Gh. Yu et al., The nopaline synthase (nos) promoter is inducible by UV-B radiation through a pathway dependent on reactive oxygen species, PL CELL ENV, 21(11), 1998, pp. 1163-1171
The molecular mechanism of plant response to UV-B radiation was studied usi
ng the nopaline synthase (nos) promoter, which has been shown to be inducib
le by methyl jasmonate (MJ) and reactive oxygen species (ROS). In the leave
s of transgenic tobacco (Nicotiana tabacum L.) plants that carried a fusion
between the nos promoter and the chloramphenicol acetyltransferase (cat) g
ene, 2 h of UV-B treatment resulted in a transient increase in the level of
cat mRNA, a maximum being reached at 6 h after the UV-B treatment. It was
also found that MJ and UV-B enhance nos promoter expression via separate pa
thways. Diethyldithiocarbamic acid, a potent inhibitor of jasmonate product
ion, had little effect on UV-B stimulation of the nos promoter In contrast,
antioxidants, such as dimethylthiourea, reduced glutathione, cysteine, N-a
cetylcysteine and DTT, blocked UV-B induction of the nos promoter, but did
not affect MJ induction of the nos promoter, These results suggest that UV-
B induction of the nos promoter is mediated via a pathway that requires rea
ctive oxygen species and is distinct from the jasmonate or MJ mediating pat
hway.