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Light acclimation potential and xanthophyll cycle pigments in photoautotrophic suspension cells of Chenopodium rubrum
Author(s) -
Schäfer Christian,
Schmidt Elke
Publication year - 1991
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1991.tb02930.x
Subject(s) - antheraxanthin , violaxanthin , xanthophyll , photoinhibition , photoprotection , photosynthesis , zeaxanthin , biology , acclimatization , chlorophyll , chlorophyll fluorescence , botany , photosynthetic pigment , photosystem ii , lutein , carotenoid
The present study investigates the light acclimation potential of photoautotrophic suspension culture cells of Chenopodium rubrum L. grown in 16 h light/8 h dark cycles. Typical features of sun/shade acclimation could be demonstrated in cultures grown at photon flux densities of 30 and 150 μmol m −2 s −1 . Low light grown cells had lower chlorophyll a/b ratios, lower respiration rates and lower light compensation points than high light grown cells. Maximum photosynthetic rate per cell dry weight was highest in low light conditions, indicating that the cells did not enlarge their photosynthetic machinery upon exposure to high light. Transfer of cultures to 800 μmol m −2 s −1 caused photoinhibition as indicated by a decrease in photosynthetic efficiency and by the occurrence of a slowly reversible quenching of variable chlorophyll fluorescence. Extension of the photoinhibitory treatment over six light dark cycles did not result in further dramatic changes of these parameters, whereas the chlorophyll content per dry weight and the chlorophyll a/b ratio decreased. Measurements of photochemical quenching showed that the capability of the cells to dissipate excessive energy had increased during the acclimation process. The presence of the xanthophyll cycle pigments and the operation of the cycle could be demonstrated. In agreement with the putative photoprotective function of antheraxanthin and zeaxanthin these pigments could only be detected under photoinhibitory conditions. Prolonged photoinhibitory treatment resulted in increases in the xanthophyll pigment concentration but not of the potential to deepoxidate violaxanthin. The limited potential of the cells to accumulate zeaxanthin and antheraxanthin might indicate that the xanthophyll cycle is not the main factor determining their resistance to high light stress.