Chilling-induced changes to carotenoid composition, photosynthesis and the maximum quantum yield of photosystem II photochemistry in two maize genotypes differing in tolerance to low temperature

1997 ◽  
Vol 151 (5) ◽  
pp. 610-619 ◽  
Author(s):  
Pierre Haldimann
Keyword(s):  
Quantum Yield ◽  
Low Temperature ◽  
Photosystem Ii ◽  
Maximum Quantum Yield ◽  
Maize Genotypes ◽  
Photosystem Ii Photochemistry ◽  
Carotenoid Composition ◽  
Induced Changes

scholarly journals Potential Maximum Quantum Yield of Photosystem II Reflects the Growth Rate of Chattonella marina in Field Bloom Samples

2016 ◽  
Vol 61 (2) ◽  
pp. 331-335 ◽  
Author(s):  
Xuchun Qiu ◽  
Kouki Mukai ◽  
Yohei Shimasaki ◽  
Michito Tsuyama ◽  
Tadashi Matsubara ◽  
...  
Keyword(s):  
Growth Rate ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Maximum Quantum Yield ◽  
Chattonella Marina ◽  
Potential Maximum

Changes in photosynthesis, chlorophyll fluorescence, and antioxidant enzymes of mulberry (Morus ssp.) in response to salinity and high-temperature stress

Biologia ◽  
2013 ◽  
Vol 68 (3) ◽  
Author(s):  
Cui Yu ◽  
Shujun Huang ◽  
Xingming Hu ◽  
Wen Deng ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
High Temperature ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Peroxidase Activity ◽  
High Temperature Stress ◽  
The Other ◽  
Fluorescence Parameters ◽  
Photosystem Ii Photochemistry ◽  
Chl Fluorescence

AbstractPhotosynthesis, chlorophyll (Chl) fluorescence, and antioxidant enzymes were measured in the mulberry (Morus spp.) cultivars Da 10, Hongguo 2, Anza 1, and Taiwan 72C002, which were subjected to salinity and high-temperature stress (STS; 0.1%, 0.3%, and 0.5% NaCl concentrations, 34.5°C–40.5°C/27.8°C–29.2°C day/night temperatures). Control plants were watered with 1 L of full-strength Hoagland’s nutrient solution with no added NaCl. Net photosynthetic rate (P N), stomatal conductance (g s), and effective quantum yield of photosystem II photochemistry (ΦPSII) increased in Anza 1 and Taiwan 72C002 under 0.1% STS but decreased in Da 10 and Hongguo 2 compared with the control. However, all the above parameters, including Chl content, maximum quantum yield of photosystem II photochemistry (Fv/Fm), nonphotochemical quenching (NPQ), and maximum carboxylation velocity of Rubisco (V cmax, decreased in Taiwan 72C002, Honggua 2, and Da 10 under 0.3% and 0.5% STS, suggesting that photoinhibition occurred under severe STS. Under STS, there were no significant changes in P N, Fv/Fm, ΦPSII, ascorbate peroxidase (APX) activity, superoxide dismutase (SOD) activity, catalase activity, superoxide anion radical (O2−) content, malondialdehyde (MDA) content, soluble sugar content (SSC), and leaf biomass in Anza 1 even at 0.5% STS, showing that Anza 1 displays high resistance to STS. In addition, peroxidase activity was significantly higher in Anza 1 than in the other mulberry cultivars. Significant adverse effects of severe salinity on photosynthesis and Chl fluorescence parameters were observed in Da 10. Additionally, SOD, peroxidase, and APX activities were lower in Da 10, whereas O2− and MDA contents were higher in comparison with the other mulberry cultivars under 0.3% and 0.5% STS, suggesting that Da 10 had low resistance to STS. These results show that 0.1% STS had a positive effect on photosynthesis and Chl fluorescence parameters in Anza 1 and Taiwan 72C002, and higher peroxidase activity can to a certain extent explain the higher STS tolerance in Anza 1. Damages to DSM photosystems might be related to lower SOD, POD, and APX activities, which resulted in the accumulation of reactive oxygen species.

scholarly journals Surface Canopy Position Determines the Photosystem II Photochemistry in Invasive and Native Prosopis Congeners at Sharjah Desert, UAE

