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Tingyun Kuang - One of the best experts on this subject based on the ideXlab platform.
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photosystem ii photochemistry and Photosynthetic Pigment composition in salt adapted halophyteartimisia anethifolia grown under outdoor conditions
Journal of Plant Physiology, 2003Co-Authors: Gaoming Jiang, Baoshan Wang, Tingyun KuangAbstract:Summary The effects of high salinity (0-400 mmol/L NaCl) on photosystem II (PSII) photochemistry and Photosynthetic Pigment composition were investigated in the halophyte Artimisia anethifolia grown under outdoor conditions and exposed to full sunlight. High salinity resulted in an inhibition in plant growth and a significant accumulation of sodium and chloride in leaves. However, high salinity induced no effects on the actual PSII efficiency, the efficiency of excitation energy capture by open PSII reaction centres, photochemical quenching, and non-photochemical quenching at midday. High salinity also induced neither changes in the maximum efficiency of PSII photochemistry, the efficiency with which a trapped exciton can move an electron into the electron transport chain further than Q A and the quantum yield of electron transport beyond Q A , nor changes in absorption, trapping and electron transport fluxes per PSII reaction centre. No significant changes were observed in the levels of neoxanthin, lutein, β-carotene, violaxanthin, antheraxanthin, and zeaxanthin expressed on a total chlorophyll basis in salt-adapted plants. Our results suggest that Artimisia anethifolia showed high resistance not only to high salinity, but also to photoinhibition even if it was treated with high salinity as high as 400 mmol/L NaCl and exposed to full sunlight. The results indicate that tolerance of PSII to high salinity and photoinhibition can be viewed as an important strategy for Artimisia anethifolia , a halophyte plant, to grow in very high saline soil.
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does salt stress lead to increased susceptibility of photosystem ii to photoinhibition and changes in Photosynthetic Pigment composition in halophyte suaeda salsa grown outdoors
Plant Science, 2002Co-Authors: C Lu, Qingtao Lu, Baoshan Wang, Tingyun KuangAbstract:Abstract The effects of salt stress (0–400 mM NaCl) on PSII photochemistry, photoinhibition and Photosynthetic Pigment composition were investigated in the halophyte Suaeda salsa grown under outdoor conditions and exposed to full sunlight. Salt stress resulted in a growth stimulation which was optimal at 200 mM NaCl. With increasing salt concentration, leaf water potential and evaporation rate decreased significantly while there were no changes in leaf relative water content. Salt stress also resulted in a significant accumulation of sodium and chloride in leaves. Salt stress induced neither effects on the maximal efficiency of PSII photochemistry measured either at predawn or at midday nor effects on the actual PSII efficiency (ΦPSII), the efficiency of excitation energy capture by open PSII reaction centres, photochemical quenching, and non-photochemical quenching (NPQ) at midday. No significant changes were observed in the contents of neoxanthin, lutein, β-carotene, violaxnthin, antheraxthin, zeaxanthin, chlorophyll a and b in salt-stressed plants. Our results suggest that S. salsa showed high resistance not only to salinity stress but also to photoinhibition even when treated with high salinity as high as 400 mM NaCl and exposed to full sunlight. The results indicate that tolerance of PSII to high salinity stress and high light stress can be viewed as an important strategy for S. salsa to grow in very high saline soil.
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characterization of Photosynthetic Pigment composition photosystem ii photochemistry and thermal energy dissipation during leaf senescence of wheat plants grown in the field
Journal of Experimental Botany, 2001Co-Authors: Jianhua Zhang, Tingyun KuangAbstract:Photosynthetic Pigment composition and photosystem II (PSII) photochemistry were characterized during the flag leaf senescence of wheat plants grown in the field. During leaf senescence, neoxanthin and beta-carotene decreased concomitantly with chlorophyll, whereas lutein and xanthophyll cycle Pigments were less affected, leading to increases in lutein/chlorophyll and xanthophyll cycle Pigments/chlorophyll ratios. The chlorophyll a/b ratio also increased. With the progression of senescence, the maximal efficiency of PSII photochemistry decreased only slightly in the early morning (low light conditions), but substantially at midday (high light conditions). Actual PSII efficiency, photochemical quenching and the efficiency of excitation capture by open PSII centres decreased significantly both early in the morning and at midday and such decreases were much greater at midday than in the early morning. At the same time, non-photochemical quenching, zeaxanthin and antheraxanthin contents at the expense of violaxanthin increased both early in the morning and at midday, with a greater increase at midday. The results in the present study suggest that a down-regulation of PSII occurred in senescent leaves and that the xanthophyll cycle plays a role in the protection of PSII from photoinhibitory damage in senescent leaves by dissipating excess excitation energy, particularly when exposed to high light.
