scholarly journals Physiological Responses of the Submerged Macrophyte Stuckenia pectinata to High Salinity and Irradiance Stress to Assess Eutrophication Management and Climatic Effects: An Integrative Approach

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1706
Author(s):  
Lamprini Malea ◽  
Konstantinia Nakou ◽  
Apostolos Papadimitriou ◽  
Athanasios Exadactylos ◽  
Sotiris Orfanidis
Keyword(s):  
High Salinity ◽  
Photosynthetic Pigment ◽  
High Irradiance ◽  
Growth Strategy ◽  
Submerged Macrophyte ◽  
Integrative Approach ◽  
Climatic Effects ◽  
Chl A ◽  
Stuckenia Pectinata ◽  
Acclimation Potential

Stuckenia pectinata, a submerged macrophyte of eutrophic to hyper-eutrophic fresh to brackish waters, faces management and climatic-forced increment of salinity and irradiance in Vistonis Lake (Greece) that may endanger its existence and the ecosystem functioning. A pre-acclimated clone under low irradiance and salinity conditions was treated to understand the effects of high salinity and irradiance on a suite of subcellular (chlorophyll a fluorescence kinetics and JIP-test, and chlorophyll content) to organismal (relative growth rate—RGR) physiological parameters. The responses to high irradiance indicated the plant’s great photo-acclimation potential to regulate the number and size of the reaction centers and the photosynthetic electron transport chain by dissipation of the excess energy to heat. A statistically significant interaction (p < 0.01) of salinity and irradiance on Chl a, b content indicated acclimation potential through adjusting the Chl a, b contents. However, no significant (p > 0.05) difference was observed on Chl a/b ratio and the RGR, indicating the species’ potential to become acclimatized by reallocating resources to compensate for growth. Thus, the regulation of photosynthetic pigment content and photosystem II performance consisted of the primary growth strategy to present and future high salinity and irradiance stressful conditions due to eutrophication management and the ongoing climatic changes.

scholarly journals Leaf Gas Exchange and Chlorophyll a Fluorescence Imaging of Rice Leaves Infected with Monographella albescens

2015 ◽  
Vol 105 (2) ◽  
pp. 180-188 ◽  
Author(s):  
Sandro Dan Tatagiba ◽  
Fábio Murilo DaMatta ◽  
Fabrício Ávila Rodrigues
Keyword(s):  
Gas Exchange ◽  
Fluorescence Imaging ◽  
Leaf Gas Exchange ◽  
Photosynthetic Pigment ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Chl A ◽  
Chl A Fluorescence ◽  
Rice Leaves

This study was intended to analyze the photosynthetic performance of rice leaf blades infected with Monographella albescens by combining chlorophyll (Chl) a fluorescence images with gas exchange and photosynthetic pigment pools. The net CO2 assimilation rate, stomatal conductance, transpiration rate, total Chl and carotenoid pools, and Chl a/b ratio all decreased but the internal CO2 concentration increased in the inoculated plants compared with their noninoculated counterparts. The first detectable changes in the images of Chl a fluorescence from the leaves of inoculated plants were already evident at 24 h after inoculation (hai) and increased dramatically as the leaf scald lesions expanded. However, these changes were negligible for the photosystem II photochemical efficiency (Fv/Fm) at 24 hai, in contrast to other Chl fluorescence traits such as the photochemical quenching coefficient, yield of photochemistry, and yield for dissipation by downregulation; which, therefore, were much more sensitive than the Fv/Fm ratio in assessing the early stages of fungal infection. It was also demonstrated that M. albescens was able to impair the photosynthetic process in both symptomatic and asymptomatic leaf areas. Overall, it was proven that Chl a fluorescence imaging is an excellent tool to describe the loss of functionality of the photosynthetic apparatus occurring in rice leaves upon infection by M. albescens.

