Fig 2. Effects of drought stress on photosynthesis. Drought stress causes accumulation of reactive oxygen species by disturbing the balance between productions of reactive oxygen species and the antioxidant defense which induces oxidative stress. During drought stress plants close stomata which decrease the CO2 influx. Besides reducing the carboxylation reduction in CO2 also directs more electrons to form reactive oxygen species. Under severe drought condition photosynthesis is limited by decrease in the activities of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPCase), NADP-malic enzyme (NADP-ME), fructose-1, 6-bisphosphatase (FBPase) and pyruvate orthophosphate dikinase (PPDK). To match the reduced requirements of NADPH production, non-cyclic electron transport is down regulated which reduce ATP synthesis (Farooq et al., 2008).
Photosynthesis is highly sensitive to water stress. Plant photosynthesis decrease with reduction in relative water content and leaf water potential. Mechanism of photosynthesis involves various components such as photosynthetic pigments and photosystem, the electron transport
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Drought stress affects plant growth and overall yield. Following drought stomata close which results decline in net photosynthesis. Stomata conductance is controlled by soil moisture availability as well as by complex interaction of intrinsic and extrinsic factors. Depending upon the severity of drought activities of enzymes involved in carbon assimilation and adenosine triphosphate synthesis decrease and sometimes even inhibited. The main factors for reduction in plant growth and productivity under drought is the production of reactive oxygen species in organelles including chloroplast, mitochondria, and peroxisomes. The reactive oxygen species target the peroxidation of cellular membrane lipids and degradation of enzyme proteins and nucleic
The majority of life on Earth depends on photosynthesis for food and oxygen. Photosynthesis is the conversion of carbon dioxide and water into carbohydrates and oxygen using the sun’s light energy (Campbell, 1996). This process consists of two parts the light reactions and the Calvin cycle (Campbell, 1996). During the light reactions is when the sun’s energy is converted into ATP and NADPH, which is chemical energy (Campbell, 1996). This process occurs in the chloroplasts of plants cell. Within the chloroplasts are multiple photosynthetic pigments that absorb light from the sun (Campbell, 1996).
Carter, E., Theodorou, M., and Morris, P. 1997. Responses of lotus corniculatus to environmental Change I. effects of elevated CO2, temperature and drought on growth and plant development. New Phytologist. 136: 245-253.
The high rate of absorbance change in blue light in the chloroplast samples (Figure 1) can be attributed to its short wavelength that provides a high potential energy. A high rate of absorbance change is also observed in red light in the chloroplast samples (Figure 1), which can be accredited to the reaction centre’s preference for a wavelength of 680nm and 700nm – both of which fall within the red light range (Halliwell, 1984). Green light showed low rates of photosynthetic activity and difference in change in absorbance at 605nm in the chloroplast samples (Figure 1) as it is only weakly absorbed by pigments, and is mostly reflected. The percentage of absorption of blue or red light by plant leaves is about 90%, in comparison to the 70–80% absorbance in green light (Terashima et al, 2009). Yet despite the high absorbance and photosynthetic activity of blue light, hypocotyl elongation was suppressed and biomass production was induced (Johkan et al, 2012), which is caused by the absorption of blue light by the accessory pigments that do not transfer the absorbed energy efficiently to the chlorophyll, instead direction some of the energy to other pathways. On the other hand, all of the red light is absorbed by chlorophyll and used efficiently, thus inducing hypocotyl elongation and the expansion in leaf area (Johkan et al, 2012).
at the small end of the axis to see a more reliable pattern. I could
The Effect of Light Intensity on the Rate of Oxygen Production in a Plant While Photosynthesis is Taking Place
An Analysis and Evaluation of Data from Photosynthesis Experiments Graph analysis This is my analysis for the investigation in to the affect of light intensity on the rate of photosynthesis to the Canadian pondweed, elodea. In the results the pattern is that when the light intensity is higher the readings are generally higher. On the graph the less the light intensity the lower the gradient of the curve. the equation for the photosynthesis process is; CO2 + 2H2O + Light Energy = =
In this laboratory experiment, the rate of photosynthesis was measured through the use of the “floating leaf disk technique.” The leaf disks were placed into a syringe and the O2 and CO2 in the mesophyll layers of the leaves were removed and then replaced with sodium bicarbonate or water, causing the leaves to sink to the bottom of the container. If one determines the number of leaf disks rising to the top as a result of an increase in oxygen gas in the mesophyll cells, then the rate of photosynthesis is able to be measured because O2 is a product of photosynthesis. The first step of this experiment was a feasibility study of the variance in the photosynthetic activity of the leaf disks in both water and bicarbonate solutions. After five minutes of light exposure, all of the leaf disks in the bicarbonate solution (10 disks) had ...
