Mississippi State University
Reddy, K. Raja
Date of Degree
Dissertation - Campus Access Only
Life Science (Biochemistry)
Doctor of Philosophy (Ph.D)
College of Agriculture and Life Sciences
Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology
Drought and temperature stress are the two most important factors limiting crop productivity. A physiological and proteomic analysis of soybean was performed to investigate the negative impact of these variables. The previous studies reported the beneficial effect of silicon under stress conditions. Silicon supplementation may promote plant growth under drought stress, although the mechanism to alleviate drought stress is uncertain. The proteomic analysis of chloroplast proteins was carried out to study the response of silicon supplementation under drought stress.
Similarly, temperature stress, mainly heat stress, has an adverse effect on soybean plants. The comparative analysis of two soybean cultivars, DS25-1 and DS31-243 was examined under ambient and elevated CO2 levels. The proteomic study employed two-dimensional gel analysis and mass spectrometry techniques to identify differentially expressed proteins under drought and temperature stress. The identified proteins are involved in metabolic processes, photosynthesis, signaling, redox homeostasis, and other cellular pathways. Most of these proteins were involved in metabolism, response to heat and photosynthesis showing significant cross-tolerance mechanisms.
The physiological parameters like stomatal conductance, transpiration, photosynthesis, and chlorophyll pigments were also studied. Silicon application improved plant growth under drought stress. However, at the elevated CO2 level, plants showed better growth under heat stress.
Together, these findings suggested the role of silicon and elevated CO2 concentration in drought and temperature stress in soybean. The differentially expressed proteins helped mitigate the negative impact of these stress, mainly the photosynthetic, antioxidant and heat shock proteins, and enhance crop growth and productivity under drought and heat stress.
Kaur, Amandeep, "Physiological and proteomic analysis of soybean in response to drought and heat stress" (2023). Theses and Dissertations. 5757.