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 740
Author(s):  
M. Iftikhar Hussain ◽  
François Mitterand tsombou ◽  
Ali El-Keblawy
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
United Arab Emirates ◽  
Photochemical Quenching ◽  
Leaf Biomass ◽  
Photosystem Ii Photochemistry ◽  
Canopy Position ◽  
Excess Light ◽  
Arid Desert ◽  
The Impact

Plants have evolved photoprotective mechanisms in order to counteract the damaging effects of excess light in hyper-arid desert environments. We evaluated the impact of surface canopy positions on the photosynthetic adjustments and chlorophyll fluorescence attributes (photosystem II photochemistry, quantum yield, fluorescence quenching, and photon energy dissipation), leaf biomass and nutrient content of sun-exposed leaves at the south east (SE canopy position) and shaded-leaves at the north west (NW canopy position) in the invasive Prosopis juliflora and native Prosopis cineraria in the extreme environment (hyper-arid desert area, United Arab Emirates (UAE)). The main aim of this research was to study the photoprotection mechanism in invasive and native Prosopis congeners via the safe removal—as thermal energy—of excess solar energy absorbed by the light collecting system, which counteracts the formation of reactive oxygen species. Maximum photosynthetic efficiency (Fv/Fm) from dark-adapted leaves in P. juliflora and P. cineraria was higher on NW than SE canopy position while insignificant difference was observed within the two Prosopis congeners. Greater quantum yield was observed in P. juliflora than P. cineraria on the NW canopy position than SE. With the change of canopy positions from NW to SE, the reduction of the PSII reaction center activity in the leaves of both Prosopis congeners was accelerated. On the SE canopy position, a significant decline in the electron transport rate (ETR) of in the leaves of both Prosopis congeners occurred, which might be due to the blockage of electron transfer from QA to QB on the PSII acceptor side. On the SE canopy position; Prosopis leaves dissipated excess light energy by increasing non-photochemical quenching (NPQ). However, in P. cineraria, the protective ability of NPQ decreased, which led to the accumulation of excess excitation energy (1 − qP)/NPQ and the aggravation of photoinhibition. The results also explain the role of different physiological attributes contributing to invasiveness of P. juliflora and to evaluate its liaison between plasticity of these characters and invasiveness.

scholarly journals Copper-, Lead- and Mercury-Induced Changes in Maximum Quantum Yield, Chlorophyll A Content and Relative Growth of Three Malaysian Green Macroalgae

2013 ◽  
Vol 9 (1) ◽  
Author(s):  
Hazlina Ahamad Zakeri ◽  
Luqman Abu Bakar
Keyword(s):  
Quantum Yield ◽  
Algal Species ◽  
Maximum Quantum Yield ◽  
Green Macroalgae ◽  
Relative Growth ◽  
Chl A ◽  
Caulerpa Lentillifera ◽  
Induced Changes ◽  
Chlorophyll A Content ◽  
Positive Effect

In this study, we reported on the responses of three Malaysian green algae, Caulerpa racemosa, Caulerpa lentillifera and Ulva reticulata against three heavy metals, copper (Cu), lead (Pb) and mercury (Hg). Responses were determined as maximum quantum yield (Fv/Fm) for photosynthetic quantum efficiency, chlorophyll (chl) a content and relative growth measured as changes in fresh weight. The algae were exposed for 8h in two concentrations of metals, which were 1 mg/L and 2 mg/L. In general, all algae were severely affected by the presence of Hg compared to the other two metals. Fv/Fm of the algae was significantly reduced to the lowest of 18% in 1 mg/L Hg as observed in C. racemosa while the lowest for Cu and Pb was 29% and 41%, respectively, also observed in similar algal species. All algae showed an undetected value of Fv/Fm when concentration of Hg was increased to 2 mg/L. An increase in Fv/Fm was observed for C. lentillifera in 1 mg/L of Cu and Pb but the value showed a reduction when the concentration of both metals was increased to 2 mg/L. Among the algae, Fv/Fm of C. racemosa was severely affected by the presence of all metals particularly at 2 mg/L where it showed undetected value. An increase in the content of chl a was observed in C. racemosa and C. lentillifera for each metals at both concentrations while a decrease in the content was observed in U. reticulata. Algal relative growth was negatively affected by the presence of metals with Hg showed the strongest effect. However, some algae showed a positive effect of Pb on their growth.

