A better understanding of the metabolic and diffusional limitations of photosynthesis in fluctuating irradiance can help identify targets for improving crop yields. We used different genotypes of Arabidopsis thaliana to characterise the importance of Rubisco activase (Rca), stomatal conductance (gs), non-photochemical quenching of chlorophyll fluorescence (NPQ) and sucrose phosphate synthase (S...

BACKGROUND AND AIMS Most lichens form associations with Trebouxia phycobionts and some of them simultaneously include genetically different algal lineages. In other symbiotic systems involving algae (e.g. reef corals), the relative abundances of different endosymbiotic algal clades may change over time. This process seems to provide a mechanism allowing the organism to respond to environmental ...

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...

We tested the hypothesis that ferredoxin (Fd) limits the activity of cyclic electron flow around PSI (CEF-PSI) in vivo and that the relief of this limitation promotes the non-photochemical quenching (NPQ) of Chl fluorescence. In transplastomic tobacco (Nicotiana tabacum cv Xanthi) expressing Fd from Arabidopsis (Arabidopsis thaliana) in its chloroplasts, the minimum yield (F(o)) of Chl fluoresc...

The photosynthetic performance of the canopy boll-leaf system (BLS) reflects material and energy exchange abilities between plant external environment. A two-year field experiment determined response to irrigation regimes [600 (W1), 480 (W2), 360 (W3) m3 ha-1] cotton BLS physio-biochemical traits. Decreasing irrigation, photochemical quenching coefficient, electron transfer rate PSII, chlorophy...

Green tides have occurred in the Yellow Sea, China, every year from 2007 to 2015. The free-floating Ulva prolifera (Müller) J. Agardh was the causative macroalgal species. The co-occurring, attached U. intestinalis was also observed. Photosynthetic capacities were determined using chlorophyll fluorescence in situ and after 7 days lab acclimation, and a significant differences were noted. Pigmen...

'Cleopatra' tangerine (Citrus reshni Hort. ex Tanaka) seedlings were irrigated daily for 8 weeks with 1/4 strength Hoagland's nutrient solution containing 0 (control) or 2 mM aluminum (Al). Leaves from Al-treated plants had decreased CO2 assimilation and stomatal conductance, but increased intercellular CO2 concentrations compared with control leaves. On a leaf area basis, 2 mM Al increased act...

Populus alba Villafranca clone was chosen for a proof of concept study to determine the potential uptake and accumulation of antibiotics by trees. Plants were grown hydroponically and irrigated with a recirculating Hoagland's nutrient solution (control) and Hoagland's nutrient solution fortified with erythromycin at 0.01, 0.1 and 1mgL(-1). After 3 and 28days of treatment, poplar plants were sep...

Multi-wavelength chlorophyll fluorescence analysis was utilised to examine the photosynthetic efficiency of the biofuel-producing alga Nannochloropsis oculata, grown under two light regimes; low (LL) and high (HL) irradiance levels. Wavelength dependency was evident in the functional absorption cross-section of Photosystem II (σII(λ)), absolute electron transfer rates (ETR(II)), and non-photoch...

Nonphotochemical quenching (NPQ) of Photosystem II fluorescence is one of the most important photoprotection responses of phototropic organisms. NPQ in Macrocystis pyrifera is unique since the fast induction of this response, the energy dependent quenching (qE), is not present in this alga. In contrast to higher plants, NPQ in this organism is much more strongly related to xanthophyll cycle (XC...