Growth and physiological responses to arbuscular mycorrhizal fungi and salt stress in dioecious plant Populus tomentosa

2014 ◽  
Vol 44 (9) ◽  
pp. 1020-1031 ◽  
Author(s):  
Yanwei Lu ◽  
Guangquan Wang ◽  
Qingjie Meng ◽  
Wenhui Zhang ◽  
Baoli Duan
Keyword(s):  
Mycorrhizal Fungi ◽  
High Salinity ◽  
Photosynthetic Pigment ◽  
Arbuscular Mycorrhizal ◽  
Populus Tomentosa ◽  
Salinity Level ◽  
Fungal Colonization ◽  
Guaiacol Peroxidase ◽  
Fungal Treatment ◽  
Low Salinity

This study elucidated whether the beneficial effect of arbuscular mycorrhizal (AM) symbiosis was different in male and female Populus tomentosa Carrière trees. Female and male cuttings of P. tomentosa were treated with two AM fungal regimes, with or without an AM fungus (Glomus constrictum Trappe) inoculation, and with three salt regimes, no salt, low-salinity level (100 mmol·L–1 NaCl), and high-salinity level (200 mmol·L–1 NaCl). Our results showed that AM fungal colonization alleviated the salt-induced reduction in growth, gas exchange, photosynthetic pigment content, and nitrogen (N) and phosphorus (P) concentrations in the leaves, stems, and roots under low-salinity conditions. However, these effects were not alleviated under high-salinity conditions. AM fungal colonization was associated with a reinforcement of the activity of superoxide dismutase (SOD) and guaiacol peroxidase (GPx) and an inhibition of malondialdehyde (MDA) in treated plants of both genders under low-salinity conditions. Furthermore, sodium (Na+) and chlorine (Cl–) concentrations in tree organs were lower in the AM than the non-AM plants under the low-salinity condition in both sexes. AM fungal treatment may protect salt-stressed plants via the inhibition of salt-induced oxidative stress, which improves nutrient absorbance and inhibits Na+ transport from the roots to the shoots. In addition, small differences in plant growth induced by AM fungal colonization were observed between sexes, but significant gender differences were obtained in other parameters such as SOD and GPx activities and N and P concentrations.

scholarly journals METABOLIC BALANCE OF THE POLYP-ALGAE MUTUALISTIC SYMBIOSIS IN THE HERMATYPIC CORAL Porites panamensis IN LA PAZ, BAJA CALIFORNIA SUR, MÉXICO

2014 ◽  
Vol 29 (1) ◽  
pp. 1
Author(s):  
S. D. Rico -Esenaro ◽  
M. Signoret -Poillon ◽  
J. Aldeco ◽  
H. Reyes -Bonilla
Keyword(s):  
Adaptive Response ◽  
Baja California ◽  
High Irradiance ◽  
Baja California Sur ◽  
Metabolic Balance ◽  
La Paz ◽  
Chl A ◽  
Mutualistic Symbiosis ◽  
Hermatypic Corals ◽  
Chlorophyll Concentrations

