CHANGES IN ENDOGENOUS CYANIDE AND 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID LEVELS DURING THE HYPERSENSITIVE RESPONSE OF TOBACCO MOSAIC-VIRUS-INFECTED TOBACCO-LEAVES
F. Siefert et al., CHANGES IN ENDOGENOUS CYANIDE AND 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID LEVELS DURING THE HYPERSENSITIVE RESPONSE OF TOBACCO MOSAIC-VIRUS-INFECTED TOBACCO-LEAVES, Plant growth regulation, 17(2), 1995, pp. 109-113
Leaves of Nicotiana tabacum L. cv. Xanthi necroticum plants form, loca
l necrotic lesions at the site of infection by tobacco mosaic virus. D
uring the first seven days post-inoculation, endogenous levels of 1-am
inocyclopropane-1-carboxylic acid (ACC) and N-malonyl-ACC increased in
the lesion area. The time course of ACC accumulation coincided with a
n increase in the endogenous cyanide level which began within two days
after inoculation Concomitantly, the activity of beta-cyanoalanine sy
nthase, the main HCN detoxifying enzyme, decreased. Likewise, treatmen
t of leaf discs of uninfected plants with ACC led to cyanide accumulat
ion. Exogenously applied KCN caused necrotic spots on tobacco leaves v
ery similar to the whitish centers of virus-induced local lesions. Pos
sible implications of cyanide in cell death during TMV-induced lesion
development are discussed.