Characteristics of Mango Leaf Photosynthetic Inhibition by Enhanced UV-B Radiation

To investigate the photosynthetic change characteristics of mango leaves under enhanced UV-B radiation, adult ‘Tainong No. 1’ mango (Mangifera indica) trees were treated (N=nine individuals) with simulated enhanced UV-B radiation [24 and 96 kJ/(m2·d)] in the field, and the photochemical reactions, activities of key enzymes in carbon assimilation, and the expression of genes were observed. The results showed that compared with the control, there was a decrease in tree yield and nutritional flavor quality of the fruits under the 96 kJ/(m2·d) treatment, while no significant changes were observed under 24 kJ/(m2·d). After 20 or 40 days, leaves’ net photosynthetic rate (Pn), stomatal conductance (Sc), transpiration rate (Tr), intercellular CO2 concentration (Ci), and chlorophyll a/b under exposure to 96 kJ/(m2·d) of UV-B were significantly lower than in the control, whereas chlorophyll a, chlorophyll b, carotenoids, Hill reaction activity, photochemical quenching coefficient (qP), and Rubisco activities were significantly higher. By contrast, the Hill activity and Rubisco activity under 24 kJ/(m2·d) were significantly higher than the control, while Pn, Sc, Tr, Ci, and the content of photosynthetic pigments were similar to the control. The expression of gene coding the Rubisco big subunit (rbcL) was inhibited by the 96 kJ/(m2·d) treatment. We conclude that stomatal limitation was directly induced by 96 kJ/(m2·d), resulting in the inhibition of photosynthesis and the reduction in yield and deterioration of the quality of mango.

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Antioxidant Protection of Photosynthesis in Two Cashew Progenies Under Salt Stress

Journal of Agricultural Science ◽

10.5539/jas.v10n10p388 ◽

2018 ◽

Vol 10 (10) ◽

pp. 388

Author(s):

Anselmo F. da Silva ◽

Valéria F. de O. Sousa ◽

Gisele L. dos Santos ◽

Eugênio S. Araújo Júnior ◽

Sérgio L. F. da Silva ◽

...

Keyword(s):

Salt Stress ◽

Quantum Efficiency ◽

Salinity Stress ◽

Intercellular Co2 Concentration ◽

Co2 Concentration ◽

Co2 Assimilation ◽

Photochemical Activity ◽

Photochemical Quenching ◽

Tree Seedlings ◽

Cashew Tree

The present work evaluated the indicators of photosynthetic efficiency and antioxidative protection in cashew tree seedlings subjected to salinity stress. The study was conducted with seedlings of two advanced dwarf cashew clones (CCP09 and CCP76) subjected to salt stress with increasing doses of NaCl (0, control; 25; 50; 75; 100 mM) in the nutrient solution for 30 days under greenhouse conditions. The variables of gas exchange, CO2 assimilation (PN), stomatal conductance (gS), transpiration (E), intercellular CO2 concentration (CI), photochemical activity, potential quantum efficiency (Fv/Fm), effective quantum efficiency (ΔF/Fm’) of photosystem II (PSII), photochemical quenching (qP), non-photochemical quenching (NPQ) electron transport rate (ETR) as well as the indicators of damage and oxidative protection were measured. Under these conditions, there was an intense accumulation Na+ associated with a reduction in the K+/Na+ ratio in the leaves of both clones in response to salt, with higher values for this ratio in clone CCP09 than in CCP76 the highest concentration of NaCl (100 mM). Salinity reduced PN, gS and E in the two clones evaluated, with lower reductions in CCP09 than in CCP76 at the highest salt dose. Instantaneous carboxylation (PN/CI) and water use (PN/E) efficiencies were strongly restricted by salinity but were less affected in CCP09 than in CCP76. Salinity stress also increased hydrogen peroxide (H2O2) levels in CCP09, whereas lipid peroxidation decreased in both progenies. The clones presented specific antioxidant responses due to greater enzymatic and non-enzymatic activity in CCP76, in addition to the activity of phenol peroxidase (POX) in CCP09.

