Effects of methanol on photosynthetic processes and growth of Lemna gibba.
Effects of methanol on growth and photosynthetic activity of Lemna gibba exposed under continuous illumination were examined. As a higher plant, L. gibba appeared to be much more sensitive to methanol inhibitory effect compared with some algae (Theodoridou et al. [2002] Biochim. Biophys. Acta, 1573, 189-198). We found that stimulatory or inhibitory effects were strongly dependent on the methanol concentration and the time of exposure. When the exposure was up to 0.2% methanol, the growth rate of biomass was improved by 50%. However, stimulatory effect of methanol appeared to be smaller when plants were exposed for 48 h compared with 24 h. Increase in biomass induced by methanol was not based on the increase in primary photosynthetic process but rather on accommodation of energy dissipation during photosynthesis. Inhibitory effect on the growth of L. gibba already observed for 0.5% methanol was strongly associated with the increase in the nonphotochemical energy dissipation. The ratio between biomass and methanol concentration appeared to determine the stimulatory or the inhibitory effect. Suggested explanations for the stimulatory and the inhibitory effects are presented.
Dewez
David
D
Département de Chimie-Biochimie, TOXEN, Université du Québec à Montréal, Succursale Centre-Ville, Montreal, Canada.
Dautremepuits
Claire
C
Jeandet
Philippe
P
Vernet
Guy
G
Popovic
Radovan
R
D000432:Methanol / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects*; D063245:Plant Development
D000432:Methanol