EFFECT OF CHLOROPHYLL-A ON THE STRUCTURE OF 2 KINDS OF PHOSPHOLIPIDS UNDER ILLUMINATION - POSSIBLE BEHAVIOR OF LIPIDS IN THE PHOTODAMAGE PROCESS OF PHOTOSYSTEM-II

In the model system of lipid-pigment vesicles, excessive illumination causes structural changes of lipid molecules, such as the increase of unsaturation degree of their acyl chain and the decrease of the abilit y of hydrogen bonding. Chemically generated singlet oxygen only has th e former effect on lipid. The terminal component of the acyl chain rem ains unchanged in both cases. These results imply that there may be in jury of lipids besides proteins and pigments in the photoinhibition pr ocess of photosynthetic system. This kind of possible damage of lipids remains to be confirmed and its effect on some physiological features of plants such as temperature sensitivity is yet to be revealed.