The aim of this study is to evaluate the  effects of water deficit stress on chlorophyll fluorescence (CF) characteristics of photosystem II (PSII) and pigment contents in two rootstock seedlings (Pistacia atlantica L. and P. khinjuk L.). Three levels of soil water potential (Ψs) was used, including WWD (-0.05 MPa), MWD (-0.7 MPa) and SWD (-1.5 MPa). It was found that water stress increased the...

In order to study the effects of desiccation on a photosynthetic system, light harvesting and light-induced electron transport processes were examined in pea cotyledons at various moisture levels, using in vivo fluorescence excitation spectra and fluorescence induction kinetics. Water sorption isotherms yielded thermodynamic data that suggested very strong water binding between 4 to 11% water, ...

the changes of chl a fluorescence induction curve in response to different salinity levels in canola (barassica napus, l.) plants were investigated. the canola seedlings were exposed to salt stress (100 mm and 200 mm nacl) for 7 days and chl a fluorescence induction kinetics was analysed. by using the ojip-test, various parameters like vj, area, n, φpo, φeo, ψo, rc/abs and piabs were calculated...

The effects of short-term salt stress on gas exchange and the regulation of photosynthetic electron transport were examined in Arabidopsis (Arabidopsis thaliana) and its salt-tolerant close relative Thellungiella (Thellungiella halophila). Plants cultivated on soil were challenged for 2 weeks with NaCl. Arabidopsis showed a much higher sensitivity to salt than Thellungiella; while Arabidopsis p...

The changes in pigment composition, photosynthesis and PSII photochemistry were investigated in cells of Spirulina platensis adapted to salt stress (!0±75 M NaCl). A decrease in the phycocyanine}chlorophyll and no significant change in the carotenoid}chlorophyll ratio were observed in salt-adapted cells. Salt stress inhibited the apparent quantum efficiency of photosynthesis and PSII activity w...

(Z. Naturforsch. 30 c, 489—498 [1975]; received March 3/April 18, 1975) Primary Photosynthetic Electron Transport, Computer Simulation, Fluorescence Induction, Oxygen Exchange Transient A computer model describing the “Z-scheme” of photosynthetic electron transport in terms of reduction and oxydation of coupled redox pools was built up. Starting from a certain initial state corresponding to the...

Plant photosynthesis and photosystem II (PSII) are susceptible to high temperature. However, photosynthetic electron transport process under heat stress remains unclear. To reveal this issue, chlorophyll a fluorescence and modulated 820 nm reflection were simultaneously detected in sweet sorghum. At 43°C, J step in the chlorophyll a fluorescence transient was significantly elevated, suggesting ...

Preincubation of chloroplasts from pea leaves (Pisum sativum L. cv. Kelvedon) with 0.5 millimolar ferricyanide in the dark, caused a parallel inhibition of the rate of rise of the variable fluorescence and the rate of electron transport. Both reactions were inhibited to a similar extent by varying the time of preincubation, the concentration of ferricyanide during preincubation, and by raising ...