Analysis of temperature-jump chlorophyll fluorescence induction in plants

摘要: Abstract A newly observed general chlorophyll fluorescence induction effect in plants is described. Fluorescence yield can rise through as many four different phases (α, β, γ, δ) the dark, when intact cells or leaves are rapidly heated (within approx. 2.5 s) from 20 to 40–50 °C. An analysis of this temperature-jump Scenedesmus obliquus leads following: 1. Phase α due removal S-quenching and appears be related heat deactivation water-splitting enzyme system. With prolonged heating, irreversibility upon recooling reflects irreversible damage 2. β independent S-states redox state primary System II acceptor Q. It suggested that parallels functional separation Q trapping centre. This highly reversible. 3. γ δ reflect reduction by a heat-induced endogenous reductant, which probably identical hydrogenase. Critical temperatures for pronounced differ markedly plants. Possible correlations between induction, thylakoid membrane lipid composition, phase transition lipid-protein interactions discussed.