Our interests range from evolutionary genetics, computational biology, plant physiology and molecular biology to translational photosynthesis and increasing crop productivity via genetic modifications.
Improving global crop yield to meet the demands of an increasing world population for food and fuel in the conditions of increasing climate volatility is a central challenge for plant biology. One of the bottle-necks in photosynthesis is the performance of the bifunctional CO2 fixing enzyme, ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco). Under present-day atmospheric conditions, the carboxylase activity of Rubisco is only just over 50% saturated in C3 plants, and its second – oxygenase – activity gives rise to the competing process of photorespiration. Improvement of plant photosynthetic performance by reducing the Rubisco oxygenase reaction will play a central role in achieving increases in global crop yield in the near to midterm (Parry et al., 2013). We showed that there is significant variability in Rubisco kinetics within plants, while many crop species do not possess the most efficient forms of this enzyme (Hermida-Carrera et al., 2016; Orr et al., 2016). Rubisco suboptimal performance in many crops can also result from their cultivation in climates quite different to those experienced by their ancestors. A constellation of recently discovered Rubisco chaperones (e.g. Feiz et al., 2012; 2014) are often species specific, and, as we showed, could curb transplantation of Rubisco between species (Whitney et al., 2015). Here we try to solve two complimentary challenges in improving Rubisco performance in crops: overcoming natural limitations of Rubisco assembly and catalysis, and customizing Rubisco in different crop species and varieties to better fit their current and future growth environments. The underlying causes of the variation in Rubisco kinetics and temperature sensitivity as well as its interactions with assembly and catalytic chaperones are studied using genomic, transcriptomic, proteomic and structural analyses combined with investigation of Rubisco assembly, performance and kinetic properties (e.g. Whitney et al., 2015; Sharwood et al., 2016; Kapralov et al. unpublished). Using tobacco as a screening surrogate, we showed the possibility of improving and fine-tuning the catalytic properties of Rubisco in a range of crop species (Kapralov, Birch & Whitney, unpublished). This research has a potential to be translated into bioengineering Rubisco and its chaperones in crops grown under different climates. This research theme will be performed together with my current collaborators: Dr. Spencer Whitney (Australian National University), Professor Martin Parry (Lancaster University), Dr. Maria Anisimova (Zurich University of Applied Sciences), Dr. Asaph Cousins (Washington State University, USA).
How do plants evolve tolerance to extreme environmental conditions? This is another important question in plant science and agriculture, especially if climate change leads to rising temperature and rapid alterations to environmental conditions in the future – from droughts to flooding. Together with collaborators from Oxford (Dr Robert Grant-Downton) and Newcastle (Professor Anne Borland), we study two extreme survival specialists: (1) ‘resurrection plants’ from the Linderniaceae family, which have the extraordinary ability to lose almost all of their cellular water and desiccate for considerable periods of time, while returning to normal growth without significant damage after rehydration; and (2) CAM plants from the Crassulaceae family, which developed high water use efficiency by switching to nocturnal CO2 fixation. Although these two groups of plants do not contain crop species, our work on mechanisms of their survival in extreme conditions informs research on both Rubisco and Crop Improvement.