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 Responses of trifoliate orange (poncirus trifoliata (l.) raf.) to continuously and gradually increasing nacl concentration

2014 ◽  
Vol 73 (1) ◽  
pp. 285-290
Author(s):  
Christos Chatzissavvidis ◽  
Chrysovalantou Antonopoulou ◽  
Ioannis Therios ◽  
Kortessa Dimassi
Keyword(s):  
High Salinity ◽  
Growth Parameters ◽  
Sodium Concentration ◽  
Poncirus Trifoliata ◽  
Sugar Accumulation ◽  
Continuous Exposure ◽  
Trifoliate Orange ◽  
Nacl Concentration ◽  
Negative Effect

Abstract The effect of continuous or gradual stress due to NaCl on in vitro growth, proline and sugar accumulation and nutrient acquisition of trifoliate orange (Poncirus trifoliata (L.) Raf.) explants was studied. Apical shoot tips obtained from previous subculture were transferred to a Murashige and Skoog nutrient medium for proliferation and were exposed to continuous or gradual salinity stress for 42 days. The salt used to induce salinity was NaCl added in six concentrations: 0, 50, 100, 150, 200 and 300 mM. Gradual salinization was achieved by transferring the explants sequentially every week to the above mentioned NaCl concentrations. Most salt treatments had a negative effect on the growth parameters of explants. Sodium concentration of explants increased in all NaCl treatments compared to control and it was higher in the treatments with gradual exposure to salinity. Potassium concentration was reduced, mostly in the treatments with continuous exposure. Calcium andMg concentrations increased in all saline treatments. In general, the high salinity level in the substrate enhanced the proline and sugar concentrations of the studied explants. In conclusion, salinity had significant impacts on the growth and chemical status of P. trifoliata.

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