Physiological and Environmental Aspects of Photosynthesis

Kluge, Ricardo Alfredo; Tezotto-Uliana, Jaqueline Visioni; Silva, Paula P. M. da

doi:10.5935/1984-6835.20150004

Cited by 21 publications

(14 citation statements)

References 11 publications

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“…The cytokines produced in the root are transported through the xylem to the shoot of the plants to regulate their growth (Takey et al, 2001). Photosynthetic pigments present in plants, such as chlorophyll and carotenoids, are essential for photosynthesis, capturing solar radiation and initiating the photochemical step by fixing CO 2 and producing carbohydrates (Kluge et al, 2015). According to Bird (1974), nematodes can use these growth hormones (cytokine and auxin) for their own purpose and require a certain level in their host plants for their growth and reproduction.…”

Section: Discussionmentioning

confidence: 99%

Gas exchange and photosynthetic light response curves in nematode-infected tomato plants treated with Thuya occidentalis

Mioranza¹,

Inagaki²,

Müller³

et al. 2018

Aust J Crop Sci

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The use of homeopathic formulations on plants may cause changes in plant metabolism and result in disease control by inducing resistance. This work aimed to study the physiological responses of tomato plants infected with nematode (Meloidogyne incognita) and treated with highly diluted preparations of Thuya occidentalis, a homeopathic remedy. The different treatments included T. occidentalis 6CH, 24CH, and 50CH (Centesimal Hahnemanian), a water control (with nematode and without treatment), and an absolute control (no treatment and no nematode). The assay was conducted in a greenhouse using a randomized block design with four replications. Gas exchange parameters were measured at specific times before and after nematode inoculation. Photosynthetic rate, stomatal conductance, transpiration, leaf internal CO 2 concentration, and leaf temperature were measured at various photosynthetic photon flux densities. No significant difference was found in the different gas exchange specific measure parameters between the treatments. Untreated infected plants showed an increase in net photosynthesis and in the carboxylation capacity, as shown by the light response curve. Treatment with T. occidentalis 24CH inhibited the increase in CO 2 fixation in tomato plants inoculated with M. incognita, leading to a similar behavior as healthy plants, independently of the photon density.

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Section: Discussionmentioning

confidence: 99%

Gas exchange and photosynthetic light response curves in nematode-infected tomato plants treated with Thuya occidentalis

Mioranza¹,

Inagaki²,

Müller³

et al. 2018

Aust J Crop Sci

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“…The magnitude of the effects was different for each of the five fungicides tested, with Flux + Pyra treatment, followed by Me + Pyra being those that provided greater leaf development, allowing these plants greater photosynthetic capacity (Kluge et al, 2014). In addition to better development and productivity gains, since 90% of the dry mass of the plant is formed by photoassimilates that have been converted into biomass (Popov et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…The higher photosynthetic efficiency observed in plants treated with Flux + Pira is related to the higher g s , which allowed greater CO 2 diffusion to the substamatic chamber increasing A net and, consequently, the amount of photoassimilates produced, allowing greater plant development. The higher the A net value, the greater the photosynthetic gain, as the increase in liquid photosynthesis is a result of the increase of gross photosynthesis and reduction of respiration (Kluge et al, 2014).…”

Section: Wuementioning

confidence: 99%

Photoynthetic and productive increase in tomato plants treated with strobilurins and carboxamides for the control of Alternaria solani

Marek

Azevedo

Ono

et al. 2018

Scientia Horticulturae

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A B S T R A C TDuring two years (2015 and 2016), an experiment was carried out to investigate the effects of the application of strobilurin and carboxamides on the photosynthetic efficiency and yield of tomato plants inoculated with A. solani grown in greenhouse in southern Brazil. The experimental design was randomized blocks with five replicates and seven treatments: inoculated control (water + inoculum), absolute control (water), boscalid (0.075 g L −1 ), boscalid (0.100 g L −1 ) + kresoxim-methyl (0.050 g L −1 ), pyraclostrobin (0.100 g L −1 ), fluxapyroxad (0.058 g L −1 ) + pyraclostrobin (0.116 g L −1 ) and methyl (1.100 g L −1 ) + pyraclostrobin (0.100 g L −1 ), applied at 15 days after transplantation, at intervals of 15 days, totaling 6 applications. The effect on plant development was evaluated by plant height, leaf area, fresh and dry mass of leaves, stem and roots. To verify the photosynthetic efficiency, gas exchange, chlorophyll a fluorescence, content of photosynthetic pigments, nitrate reductase enzyme activity, carbohydrate content and yield were evaluated. All fungicides positively affected the evaluated parameters, improving photosynthetic efficiency and fruit production, in addition to providing efficient disease control. However, treatments using fluxapyroxad with pyraclostrobin, followed by metiram with pyraclostrobin stood out for promoting high photochemical yield due to the higher levels of photosynthetic pigments, activity of the nitrate reductase enzyme and, consequently, increase in the synthesis and translocation of photoassimilates. These results demonstrate the benefits of the use of these agrochemicals in the control of A. solani in tomato.

