Fundamental Research Aimed at Diverting Excess Reducing Power in Photosynthesis to Orthogonal Metabolic Pathways

Project: Research project

Project Details

Description

Plants require sunlight to fuel the conversion of carbon dioxide into sugar. Sunlight however, is not always the rate-limiting factor in plant growth. During the two hours before and two hours after solar noon, sunlight often exceeds the amount of light energy plants can use because other rate limiting factors come into play, particularly the intake of carbon dioxide. The excess light energy during this four-hour interval would be damaging to the plant were it not for the existence of biochemical mechanisms that turn it into harmless heat. In this study, we have devised two independent strategies aimed at diverting this otherwise wasted energy into alternative biochemical pathways that could generate useful chemical compounds. The work involves basic research into tethering enzymes directly to photosystem I, one of the two protein complexes in plants that convert light energy into chemical energy. The tether will be attached to photosystem I entirely within the living cell, either at its terminal iron-sulfur cluster or at the intermediary quinone. In the former, a naturally occurring protein that contains iron-sulfur clusters will be used to bind photosystem I to a catalytic enzyme such as hydrogenase, which generates hydrogen. In the latter, a molecular wire containing a menaquinone will displace the naturally occurring plastoquinone-9, thereby providing an alternative pathway for the extra energy to spill over to an attached catalyst. If the work is successful, a significant increases into plant productivity could be achieved.The work addresses the DOE-BES Photosynthetic Systems Program mission to develop a multidimensional understanding of photosynthesis to serve as a guide for the development of bioinspired, biohybrid, and biomimetic energy systems and to inform strategies for the improvement of biological photosynthesis.
StatusFinished
Effective start/end date9/15/218/14/23

Funding

  • Basic Energy Sciences: $1,251,005.00

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