Honors Program


Document Type



Nelson, A. 2022. Investigation of the Role of Overexpression of PsbS Under Stress Inducible and Constitutive Promoters to Improve Water Use Efficiency. Undergraduate Honors Thesis. University of Nebraska-Lincoln.


Copyright Annie Nelson 2022.


As climate change continues to impact environmental growth conditions, it has become increasingly more important to identify potential mechanisms of crop development to resist these changes. Previous studies have identified the role of PsbS in the non-photochemical quenching (NPQ) mechanism in the plant by identifying its direct effect on the rate in which excitation energy absorbed by photosystem II is dissipated as heat. It was identified also that PsbS via NPQ oxidizes chloroplastic quinone A (QA) which is a signal for stomatal opening in response to light. By identifying this relationship between PsbS and the signal for stomatal opening in response to light it is hypothesized that the gene has a potential vitality in the plants water use efficiency. This study aims to identify PsbS impact on the photoprotection system as well as water use efficiency through overexpression of the gene under stress inducible promoters. Our results show that overexpression of PsbS did result in increased water use efficiency in pre flowering transgenic tobacco.