Howard Griffiths (scientist)
- For other people of the same name, see Howard Griffiths.
Howard Griffiths holds the Chair of Plant Ecology at Cambridge University, Cambridge, England, since 2000, where he is a fellow of Clare college. His scientific interests focus on plant physiological ecology, particularly in the application of molecular techniques to whole-plant physiology to investigate the regulation of photosynthetic responses and plant water use; his specialisations include:
- responses to climate change, reflected by his membership of the Cambridge Centre for Climate Science, CCfCS, ;
- global food security, a University of Cambridge Research Theme
- conservation and bioenergy crops, through his membership of the Cambridge Conservation Initiative .
Howard has a particular interest in introducing the dynamics of plant processes without the need for time-lapse photography. Lectures demonstrate how the spatial segregation of photosystem 1 and photosystem 2 creates a highly dynamic system, with lateral mobility and migration of damaged reaction centres through thylakoid membranes. He studies the reaction mechanism of RuBisCO and how plants have evolved turbocharging "carbon concentrating mechanisms" to enhance the operating efficiency of photosynthesis. His work uses stable isotopes of carbon (carbon-13 and oxygen Δ18O to integrate carbon and hydrological cycles for individual plants, rainforest ecosystems and Antarctic moss deposits.
His research focuses on biochemical mechanisms such as C4 carbon fixation which spatially separate one of the anaplerotic reactions of CO2 fixation by Phosphoenolpyruvate carboxylase within mesophyll tissues and RuBisCO in an inner bundle sheath cell: CO2 concentrations are elevated and offset the wasteful oxygenase activity and the salvage pathway, photorespiration, leading to improved radiation, water and nitrogen use by C4 plants. Current programmes are focusing on (i) the energetics and leakiness of the C4 pathway at low light and loss of canopy carbon gain; (ii) evolutionary origins and physiological function of the bundle sheath cell system, perhaps as a means of enhancing stem and leaf hyraulic conductance under drought and low temperatures. He has longstanding interests in crassulacean acid metabolism and has worked in Trinidad and Panama on tropical epiphytes such as the bromeliad and orchid and cacti families, and now has interests in bioenergy production by Agave.
He has investigated carbon concentrating mechanisms (see photosynthesis) in algae and hornworts, focusing on the molecular determinants of the chloroplast pyrenoid in Chlamydomonas. He has a major collaboration funded by BBSRC and NSF to explore the possibility of introducing elements of the algal carbon concentrating mechanism into higher plants (CAPP - Combining Algal and Plant Photosynthesis).
References
- ↑ http://www.plantsci.cam.ac.uk/research/howardgriffiths.html University of Cambridge - Department of Plant Sciences: Howard Griffiths (Accessed April 1, 2011)