Research Fellows Directory
Professor Luciano Freschi
University of Liverpool
Crassulacean acid metabolism (CAM) and the C4 pathway are photosynthetic adaptations that significantly improve plant water use efficiency, which is the amount of water lost for each molecule of carbon dioxide converted into sugars via photosynthesis. In CAM plants, water use efficiency can be up to 16 times greater than in C3 crops. Hence, engineering stress-induced CAM-like traits into non-CAM crops represents a promising approach to increase plant water use efficiency and minimize agricultural losses due to drought. Some non-crop species naturally have this capacity of shifting from C3 or C4 to CAM under stressful situations. Among them, Portulaca oleracea is one of the few plants known to switch between C4 and CAM photosynthesis depending on the environmental conditions. We have recently generated an efficient stable genetic transformation protocol for this species, and now a detailed functional analysis of genes coding for isoforms of key enzymes shared by both C4 and CAM is being conducted. Besides uncovering the relevance of these genes for both photosynthetic pathways, we are also generating CAM- and C4-deficient transgenic lines, which will be critical for determining the importance of CAM-induction under stressful conditions. Moreover, by using state-of-the-art approaches, we are characterizing the signaling mechanisms controlling the rapid and completely reversible shifts in photosynthetic modes observed in this flexible plant model. Therefore, this research will provide fundamental scientific knowledge that may facilitate future biotechnological improvements in the drought tolerance of crops, which can be a valuable contribution to humanity’s response to the global food security crisis.
Interests and expertise (Subject groups)