Effect of High Temperature on Photosynthesis in Beans (II. CO2 Assimilation and Metabolite Contents)

摘要: The effect of high temperatures on CO2 assimilation, metabolite content, and capacity for reducing power production in non-photorespiratory conditions has been assessed two different bean (Phaseolus vulgarus L.) varieties, Blue Lake (commercially available the United Kingdom) Barbucho (a noncommercially bred Chilean variety), which are known to differ their resistance extreme temperatures. maintains its photosynthetic functions a longer period time under heat compared with Lake. assimilation rate was increased by increases temperature, decrease ratio rates differing 10[deg]C. It is suggested that limitations caused metabolic restrictions can be differentiated between those occurring range 20 30[deg]C 30 35[deg]C. likely changes Calvin cycle regeneration starch synthesis affect photosynthesis 30[deg]C. But following an increase temperature from 35[deg]C, supply becomes limiting. From analysis adenylate concentration, transthylakoid energization, and, indirectly, NADPH/NADP+ ratio, it concluded limitation assimilatory due oxidation pool. In photosystem I quantum yield II maintained value. We conclude reorganization thylakoids observed at 35[deg]C excitation I, inducing cyclic electron transport NADPH, limiting carbon assimilation.