scholarly journals Maximum quantum yield of photosystem II to assist in the measurement of herbicide selectivity in popcorn

2014 ◽  
Vol 1 (2) ◽  
pp. 80-85
Author(s):  
Ismael Lourenço de Jesus Freitas ◽  
Weverton Pereira Rodrigues ◽  
Antonio Teixeira Amaral Junior ◽  
Silvério Paiva Freitas ◽  
Reynaldo Tancredo Amim ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
Maximum Quantum Yield

scholarly journals Use of the method of measurement of chlorophyll fluorescence to determine the phytotoxicity of mesotrione in poppy (Papaver somniferum) in relation to application factors

2010 ◽  
Vol 58 (5) ◽  
pp. 107-116
Author(s):  
Jana Filová ◽  
Vojtěch Kocurek ◽  
Vladimír Smutný
Keyword(s):  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Research Work ◽  
Papaver Somniferum ◽  
Maximum Quantum Yield ◽  
Herbicide Application ◽  
Chlorophyll Fluorescence Parameter ◽  
Fluorescence Parameter ◽  
Method Of Measurement

The aim of the research work was to evaluate phytotoxicity of mesotrione in poppy (Papaver somniferum). The amount of spraying water (150, 300 and 450 l per hectare) was compared as well. In the end, the different growth stimulators (Atonik – 0.6 l . ha−1, Route – 0.8 l . ha−1) and the adjuvants (Atplus 463 – 0.5% solution, Silwet 77 – 0.1 l . ha−1) wre tested. Degree of phytotoxicity of individual va­riants was assessed by measuring chlorophyll fluorescence (parameter: maximum quantum yield of electron transport in photosystem II - QY) in 1st to 21st day after treatment. The results showed that the application of mesotrione caused phytotoxicity on poppy plants. The most significant phy­to­to­xi­ci­ty is evident at doses of 450 l spraying water per hectare. Addition of growth stimulators and adjuvants increases the phytotoxicity (decreases the value of QY) compared to the herbicide application itself. The mesotrione reduced the weight of dry plants by 15 % (150 l of spraying water), 1 % (300 l of spraying water) and 64 % (450 l of spraying water) compared to control variant.

scholarly journals Inhibitory effects of extracts from Cinnamomum camphora fallen leaves on algae

2018 ◽  
Vol 77 (11) ◽  
pp. 2545-2554 ◽  
Author(s):  
Zumulati Yakefu ◽  
Wulan Huannixi ◽  
Chaolin Ye ◽  
Tiefeng Zheng ◽  
Silan Chen ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Cinnamomum Camphora ◽  
Maximum Quantum Yield ◽  
Inhibitory Effects ◽  
Chl A ◽  
Water Extracts ◽  
Methanol Extracts ◽  
Potential Value ◽  
Photosystem Ii Photochemistry ◽  
Fallen Leaves

Abstract Natural allelochemicals are considered as a source of algaecides. To uncover the anti-algal activity of Cinnamomum camphora fallen leaves and promote their usage as algaecides, the composition of their water and methanol extracts was analyzed, and the inhibitory effects of extracts on the growth of Microcystis aeruginosa and Chlamydomonas reinhardtii, and chlorophyll (Chl) content and photosynthetic abilities in C. reinhardtii were investigated. Twenty-five compounds were detected in the water extracts, mainly including terpenoids, esters, alcohols, and ketones. Compared to water extracts, there were more compounds and higher concentration in methanol extracts. Both water and methanol extracts inhibited the growth of the two algae, and 15 mg·ml−1 methanol extracts killed the algal cells after 48 h. The levels of Chl a and Chl b, as well as maximum quantum yield of photosystem II photochemistry (Fv/Fm) in C. reinhardtii cells reduced gradually with increasing the concentration of extracts, while the maximum quantum yield of non-photochemical de-excitation (φDO) increased gradually. At the same concentration, methanol extracts showed stronger inhibitory effects than water extracts, due to their higher number of compounds and higher concentration. Therefore, C. camphora fallen leaves have a potential value as an algaecide.

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