Mineral uptake and soluble carbohydrates of lettuce: Effects of air temperatures and mineral supply levels

Both low and high temperatures affect plant growth and development at whole plant level, tissue and even cell level through a variety of metabolic changes. In this paper we investigated the extent of the inhibition of growth, macro-element uptake and soluble carbohydrate production, and the effect of extra-supply of minerals as a means of the recovery from the damage. Lettuce plants were grown four different growth temperatures (15/8, 22/15, 25/18 and 28/21°C), and extra-supply of minerals was composed of 1.5- and 2.0-fold stronger than the standard nutrition (1/2 strength of Hoagland's solution). Low and high temperatures significantly adversely affected lettuce growth, mineral uptake and soluble carbohydrate production, and the extra-supply of minerals didn't play any crucial roles to promote and recover them. Merely, P uptake was slightly increased by an extra-supply of nutrients in all temperature conditions. From this study, it was strongly suggested that further research should include the effect of extra-supply of minerals when plants are recovered from low or high temperature stress, and metabolic interaction such as mineral uptake and carbohydrates between shoot and root.