ABSTRACT
The temperature dependence of steady-state millisecond delayed luminescence (DL) is studied within the temperature range from -23 to 45 degrees C in leaf segments of chinese rose (Hibiscus rosa-sinensis L.) and bean (Ficia faba). To describe the experimental dependence of DL steady-state intensity on temperature theoretically, we suggest the temperature dependences of rate constants in earlier proposed model of photosynthesis. Under these conditions, the temperature dependence of DL steady-state value has the same form as experimental curve.
Subject(s)
Luminescent Measurements , Models, Biological , Photosynthesis/physiology , Photosynthesis/radiation effects , Plant Leaves/metabolism , Plant Leaves/radiation effects , Temperature , Biosensing Techniques/methods , Computer Simulation , Electron Transport/radiation effects , Energy Transfer/physiology , Energy Transfer/radiation effects , Hibiscus/metabolism , Hibiscus/radiation effects , Hot Temperature , Kinetics , Spectrometry, Fluorescence/methods , Vicia faba/metabolism , Vicia faba/radiation effectsABSTRACT
The temperature dependence of delayed luminescence of Hibiscus rosa sinensis leaves was studied in the temperature range from -25 degrees C to degrees C. Temperature dependence of the steady-state delayed luminescence intensity has two maxima, at -10 and at +35 degrees C. For the theoretical modeling, the mathematical model of plant photosynthesis developed earlier was used. The temperature dependence of the delayed fluorescence induction was obtained by introducing into the model the temperature dependences for 12 rate constants derived from the data on the effect of temperature on different stages of photosynthesis. The theoretical temperature dependence of the steady-state delayed luminescence was shown to have the same shape as the experimental one.
Subject(s)
Hibiscus/physiology , Hibiscus/chemistry , Luminescence , Models, Biological , Photoperiod , Photosynthesis , TemperatureABSTRACT
The temperature dependence of parameters of light-induced changes in millisecond delayed luminescence (half-width of the maximum, maximal and steady-state luminescence intensity) is studied within the temperature range from -23 to 45 degrees C in leaf segments of Chinese rose (Hibiscus rosa sinensis). Delayed luminescence (DL) is induced and registered by a homemade setup based on a Lewis-Kasha-type phosphoroscope. The temperature dependence of steady-state luminescence intensity is shown to have two maxima, at -10 and 35 degrees C. At room temperatures, the steady-state value of luminescence intensity is minimal, and its value correlates with the temperature tolerance of the plant. Depending on cooling and heating regimes, the DL steady-state value vs. temperature curves is found to be different. We suppose this effect to be caused by temperature-induced destructive changes in the structure of photosystem 2 reaction centre and probably by salting out.
