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|Title:||The effects of growth salinity and irradiance on thylakoid stacking in lettuce plants|
|Author(s):||Carter, Douglas R.|
|Doctoral Committee Chair(s):||Cheeseman, John M.|
|Department / Program:||Plant Biology|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
Biology, Plant Physiology
|Abstract:||The basic objective of this research, which emphasizes the dynamic nature of thylakoid stacking, was to elaborate on the responsiveness of thylakoid membrane stacking to environmental conditions in order to investigate the role of stacking in the adaptive processes of photosynthesis. By integrating the information on salinity-induced cation changes in leaves with information on the in vitro effects of cations on thylakoid stacking, we provided a basis for testing the sensitivity of the stacking process to growth salinity, an environmental factor which had not been previously discussed in those terms. We accomplished this by using methods of digitonin fractionation to show that growth salinity altered the degree of thylakoid stacking in lettuce plants. Furthermore, we established that growth salinity and irradiance interacted in such a way that the moderate salinization of the nutrient solution was associated with less stacking at high irradiances and more stacking at low irradiances, both relative to controls.
Attention was also given to the relationship of thylakoid stacking and photosynthetic efficiency in mature leaves. Using different combinations of growth salinity and irradiance to manipulate the degrees of stacking, our results suggested a positive correlation between the degree of stacking and the photon yield of O$\sb2$ evolution. Another consideration was the susceptibility of high-irradiance lettuce plants to photoinhibition based on salinity-induced differences in thylakoid stacking. Overall, high-irradiance plants in which thylakoid stacking had been reduced by growth salinity showed fewer signs of photoinhibition than high-irradiance plants with more stacking.
|Rights Information:||Copyright 1990 Carter, Douglas R.|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9114190|