The sweet and musky scent of home: biogenic ethylene fine-tunes seed germination in wetlands (Plant Biol.)

Light, temperature, substrate moisture and oxygen availability are renowned germination triggers for wetland species. However, wetlands sediments are a significant source of gases that might shape the species germination behavior, such as ethylene –a renowned germination promoter. Still, little is known about how this gas interacts with other biotic and abiotic factors, limiting our knowledge about its ecological relevance. Here, Phartyal and colleagues assessed the effect of ethylene on the germination of six wetland species and its interaction with dormancy and other germination triggers. Ethylene was ineffective in breaking the dormancy of these species. Still, it accelerated the germination of non-dormant seeds and increased it in light, temperature and oxygen conditions that otherwise were suboptimal. Since ethylene concentration varies according to seasonal fluctuations in water level, the concentration of this compound acts as a flooding-sensing mechanism that helps seeds synchronize germination with ideal conditions for seedling establishment. Therefore, this research provides an exciting starting point for future studies about the effect of this gas on the germination ecology of wetland species. (Summary by Carlos A. Ordóñez-Parra @caordonezparra) Plant Biol. 10.1111/plb.13385