scholarly journals The orientations of core antenna chlorophylls in photosystem II are optimized to maximize the quantum yield of photosynthesis

FEBS Letters ◽  
2004 ◽  
Vol 561 (1-3) ◽  
pp. 111-116 ◽  
Author(s):  
Sergei Vasil’ev ◽  
Jian-Ren Shen ◽  
Nobuo Kamiya ◽  
Doug Bruce
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
Antenna Chlorophylls

scholarly journals Nitrogen and Phosphorus Addition to Soil Improves Seed Yield, Foliar Stomatal Conductance, and the Photosynthetic Response of Rapeseed (Brassica napus L.)

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 483
Author(s):  
Esmaeil Zangani ◽  
Kamran Afsahi ◽  
Farid Shekari ◽  
Eileen Mac Sweeney ◽  
Andrea Mastinu
Keyword(s):  
Stomatal Conductance ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Chlorophyll Content ◽  
Seed Yield ◽  
Nitrogen Application ◽  
Flowering Stage ◽  
Nitrogen And Phosphorus ◽  
Brassica Napus L ◽  
Phosphorus Levels

The effects of nitrogen and phosphorus levels on the physiological traits, yield, and seed yield of rapeseed (Brassica napus L.), were studied in a farm research project of Zanjan University. Three levels of nitrogen (0, 100, and 200 kg/ha) and three levels of phosphorus (0, 75, and 150 kg/ha) were considered. The results showed that an increase in nitrogen level caused an increase in the leaf chlorophyll content so that the application of 200 kg/ha of nitrogen increased the chlorophyll content of the leaves until the mid-grain filling stage. Nitrogen application lowered leaf stomatal conductance in the early flowering stage whereas the stomatal conductance was increased during the late flowering stage. Nitrogen application (100 and 200 kg/ha) also increased the quantum yield of photosystem II. On the other hand, with the application of 150 kg/ha and 75 kg/ha of phosphorus, the leaf stomatal conductance and the quantum yield of photosystem II in the early flowering stage increased respectively. The results showed that the application of 200 kg/ha of nitrogen and 75 kg/ha of phosphorus significantly increased seed and oil yield compared to the control. In addition, the number of siliques per plant and the weight of 1000 seeds showed an increasing trend that was affected by nitrogen and phosphorus levels. This study demonstrated that nitrogen enhanced the chlorophyll content, leaf area, and consequently, the quantum yield of photosystem II. Nitrogen also augmented the seed filling duration, seed yield, and oil yield by increasing gas exchange. As a result, the application of 100 kg/ha of nitrogen together with 75 kg/ha phosphorus showed the greatest effect on the qualitative and quantitative yield of rapeseed. However, the application of 200 kg/ha of nitrogen alone or in combination with different levels of phosphorus did not significantly increase many of the studied traits.

Photosynthetic and anatomical responses of three plant species at two altitudinal levels in the Neotropical savannah

2016 ◽  
Vol 64 (8) ◽  
pp. 696 ◽  
Author(s):  
Vinícius Coelho Kuster ◽  
Silvana Aparecida Barbosa de Castro ◽  
Fernando Henrique Aguiar Vale
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
Plant Species ◽  
Photosynthetic Pigments ◽  
Abiotic Factors ◽  
Palisade Parenchyma ◽  
Structural Modifications ◽  
Physiological Alterations ◽  
Roupala Montana ◽  
Plastic Responses

The phytophysiognomies of the Neotropical savannah occur at different altitudes, which can determine distinctions in the levels of light and shade that plants are exposed. The focus of the study is analysing the functional traits of the leaves of Byrsonima verbascifolia (L.) Rich., Roupala montana Aubl. and Solanum lycocarpum A. St.-Hil. growing in phytophysiognomies at two distinct altitudes. We evaluated leaf anatomy, the quantum yield of photosystem II, and the photosynthetic pigments in plants occurring at two areas of Campo sujo, which are separated by 700 m of altitude, during the rainy season. The three plant species occurring at higher altitudes had thicker adaxial epidermis. B. verbascifolia and S. lycocarpum occurring at higher altitudes had thicker palisade parenchyma, whereas only B. verbascifolia had thicker spongy parenchyma at the same site. The quantum yield of photosystem II, and photosynthetic pigments had little differences between plants occurring at higher and lower altitudes. The results analysed show high structural modifications and low physiological alterations from altitudinal conditions. Thus, the influence of the abiotic factors appears to modulate the plastic responses of plants across altitude.

