Sorbitol-induced changes in various growth and biochemical parameters in maize

Treatment of maize seedlings with different concentrations of sorbitol decreased the rate of germination substantially. Root and shoot length was also reduced by sorbitol treatment, however, decrease in root length was lower than shoot length. Incubation of leaf segments from maize seedlings grown in continuous light with sorbitol decreased the fresh weight and increased the dry weight in a concentration-dependent manner. Sorbitol treatment also reduced the total chlorophylls, chlorophyll a as well as chlorophyll b; the decrease in chlorophyll 'b' being more prominent than chlorophyll 'a', however, carotenoid content was declined marginally. Supply of sorbitol decreased the protein and RNA content; however, proline content and in vivo nitrate reductase activity (NRA) were increased. The results demonstrate an inhibitory effect of sorbitol-induced stress on overall growth in maize. Amongst the biochemical parameters analysed, chlorophyll, protein and RNA contents were declined, while proline content and nitrate reductase activity were enhanced with sorbitol treatment.