scholarly journals Short-Term Responses in Maximum Quantum Yield of PSII (Fv/Fm) to ex situ Temperature Treatment of Populations of Bryophytes Originating from Different Sites in Hokkaido, Northern Japan

Plants ◽  
2016 ◽  
Vol 5 (2) ◽  
pp. 22 ◽  
Author(s):  
Annika Jägerbrand ◽  
Gaku Kudo
Keyword(s):  
Quantum Yield ◽  
Temperature Treatment ◽  
Ex Situ ◽  
Maximum Quantum Yield ◽  
Short Term ◽  
Quantum Yield Of Psii ◽  
Northern Japan

Zinc requirement for two phytoplankton strains of the Tasman Sea

2017 ◽  
Vol 68 (2) ◽  
pp. 361 ◽  
Author(s):  
Marie Sinoir ◽  
Andrew R. Bowie ◽  
Mathieu Mongin ◽  
Edward C. V. Butler ◽  
Christel S. Hassler
Keyword(s):  
Growth Rate ◽  
Quantum Yield ◽  
Maximum Quantum Yield ◽  
Biological Transport ◽  
Short Term ◽  
Pennate Diatom ◽  
Cellular Energy ◽  
Zn Uptake ◽  
Tasman Sea ◽  
Zinc Concentrations

Zinc has been proposed as a limiting, or co-limiting, micronutrient for phytoplankton. In the Tasman Sea, extremely low zinc concentrations have been reported, raising the possibility there of limitation of phytoplankton growth by zinc. The pennate diatom Nitzschia closterium (CS-1) and the coccolithophorid Emiliania huxleyi (CS-812) were cultured in two low zinc concentrations (Zn2+ = 1.5 pmolL–1 and Zn2+ = 1.5 nmolL–1) mimicking conditions found in coastal and pelagic Tasman Sea. To monitor phytoplankton health and productivity, the maximum quantum yield (Fv/Fm), growth rate and cell size were analysed. These parameters showed that both strains were able to adapt and still grow. Short-term uptake experiments revealed an effect on Zn biological transport, with consequences for its bioavailability. When grown at low Zn2+ concentrations, E. huxleyi showed an induction of a two-transporter system, highly dependent on photosynthetic energy for Zn uptake. N. closterium was able to survive without inducing a higher-affinity Zn transporter. Its Zn uptake was also highly dependent on cellular energy and the ability to potentially access labile complexed forms of Zn. This strategy, thus, represented an advantage over E. huxleyi. Results are discussed in the context of the conditions found in the Tasman Sea.

Sensitivity to high salinity in tetraploid citrus seedlings increases with water availability and correlates with expression of candidate genes

2010 ◽  
Vol 37 (7) ◽  
pp. 674 ◽  
Author(s):  
Wafa Mouhaya ◽  
Thierry Allario ◽  
Javier Brumos ◽  
Fernando Andrés ◽  
Yann Froelicher ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Candidate Genes ◽  
High Salinity ◽  
Chloride Transport ◽  
Poncirus Trifoliata ◽  
Daily Maximum ◽  
Saline Stress ◽  
Maximum Quantum Yield ◽  
Trifoliate Orange ◽  
Quantum Yield Of Psii

We investigated tolerance to high salinity in well-irrigated diploid and tetraploid citrus. Comparisons were made between two diploids (2×) of trifoliate orange (Poncirus trifoliata (L.) Raf.) and willow leaf mandarin (Citrus deliciosa Ten), their respective doubled diploids (4×) and the allotetraploid (FLHORAG1) obtained from the protoplast fusion of trifoliate orange and Willow leaf mandarin. Salinity stress was applied by progressively increasing the concentration of NaCl from 50 mM to 400 mM for 8 weeks. Two-year-old plants were watered daily. Maximum quantum yield of PSII, and leaf and root chloride and sodium content were monitored. We previously reported that under moderate saline stress, citrus 4× genotypes were more tolerant that the 2×, but under these experimental conditions, 4× seedlings were certainly more sensitive to salt stress than 2×, as they accumulated more toxic ions and were more affected than 2×. Chloride accumulation in 4× leaves was greater and the maximum quantum yield of PSII was more reduced in 4× than in 2×. The expression of several candidate genes involved in signal transduction, sodium and chloride transport, osmotic adjustment, regulation of the stomata opening and detoxification processes were also investigated by quantitative real-time reverse transcription-PCR. A high correlation was observed between phenotype of sensitivity to stress and gene expression changes.

scholarly journals Physiological, morphological and anatomical leaf traits variation across leaf development in 'Corylus avellana'

