THE EFFECT OF DARKENING ON THE SUSCEPTIBILITY OF FRENCH BEAN TO TOBACCO NECROSIS VIRUS

1967 ◽  
Vol 45 (5) ◽  
pp. 543-553 ◽  
Author(s):  
W. C. Kimmins
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
French Bean ◽  
Tobacco Necrosis Virus ◽  
Plant Water ◽  
Necrosis Virus ◽  
Free Air ◽  
Detached Leaves ◽  
Resistance To Infection ◽  
Increased Susceptibility

Darkening of plants of Phaseolus vulgaris var. Prince for 3–108 h before inoculation with tobacco necrosis virus increased the susceptibility of the primary leaves to infection. The maximum number of lesions was obtained when plants were in darkness for 96 h. Darkening produced similar results on detached leaves and decapitated plants. The largest differences in susceptibility between shaded and illuminated plants were found in plants 9–12 days old. In plants 22–24 days old, darkening did not increase susceptibility. When 10-day-old plants were darkened for 24 h, the increased susceptibility that resulted persisted up to 6–8 h after the plants had been returned to light. Short periods (1, 10, and 20 min) of light given at varying times throughout a 24-h period of darkening did not alter susceptibility. Lowering of the light intensity to 250 lumens/ft2 failed to reduce resistance to infection. However, below 250 lumens/ft2 susceptibility increased with decreasing light intensity. Plants in the light or dark were more susceptible when supplied with carbon dioxide free air. When a relative humidity of 20% was used, darkening the plants no longer increased their susceptibility.It is suggested that there are a greater number of infectible sites present in darkened plants, and that this situation may be effected through some aspect of plant water relationships.

Stipple streak disease of French bean caused by a tobacco necrosis virus in Queensland

1968 ◽  
Vol 19 (5) ◽  
pp. 731 ◽  
Author(s):  
GM Behncken
Keyword(s):  
French Bean ◽  
Tobacco Necrosis Virus ◽  
Serological Evidence ◽  
Necrosis Virus ◽  
Leaf Vein ◽  
Satellite Virus ◽  
Vein Necrosis ◽  
Stem Necrosis ◽  
Olpidium Brassicae

A disease of beans in the Nambour district of Queensland has been shown to be stipple streak disease caused by a tobacco necrosis virus. Symptoms include leaf vein necrosis, stem necrosis, and occasionally necrotic lesions on the pods. In glasshouse tests symptoms developed more rapidly, and were more severe, at temperatures of 80–88°F than at 62–70°. The virus was readily transmitted by zoospores of a lettuce isolate of the fungus Olpidium brassicae (Wor.) Dang. Serological evidence is presented which indicates that the virus is an "A" serotype strain of tobacco necrosis virus. No evidence for the presence of an associated satellite virus was found.

THE EFFECT OF LEAF WATER BALANCE ON THE SUSCEPTIBILITY OF FRENCH BEAN TO TOBACCO NECROSIS VIRUS

1967 ◽  
Vol 45 (11) ◽  
pp. 2115-2118 ◽  
Author(s):  
W. C. Kimmins ◽  
R. E. Litz
Keyword(s):  
Relative Humidity ◽  
Turgor Pressure ◽  
Continuous Light ◽  
French Bean ◽  
Tobacco Necrosis Virus ◽  
Culture Solution ◽  
Pressure Measurements ◽  
Necrosis Virus ◽  
Continuous Darkness ◽  
High Suction

French beans were germinated under constant temperature, relative humidity, and day period, and were transferred to Hoagland's culture solution. Variations of the preinoculation treatment were begun at an age of 10 days for a period of 24 h. Treatments were selected which would induce turgor changes in the primary leaves.It was observed that susceptibility to tobacco necrosis virus infection was increased by preinoculation conditions of continuous darkness, high relative humidity, and low suction tension of the culture solution. Susceptibility was lowered by preinoculation conditions of continuous light, low relative humidity, and high suction tension of the culture solution.Diffusion pressure deficit, osmotic pressure, and turgor pressure measurements were made with the primary leaves at time of inoculation. Considerable agreement was noted between turgor changes and susceptibility.Preinoculation treatments such as darkening will alter susceptibility through changes in turgor pressure. It is suggested that there may be a direct effect of leaf turgor on the number of infectible sites.