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Photosynthetic responses of young cashew plants to varying environmental conditions

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2005000800002 ◽

2005 ◽

Vol 40 (8) ◽

pp. 735-744 ◽

Cited By ~ 12

Author(s):

Rogéria Pereira de Souza ◽

Rafael Vasconcelos Ribeiro ◽

Eduardo Caruso Machado ◽

Ricardo Ferraz de Oliveira ◽

Joaquim Albenísio Gomes da Silveira

Keyword(s):

Gas Exchange ◽

Intercellular Co2 Concentration ◽

Co2 Concentration ◽

Co2 Assimilation ◽

Photon Flux ◽

Photochemical Quenching ◽

Photon Flux Density ◽

Effective Quantum Yield ◽

Water Losses ◽

Controlled Conditions

The aim of this study was to characterize gas exchange responses of young cashew plants to varying photosynthetic photon flux density (PPFD), temperature, vapor-pressure deficit (VPD), and intercellular CO2 concentration (Ci), under controlled conditions. Daily courses of gas exchange and chlorophyll a fluorescence parameters were measured under natural conditions. Maximum CO2 assimilation rates, under optimal controlled conditions, were about 13 mmol m-2 s-1 , with light saturation around 1,000 mmol m-2 s-1. Leaf temperatures between 25ºC and 35ºC were optimal for photosynthesis. Stomata showed sensitivity to CO2, and a closing response with increasing Ci. Increasing VPD had a small effect on CO2 assimilation rates, with a small decrease above 2.5 kPa. Stomata, however, were strongly affected by VPD, exhibiting gradual closure above 1.5 kPa. The reduced stomatal conductances at high VPD were efficient in restricting water losses by transpiration, demonstrating the species adaptability to dry environments. Under natural irradiance, CO2 assimilation rates were saturated in early morning, following thereafter the PPFD changes. Transient Fv/Fm decreases were registered around 11h, indicating the occurrence of photoinhibition. Decreases of excitation capture efficiency, decreases of effective quantum yield of photosystem II, and increases in non-photochemical quenching were consistent with the occurrence of photoprotection under excessive irradiance levels.

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Peranan rizobakteri dan fungi mikoriza arbuskular dalam proses fotosintesis dan produksi gula sorgum manis (Sorghum bicolor L. Moench) Role of rhizobacteria and arbuscular mycorrhizal fungi in increasing photosynthesis process and sugar production of sweet sorghum (Sorghum bicolor L. Moench)

E-Journal Menara Perkebunan ◽

10.22302/ppbbi.jur.mp.v83i1.13 ◽

2016 ◽

Vol 83 (1) ◽

Author(s):

Bedah RUPAEDAH ◽

Iswandi ANAS ◽

Dwi Andreas SANTOSA ◽

Wahono SUMARYONO ◽

Sri Wilarso BUDI

Keyword(s):

Sorghum Bicolor ◽

Chlorophyll Content ◽

Mycorrhizal Fungi ◽

Sweet Sorghum ◽

Sugar Content ◽

Intercellular Co2 Concentration ◽

Carbon Assimilation ◽

Co2 Concentration ◽

Mycorrhizal Colonization ◽

Sorghum Bicolor L

AbstractDual inoculation effects of rhizobacteria andAMF as well as the addition of chemical fertilizerson photosynthesis were studied by analyzingprocess of CO2 gas exchange, chlorophyll content,nutrient uptake, sugar content and growth of sweetsorghum. AMF inoculation as a single cultureincreased carbon assimilation, stomatal conductance,intercellular CO2 concentration, phosphoruscontent, chlorophyll content, sugar content, plantheight, shoot weight and mycorrhizal colonization.Interaction of AMF and rhizobacteria increasedsugar content of sweet sorghum stems andpotassium content of sweet sorghum leaves,whereas its interaction with chemical fertilizerssignificantly increased chlorophyll content, sugarcontent and mycorrhizal colonization of sorghumplant roots. Interaction of AMF, rhizobacteria andchemical fertilizers increased sugar content, rootweight and mycorrhizal colonization. The use ofAMF solely or its interaction with rhizobacteriaand chemical fertilizers had a great potential inimproving photosynthesis process of sweetsorghum. The process is associated with increasingcrop productivity, such as sugar content ofsorghum which is potential as a source ofrenewable energy.AbstrakPengaruh inokulasi ganda rizobakteri danFMA dengan penambahan pupuk kimia dipelajaridengan cara menganalisis proses pertukaran gas CO2, kandungan klorofil, kandungan hara dan gula,pertumbuhan dan produktivitas sorgum manis.Inokulasi FMA sebagai kultur tunggal dapatmeningkatkan asimilasi karbon, konduktansistomata, konsentrasi CO2 interselular, kandunganfosfor, kandungan klorofil, kandungan gula, tinggitanaman, berat batang dan derajat kolonisasimikoriza. Interaksi antara rizobakteri dan FMAdapat meningkatkan kandungan gula batang dankalium daun sorgum manis, sedangkan interaksinyadengan pupuk kimia dapat meningkatkan kandunganklorofil dan gula serta derajat kolonisasimikoriza pada perakaran sorgum manis. Sementaraitu, interaksi FMA, rizobakteri dan pupuk kimiadapat meningkatkan kandungan gula batang, beratakar dan derajat kolonisasi mikoriza pada perakaransorgum manis. Penggunaan FMA baik sendirimaupun interaksinya dengan rizobakteri dan pupukkimia memiliki potensi besar dalam meningkatkanproses fotosintesis sorgum manis. Proses tersebutberkaitan dengan peningkatan produktivitas sorgummanis dalam hal ini kandungan gula sorgum manisyang berpotensi sebagai sumber energi terbarukan.

