Date of Award


Degree Type


Degree Name

Master of Science (MS)



Committee Chair

Cankui Zhang

Committee Member 1

Shaun N. Casteel

Committee Member 2

Yiwei Jiang


Drought and heat are two of the major adverse environmental stresses for plants. The plant growth, productivity, morphology, physiology and biochemistry are found to be changed when the plants are grown at either drought or heat or combined stress conditions. Photosynthesis, stomata conductance, transpiration, water potential, and antioxidant systems were found to be involved in facilitating the stress responses. In addition, multiple molecular pathways, e.g., protective compound synthesis, protein and mRNA chaperones, cell membrane fluidity, plant hormone synthesis and transport, secondary metabolite synthesis, and flowering, have also been discovered to be involved in the response to these conditions. Soybean is an important crop for the US and worldwide and its productivity can be negatively impacted by these two stressors. Therefore, understanding the physiological and molecular responses in soybean to these two stressors will not only provide basic knowledge to plant physiology, the identified genes and pathways can also provide hints for future genetic manipulation targets. To achieve these goals, multiple physiological parameters were measured and mRNA transcriptomic profiling method were used to analyze the tissues collected from the soybean plants that were experiencing either drought or heat stress. The diverse responses in soybean to these two stresses indicated the complexity of the mechanisms that soybean use to cope with these stressful conditions