2019 ◽  
Vol 40 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Rosangela Catoni ◽  
Francesco Bracco ◽  
Loretta Gratani ◽  
Mirko Umberto Granata
Keyword(s):  
Quantum Yield ◽  
Leaf Development ◽  
Leaf Traits ◽  
Corylus Avellana ◽  
Leaf Mass Per Area ◽  
Second Phase ◽  
Effective Quantum Yield ◽  
Maximum Quantum Yield ◽  
Psii Photochemistry ◽  
Quantum Yield Of Psii

The study analyzed the variations of physiological, morphological and anatomical leaf traits during its development in Corylus avellana L. saplings. Three different phases were identify during leaf development: the first phase (hereafter IP) considered in the developing leaves, the second phase (IIP) in the mature green leaves and the third phase (IIIP) in the senescent leaves. In particular, variations in parameters estimated from the photosynthetic light response curves, in chlorophyll fluorescence variables and in morphological leaf traits were analyzed during the three phases. The principal component analysis (PCA) carried out using all the considered morphological characters (leaf mass per area - LMA, and leaf tissue density - LTD) and physiological traits (the maximum net photosynthetic rates - ANmax, dark respiration rates - RD, light compensation point - LCP, light saturation point – LSP, maximum quantum yield - ɸmax, fluorescence-based maximum quantum yield of PSII photochemistry - Fv/FM and effective quantum yield of PSII photochemistry - ɸPSII) showed a complete separation among the considered phases. The results showed that the major differences occur between the phases IP and IIP. In particular, a greater variation was found for LMA, ANmax, RD. On the contrary a lower variation was observed for ɸmax which remain quite constant from IP to IIP indicating that chloroplasts present in juvenile leaves are fully functional.

scholarly journals Intoxication and Physiological Aspects of Forage Plants and Weeds Submitted to Clomazone Atmospheric Waste

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M.M. SILVA ◽  
J.B. SANTOS ◽  
E.A. SANTOS ◽  
M.V. SANTOS ◽  
L.T. SARDINHA ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Plant Species ◽  
Photochemical Quenching ◽  
Maximum Quantum Yield ◽  
Physiological Variables ◽  
Fluorescence Maximum ◽  
Fodder Plants ◽  
Urochloa Brizantha ◽  
Non Photochemical Quenching ◽  
Quantum Yield Of Psii

ABSTRACT: Herbicide volatilization may generate environmental and agricultural problems and result in visual or physiological contamination of non-target plant species. Thus, the goal of this research was to study the fluorescence of chlorophyll a in weeds and fodder plants under the effect of clomazone in the form of atmospheric waste. The experiment was conducted under field conditions designed in randomized blocks with four replications, in a 6 x 4 factor scheme, with six plant species: Dolichos lablab, bicolor Sorgum, Urochloa brizantha, Macrotyloma axillare, Portulaca oleracea and Sida rhombifolia. There were four solutions containing 0, 360, 720 and 1,080 g ha-1 of clomazone (0, 0.05, 0.10 and 0.15 mg L-1, considered as the volume). Seedbeds were built and covered with transparent polyethylene film of 150 μm, with a volume of 12 m³. Fodder plants were sown in line, while weeds were selected according to the incidence. On the sixteenth day after emergence, concentrations of herbicide diluted on three petri dishes were inserted. After 72 hours of exposure, the tunnels were opened and the dishes were removed, noticing evaporation of the product. The following evaluationswere performed: plant poisoning, initial fluorescence, maximum quantum yield of PSII, photochemical quenching, non-photochemical quenching and chlorophyll content. Even at concentrations that do not promote visual effect, clomazone can cause significant damage in the photosynthetic activity of the species. The physiological variables chlorophyll, maximum quantum yield of PSII and initial chlorophyll fluorescence can be effectively used to monitor clomazone waste in the atmosphere.

scholarly journals Physiological Responses of Pocillopora acuta and Porites lutea Under Plastic and Fishing Net Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Long Ying ◽  
Sutinee Sinutok ◽  
Pathompong Pramneechote ◽  
Pattara Aiyarak ◽  
Peter J. Ralph ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photochemical Efficiency ◽  
Pigment Content ◽  
Marine Debris ◽  
Maximum Quantum Yield ◽  
Calcification Rate ◽  
Porites Lutea ◽  
Plastic Bag ◽  
Opaque Plastic ◽  
Quantum Yield Of Psii