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Growth and physiological responses of sunflower plants exposed to ultraviolet-B radiation

Ciência Rural ◽

10.1590/s0103-84782007000100014 ◽

2007 ◽

Vol 37 (1) ◽

pp. 85-90 ◽

Cited By ~ 12

Author(s):

Inês Cechin ◽

Terezinha de Fátima Fumis ◽

Anne Ligia Dokkedal

Keyword(s):

Chlorophyll A ◽

Intercellular Co2 Concentration ◽

Co2 Concentration ◽

Fluorescence Yield ◽

Significant Inhibition ◽

Ultraviolet B ◽

Natural Photoperiod ◽

Solar Noon ◽

Solar Uv ◽

Intercellular Co2

The effects of UV-B radiation were studied in sunflower plants (Helianthus annuus L. cv. Catissol-01) growning in greenhouse under natural photoperiod conditions. The plants received approximately 0.60Wm-2 (control) or 4.0Wm-2 (+UV-B) of UV-B radiation for 7h d-1, centered around solar noon from 15 days after sowing. Compared to the control, plants exposed to high UV-B radiation for 12 or 21 days did not show any difference in shoot dry matter, specific leaf weight or UV-B absorbing compounds. Enhanced UV-B radiation caused a significant inhibition of photosynthesis (A) only in the first sampling and this was accompained by reduction in stomatal conductance (g s) and transpiration rate. The inhibition in A can not be fully explained by reduction in g s since intercellular CO2 concentration was not affected by UV-B radiation. In both samplings, the total chlorophyll content was not affected by enhanced UV-B radiation whereas in the first sampling, the chlorophyll a and the ratio of chlorophyll a/b were reduced. Enhanced UV-B radiation increased the minimal fluorescence yield, but did not alter the ratio of variable to maximal fluorescence yield of dark adapted leaves. Overall, this study suggests that the present level of solar UV-B radiation affects sunflower plants performance even though the shoot dry biomass may not be affected.

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Increase rate of light-induced stomatal conductance is related to stomatal size in the genus Oryza

Journal of Experimental Botany ◽

10.1093/jxb/erz267 ◽

2019 ◽

Vol 70 (19) ◽

pp. 5259-5269 ◽

Cited By ~ 3

Author(s):

Qiangqiang Zhang ◽

Shaobing Peng ◽

Yong Li

Keyword(s):

Stomatal Conductance ◽

Time Lag ◽

Intercellular Co2 Concentration ◽

Carbon Assimilation ◽

Co2 Concentration ◽

Initial Time ◽

Stomatal Size ◽

Exponential Increase ◽

Dynamic Photosynthesis ◽

Increase Rate

Abstract The rapid response of stomatal conductance (gs) to fluctuating irradiance is of great importance to maximize carbon assimilation while minimizing water loss. Smaller stomata have been proven to have a faster response rate than larger ones, but most of these studies have been conducted with forest trees. In the present study, the effects of stomatal anatomy on the kinetics of gs and photosynthesis were investigated in 16 Oryza genotypes. Light-induced stomatal opening includes an initial time lag (λ) followed by an exponential increase. Smaller stomata had a larger maximum stomatal conductance increase rate (Slmax) during the exponential increase phase, but showed a longer time lag and a lower initial stomatal conductance (gs,initial) at low light. Stomatal size was, surprisingly, negatively correlated with the time required to reach 50% of maximum gs and photosynthesis (T50%gs and T50%A), which was shown to be positively correlated with λ and negatively correlated with gs,initial. With a lower gs,initial and a larger λ, small stomata showed a faster decrease of intercellular CO2 concentration (Ci) during the induction process, which may have led to a slower apparent Rubisco activation rate. Therefore, smaller stomata do not always benefit photosynthesis as reported before; the influence of stomatal size on dynamic photosynthesis is also correlated with λ and gs,initial.