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

Quantum Yields of Photosystem II Electron Transport and Carbon Dioxide Fixation in C4 Plants

1990 ◽  
Vol 17 (5) ◽  
pp. 579 ◽  
Author(s):  
JP Krall ◽  
GE Edwards
Keyword(s):  
Carbon Dioxide ◽  
Electron Transport ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Malic Enzyme ◽  
Co2 Fixation ◽  
C4 Plants ◽  
Quantum Yields ◽  
Ps Ii ◽  
Co2 Concentrations

The quantum yields of non-cyclic electron transport from photosystem II (determined from chlorophyll a fluorescence) and carbon dioxide assimilation were measured in vivo in representative species of the three subgroups of C4 plants (NADP-malic enzyme, NAD-malic enzyme and PEP-carboxykinase) over a series of intercellular CO2 concentrations (CI) at both 21% and 2% O2. The CO2 assimilation rate was independent of O2 concentration over the entire range of Ci (up to 500 μbar) in all three C4 subgroups. The quantum yield of PS II electron transport was similar, or only slightly greater, in 21% v. 2% O2 at all Ci values. In contrast, in the C3 species wheat there was a large O2 dependent increase in PS II quantum yield at low CO2, which reflects a high level of photorespiration. In the C4 plants, the relationship of the quantum yield of PS II electron transport to the quantum yield of CO2 fixation is linear suggesting that photochemical use of energy absorbed by PS II is tightly linked to CO2 fixation in C4 plants. This relationship is nearly identical in all three subgroups and may allow estimates of photosynthetic rates of C4 plants based on measurements of PS II photochemical efficiency. The results suggest that in C4 plants both the photoreduction of O2 and photorespiration are low, even at very limiting CO2 concentrations.

Kinetic response of photosystem II photochemistry in the cyanobacterium Spirulina platensis to high salinity is characterized by two distinct phases

1999 ◽  
Vol 26 (3) ◽  
pp. 283 ◽  
Author(s):  
Congming Lu ◽  
Giuseppe Torzillo ◽  
Avigad Vonshak
Keyword(s):  
Electron Transport ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Spirulina Platensis ◽  
High Salinity ◽  
Photochemical Quenching ◽  
Second Phase ◽  
Ps Ii ◽  
Reaction Centres ◽  
Two Phases

The kinetic response of photosystem II (PS II) photochemistry in Spirulina platensis(Norstedt M2 ) to high salinity (0.75 M NaCl) was found to consist of two phases. The first phase, which was independent of light, was characterized by a rapid decrease (15–50%) in the maximal efficiency of PS II photochemistry (Fv /Fm), the efficiency of excitation energy capture by open PS II reaction centres (Fv′/Fm′), photochemical quenching (qp) and the quantum yield of PS II electron transport (Φ PS II) in the first 15 min, followed by a recovery up to about 80–92% of their initial levels within the next 2 h. The second phase took place after 4 h, in which further decline in above parameters occurred. Such a decline occurred only when the cells were incubated in the light, reaching levels as low as 45–70% of their initial levels after 12 h. At the same time, non-photochemical quenching (qN) and Q B -non-reducing PS II reaction centres increased significantly in the first 15 min and then recovered to the initial level during the first phase but increased again in the light in the second phase. The changes in the probability of electron transfer beyond QA (ψo) and the yield of electron transport beyond QA (φ Eo), the absorption flux (ABS/RC) and the trapping flux (TRo /RC) per PS II reaction centre also displayed two different phases. The causes responsible for the decreased quantum yield of PS II electron transport during the two phases are discussed.

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