Among the external signals that plants perceive are karrikins released from bushfires. Clearing of vegetation by fire presents an opportunity for seeds to germinate and take advantage of new resources and reduced competition.
Following the discovery of karrikins at UWA, we have been trying to understand how plants perceive and respond to these compounds. Using the model plant Arabidopsis thaliana (thale cress), we have identified a number of proteins necessary for karrikin responses. Among these is KARRIKIN INSENSITIVE2 (KAI2), the protein that binds and recognises karrikin molecules.
Our work involves understanding the function of KAI2, the mechanisms of karrikin recognition, and the evolution of karrikin perception as an adaptation to fire.
Many molecular biological processes can be broken down into their component parts, taken out of their original cellular context, and studied in isolation. Likewise, different parts assembled in different ways can produce novel outcomes and functions. The principle of synthetic biology is to engineer useful solutions using existing biological parts in new, imaginative combinations.
We are using synthetic biology approaches to study plant signalling processes, especially to investigate karrikin perception. By combining DNA sequences from plants with that of viruses, jellyfish, bacteria or yeast, we can ask powerful questions about the mechanisms of plant signalling.
Hormones & Plant Development
Plants use growth-promoting and growth-inhibiting chemical signals to co-ordinate development with changes in the environment. The functions of classical plant hormones such as auxins, cytokinins and gibberellins are well understood, but there are likely more signalling compounds to be discovered. One of the most recent type of hormone is the strigolactones, which are chemically similar to karrikins. By combining chemical analysis with gene discover, we are interested in understanding how strigolactones, karrikins and their analogues influence plant development.
How can we apply our findings about molecular signalling networks to improve plant performance where it matters – out in the field? We are exploiting the significant range of developmental impacts of the KAI2 signalling system to find ways that we can enhance crop productivity. Can we generate safe and effective chemical formulations that enhance the growth of plants under unfavourable conditions? We are also interested in the mechanisms that affect photosynthetic development, especially with regard to reduced light intensity associated with high crop density.