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MORPHOLOGICAL AND PHYSIOLOGICAL RESPONSES OF CROTON BONPLANDIANUM BAILL. TO AIR POLLUTION

Ecoprint An International Journal of Ecology ◽

10.3126/eco.v17i0.4103 ◽

1970 ◽

Vol 17 ◽

pp. 35-41 ◽

Cited By ~ 6

Author(s):

M. Saquib ◽

A. Ahmad ◽

K. Ansari

Keyword(s):

Air Pollution ◽

Power Plant ◽

Chlorophyll A ◽

Thermal Power Plant ◽

Plant Root ◽

Thermal Power ◽

Intercellular Co2 Concentration ◽

Plant Morphology ◽

Co2 Concentration ◽

Key Words Air Pollution

The air pollution stress around the thermal power plant lead to the significant reduction in size and biomass of root and shoot, photosynthetic rate, stomatal conductance, intercellular CO2 concentration, photosynthetic pigments and photosynthetic area of Croton bonplandianum. The resulting stresses of air pollution and reduced foliage further affected the over all morphology and physiology of the plant. Root biomass and chlorophyll a showed maximum reduction than any other selected parameters studied in the stressed area. Chlorophyll a was found to be four and half times more sensitive to air pollutants than carotenoids. Key words: Air pollution; Thermal power plant; Morphology and physiology; C. bonplandianumDOI: 10.3126/eco.v17i0.4103Ecoprint An International Journal of Ecology Vol. 17, 2010 Page: 35-41 Uploaded date: 29 December, 2010

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Peranan rizobakteri dan fungi mikoriza arbuskular dalam proses fotosintesis dan produksi gula sorgum manis (Sorghum bicolor L. Moench) Role of rhizobacteria and arbuscular mycorrhizal fungi in increasing photosynthesis process and sugar production of sweet sorghum (Sorghum bicolor L. Moench)

E-Journal Menara Perkebunan ◽

10.22302/iribb.jur.mp.v83i1.13 ◽

2016 ◽

Vol 83 (1) ◽

Author(s):

Bedah RUPAEDAH ◽

Iswandi ANAS ◽

Dwi Andreas SANTOSA ◽

Wahono SUMARYONO ◽

Sri Wilarso BUDI

Keyword(s):

Sorghum Bicolor ◽

Chlorophyll Content ◽

Mycorrhizal Fungi ◽

Sweet Sorghum ◽

Sugar Content ◽

Intercellular Co2 Concentration ◽

Carbon Assimilation ◽

Co2 Concentration ◽

Mycorrhizal Colonization ◽

Sorghum Bicolor L

AbstractDual inoculation effects of rhizobacteria andAMF as well as the addition of chemical fertilizerson photosynthesis were studied by analyzingprocess of CO2 gas exchange, chlorophyll content,nutrient uptake, sugar content and growth of sweetsorghum. AMF inoculation as a single cultureincreased carbon assimilation, stomatal conductance,intercellular CO2 concentration, phosphoruscontent, chlorophyll content, sugar content, plantheight, shoot weight and mycorrhizal colonization.Interaction of AMF and rhizobacteria increasedsugar content of sweet sorghum stems andpotassium content of sweet sorghum leaves,whereas its interaction with chemical fertilizerssignificantly increased chlorophyll content, sugarcontent and mycorrhizal colonization of sorghumplant roots. Interaction of AMF, rhizobacteria andchemical fertilizers increased sugar content, rootweight and mycorrhizal colonization. The use ofAMF solely or its interaction with rhizobacteriaand chemical fertilizers had a great potential inimproving photosynthesis process of sweetsorghum. The process is associated with increasingcrop productivity, such as sugar content ofsorghum which is potential as a source ofrenewable energy.AbstrakPengaruh inokulasi ganda rizobakteri danFMA dengan penambahan pupuk kimia dipelajaridengan cara menganalisis proses pertukaran gas CO2, kandungan klorofil, kandungan hara dan gula,pertumbuhan dan produktivitas sorgum manis.Inokulasi FMA sebagai kultur tunggal dapatmeningkatkan asimilasi karbon, konduktansistomata, konsentrasi CO2 interselular, kandunganfosfor, kandungan klorofil, kandungan gula, tinggitanaman, berat batang dan derajat kolonisasimikoriza. Interaksi antara rizobakteri dan FMAdapat meningkatkan kandungan gula batang dankalium daun sorgum manis, sedangkan interaksinyadengan pupuk kimia dapat meningkatkan kandunganklorofil dan gula serta derajat kolonisasimikoriza pada perakaran sorgum manis. Sementaraitu, interaksi FMA, rizobakteri dan pupuk kimiadapat meningkatkan kandungan gula batang, beratakar dan derajat kolonisasi mikoriza pada perakaransorgum manis. Penggunaan FMA baik sendirimaupun interaksinya dengan rizobakteri dan pupukkimia memiliki potensi besar dalam meningkatkanproses fotosintesis sorgum manis. Proses tersebutberkaitan dengan peningkatan produktivitas sorgummanis dalam hal ini kandungan gula sorgum manisyang berpotensi sebagai sumber energi terbarukan.

