Chemical prevention of growth reduction caused by supraoptimal temperatures in Arabidopsis thaliana

Abstract

In attempts to prevent the detrimental effects of supraoptimal temperatures, biotin, sucrose, malic acid, and the growth retardant phosfon-S were individually added to the agar suspension on which Arabidopsis thaliana plants were grown aseptically under both optimal and supraoptimal temperature regimes. Biotin induced increases over the untreated plants of 54 per cent in fresh weight and 66 per cent in dry weight at supraoptimal temperatures, while the corresponding biotin-induced increases over the untreated plants in fresh and dry weights at optimal temperatures were 38 and 15 per cent, respectively. Addition of 1 per cent sucrose induced 58 per cent increases in fresh and 70 per cent in dry weights of plants grown under supraoptimal temperatures, while under optimal temperature conditions, sucrose actually reduced the fresh weight 12 per cent and had only a slight (2 per cent) promotive effect on dry weights. Phosfon-S increased the fresh and dry weight 30 per cent and 16 per cent respectively, under supraoptimal temperatures and 27 and 9 per cent under the optimal temperatures. Malic acid caused a reduction in both fresh and dry weights under both temperature regimes. However, malic acid treatment was found to increase the number of seed pods, seeds, and the number of secondary roots. The size of seed pods and seeds was greatly increased by malic acid treatment under both temperature conditions.