The effect of temperature on photosynthesis 1
concentration, and soil water deficit affect stomatalresponse, gas exchange and photosynthesis (Mooney and Harrison, 1970; Berryand Bjorkman, 1980; Lieth and Pasian, 1990; Xie et al., 1996; Moriana et al.,2002). Based on changes during the day or between days, Heinicke and Childers(1937) concluded that light was the major factor affecting whole-canopy NCERof apple trees, and temperature was second most important, although Sirois andCooper (1964) concluded CO2 was second. A recent study(Corelli-Grappadelli and Magnanini, 1993) reported short-term whole-canopyNCER measurements declined with gradually declining light levels for one appletree. Photosynthesis and transpiration were greatly influenced by stomatalbehavior. Stomatal opening is affected by CO2 concentration, vaporpressure gradient (VPG), light, turgor pressure caused by change in potassiumand organic acids, and by abscisic acid (ABA) (Raschke, 1970; Schulze andHall, 1982). Berry and Bjorkman (1980) found light intensity, CO2concentration, temperature, and soil water deficit may have affected gasexchange of plants in a greenhouse. Bunce (1984) reported photosynthesisincreased when humidity was increased in the environment. Transpiration atnoon under a high temperature after 48 h of acclimation was 400% higher thanunder a moderate temperature. Stomatal resistance reached a minimum at noon,in accordance with the transpiration rate. Leaf wa
The Effect of Temperature on Photosynthesis - StudyMode
Positive values of hydrostatic pressure occur in the living cells of plants, in the symplast, and as explained above are induced by high solute concentrations and the resultant osmotic pressure. However, large negative values are common in the apoplast of plants and the soil they are growing in. These negative values arise because of capillary effects - the attraction between water and hydrophilic surfaces at an air/water interface, the effects of which can be seen in the way that water wicks into a dry dishcloth. This attraction reduces the pressure in the water, and does so more intensely the narrower are the water-filled pores. It accounts for how cell walls, which have very narrow pores, can remain hydrated despite very low water potentials in the tissue they are part of. For a geometrically simple cylindrical pore, the relation between the induced pressure and the radius of the pore can be derived as follows:
Huang CX, van Steveninck RFM (1988) Effect of moderate salinity on patterns of potassium, sodium and chloride accumulation in cells near the root tip of barley: Role of differentiating xylem vessels. Physiol Plant 73: 525-533
Graph Showing Effect of Temperature on Rate of ..
In this study we examined whether coniferous plants are better photo-synthesizers than deciduous plants under colder temperatures. We know that leaves are the site of photosynthesis in coniferous and deciduous plants, and that, during the Winter, the leaves of coniferous plants retain their needles, while the leaves of deciduous plants often die. Our hypothesis was---if coniferous plants are better photo-synthesizers than deciduous plants under colder temperatures, then they will consume more C02. We placed three species of coniferous plants and three species of deciduous plants in respiration chambers, and ran four trials on each of the six samples. Each sample was placed under light at a cold temperature (about 0 degrees C) and at room temperature (about 22 degrees C), and, as a control, under no light at the same two temperatures. We compared the C02 consumption of the coniferous plants to the deciduous plants at the two temperatures. The variation in mean rates of photosynthesis among individual species for deciduous was -8.57 and coniferous was -12.15. This data has a non-significant relationship. For this reason, we fail to accept our active hypothesis. It is evident that there were problems with our experimental design. First, one of the coniferous samples is not an appropriate measurement because the total weight, 3g, included stem weight. Thus the rate in change of CO2 will be affected by the stem size and the decreased mass of leaves. Second, under freezing and room temperatures, the rates of CO2 change in individual coniferous species, A: -29.861/ -72.296; B: -68.428/ -49.524; C: -11.071/ -9.332, varied more between species than among deciduous species, D: -36.788/ -73.969; E: -28.487/ -40.687; F: -11.921/ -33.489. The range for coniferous is -11.071 to -68.428 and the range for deciduous is -11.921 to -73.969. These wide spread ranges decrease the probability of attaining a significant mean difference between groups. Also, 2 out of 3 Coniferous plants had increased rates of photosynthesis under freezing temperatures, while 3 out of 3 Deciduous plants had increased rates of photosynthesis under room temperatures. These varying results suggest that testing variations among individual species of coniferous and deciduous may have been more compatible and conclusive than mean differences between groups. Last and most obvious, physiologically, coniferous and deciduous plants undergo the same C3 photosynthesis, and thus, one should not be a better photo-synthesizer than another. In this regard our hypothesis was flawed. A more effective variable to test would have been light since deciduous and coniferous plants differ structurally, it can be inferred that varying leaves may absorb light differently in reduced light conditions due to differences in surface area, volume, and outer-covering. Thus a design varying light conditions may have been a better indicator of difference in leaf structure to explain coniferous leaf retention in the Winter.
Effect of High Temperature on Photosynthesis in …
Those gas molecules in the Earth's atmosphere with three or more atoms are called "greenhouse gases" because they can capture outgoing infrared energy from the Earth, thereby warming the planet. The greenhouse gases include water vapor with three atoms (H2O), ozone (O3), carbon dioxide (CO2), and methane (CH4). Also, trace quantities of chloro-fluoro-carbons (CFC's) can have a disproportionately large effect.