Poster Presentation International Plant Molecular Biology Conference 2024

Elucidating and Engineering Cell-Specific Cyclic Electron Flow of C4 Photosynthesis (#198)

Samuel J Nix 1 , Kai Xun Chan 1 , Marten Moore 1 , Maria Ermakova 2 , Robert Furbank 1
  1. Australian National University, Acton, ACT, Australia
  2. School of Biological Sciences, Monash University, Melbourne, Victoria, Australia

In recent years crop yields have reached a plateau per hectare of land and are projected to not meet the demands of the growing global population1. Additionally, there is an increasing demand for sustainable fuels derived from crop biomass requiring more land use2. Increasing CO2 assimilation by improving photosynthesis could be the next green revolution, allowing for increased crop yields for food and fuel3. C4 crops represent major food crops and biomass sources for biofuel. C4 plants achieve this due to the carbon concentrating mechanism (CCM) of C4 photosynthesis allowing higher CO2 assimilation compared to C3 plants4. The C4 CCM obtains additional ATP production by Cyclic Electron Flow (CEF) wherein electrons are diverted away from NADPH production and back towards ATP production5. One of these genes involved in CEF, the PGR5-Like Photosynthetic Phenotype 1 (PGRL1), duplicated early in the grass family (Poaceae) and shows cell-differential regulation in NADP-ME subtype C4 grasses. My project aims to elucidate the cell-specific and -differential expression of proteins involved in CEF. I also aim to increase CEF in C4 grasses to further improve ATP synthesis and CO2 assimilation.

  1. Ray, D. K., Mueller, N. D., West, P. C. & Foley, J. A. Yield Trends Are Insufficient to Double Global Crop Production by 2050. PLOS ONE 8, e66428, doi:10.1371/journal.pone.0066428 (2013).
  2. Liu, Y. et al. Biofuels for a sustainable future. Cell 184, 1636-1647, doi:https://doi.org/10.1016/j.cell.2021.01.052 (2021).
  3. Simkin, A. J., López-Calcagno, P. E. & Raines, C. A. Feeding the world: improving photosynthetic efficiency for sustainable crop production. Journal of Experimental Botany 70, 1119-1140, doi:10.1093/jxb/ery445 %J Journal of Experimental Botany (2019).
  4. von Caemmerer, S. & Furbank, R. T. The C4 pathway: an efficient CO2 pump. Photosynthesis Research 77, 191, doi:10.1023/A:1025830019591 (2003).
  5. Munekage, Y. N. Light harvesting and chloroplast electron transport in NADP-malic enzyme type C4 plants. Current Opinion in Plant Biology 31, 9-15, doi:https://doi.org/10.1016/j.pbi.2016.03.001 (2016).