Factors affecting the formation of local lesions by tobacco mosaic virus

The increase in knowledge of the virus diseases of plants has led to the possibility of attempting an investigation of the nature of the virus agent itself. It has been proved that various plants, notably N. glutinosa , react to inoculation with the virus of tobacco mosaic by the formation of necrotic lesions on the rubbed leaves. It has been shown, further, that the number of lesions formed increases with the concentration of the virus up to a definite value, which varies with the experimental conditions (Caldwell, 1933). At high concentrations of the virus, there is apparently not a sufficient number of susceptible areas on the leaves to allow of reaction to all the virus units present, and the number of susceptible areas becomes the limiting factor in lesion formation. At lower concentrations the number of virus units is the main factor involved. Youden, Beale, and Guthrie (1935) have recently published a paper in which they show that all the available data on the formation of lesions by different dilutions of virus, obtained by different workers, can be fitted to a curve with the formula y = N (1 - e -ax ).

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Factors affecting the amount of tobacco mosaic virus nucleic acid in phenol-treated extracts from tobacco leaves

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1972.0081 ◽

1972 ◽

Vol 182 (1068) ◽

pp. 297-318 ◽

Cited By ~ 4

Keyword(s):

Nucleic Acid ◽

Tobacco Mosaic Virus ◽

Mosaic Virus ◽

Tobacco Plants ◽

Factors Affecting ◽

Susceptibility To Infection ◽

The Difference ◽

Apparent Susceptibility ◽

Main Factor

Extracts from the lower leaves of tobacco plants infected with tobacco mosaic virus and pulped in the presence of phenol are less infective than extracts from leaves pulped and then treated with phenol. Extracts from uninfected leaves mixed with purified virus behave similarly. The difference becomes progressively smaller as leaves are taken from further up the plant. The difference is smaller when the interval between pulping and adding phenol is short, and it is still smaller if air is rigidly excluded during the interval. Fixation of virus nucleic acid to the leaf fibre is the main factor responsible for this difference. Part of the normal nucleic acid of the leaf is fixed similarly. Fixation is partly prevented by including yeast nucleic acid in the extraction fluid, or by excluding Ca 2+ from it by adding citrate. Part of the nucleic acid is held tenaciously by the fibre. The possible significance of this fixation in vivo in controlling the apparent susceptibility to infection of plants in different physiological states is discussed.

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Local lesion formation by ultraviolet irradiation on leaves systemically infected with TMV

Canadian Journal of Botany ◽

10.1139/b73-104 ◽

1973 ◽

Vol 51 (4) ◽

pp. 825-826 ◽

Cited By ~ 1

Author(s):

Yasushi Takagi ◽

Yukio Sugimura

Keyword(s):

Tobacco Mosaic Virus ◽

Mosaic Virus ◽

Ultraviolet Light ◽

Ultraviolet Irradiation ◽

Local Lesion ◽

Lesion Formation ◽

Local Lesions ◽

Local Lesion Formation

When the leaves of Xanthi tobacco systemically infected with tobacco mosaic virus were irradiated with ultraviolet light, local lesions were induced on the treated leaves.

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Some Variables Affecting the Use of Cowpea as an Assay Host for Cucumber Mosaic Virus

Australian Journal of Biological Sciences ◽

10.1071/bi9540141 ◽

1954 ◽

Vol 7 (2) ◽

pp. 141 ◽

Cited By ~ 5

Author(s):

NC Crowley

Keyword(s):

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Vigna Sinensis ◽

Factors Affecting ◽

Local Lesions

A study was made of the factors affecting the production of local lesions by cucumber mosaic virus on cowpea (Vigna sinensis (L.) Endl. ex Hassk.).

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Interaction of calcium with indole-3-acetic acid and kinetin during the formation of local lesions in bean (Phaseolus vulgaris) by alfalfa mosaic virus

Canadian Journal of Botany ◽

10.1139/b86-150 ◽

1986 ◽

Vol 64 (6) ◽

pp. 1097-1100 ◽

Cited By ~ 1

Author(s):

J. C. Tu

Keyword(s):

Mosaic Virus ◽

Alfalfa Mosaic Virus ◽

Local Lesion ◽

Distilled Water ◽

Lesion Formation ◽

Water Sprays ◽

Local Lesions ◽

Lesion Number ◽

Local Lesion Formation ◽

Indole 3 Acetic Acid

A study was conducted on the interaction of Ca2+ with 3-indoleacetic acid (IAA) and kinetin on local lesion formation by alfalfa mosaic virus on bean leaves. Local lesion number was reduced when IAA solutions alone were applied as postinoculation sprays, as compared with water sprays. The reduction was slight at 10−4 and 10−5 M but was large at 10−3 M. Although addition of 0.03 M CaCl2 to 10−4 and 10−5 M IAA sprays reversed the effect of IAA on local lesion formation, addition of the same concentration of calcium to 10−3 M IAA had little effect on local lesion production. Kinetin, except at the 10−4 M concentration, caused no increase in the number of local lesions, as compared with treatment with distilled water. However, with 0.03 M CaCl2 added, the local lesion production at all kinetin concentrations increased significantly over distilled water or 0.03 M CaCl2. The sizes of local lesions on leaves sprayed with 10−3, 10−4, and 10−5 M IAA were reduced by approximately 52, 26, and 10%, respectively, and on leaves sprayed with kinetin by approximately 44, 26, and 24%, respectively. Addition of 0.03 M CaCl2 to IAA and kinetin lessened their effect on the size of local lesions but did not eliminate the effect totally.

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