Abstract:
High  temperature  causes  changes  in  the  struc-tural organization of thylakoid membranes affect-ing  excitation  energy  distribution  as  the  well  asrates of photochemical reactions. Thus, high tem-perature  causes  alterations  not  only  in  the  physi-ochemical  properties  but  also  the  functional  or-ganization of the thylakoid membranes (Pastenesand Horton, 1996). Heat stress has been reportedto  affect various  photosynthetic processes  includ-ing electron flow on the donor side of PSII (Nashet al., 1985; Enamiet al., 1994) and at the acceptorside of PSII (Bukhovet al., 1990; Cao and Govind-jee, 1990), inactivation of enzymes like ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco) andferredoxin-NADP  reductase  (FNR),