Studies on metabolic balance in hermatypic corals have been unable to separate the analysis of animal’s respiration from that of plant. The objective of this research was to determine the metabolic balance in the mutualistic symbiosis polyp-algae through incubations in respirometric chambers of twelve fragments of coral. The species studied Porites panamensis (Scleractinia: Poritidae), Verrill, 1866 was collected near La Paz, Baja California Sur, México. Experiments were performed during fall 2009 and winter 2010. Water temperature, salinity, dissolved oxygen, pH, irradiance and photosynthetic pigments were measured every two hours during the incubation times. The concentration of pigments was determined through spectrophotometry. The maximum primary production was at 12:00 h, with 3.80 mg O2∙l-1∙h-1 for fall and 4.92 mg O2∙l-1∙h-1 for winter. According to the P : R (Production : Respiration) ratio of 1.90 for fall and 2.07 for winter, the mutualistic symbiosis in P. panamensis showed a predominantly autotrophic behavior. The relative quotients of chlorophyll concentrations (mg∙polyp-1), Chl a : Chl c2, were 1.0 : 0.69 for fall and 1.0 : 1.22 for winter; while ratio of concentrations chlorophyll a : carotenes , Chl a : carotenes (both in mg∙polyp-1), were 1.0 : 2.13 for fall and 1.0 : 1.88 for winter. The high relative concentrations of Chl c2 and carotenes with respect to Chl a is explained as an adaptive response to high irradiance. Balance metabólico en la simbiosis mutualista pólipo-alga en el coral hermatípico Porites panamensis en La Paz, Baja California Sur, México Estudios del balance metabólico en corales hermatípicos han sido incapaces de separar el análisis de la respiración animal y vegetal. El objetivo en este trabajo fue determinar el balance metabólico en la simbiosis mutualista alga-pólipo a través de incubaciones en cámaras respirométricas en doce fragmentos de coral. Los experimentos se realizaron en otoño del 2009 e invierno del 2010. La especie estudiada fue Porites panamensis (Scleractinia: Poritidae), Verrill, 1866, recolectada en La Paz, Baja California Sur, México. La temperatura del agua, salinidad, oxígeno disuelto, pH, irradiación y pigmentos fotosintéticos fueron registrados cada dos horas durante los tiempos de incubación. Los pigmentos fotosintéticos se determinaron mediante espectrofotometría. La producción primaria máxima fue a las 12:00 h, con 3.80 mg O2∙l-1∙h-1 para otoño y 4.92 O2∙l-1∙h-1 para invierno. De acuerdo con el cociente P : R (Producción : Respiración) con valor de 1.90 para el otoño, y 2.07 para el invierno, la simbiosis mutualista en P. panamensis muestra un comportamiento predominantemente autótrofo. Los cocientes relativos de concentración de clorofilas (mg ∙polyp-1), Cl a : Cl c2, fueron 1.0 : 0.69 para otoño y 1.0 : 1.22 para invierno, mientras que la relación de clorofila a : carotenos, Cl a : carotenos (ambos en mg∙polyp-1), fueron de 1.0 : 2.13 para otoño y 1.0 : 1.88 para invierno. Las altas concentraciones relativas de Cl c2 y carotenos con respecto a Cl a se explican como una respuesta adaptativa a una mayor irradiancia.

scholarly journals Effect of Chlorella vulgaris on Growth and Photosynthetic Pigment Content in Swiss Chard (Beta vulgaris L. subsp. cicla)

2020 ◽  
Vol 69 (2) ◽  
pp. 235-238
Author(s):  
TIMEA HAJNAL-JAFARI ◽  
VLADIMIRA SEMAN ◽  
DRAGANA STAMENOV ◽  
SIMONIDA ĐURIĆ
Keyword(s):  
Chlorella Vulgaris ◽  
Photosynthetic Pigment ◽  
Pigment Content ◽  
Alternative Measure ◽  
Initial Growth ◽  
Chlorophyll B ◽  
Fresh Leaf ◽  
Chl A ◽  
Swiss Chard ◽  
Photosynthetic Pigment Content

Microalgae application in agriculture is an alternative measure that could be highly beneficial to plants. The application of microalgae Chlorella vulgaris S45 and its effect on plant growth and pigment content in Swiss chard were investigated. In the treatments, 5% and 10% algal suspensions were applied by spraying on plants and in soil, respectively. C. vulgaris S45 affected the initial growth of Swiss chard and the content of photosynthetic pigments positively. The correlation analysis proved the existence of statistically significant interdependency between chlorophyll a (Chl a) content and leaf number (r = 0.876 at p < 0.05), and chlorophyll b (Chl b) content and fresh leaf weight (r = 0.783 at p < 0.05).

scholarly journals Growth and Physiological Response of Fraser Fir [Abies fraseri (Pursh) Poir.] Seedlings to Water Stress: Seasonal and Diurnal Variations in Photosynthetic Pigments and Carbohydrate Concentration

HortScience ◽  
2012 ◽  
Vol 47 (10) ◽  
pp. 1512-1519 ◽  
Author(s):  
Şemsettin Kulaç ◽  
Pascal Nzokou ◽  
Deniz Guney ◽  
Bert Michael Cregg ◽  
Ibrahim Turna
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Photosynthetic Pigments ◽  
Physiological Response ◽  
Photosynthetic Pigment ◽  
Abies Fraseri ◽  
Chl A ◽  
Fraser Fir ◽  
Seasonal And Diurnal Variations ◽  
Pigment Concentrations

