[Pigment-protein complexes nd the number of the reaction photosystem centers in pea chlorophyll mutants].
We studied fluorescent and absorption properties of the chloroplasts and pigment-protein complexes isolated by gel electrophoresis from the leaves of pea, the initial cultivar Torsdag and mutants chlorotica 2004 and 2014. Specific maxima of fluorescence and chlorophyll forms in individual complexes have been determined from the absorption and fluorescence spectra of the chloroplast chlorophyll and their secondary derivatives at 23 and -196 degrees C. Chlorotica 2004 mutant proved to have an increased intensity of a long-wave band at both 23 degrees C (745 nm) and -196 degrees C (728 nm) of the light-harvesting complex I. At the same time, this mutant featured a decreased accumulation of chlorophyll forms at 690, 697, and 708 nm forming the nearest-neighbor antenna of PSI reaction center. No spectral differences have been revealed between chlorotica 2014 mutant and the initial cultivar. Gel electrophoresis demonstrated synthesis of all chlorophyll-protein complexes in both mutants. At the same time, analysis of photochemical activity of PSI and PSII reaction centers and evaluation of the light-harvesting antenna as well as the number of reaction centers of the photosystems suggest that chlorotica 2004 mutant has 1.7 times less PSI reaction centers due to a mutation-disturbed chlorophyll a-protein complex of PSI. The primary effect of chlorotica 2014 mutation remains unclear. The proportional changes in the photosystem complexes in this mutant suggest that they are secondary and result from a 50% decrease in chlorophyll content.
Ladygin
V G
VG
Institute of Fundamental Problems in Biology, Russian Academy of Sciences, Pushchino, Moscow Oblast, 142290 Russia. ladygin@issp.serpukhov.su
D002734:Chlorophyll / Q000235:genetics; D009154:Mutation; D018532:Pisum sativum / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics / Q000502:physiology*; D045331:Photosystem I Protein Complex / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics; D013050:Spectrometry, Fluorescence
D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D002734:Chlorophyll