Authors:Zorana Katanić, Lejla Atić, Dž. Ferhatović, Vera Cesar, and H. Lepeduš
Vegetative buds represent developmental stage of Norway spruce (Picea abies L. Karst.) needles where chloroplast biogenesis and photosynthetic activity begin. We used the analyses of polyphasic chlorophyll a fluorescence rise (OJIP) to compare photosystem II (PSII) functioning in vegetative buds and fully photosynthetically active mature current-year needles. Considerably decreased performance index (PIABS) in vegetative buds compared to needles pointed to their low photosynthetic efficiency. Maximum quantum yield of PSII (Fv/Fm) in buds was slightly decreased but above limited value for functionality indicating that primary photochemistry of PSII is not holdback of vegetative buds photosynthetic activity. The most significant difference observed between investigated developmental stages was accumulation of reduced primary quinine acceptor of PSII (QA−) in vegetative buds, as a result of its limited re-oxidation by passing electrons to secondary quinone acceptor, QB. We suggest that reduced electron transfer from QA− to QB could be the major limiting factor of photosynthesis in vegetative buds.
Authors:Rabiye Terzi, Neslihan Saruhan, A. Sağlam, Hatice Nar, and A. Kadioğlu
Biehler, K., Haupt, S., Beckmann, J., Fock, H., Becker, T. W. (1997) Simultaneous CO
-gas exchange and fluorescencemeasurements indicate differences in light energy dissipation between the wild-type and the
Authors:Carlos Florindo, Cinthia Alves Barroco, Inês Silvestre, Vera Damião, João Paulo Gomes, Barbara Spellerberg, Ilda Santos-Sanches, and Maria José Borrego
-iT PicoGreen was added to an equal volume of each supernatant, previously diluted in 1× Tris–EDTA (TE) buffer. After 5 min of incubation at room temperature, in the dark, we proceeded to the fluorescencemeasurement (Fluorimeter – Anthos Zenith 3100) in 96-well
) Contribution of hydroxycinnamates and flavonoids to epidermal shielding of UV-A and UV-B radiation in developing rye primary leaves as assessed by ultraviolet-induced chlorophyll fluorescencemeasurements . Plant Cell. Environ. 23 , 1373 – 1380