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 Separate photosensitizers mediate degradation of the 32-kDa photosystem II reaction center protein in the visible and UV spectral regions

1989 ◽  
Vol 86 (17) ◽  
pp. 6617-6620 ◽  
Author(s):  
B M Greenberg ◽  
V Gaba ◽  
O Canaani ◽  
S Malkin ◽  
A K Mattoo ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
Protein Degradation ◽  
Reaction Center ◽  
Spectral Range ◽  
Photosynthetic Pigments ◽  
Redox States ◽  
Reaction Center Protein ◽  
Broad Spectral Range ◽  
Uv Visible

A component of the photosystem II reaction center, the 32-kDa protein, is rapidly turned over in the light. The mechanism of its light-dependent metabolism is largely unknown. We quantified the rate of 32-kDa protein degradation over a broad spectral range (UV, visible, and far red). The quantum yield for degradation was highest in the UVB (280-320 nm) region. Spectral evidence demonstrates two distinctly different photosensitizers for 32-kDa protein degradation. The data implicate the bulk photosynthetic pigments (primarily chlorophyll) in the visible and far red regions, and plastoquinone (in one or more of its redox states) in the UV region. A significant portion of 32-kDa protein degradation in sunlight is attributed to UVB irradiance.

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.

scholarly journals The occurence of rare and protected plant species on the peat bog near Lake Bikcze (Łęczyńsko-Włodawskie Lakeland)

2012 ◽  
Vol 61 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Magdalena Pogorzelec ◽  
Barbara Banach
Keyword(s):  
Plant Species ◽  
Abiotic Factors ◽  
Habitat Preferences ◽  
Peat Bog ◽  
Habitat Conditions ◽  
Drosera Rotundifolia ◽  
Western Shore ◽  
Betula Humilis ◽  
Menyanthes Trifoliata

This paper presents the results of a pilot field study, conducted in July 2007, designed to make floristic evaluation of the peat bog area adjacent to the western shore of Lake Bikcze (Łęczyńsko-Włodawskie Lakeland). The main aim of the study was to confirm the occurrence of populations of rare and legally protected plant species in this area and to identify, on a preliminary basis, habitat conditions in their stands. The occurrence of populations of the following strictly protected plant species: <i>Betula humilis</i>, <i>Salix lapponum</i>, <i>Salix myrtilloides</i>, <i>Carex limosa</i>, <i>Drosera intermedia</i>, <i>Drosera rotundifolia</i>, <i>Dactylorhiza incarnata</i>; and partially protected species: <i>Menyanthes trifoliata</i>, has been confirmed in the studied peat bog. Both an investigation of abiotic factors, conducted <i>in situ</i>, and an analysis of the species composition of the flora in terms of habitat preferences of particular groups of taxa have shown that the described rare plant species find suitable conditions for their growth and development in the studied peat bog.

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

Competition between native and non-native plants.

2020 ◽  
pp. 291-307
Author(s):  
Elizabeth M. Wandrag ◽  
◽  
Jane A. Catford ◽  
◽  
◽  
...  
Keyword(s):  
Plant Species ◽  
Plant Communities ◽  
Native Species ◽  
Abiotic Factors ◽  
Invasion Biology ◽  
Competitive Interactions ◽  
Native Plant ◽  
Native Plant Species ◽  
New Locations ◽  
Strength Of Competition

The introduction of species to new locations leads to novel competitive interactions between resident native and newly-arriving non-native species. The nature of these competitive interactions can influence the suitability of the environment for the survival, reproduction and spread of non-native plant species, and the impact those species have on native plant communities. Indeed, the large literature on competition among plants reflects its importance in shaping the composition of plant communities, including the invasion success of non-native species. While competition and invasion theory have historically developed in parallel, the increasing recognition of the synergism between the two themes has led to new insights into how non-native plant species invade native plant communities, and the impacts they have on those plant communities. This chapter provides an entry point into the aspects of competition theory that can help explain the success, dominance and impacts of invasive species. It focuses on resource competition, which arises wherever the resources necessary for establishment, survival, reproduction and spread are in limited supply. It highlights key hypotheses developed in invasion biology that relate to ideas of competition, outlines biotic and abiotic factors that influence the strength of competition and species' relative competitive abilities, and describes when and how competition between non-native and native plant species can influence invasion outcomes. Understanding the processes that influence the strength of competition between non-native and native plant species is a necessary step towards understanding the causes and consequences of biological invasions.

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