Experiments and observations on the aftereffect of wilting on stomata of Rumex sanguineus

1970 ◽  
Vol 48 (3) ◽  
pp. 513-521 ◽  
Author(s):  
W. G. Allaway ◽  
T. A. Mansfield
Keyword(s):  
Carbon Dioxide ◽  
Water Stress ◽  
Water Content ◽  
Intercellular Space ◽  
Carbon Dioxide Concentration ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Intercellular Spaces ◽  
Free Air ◽  
Detached Leaves

Stomata of Rumex sanguineus showed an aftereffect of wilting, those of previously wilted plants failing to open as widely as usual. The water content of previously wilted leaves recovered rapidly after watering. The wilting treatment killed about 2% of the guard cells, and was followed by a persistent 5.5 to 7% increase in the carbon dioxide compensation point of leaves. Replacing the air in the intercellular spaces with carbon-dioxide-free air did not remove the aftereffect of wilting on the stomata. Detached leaves also showed the aftereffect, although it was apparently smaller than in leaves attached to the plant. Neither persistent water deficits, nor killing of guard cells, nor increased intercellular space carbon dioxide concentration could explain the aftereffect of wilting on stomata. The results are, however, consistent with the view that an inhibitor of stomatal opening accumulates in leaves after a period of water stress or, alternatively, that there is a deficiency of a substance which promotes opening.

scholarly journals Regioselective Base-induced Condensations of Acrylic Acid Derivatives

1999 ◽  
Vol 23 (3) ◽  
pp. 174-175
Author(s):  
E. Abdel-Ghani
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Dicarboxylic Acid ◽  
Ethyl Acetoacetate ◽  
Tobacco Necrosis Virus ◽  
Necrosis Virus ◽  
Antiviral Activities

The orientation of cyclization of the reaction of methyl aroylacrylate (1) and aroylacrylic acid (8) with ethyl acetoacetate and/or thiourea leading to the formation of 4-aroylmethylcyclopentane-1,3-dione (2) 5-aryl-3-oxocyclohexene-1,2-dicarboxylic acid (9), 2-imino-5-aroylmethylthiazolidin-4-one (11) and 6-aryl-2-sulfonylpyrimidine-4-carboxylic acid (14) depends on the medium employed; some compounds show moderate antiviral activities against tobacco necrosis virus.

scholarly journals The 3' untranslated region of satellite tobacco necrosis virus RNA stimulates translation in vitro.

1993 ◽  
Vol 13 (6) ◽  
pp. 3340-3349 ◽  
Author(s):  
X Danthinne ◽  
J Seurinck ◽  
F Meulewaeter ◽  
M Van Montagu ◽  
M Cornelissen
Keyword(s):  
Tobacco Necrosis Virus ◽  
Translation System ◽  
Coding Region ◽  
Necrosis Virus ◽  
Untranslated Sequence ◽  
Virus Rna ◽  
Free Translation ◽  
Order Of Magnitude ◽  
A Cell

The RNA of satellite tobacco necrosis virus (STNV) is a monocistronic messenger that lacks both a 5' cap structure and a 3' poly(A) tail. We show that in a cell-free translation system derived from wheat germ, STNV RNA lacking the 600-nucleotide trailer is translated an order of magnitude less efficiently than full-size RNA. Deletion analyses positioned the translational enhancer domain (TED) within a conserved hairpin structure immediately downstream from the coat protein cistron. TED enhances translation when fused to a heterologous mRNA, but the level of enhancement depends on the nature of the 5' untranslated sequence and is maximal in combination with the STNV leader. The STNV leader and TED have two regions of complementarity. One of the complementary regions in TED resembles picornavirus box A, which is involved in cap-independent translation but which is located upstream of the coding region.

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