Sulfur may enter the plants in few ways such as enter through the roots in form of sulphate ion, dissolved in water with form of sulphate ion or in form of gaseous sulfur dioxide (SO2) which can penetrates into the leaves through the stomata. But both of it can be utilized by plants through the metabolism of normal sulfur, although the limited pathway via cuticle was proof. However, the aperture of the stomata was largely controlled by conditions of the environment, such as temperature, ligh...
[IMAGE]Carbon dioxide + water Light Energy glucose + oxygen Chlorophyll [IMAGE]6CO2 + 6H20 Light Energy C6 H12 O6 + 6O 2 Chlorophyll Photosynthesis occurs in the leaves of the plant in the palisade layer. Chlorophyll in the cells in the palisade layer absorb light for photosynthesis. The plant releases the oxygen created in photosynthesis back into the air but it uses or stores the glucose for energy, respiration, growth and repair. The leaves and plants are also specially adapted for photosynthesis in their structure and cell alignment. Preliminary Experiment Apparatus * Piece of Elodea Canadensis * Bulb * Voltmeter * Test tube * Beaker * Box *
The effect of water quality on Vegetative measurements and photosynthesis indices of the trees are presented in Table 1. No significant differences were found between parameters: gs, shoot number in both years, but others were higher in RW application. Height of trees and leaf area in first year was not significant but in second year it increased by 42 and 29% respectively in application RW. Photosynthesis rate appears significantly higher (23.4 µmol m−2 s−1) in plants receiving recycle water than clean water.
Photosynthesis is a process in which plants and other organisms convert the light energy from the sun or any other source into chemical energy that can be released to fuel an organism’s activities. During this reaction, carbon dioxide and water are converted into glucose and oxygen. This process takes place in leaf cells which contain chloroplasts and the reaction requires light energy from the sun, which is absorbed by a green substance called chlorophyll. The plants absorb the water through their roots from the earth and carbon dioxide through their leaves.
The Effect of Light Intensity on the Rate of Photosynthesis in an Aquatic Plant Introduction The input variable I will be investigating is light, as light is just one of the 4 factors required in the green-plant process of photosynthesis. Photosynthesis is the process by which green-plants use sunlight, carbon dioxide, water & chlorophyll to produce their own food source. This process is also affected by the temperature surrounding the plant (the species of plant we experimented with, pond weed, photosynthesised best at around 20 degrees centigrade.) Light, temperature & CO2 are known as limiting factors, and each is as important as the next in photosynthesis. Light is the factor that is linked with chlorophyll, a green pigment stored in chloroplasts found in the palisade cells, in the upper layer of leaves.
In some way, shape, or form energy is one of the several reasons why there is an existence of life on earth. Cellular respiration and Photosynthesis form a cycle of that energy and matter to support the daily functions that allow organisms to live. Photosynthesis is often seen to be one of the most important life processes on Earth. Photosynthesis is a process by which plants use the energy of sunlight to convert carbon dioxide and water into glucose so other organisms can use it as food and energy. It changes light energy into chemical energy and releases oxygen. This way organisms can stay alive and have the energy to function. Chlorophyll is an organelle generally found in plants, it generates oxygen as a result too. As you can see without
Photosynthesis is the process in which living cells from plants and other organisms use sunlight to produce nutrients from carbon dioxide and water, the image below “Diagram of photosynthesis 1,” helps show this process. Photosynthesise generally creates oxygen as a by-product through the use of the green pigment, chlorophyll, found in the plant that helps this reaction occur. “Photosynthesis provides us with most of the oxygen we need in order to breathe. We, in turn, exhale the carbon dioxide needed by plants,” (factmonster,2017). This is able to show us why photosynthesis is so greatly needed to occur through plants in order to give one another essentials needed for continuity of life. “Plants perform photosynthesis because it generates the food and energy they need for growth and cellular respiration,” (photosynthesieeducation, 2016).
Increases in temperature can decrease the efficiency of photosynthesis; however the extent of this impact may be determine on the species' dependency on light.