Generation of synthetic tools for the engineering of C4 photosynthesis.
The C4 photosynthetic pathway is the most productive photosynthetic pathway existing on earth especially in hot and arid climates. It has evolved 60 times independently in 19 different plant families. The understanding of the genetic basis of this great example of convergent evolution would allow us to integrate the C4 photosynthetic pathway into major C3 crop plants like rice to improve their water and nitrogen use efficiencies.
A striking characteristic of the vast majority of C4 plants is a specialised anatomy named `Kranz anatomy`. This anatomical adaptation is a major evolutionary prerequisite to evolve the C4 carbon concentrating cycle and represents a major engineering challenge due to complexity of the trait. It is not yet fully understood which developmental factors determine Kranz anatomy but we agree that a cohort of genes is needed to initiate this specialised anatomy early in development prior to the integration of the two-celled C4 photosynthetic cycle. Therefore, the conversion of leaf anatomy and the integration of an entire photosynthetic pathway can only be achieved by multigene transformation (MGT) whereby every nuclear transgene requires its own promoter. The promoter of choice should allow the expression of an array of developmental factors, transporters and photosynthetic enzymes to be targeted to the right cell-type within the leaf. Moreover, it requires a toolbox of cis-regulatory modules (CRM) to drive cell-type specific expression.
My research focuses on biological and methodological aspects: 1. The functional characterisation of genetic regulators of Kranz anatomy. 2. The identification of cis-regulatory modules driving expression early in vascular development in leaf primordia. 3. The generation of an experimental system for multigene targeting to bundle sheath cell.
Keywords expertise: Kranz anatomy, C4 photosynthesis, bundle sheath cells, leaf development, synthetic biology