fotosistemas i y ii pdf file. Quote. Postby Just» Tue Aug 28, am. Looking for fotosistemas i y ii pdf file. Will be grateful for any help! Top. of foliage loss, altered leaf orientation, stomatal closure, and photosystem II downregulation. la regulaci6n del fotosistema a la baja en el PSII, mientras que esta conducta TUCKER, C. J., I. Y. FUNG, C. D. KEELING, AND R. H. GAMMON. of foliage loss, altered leaf orientation, stomatal closure, and photosystem II downregulation. la regulación del fotosistema a la baja en el PSII, mientras que esta conducta TUCKER, C. J., I. Y. FUNG, C. D. KEELING, AND R. H. GAMMON.

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Food and Agriculture Organization of the United Nations.

Physicochemical characterization of ‘Pinot Noir’ grapevine Vitis vinifera L. DNA damage and repair in plants. This was directly attributed to this species’ tolerance to high radiation, as non-defoliated plants of the same species only showed photoinhibition when they were exposed to 24 h of continuous illumination. This agrees with the results of the present study, in which the value of Y II ji in the defoliated plants at the same time as photochemical quenching and maximum quantum yield of PSII.

It is possible for F o values to increase when there is a slowdown in excitation energy transfer from the light collection system to the reaction center Baker and Rosenqvist,or when there is some type of damage in the PSII reaction centers themselves Vieira et al.

This explains the behavior of the defoliated plants in the present study, since a higher exposure to direct radiation after a reduction in leaf number increases photon flow and leaf temperature and finally triggers a failure of the photosynthetic system.

Journal Experimental Botany 55 Response of sunflower plants fotosistea physical injury.


Plant responses to foliar attack. Every two weeks, one of every two recently-emerged leaves was removed from the non-control plants.

In this sense, it is possible that the grape plants of the present study modified their photosynthetic capacity in response to defoliation, raising total chlorophyll content Richards, or diminishing the senescence rate of the remaining leaves Hunter and Visser, General Subjects 2: Photosynthetic responses of wheat, Triticum aestivum L.

Final production of a fotossitema is affected by the conditions in which it was grown.

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fotosistemas i y ii pdf file – PDF Files

Applications of chlorophyll fluorescence can improve crop production strategies: This is because the remaining leaves in defoliated plants lengthen their useful life to compensate for lost leaf area, which modifies the chemical composition of these leaves in the form of increased sugar and lower concentrations of amino acids and organic acids Hunter and Visser,which affect the leaf photosynthetic capacity.

Thus, there was no positive relation found between chlorophyll content of leaves and their photosynthetic efficiency. Photoinhibition in Vitis californica: Chardonnay grown in the highland tropics. The chlorophyll content and fluorescence were determined in five-year-old grape plants Vitis vinifera L.

Defoliation fotodistema Do physiological and morphological responses lead to over compensation. Higher plants and UV-B radiation: On the other hand, Y NPQ determines the fraction of excitation energy dissipated as heat through photo-protection mechanisms, while the Y NO factor shows the total non-photochemical losses, other than heat. The value of minimum fluorescence increased by Early partial defoliation induced an increase in stress in the grape plants evaluated.

On the other hand, Layne and Flore reported a reduction in minimum fluorescence values measured seven days after defoliation of Prunus cerasus plants exposed to 14 h of daily light. This procedure is utilized in the majority of wine-producing countries to increase the concentration of various compounds in the fruits, such as phenols, thus giving new characteristics of flavor and aroma to the wine Kemp et al.

Furthermore, it must be noted that secondary metabolites do not only determine fotoxistema quality, but they also play an important role as antioxidants that benefit human health by protecting against oxidative stress caused by highly-reactive free radicals in ftosistema body Quijano, The average value for electron transport rate decreased Figure 3 shows the partitioning of excitation energy in light-adapted plants.

Nevertheless, the photochemical quenching coefficient qP was reduced by General Subjects 1: Nevertheless, in the present study, a fotosistemz was observed in this value, which indicates that defoliation induces a higher degree of stress in Chardonnay grape plants, perhaps due to higher exposure of the remaining leaves to direct radiation, which elevates leaf fotlsistema and affects photosynthesis mechanisms.

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Though changes in chlorophyll content fotosiatema related to photosynthesis, chlorophyll concentration is not always directly proportional to a plant’s photosynthesis rate. When Ilex aquifolium plants were subjected to a reduction in leaf area, the behavior of maximum quantum yield fluctuated according to the type of defoliation.


It is evident that a reduction in leaf area modifies the partitioning of excitation energy destined for photochemical and non-photochemical processes, thus directly influencing the photosynthetic process of the plants evaluated. Annales Botanici Fennici Nevertheless, human actions partially or completely modify the behavior of each factor, thus determining the terroir of the vine’s development Vaudour, ; Quijano, With regards to this result, Otronen and Rosenlund found no significant difference in maximum photochemical quantum yield of PSII when they subjected Pinus sylvestris plants to different levels of defoliation.

The authors presume that the reduction in these indicators of photochemical function was related to oversaturation of light, leading to photoinhibition, and perhaps damage from high UV radiation in the remaining leaves on the defoliated plants. Karukstis stated that reductions in maximum quantum efficiency of PSII occur simultaneously with a reduction in net assimilation of CO2, and if this reduction is shown in continuously illuminated leaves, it is possible that the effect is due to photoinhibition.

New fluorescence parameters for the determination of QA redox state and excitation energy fluxes. The distribution of energy in these three processes occurs simultaneously, so that an increase in efficiency of one process results in the reduction of the other fotosistemq. The effect of partial defoliation, leaf position and developmental stage of the vine on leaf chlorophyll concentration in relation to the photosynthetic activity and light intensity in the canopy of Vitis vinifera L.

Compensatory plant-growth as a response fofosistema herbivory. Leaf gas exchange, chlorophyll fluorescence, water relations and carbohydrate concentrations. In this part of the country, it is possible, with good crop management, to obtain two harvests per year, thanks to the local agroclimatic conditions Almanza et al. Chlorophyll fluorescence is a widely-used technique for tracking this phenomenon, fitosistema in cultivated and wild plants. Chlorophyll content was higher in leaves of the defoliated plants, but this did not correlate with a higher photosynthetic efficiency.

Trends in Plant Science 3 4: UV-B also causes respiration to increase, as well as the demand for resources to protect and repair photosynthesis mechanisms, both of fotosistemaa rob efficiency from photosynthetic electron transport Gwynn-Jones,