Isolation of the major germination cue from plant-derived

A highly active, heat stable, long lasting compound, 3-methyl-2H-furo[2,3-c]pyran-2-one (1), that stimulates seed germination was isolated from plant-derived smoke water using bioactivity-guided fractionation. The identification of this natural molecule, the major germi-nation cue from smoke, should now rapidly lead to a more comprehensive understanding of the role of smoke as a promoter of seed germination. Fire is well established as a major evolutionary driving force in seed biology and is clearly regulated and mediated via both physical and chemical cues involved in the germination process (Van Staden et al. 2000). The occurrence of wild fires during dry seasons in many parts of the world results in large volumes of volatile compounds being released into the atmosphere (Figure 1). These smoke clouds contain partic-ulate matter, water vapour, gases and pyrolysis products which can drift over vast distances and may potentially impact on plants outside the immediate vicinity of the fire, either directly as aerosol smoke, or via aqueous media, be it moist soil or water runoff into streams, lakes and impound-ments. For this reason, the burning of plant material is banned in many countries. Figure 1 shows the result of a grassland fire in a Themeda triandra climax community in KwaZulu-Natal, South Africa. The fascinating discovery that cold aerosol smoke and aqueous smoke solutions stimulate seed germination in nature (De Lange and Boucher 1990) led to many attempts to understand the phenomenon of smoke-stimulated see