The use of sunlight by plants for the production of biomass is constrained by a number of key biophysical and biochemical limitations and only 4-7% of the energy in sunlight falling onto a crop is captured into organic matter under the best conditions.

Key factors which limit this conversion efficiency include:

  • about half of the solar spectrum cannot be absorbed by chlorophyll and thus is unavailable

  • photosynthetic electron transport is driven by quantum events, rather than the energy content of the photon

  • absorption of bright sunlight may exceed the capacity of metabolic reactions within the chloroplast to process it

  • the distribution of photosynthetic resources between chloroplasts and leaves in crop canopies cannot always match the dynamic light environment.



Program 2 focused on identifying strategies for maximising light interception by the leaf. It also aimed to minimise the wastage of light absorbed in excess which can be usefully converted in various parts in the crop canopy. Professor Min Chen at University of Sydney and Professor John Evans at ANU were the lead researchers of this Program.


Research areas and outcomes for this Program included:

Studying the fundamental differences in antenna complexes throughout evolution, extending the spectrum of light antennae absorption through introducing new chlorophylls such as chlorophyll-f and manipulating the size of the light antenna complex. Professor Min Chen leads this project at The University of Sydney.

Key outcomes: We demonstrated that chlorophyll d biosynthesis is independent of oxygen levels and reported a “switchable” photosynthetic apparatus in response to changed environments.



Developing strategies to enhance C4 photosynthesis through removing metabolic limitations. This project leaders include Professor Susanne von Caemmerer, Associate Professor Oula Ghannoum, Professor Robert Furbank and Professor John Evans.

Key outcomes: we  demonstrated that C4 photosynthesis is less negatively affected by sugar feedbacks than C3 photosynthesis.


Developing approaches for removing metabolic blockages when light is in excess. Professor Susanne von Caemmerer and John Evans lead this project at ANU.

Key outcomes: We demonstrated that increasing the photosynthetic electron transport capacity by increasing the protein content of cytochrome f, increases CO2 assimilation rate.