ENERGY-TRANSFER FOR LOW-TEMPERATURE FLUORESCENCE IN PS-II MUTANT THYLAKOIDS

The Chl-protein complexes of three maize (Zea mays L.) mutants and one barley (Hordeum vulgare L.) mutant were analyzed using low temperatur e Chl fluorescence emissions spectroscopy and LDS-polyacrylamide,eel e lectrophoresis. The maize mutants hcf-3, hcf-19, and hcf-114 all exhib ited a high Chl fluorescence (hcf) phenotype indicating a disruption o f the energy transfer within the photosynthetic apparatus. The mutatio ns in each of these maize mutants affects Photosystem II. The barley m utant analyzed was the well characterized Chl b-less mutant chlorina-f 2, which did not exhibit the hcf phenotype. Chlorina-f2 was used becau se no complete Chl b-less mutant of maize is available. Analysis of hc f-3, hcf-19, and hcf-114 revealed that in the absence of CP43, LHC II can still transfer excitation energy to CP47. These results suggest th at in mutant membranes LHC II can interact with CP47 as well as CP43. This functional interaction of LHC II with CP47 may only occur in the absence of CP43, however, it is possible that LHC II is positioned in the thylakoid membranes in a manner which allows association with both CP43 and CP47.