R Panneerselvam - One of the best experts on this subject based on the ideXlab platform.
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Treatment with Different Sodium Salts Alters Growth and Photosynthetic Pigment Constituents in Withania somnifera
2009Co-Authors: Cheruth Abdul Jaleel, R Panneerselvam, Saudi ArabiaAbstract:In the present investigation, experiments were conducted to study the effects of different sodium salts viz., sodium chloride (NaCl), sodium sulphate (Na2SO4) and sodium carbonate (Na2CO3) on morphological parameters (germination percentage, root and shoot length, dry weight of root and shoot) and Photosynthetic Pigment contents (chlorophyll 'a', chlorophyll 'b', total chlorophyll and carotenoids) of Withania somnifera plants. The germinating Withania somnifera seeds were treated with 10, 20 and 50mM NaCl and Na2SO4 and 5, 10 and 15mM Na2CO3. The parameters were analysed on 25 DAS. All the treatments decreased the germination percentage; shoot length, root length and dry weight, chlorophyll and carotenoids contents significantly. This effect was very high in the Na2CO3 treated seedlings this was followed by Na2SO4 and NaCl treated seedlings. From the results of this investigation, it is clear that, the Withania somnifera were affected significantly in the Na2CO3 treatments and followed by Na2SO4 and NaCl treatments.
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alterations in morphological parameters and Photosynthetic Pigment responses of catharanthus roseus under soil water deficits
Colloids and Surfaces B: Biointerfaces, 2008Co-Authors: Abdul C Jaleel, P Manivannan, Ganapathy Murugan Alagu Lakshmanan, M Gomathinayagam, R PanneerselvamAbstract:An experiment was conducted in two varieties, rosea and alba, of Catharanthus roseus plants with two watering treatments viz., 100 and 60% of field capacity, to understand the effects of water deficit on early growth, biomass allocation and Photosynthetic Pigment responses. We found that there were significant differences in early growth, dry matter accumulation and Pigment variations between the two varieties. The root length, shoot length, total leaf area, fresh and dry weights were significantly reduced under water stress treatments. There was a significant reduction in the Photosynthetic Pigment contents in both the varieties. The rosea variety was more affected due to water deficit when compared to alba variety.
Jian Ren - One of the best experts on this subject based on the ideXlab platform.
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uv spectra dependence of seedling injury and Photosynthetic Pigment change in cucumis sativus and glycine max
Environmental and Experimental Botany, 2006Co-Authors: Yinan Yao, Yongqing Yang, Jian RenAbstract:The effects of different UV-spectra on the growth inhibition, cell oxidation and Photosynthetic Pigment change of cucumber and soybean seedlings were investigated under controlled environmental conditions. Spectra-dependent differences in growth and oxidation indices existed within UV-A bands as well as UV-B bands. The plant growth biologically spectra weighting function (BSWF) matched well with average plant response in UV-B region, but not in UV-A region. Shorter UV-A wavelength imposed more negative impact than longer UV-A wavelength did in both species. The previous literatures and our results add weight to suggestion that dicotyledonous species would be more sensitive to shorter UV-A wavelength than monocotyledonous species. While we await continued and further studies on plant responses to different UV-spectra treatments under different experimental conditions with diverse taxa. The effect on Photosynthetic Pigment was related to different UV bands and different species. Under disproportionate UV/PAR light conditions, Photosynthetic Pigment content was decreased by UV-A spectra as well as by UV-B spectra, but the ratio of total carotenoids to total chlorophyll was increased in cucumber seedlings. The possible implications of these observations were also discussed. (c) 2005 Elsevier B.V. All rights reserved.
Jianhua Zhang - One of the best experts on this subject based on the ideXlab platform.