Four-year-old seedlings of Abies fraseri [(Pursh) Poir] (fraser fir) were grown in semicontrolled conditions in hoop houses with five watering regimes (0.00, 0.62, 1.25, 2.50, and 3.70 cm/week) with the goal of determining the seasonal variation in the physiological response to drought stress. Drought stress was monitored by measuring predawn (Ψpd) and midday (Ψmd) potentials in a subset of plants from each treatment. Physiological variables monitored were chlorophyll fluorescence (Fv/Fm), Chl a, Chl b, total carotenes, and total carbohydrate concentrations. Morphological characteristics including height growth, root collar diameter, and terminal shoot growth were also measured. Predawn stem water potential values were generally higher (–0.8 to –1.9 Mpa) than midday values (–1.3 to –2.9 Mpa). Irrigation consistently increased Ψpd and Ψmd compared with non-irrigated treatments. Photosynthetic pigments (Chl a, Chl b, and carotenes) decreased midseason (14 July) and increased toward the end of the season (25 Aug.) in predawn and midday measurements. There was a significant effect (P < 0.05) of drought stress on photosynthetic pigment concentrations in predawn and midday samples in the late-season measurements (25 Aug.). These results were accompanied with a similar significant difference in Fv/Fm between non-irrigated and irrigated trees. We concluded that significant effects observed on photosynthetic pigment concentrations in some of the treatments did not affect carbohydrate concentrations. Exposure of A. fraseri to water stress did not cause a reduction in supply of metabolic carbohydrates; consequently, the decline and mortality in water-stressed plants can only be the result of hydraulic failure caused by xylem cavitation leading to cessation of water flow in tissues, desiccation, and cellular death. Further studies are needed to confirm these preliminary conclusions.

scholarly journals Effects of Soil Exogenous Nitrogen on Bamboo Shoots, Photosynthetic Characteristics, and Nitrogen Metabolism in Dendrocalamus Latiflorus Munro

2021 ◽  
Author(s):  
Fan Lili ◽  
Lili Fan ◽  
Muhammad Waqqas Khan Tarin ◽  
Yongzhen Han ◽  
Wenfeng Hu ◽  
...  
Keyword(s):  
Management Practices ◽  
Nutrient Management ◽  
Photosynthetic Pigment ◽  
Enzymatic Reaction ◽  
Physiological Mechanism ◽  
N Fertilizer ◽  
Chl A ◽  
Dendrocalamus Latiflorus ◽  
Essential Nutrient ◽  
N Metabolism

Abstract BackgroundNitrogen (N) is an essential nutrient element that is involved in almost every aspect of a plant's physiological mechanism. Therefore, the current research aims to determine the optimal amount of N fertilizer to bamboo seedlings for better nutrient management practices to minimize N pollution in bamboo forests. We evaluated the physiological response of Dendrocalamus latiflorus Munro grown under five varying levels of N fertilizer; such as N0, N1, N2, N3, N4, and N5 (0, 1.5, 3.0, 4.5, 6.0, and 7.5 g·pot-1, respectively). ResultsN4 treatment had a significant effect on the number of shoots, which was greatly correlated with net photosynthetic rate (Pn) and photosynthetic pigment (Car, Chls, and Chl a/b) as well as N-related indices [leaf N, leaf ammonium N (NH4+-N), and nitrate reductase (NR)]. N supply significantly increased soil carbon and N contents, which could be conducive to the accumulation of leaf chlorophyll content, improving leaf photosynthesis mechanism, and accelerating N metabolism and conversion through an enzymatic reaction. ConclusionsOverall, the N application of 6 g·pot-1 was advantageous to improve physiological characteristics and shoot production of seedlings. As a consequence, we suggest that optimal nitrogen supply can be effective to improve soil fertility to attain high bamboo production.

