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Chlorophyll fluorescence quenching and violaxanthin deepoxidation of FBPase antisense plants at low light intensities and low temperatures
Author(s) -
Fisahn Joachim,
Kossmann Jens,
Matzke Gernot,
Fuss Heidemarie,
Bilger Wolfgang,
Willmitzer Lothar
Publication year - 1995
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.1399-3054.1995.tb00800.x
Subject(s) - photoinhibition , chlorophyll fluorescence , violaxanthin , photosystem ii , chlorophyll , photosynthesis , biology , acclimatization , fructose 1,6 bisphosphatase , botany , quenching (fluorescence) , non photochemical quenching , horticulture , photoprotection , nicotiana tabacum , plastoquinone , fluorescence , chemistry , fructose , biochemistry , thylakoid , chloroplast , carotenoid , zeaxanthin , lutein , physics , quantum mechanics , gene
Genetically modified potato ( Solanum tuberosum L. cv. Desiree) and tobacco ( Nicotiana tabacum cv. Samsun N.N.) plants were used to analyze the effects exerted by the chloroplastic (cp) fructose‐ 1,6‐bisphosphatase (FBPase) on the regulation of light energy discrimination at the level of photosystem II. The cp‐FBPase activity was progressively inhibited by an mRNA antisense to this FBPase. The chlorophyll fluorescence quenching parameters of these transgenic plants were compared to those of wild‐type and transgenic plants that were acclimated to low temperatures. In particular various lines of the transgenic potato and tobacco plants were exposed to a temperature treatment of 10 and 20°C for 10 days. Light intensities were kept low to reduce photoinhibition so that we could analyze exclusively the effects of a modification in the carbon fixation cycle on the chlorophyll fluorescence quenching parameters. The photon flux densities (PFDs) employed at the level of the middle leaves of all plants were set to two different values of 10 μmol m −2 s −1 and 50 μmol m −2 s −1 . Subsequent to this 10‐day acclimation the chlorophyll‐fluorescence parameters of all plants were measured. Photoinhibition as expressed by the F y /F m ratio was minor in plants subjected to a PFD of 10 μmol m −2 s −1 . Higher photon fluence rates of 50 μmol m −2 s −1 at temperatures of 10°C gave rise to a significant reduction in the F y /F m ratios obtained from the transgenic plants which were characterized by a restriction in cp‐FBPase capacity to 20% of normal activity. Furthermore, a progressive inhibition of the cp‐FBPase activity induced an amplified nonphotochemical quenching of chlorophyll fluorescence with in the genetically manipulated species (except at 10°C and 50 μmol m −2 s −1 ). The increase in nonphotochemical quenching depended upon light and temperature. Photochemical quenching of light quanta within the antisense plants declined relative to that in the wild type. To further characterize the mechanisms producing higher levels of nonphotochemical fluorescence quenching. we analyzed several of the xanthophyll cycle pigments. The deepoxidation state of the xanthophyll cycle pigments in potato plants increased with attenuating FBPase activities under all conditions. For tobacco plants, this elevation of the deepoxidation state was only observed at a PFD of 50 μmol m −2 s −1 .