After the smoke has settled on the bushfire that destroyed more than 40ha of Kings Park and threatened nearby buildings, the name of a substance that could play a major role in regenerating the park has been revealed in the world's most highly cited plant journal - Plant Physiology.
A collaborative research program between researchers at Kings Park and Botanic Garden and The University of Western Australia have given the Noongar name - Karrikin - to a substance that stimulates seed germination and seedling growth in many plants after bushfires.
It has long been recognised that smoke provides a germination cue for more than 1200 species from 80 genera including representatives from all of the major plant families. The identification of the active compound in smoke, a butenolide (3-methyl-2H-furo[2,3-c]pyran-2-one) was a major step forward in elucidating the new class of plant signalling molecules. A number of analogues of the butenolide, both synthesized and identified in smoke, have since been shown to have germination promotive activity.
As the butenolide class of compounds represents a very broad range of naturally occurring molecules (identified in fungi), it was important to distinguish the germination stimulating butenolide in smoke from others. In deriving a name for the new class of signalling compounds UWA Professor of Linguistics Alan Dench advised that the first recorded Noongar word for smoke from the Perth area in the 1830s is ‘karrik'. From this foundation the family of karrikins was born with the -in suffix being added to conform with the naming of other bioactive substances. The name karrikin acknowledges that the scientific discovery was made on Noongar land, reflecting the importance of fire and smoke to plant ecology and to indigenous culture.
Research is continuing into identifying the mode of action of this new class of signalling compounds, with several nationally competitive grants being funded by the Australian Research Corporation. This fundamental research links in with the research of Kings Park scientists looking to understand the use of the karrikin molecules in ecosystem restoration.
Article by Jason Stevens.
1. Nelson et. al. (2009). Karrikins Discovered in Smoke Trigger Arabidopsis Seed Germination by a Mechanism Requiring Gibberellic Acid Synthesis and Light. Plant Physiology. 149(2): 863 - 873.
2. Dixon et. al. (2009). Karrikinolide - a Phytoreactive Compound Derived from Smoke with Applications in Horticulture, Ecological Restoration and Agriculture. Acta Horticulturae (ISHS) 813: 155-170.
3. Rokich and Dixon (2007). Recent advances in restoration ecology, with a focus on the Banksia woodland and the smoke germination tool. Australian Journal of Botany. 55: 375-389.