Marine debris has become a global problem affecting coral health around the globe. However, the photophysiological responses of corals to marine debris stress remain unclear. Therefore, this study firstly investigated transparent and opaque plastic bag shading and fishing nets directly contacting the coral. Photosynthetic performance, pigment content, symbiont density, and calcification rate of a branching coral Pocillopora acuta and a massive coral Porites lutea were investigated after 4 weeks of exposure to marine debris. The results show that the maximum quantum yield of PSII significantly decreased in P. lutea with all treatments, while P. acuta showed no effect on the maximum quantum yield of PSII from any treatments. Transparent plastic bag shading does not affect P. acuta, but significantly affected the maximum photochemical efficiency of P. lutea. Photoacclimation of cellular pigment content was also observed under opaque plastic bag shading for both species at week 2. Fishing nets had the strongest effect and resulted in P. acuta bleaching and P. lutea partial mortality as well as a decline in zooxanthellae density. Calcification rate of P. acuta significantly decreased with treatments using opaque plastic bag and fishing net, but for P. lutea only the treatment with fishing net gave any observable effects. This study suggests that the sensitivities of corals to marine debris differ strongly by species and morphology of the coral.

scholarly journals Polyphasic OKJIP Chlorophyll a Fluorescence Transient in a Landrace and a Commercial Cultivar of Sweet Pepper (Capsicum annuum, L.) under Long-Term Salt Stress

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 887
Author(s):  
Pasquale Giorio ◽  
Mohamed Houssemeddine Sellami
Keyword(s):  
Salt Stress ◽  
Quantum Yield ◽  
Heat Dissipation ◽  
Sweet Pepper ◽  
Oxygen Evolving Complex ◽  
Maximum Quantum Yield ◽  
Commercial Cultivar ◽  
Oxygen Evolving ◽  
Quantum Yield Of Psii

In a soilless long-term salt-stress experiment, we tested the differences between the commercial sweet pepper cultivar “Quadrato d’Asti” and the landrace “Cazzone Giallo” in the structure and function of PSII through the JIP test analysis of the fast chlorophyll fluorescence transients (OKJIP). Salt stress inactivated the oxygen-evolving complex. Performance index detected the stress earlier than the maximum quantum yield of PSII, which remarkably decreased in the long term. The detrimental effects of salinity on the oxygen evolving-complex, the trapping of light energy in PSII, and delivering in the electron transport chain occurred earlier and more in the landrace than the cultivar. Performance indexes decreased earlier than the maximum quantum yield of PSII. Stress-induced inactivation of PSII reaction centers reached 22% in the cultivar and 45% in the landrace. The resulted heat dissipation had the trade-off of a correspondent reduced energy flow per sample leaf area, thus an impaired potential carbon fixation. These results corroborate the reported higher tolerance to salt stress of the commercial cultivar than the landrace in terms of yield. PSII was more affected than PSI, which functionality recovered in the late of trial, especially in the cultivar, possibly due to heat dissipation mechanisms. This study gives valuable information for breeding programs aiming to improve tolerance in salt stress sensitive sweet pepper genotypes.

scholarly journals Short term fluctuating temperature alleviates Daphnia stoichiometric constraints

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esteban Balseiro ◽  
Cecilia Laspoumaderes ◽  
Facundo Smufer ◽  
Laura Wolinski ◽  
Beatriz Modenutti
Keyword(s):  
Nutrient Limitation ◽  
Temperature Fluctuation ◽  
Diel Vertical Migration ◽  
Temperature Treatment ◽  
Short Term ◽  
Fluctuating Temperature ◽  
Rna Content ◽  
Temperature Regimes ◽  
Lake Temperature ◽  
The Mean

AbstractIn this study, we analysed how short term temperature fluctuation interacts with nutrient limitation in the vertical migrating Daphnia commutata. We hypothesize that short term (daily) temperature fluctuation will alleviate nutrient limitation. We carried out experiments analysing growth rates, phosphorus and RNA content of D. commutate grown under four different temperature regimes and two P-limited conditions. Our experiments showed that individuals grown under fluctuating temperature grew more than at the mean temperature. We estimated the expected sizes for the 15 °C treatment based on the Q10 and for the fluctuating temperature treatment. These expected sizes for both treatments resulted well below the observed ones. The P and RNA content of individuals grown at 10 °C were significantly higher than those at 20 °C, and when individuals grown at 10 °C were translocated to 20 °C they exerted an increased growth rate. Our results suggest that, under a regime of diel vertical migration, the temperature alternation would allow migrating organisms to alleviate the effect of severe nutrient limitation maintaining population growth. Under a scenario of global warming, where epilimnetic temperatures will increase, lake temperature will interact with nutrient limitation for consumers, but, organisms may be able to face these changes if they can still regularly move from a cold hypolimnion to a warmer epilimnion.

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