Effects of a butenolide present in smoke on light-mediated germination of Australian Asteraceae

This study investigated the effects of 3-methyl-2H-furo[2,3-c]pyran-2-one, a germination active butenolide present in plant-derived smoke, gibberellic acid and smoke water on seeds of Australian Asteraceae exposed to different light regimes. Seeds of all species required light, with maximum germination occurring under white light, or light dominated by 640 nm. Compared to untreated seeds, butenolide increased germination of Angianthus tomentosus, Gnephosis tenuissima, Myriocephalus guerinae, Podolepis canescens and Rhodanthe citrina at suboptimal light wavelengths and in the dark to a level equal to, or greater than, smoke water. Germination of Erymophyllum glossanthus and Gnephosis acicularis was not promoted by butenolide or smoke water under any light regime. The action of gibberellic acid was compared to that of butenolide for three species (Angianthus tomentosus, Myriocephalus guerinae and Podolepis canescens), and both compounds were found to stimulate germination. This study provides evidence that butenolide can act in a similar fashion as gibberellic acid in promoting seed germination of light-sensitive seeds. The ecological significance of these findings is discussed.