Effects of Nitrogen on the Photosynthetic Apparatus of Clematis vitalba Grown at Several Irradiances

1997 ◽  
Vol 24 (2) ◽  
pp. 205 ◽  
Author(s):  
Ralph A. Bungard ◽  
David McNeil ◽  
James D. Morton
Keyword(s):  
Soluble Protein ◽  
Photosynthetic Pigment ◽  
Photosynthetic Apparatus ◽  
High Irradiance ◽  
Nitrogen Supply ◽  
Total Carotenoid ◽  
Rubisco Activity ◽  
Soluble Protein Content ◽  
N Supply ◽  
Clematis Vitalba

Effects of nitrogen supply (N-supply) on the photosynthetic apparatus of Clematis vitalba L. grown at several irradiances were determined by measuring soluble protein content, rubisco activity, photosynthetic pigment content and composition, and the photochemical efficiency of photosystem II (Fv/Fm). Compared to low irradiance (3 and 10% full sunlight), leaves grown at higher irradiance (up to full sunlight) had up to 5–6 times the soluble protein content and rubisco activity, and up to 2–4 times the total carotenoid content, on both a leaf area and a chlorophyll basis. On a leaf area basis, decreased N-supply reduced soluble protein concentration, rubisco activity and total carotenoid concentration to a greater extent at high compared to low irradiance. On a chlorophyll basis, in contrast, soluble protein and rubisco activity decreased by over 40% with increased N-supply (1.0–0.1 mol m-3) at high irradiance but N-supply did not influence the concentration of total carotenoids. Leaves grown at high compared to low irradiance had a greater concentration of xanthophyll cycle pigments (V+A+Z), β-carotene and lutein (but not neoxanthin) on a chlorophyll basis, and a slightly lower Fv/Fm. Nitrogen- supply did not influence the composition of the photosynthetic pigment pool, Fv/Fm, or the extent of de-epoxidation of the V+A+Z pool. The results suggest that irradiance-acclimation of C. vitalba can occur regardless of N-supply. Under N limitation at high irradiance, a balance between light capture and photosynthetic capacity is important rather than an increase in xanthophyll cycle-dependent energy dissipation. The importance of lutein as a light-harvesting pigment is questioned. A rapid method for the reversed phase-HPLC separation of carotenoids is described.

scholarly journals Differential Salt Tolerance Strategies in Three Halophytes from the Same Ecological Habitat: Augmentation of Antioxidant Enzymes and Compounds

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1100
Author(s):  
Abd El-Mageed F. M. Ghanem ◽  
Elsayed Mohamed ◽  
Ahmed M. M. A. Kasem ◽  
Abbas A. El-Ghamery
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Tolerance ◽  
High Salinity ◽  
Antioxidant Compounds ◽  
Salicornia Europaea ◽  
Tolerance Mechanism ◽  
Chl A ◽  
Chlorophyll Contents ◽  
Arthrocnemum Macrostachyum ◽  
Species Specific

Understanding the salt tolerance mechanism in obligate halophytes provides valuable information for conservation and re-habitation of saline areas. Here, we investigated the responses of three obligate halophytes namely Arthrocnemum macrostachyum, Sarcocornia fruticosa and Salicornia europaea to salt stress (0, 100, 200, 400 and 600 mM NaCl) during their vegetative growth with regard to biomass, ions contents (Na+, K+ and Ca+2), chlorophyll contents, carotenoids, phenolic compounds, flavonoids, and superoxide dismutase, peroxidase and esterase activities. S. europaea showed the lowest biomass, root K+ content, Chl a/b ratio, and carotenoids under salinity. This reduction of biomass is concomitant with the increase in proline contents and peroxidase activity. On the other hand, the promotion of growth under low salinity and maintenance under high salinity (200 and 400 Mm NaCl) in A. Macrostachyum and S. fruticosa are accompanied by an increase in Chl a/b ratio, carotenoids, phenolics contents, and esterase activity. Proline content was decreased under high salinity (400 and 600 mM NaCl) in both species compared to S. europaea, while peroxidase showed the lowest activity in both plants under all salt levels except under 600 mM NaCl in Arthrocnemum macrostachyum compared to S. europaea. These results suggest two differential strategies; (1) the salt tolerance is due to activation of antioxidant enzymes and biosynthesis of proline in S. europaea, (2) the salt tolerance in A. macrostachyum, S. fruticosa are due to rearrangement of chlorophyll ratio and biosynthesis of antioxidant compounds (carotenoids, phenolics and flavonoids) which their cost seem to need less energy than activation of antioxidant enzymes. The differential behavior in halophytes of the same habitat confirms that the tolerance mechanism in halophytes is species-specific which provides new insight about the restoration strategy of saline areas.

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