Effect of smoke-derived extracts on Spirodela polyrhiza, an aquatic plant grown in nutrient-rich and -depleted conditions

• The smoke-derived compound KAR1 enhanced growth of Spirodela polyrhiza.
• KAR1 was more effective than smoke–water at promoting growth.
• Unlike smoke–water, KAR1 had no inhibitory effect at higher concentrations.

The effect of smoke-derived extracts (crude smoke–water and karrikinolide [KAR1]) on the growth of an aquatic plant Spirodela polyrhiza was investigated. Smoke-derived compounds enhanced the growth of S. polyrhiza . The effects were also modulated by nutrient concentration with plants growing in nutrient-rich conditions (50% Hoagland’s solution) being less sensitive to high concentrations of smoke–water compared to those growing in nutrient-depleted conditions (1% Hoagland’s solution). The chemical properties of KAR1 and its ability to move through both the aerial and soil environments suggest that it is likely to eventually enter the water system. As the present results show that growth of the aquatic S. polyrhiza is significantly influenced by smoke-derived KAR1 with the response modulated by nutrient concentrations, the ecological implications of smoke-derived compounds entering freshwater systems requires further investigation.

Figure optionsDownload as PowerPoint slide