| Environmental stresses represent limiting factors for agricultural productivity worldwide. These stresses impact not only crops which are presently cultivated, but are also significant barriers to the introduction of crop plants into areas which are not at this time being used for agriculture. Abiotic stress factors include temperature, salinity, drought, anaerobic, and mechanical stresses on plants. Impending global warming conditions and increasingly erratic weather patterns in the future are likely to enhance the nature of these stresses. Globally, irrigation-induced salt stresses, record high temperatures, and long term drought conditions are presently having major consequences on crop yields.; The development of modern molecular biology has led to a better understanding of plant adaptations and responses to stress conditions. Genes responsible for adaptation processes to every example of stress have been identified. The use of transgenic plants to overexpress or silence these genes is a powerful tool in determining if they are necessary or sufficient to induce stress tolerance. However, with stress tolerance being a quantitative trait, it should not be expected that single genes confer a high level of tolerance.; This work contains research performed on the biochemical responses plants make to abiotic stresses. Arabidopsis, corn, cotton, wheat, peanut, and soybeans were all studied for their responses to one of the following stresses: heat, chilling, salt, osmotic, mechanical, or anaerobic. Accumulations of amino acids, membrane integrity, survival rates, photosynthesis capability, and fatty acid analysis were all monitored in some capacity to assess plant stress levels.; Specifically, nine genotypes of soybeans were screened using the aforementioned tools to assess which genotypes might perform best under heat stress conditions. Membrane composition, photosynthetic mechanism stability, survival rates, and membrane integrity were analyzed. Studies were also performed on Arabidopsis and various crop plants in response to heat stress, and all of the other stresses mentioned, to study the accumulation of amino acids. The results of these studies are presented hereafter. |
