[Seminar] The evolution of C4 photosynthesis

Seminar

Title: The evolution of C4 photosynthesis

Speaker: Julian Hibberd

Affiliation: University of Cambridge

Sumary

Julian will discuss processes that have enabled to evolution of C4 photosynthesis. The C4 pathway is widely considered one of the most remarkable examples of the convergent evolution of a complex trait. Despite involving alterations to leaf anatomy, cell ultrastructure and biochemistry, the C4 pathway is found in over 60 separate lineages of angiosperms. The outcome of using the C4 pathway is an enhanced photosynthetic efficiency, but also increased nitrogen and water use efficiencies.  I will discuss evidence ranging from mathematical models of its evolution, the ancestral role of proteins used in the complex pathway, to the mechanisms regulating gene expression that impact on our understanding of how this complex evolutionary transition took place.

 

Short CV

Julian Hibberd’s research aims to understand how C4 photosynthesis operates, and to provide insight into the molecular mechanisms driving its evolution. Highlights include the demonstration that C3 plants possess characteristics of C4 photosynthesis; technologies to allow specific cell types to be marked in rice, and chloroplasts from specific cells to be isolated from Arabidopsis; and the development of the most closely related C4 plant to Arabidopsis as a model. Comparative analysis of closely related C3 and C4 plants is a major part of the current programme, and in particular the use of Cleome gynandra, the C4 species most closely related to Arabidopsis. His work on C3 species has impacted on our understanding of the ancestral role of proteins that are recruited into the C4 pathway. Analysis of closely related C3 and C4 plants led to the identification of elements in cis that control the expression of multiple genes recruited into C4 photosynthesis. Together, the work provides insights into the evolution of one of the most complex examples of convergent evolution in plants.