A butenolide (furanone) compound in smoke from burning plant material has been shown in lab studies to promote seed germination in a variety of plants that depend on fire to reproduce. Understanding the mechanism of action of the compound and its analogs could provide benefits for agriculture and disturbed-land restoration, according to the Australian research team that made the discovery.

Scientists have known that some plants produce compounds that regulate seed germination, while other plants germinate better after exposure to smoke and heat from wildfires. Yet the identity of possible active ingredients in smoke that stimulate seed germination was unclear until now.

Led by chemistry graduate student Gavin R. Flematti of the University of Western Australia, Crawley, the team identified the active compound as 3-methyl-2H-furo[2,3-c]pyran-2-one and determined that it's a by-product of cellulose combustion [Science, published online July 8, http://www.sciencemag.org/cgi/content/abstract/1099944]. In a combustion chamber, the researchers burned either filter paper (cellulose) or plant material, dissolving the smoke in purified water samples.

The smoke-water extracts were then used in bioassays to monitor seed germination.

Guided by the bioassays, the researchers fractionated components of the dissolved smoke and used several analytical techniques to identify the butenolide as the main germination promoter. Because the butenolide was an unknown compound, they devised a synthesis to confirm its identity. The synthetic version and the smoke-water extracts both promoted seed germination for several plant species at concentrations in the parts-per-trillion range.

With the identity of an active ingredient from smoke in hand, the researchers note, scientists now have the opportunity to uncover how the butenolide and related compounds stimulate seed germination in the natural environment.