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“…24,25 A luz solar é absorvida pelos fotossistemas I e II (PS I e PS II), conhecidos como esquema Z, o que resulta na excitação de elétrons. Oxigênio é produzido pela oxidação da água no PS II e ATP e NADPH são produzidos no PS I, armazenando a energia solar nas ligações químicas.…”

Section: Fotossínteseunclassified

Solubilidade e reatividade de gases

Silva¹,

Carvalho²,

Lopes³

et al. 2017

Quim. Nova

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REACTIVITY AND SOLUBILITY OF GASES. This paper deals with the solubility and reactivity of gases, especially in water, covering the main aspects that influence the dissolution process, namely polarizability of atoms or molecules in gas phase and their ability to react with the solvent. The discussion highlights the importance of solubility of gases in several biological processes, such as respiration and photosynthesis, hydrogen storage and industrial processes, as the production of carbonated beverages. The discussion also addresses the importance of gas solubility in atmospheric chemistry and aquatic environments.Keywords: solubility of gases; biological processes, respiration; photosynthesis; carbonated beverages; hydrogen storage. INTRODUÇÃOHá cerca de dois bilhões de anos alguns organismos passaram a realizar fotossíntese, o que desencadeou uma grande evolução dos seres vivos. A crescente concentração de gases oxidantes como oxigênio e ozônio na baixa troposfera obrigou os organismos a se refugiarem na água. 1,2 Com o aumento progressivo da pressão parcial na atmosfera, o oxigênio foi lentamente sendo dissolvido na água e desta forma os organismos foram aos poucos se adaptando ao novo ambiente, até que nos últimos 500 milhões de anos saíram da água para povoar a superfície da Terra envolta por uma tênue camada de gases. Os gases que compõem a atmosfera mantêm as condições ideais na superfície do planeta para a criação e manutenção da vida como, por exemplo, o oxigênio, vital para os seres aeróbios, o dióxido de carbono, usado na fotossíntese e o nitrogênio, convertido pelas bactérias fixadoras de nitrogênio e utilizado pelas plantas, sendo essencial na construção de biomoléculas; além de atuar como um escudo protetor contra radiação cósmica de alta energia. 1,3 Muitos desses processos ocorrem em meio aquoso e são dependentes da capacidade de dissolução desses gases em água.Os gases são definidos como um conjunto de moléculas ou átomos, muito separados entre si, em movimento permanente e aleatório, com trajetórias pouco influenciadas por forças interatô-micas ou intermoleculares. O comportamento de cada gás pode ser descrito por uma equação que estabelece a relação entre as quatro variáveis que definem seu estado, volume (V), quantidade de matéria (n), temperatura (T) e pressão (p), p = f(T, V, n). 4 Nas condições de temperatura e pressão ordinárias (25 o C e 1 atm), o estado gasoso predomina quando as forças interatômicas ou intermoleculares inexistem (gases perfeitos) ou são de baixa intensidade, a exemplo das forças de dispersão de London, que são interações resultantes de formação de dipolos instantâneos, típicas entre moléculas apolares. No entanto, vale ressaltar que o estado gasoso não é exclusivo de moléculas apolares (Quadro 1). Há diversos tipos de gases constituí-dos por moléculas polares, nas condições ordinárias de temperatura e pressão, como são os casos do dióxido de enxofre, dos haletos de hidrogênio e da amônia, cujas interações do tipo dipolo-dipolo, ou até mesmo ligações hidrogênio, não sã...

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Physiological and Environmental Aspects of Photosynthesis

Cited by 21 publications

References 11 publications

Gas exchange and photosynthetic light response curves in nematode-infected tomato plants treated with Thuya occidentalis

Gas exchange and photosynthetic light response curves in nematode-infected tomato plants treated with Thuya occidentalis

Photoynthetic and productive increase in tomato plants treated with strobilurins and carboxamides for the control of Alternaria solani

Solubilidade e reatividade de gases

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