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characterization of Photosynthetic Pigment composition photosystem ii photochemistry and thermal energy dissipation during leaf senescence of wheat plants grown in the field
Journal of Experimental Botany, 2001Co-Authors: Jianhua Zhang, Tingyun KuangAbstract:Photosynthetic Pigment composition and photosystem II (PSII) photochemistry were characterized during the flag leaf senescence of wheat plants grown in the field. During leaf senescence, neoxanthin and beta-carotene decreased concomitantly with chlorophyll, whereas lutein and xanthophyll cycle Pigments were less affected, leading to increases in lutein/chlorophyll and xanthophyll cycle Pigments/chlorophyll ratios. The chlorophyll a/b ratio also increased. With the progression of senescence, the maximal efficiency of PSII photochemistry decreased only slightly in the early morning (low light conditions), but substantially at midday (high light conditions). Actual PSII efficiency, photochemical quenching and the efficiency of excitation capture by open PSII centres decreased significantly both early in the morning and at midday and such decreases were much greater at midday than in the early morning. At the same time, non-photochemical quenching, zeaxanthin and antheraxanthin contents at the expense of violaxanthin increased both early in the morning and at midday, with a greater increase at midday. The results in the present study suggest that a down-regulation of PSII occurred in senescent leaves and that the xanthophyll cycle plays a role in the protection of PSII from photoinhibitory damage in senescent leaves by dissipating excess excitation energy, particularly when exposed to high light.
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Characterization of Photosynthetic Pigment composition, photosystem II photochemistry and thermal energy dissipation during leaf senescence of wheat plants grown in the field
Science Access, 2001Co-Authors: Q-t Lu, Jianhua Zhang, T-y KuangAbstract:Photosynthesis, Photosynthetic Pigment composition and photosystem II (PSII) photochemistry during leaf senescence of wheat plants grown in the field were characterized. During leaf senescence, neoxanthin and b -carotene decreased concomitantly with chlorophyll, whereas lutein and xanthophyll cycle Pigments were less affected, leading to increases in lutein/chlorophyll and xanthophyll cycle Pigments/chlorophyll ratios. The chlorophyll a/b ratio also increased. With the progressing of senescence, maximal efficiency of PSII photochemstry decreased only slightly in the early morning but substantially at midday. Actual PSII efficiency, photochemical quenching, efficiency of excitation capture by open PSII centers, and the I-P phase of fluorescence induction curves decreased significantly both in the early morning and at midday and such decreases were much greater at midday than early in the morning, while the O-I phase of fluorescence induction curves remained unchanged. At the same time, non-photochemical quenching, thermal dissipation and de-epoxidation status of the xanthophyll cycle increased both early in the morning and at midday, with a greater increase at midday. Such increases indicated that the xanthophyll cycle played a role in photoprotection of PSII in senescent leaves by dissipating excess excitation energy and that D pH could be the main factor controlling thermal dissipation. Taking into consideration the substantial loss of Photosynthetic capacity during senescence, our data seem to support the view that the decrease in actual PSII efficiency in senescent leaves may represent a mechanism to down-regulate Photosynthetic electron transport to match the decreased CO2 assimilation capacity and avoid photodamage of PSII from excess excitation energy.
Antonio Fernando Morais De Oliveira - One of the best experts on this subject based on the ideXlab platform.
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Assessing the effects of water quality on leaf morphoanatomy, ultrastructure and Photosynthetic Pigment content of Salvinia auriculata Aubl. (Salviniaceae).
Ecotoxicology and environmental safety, 2019Co-Authors: Nathália Bandeira Carvalho Dos Santos, Emília Arruda, Gladys Flávia De Albuquerque Melo De Pinna, Adauto Gomes Barbosa Neto, Antonio Fernando Morais De OliveiraAbstract:Abstract The objective of this study is to evaluate the effects of physical-chemical and biological variables of the water of the Capibaribe River (state of Pernambuco, Brazil) on leaf anatomy, including ultrastructure and Photosynthetic Pigment of Salvinia auriculata. Specimens of S. auriculata collected in the Gurjau River, an area with a low pollution degree, were acclimatized in Hoagland's solution and then subjected to three water samples of the Capibaribe River with different levels of pollution. Twenty-one physical-chemical and biological variables were analyzed according to the Standard Methods for the Examination of Water and Wastewater. The results showed that the samples of the Capibaribe River presented nine parameters that did not comply with the current Brazilian legislation. After 15 days of bioassay, S. auriculata presented variations in mesophyll and cuticle thickness, changes in trichome morphology and accumulation of phenolic compounds. No significant differences were observed for Photosynthetic Pigment content and leaf length of S. auriculata. Multivariate analyses (PCA and Cluster) showed that the point in the Capibaribe River with the highest number of variables that do not comply with the current legislation was responsible for major structural and chemical changes observed in S. auriculata.