Engineering a C4 rice prototype: Toward a proof of concept

An IRRI Seminar

By Shanta Karki
Postdoctoral fellow
C4 Rice Project, IRRI

Thursday, 29 August 2013
Havener Auditorium, IRRI

Abstract:

The natural evolution of C4 photosynthesis provides important insights into ways by which C3 crops may be successfully engineered toward increasing yield by up to 50% in the future.

C4 rice has the potential to significantly increase rice yields by raising its photosynthetic efficiency. Installation of C4 photosynthesis in rice is a challenging endeavor because the C4 pathway is very complex and its regulatory factors are not yet well understood. An international consortium of interdisciplinary scientists are working together to overcome these challenges.

At IRRI, we have successfully over-expressed five C4 biochemical genes from maize, visualized the cellular localization of these maize proteins, and studied their physiological traits. Four of these C4 genes have been stacked into one line by intercrossing promising transgenic plants. Detailed molecular and physiological characterizations of these quadruple plants will impart information on where further optimizations are needed. To facilitate efficient transport of metabolites across subcellular compartments for the C4 pathway to function effectively, we are also over-expressing maize genes that encode C4 transporter proteins into rice.

The progress of C4 rice engineering efforts and the strategy to produce a basic C4 rice prototype will be presented.