Correlations between delayed fluorescence of chlorophyll, metabolism and yield of plants. II. Influence of moisture of leaf and temperature condition on delayed fluorescence of leaves

During various temperatures of incubation the dehydration of leaves up to 3.2-3.8% mainly in-duced increase maximum amplitude of delayed fluorescence of chlorophyll. It was shown that moisture loss with this range could be deter-mined for the most part by the growth of the electrochemical potential of thylakoid mem-branes. The further incubation of detached leaves at 36℃ temperature, with more notable moisture loss, resulted in specific its decline as opposed to cases of 22 and 6℃ of thermal in-cubation. It was confirmed that the increased temperatures and moisture loss damage of the cells of plants occurred together induce a greater influence on plants than in case of oc-curring apart. The results allow to suppose that this can be mostly caused weakly associated polypeptides fallen out from the chloroplast membrane, which may be stipulated by high temperature combined with change ionic and osmotic stresses due moisture loss. Simulta-neously, the results showed that the exposure of the critical lowered air temperature led to considerable typical changes of leaves delayed fluorescence parameters of field plants. There-fore, their use can constitute new approaches to elucidate the molecular basis of plant freezing tolerance in a timely manner, based on concen-tration-related changes and the efficiency of coupling between light and dark processes of plants.