 3H]uridine into acid-precipitable material, to curtail RNA synthesis in cucumber cotyledons. Treatment of China cucumber plants, normally resistant to infection by cucumber mosaic virus (CMV), with actinomycin D allowed an enhanced accumulation of virus infectivity, measured 4 days after infection, compared to that in control plants, the maximum observed increase occurring following injection of an actinomycin solution containing 10 μg/ml 1 h after infection. No significant influence on infectivity in susceptible Ashley plants was observed. While not ruling out alternative possibilities, the results are consistent with the hypothesis that the China cultivar responds to CMV infection with the synthesis of one or more antiviral compounds, a process restricted by actinomycin treatment. Although a different virus and cultivar were employed, these observations agree in principle with those reported by Nachman et al.

Peroxidase isoenzymes in leaves of cucumber ( Cucumis sativus L.) cultivars systemically infected with the W strain of cucumber mosaic virus

The isoperoxidases in leaf extracts of healthy and cucumber mosaic virus infected cucumber cultivars of differing susceptibility to infection and of healthy tobacco plants have been examined by disk electrophoresis. The relative intensities of the principal isoperoxidases in zymograms of extracts from systemitically infected cucumber leaves, compared with those of healthy control leaves, were correlated with symptom severity and peroxidase activity. Thus, extracts from infected leaves of the susceptible cultivars Ashley and Marketer, with pronounced symptoms, showed greater intensities of the principal isoperoxidase bands in comparison with extracts of the resistant, almost symptomless cultivar China, and had greater peroxidase activities. The changes in isoperoxidase patternsappeared to be nonspecific responses to infection, although zymograms of extracts from senescing detached leaves of the four cucumber cultivars were not identical to those from virus infected plants. Cucumber mosaic virus infection of both cucumber and tobacco cultivars resulted in increased activity or stimulated synthesis of host isoperoxidases rather than induction of virus specific ones, in support of conclusions reached by other workers, based on experiments with several viruses including tobacco mosaic, tobacco streak, tobacco necrosis and tobacco ringspot viruses.

Direct infrared spectral analysis of the cucumber mosaic virus infection process.

INFRA-RED spectroscopy may provide a means of following biochemical changes which occur in tissues as a result of virus infection, if induced spectral changes can be detected and related to the structure of the absorbing compounds.