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Effect of Enhanced UV-B Radiation on Fruit Maturity and Quality, and Leaf Photosynthesis in ' Guifei ' Mango

10.20944/preprints202111.0211.v1 ◽

2021 ◽

Author(s):

Xiaokai Lin ◽

Haizhi Liao ◽

Jingjia Du ◽

Junjie Peng ◽

Kaibing Zhou

Keyword(s):

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Fruit Quality ◽

Radiation Treatment ◽

Mangifera Indica ◽

Photosynthetic Pigment ◽

Photochemical Quenching ◽

Hill Reaction ◽

Early Maturity ◽

Fruit Maturity

(1) Background: Investigating the characteristics of photosynthetic physiological changes of leaves in Mangifera indica L. cv. 'GuIfei' under enhanced UV-B radiation, natural light exposed trees were regarded as control, and 96 kJ·m-2·d-1enhanced UV-B radiation was artificially simulated in the field; (2) Methods: The changes of fruit maturity and fruit quality, leaf net photosynthetic rate (Pn), photosynthetic pigments contents, photochemical reaction, activities of photosynthetic enzymes and their genes expressions were determined; (3) Results: Compared with CK, the percentage of mature fruits of the treatment was significantly increased, and fruit quality was better. The net photosynthetic rate (Pn), the contents of photosynthetic pigment, Hill reaction activity and photochemical quenching coefficient (qP) of the treatment leaves showed a significantly higher trend than CK. The activities of Rubisco and RCA, and the expression of Rubisco genes rbcL and rbcS were significantly increased; (4) Conclusions: 96 kJ·m-2·d-1 enhanced UV-B radiation treatment improved Rubisco activity through increasing the expression of Rubisco genes rbcL and rbcS, thereby enhancing the CO2-fixing capacity and dark reaction capacity of leaves. Based on this, it raised the net photosynthetic rate of leaves, which promoted the early maturity of 'Guifei' mango by the fast accumulating photosynthetic products.

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Effects of Low Temperature and Light Stress on Gas Exchange and Chlorophyll Fluorescence of Pumpkin Seedlings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.450-451.537 ◽

2012 ◽

Vol 450-451 ◽

pp. 537-542

Author(s):

En Xiang Kang ◽

Jun Jie Luo ◽

Hui Zhen Qiu ◽

Nian Lai Chen ◽

Dan Su ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Low Temperature ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Evaporation Rate ◽

Light Stress ◽

Intercellular Co2 Concentration ◽

Co2 Concentration ◽

Photochemical Quenching ◽

Intercellular Co2

Pumpkin（Cucubita pepo L.）seedlings were exposed under different low temperature-light regimes to investigate the responses of photosynthesis and chlorophyll fluorescence to the stress. The results indicated that the contents of chlorophyll increased at first day after treatment and then decreased under special temperature(15/5、20/10、25/15°C )and poor light(50、150、250μmol•m-2•s-1).The net photosynthetic rate, evaporation rate, stomata conductance and intercellular CO2 concentration increased one day after treatment and then decreased, stomata limitation increased above15/5°C special temperature and special poor light. However, under 15/5°C temperature and special poor light, the net photosynthetic rate, evaporation rate and stomata conductance decreased, and intercellular CO2 concentration increased stomata limitation increased in 4 days after treatment then decreased. Ft、Yield(F/Fm’)、qP decreased under special temperature and poor light.The change of these parameters were less under the light density of 50μmol•m-2•s-2 than other light densities, which means that poorer light reduced the sensitivity of pumpkin to low temperature and increased the photochemical activity of PS, but the photochemical quenching (qP) decreased and the non-photochemical quenching(qN) increased at the same time.

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