Those who cultivate manicured lawns curse 'fairy rings' of mushrooms (pictured) and the rapid grass growth associated with them. The compound that stimulates this growth, 2-azahypoxanthine (AHX), was isolated from a fungus in 2010, but Choi et al. now report in Angewandte Chemie that plants also produce it (J.-H. Choi et al. Angew. Chem. Int. Edn; 2014).

The authors treated several plants with AHX, and observed that it was metabolized to a compound called 2-aza-8-oxohypoxanthine (AOH). They went on to show that both AHX and AOH are produced by plants, and are present in rice at levels similar to those of plant hormones.

Choi et al. found that a member of the purine metabolic pathway is converted to AHX and AOH in rice, and they extracted crude enzymes that catalyse the reactions involved from rice and Arabidopsis, a model plant. They conclude that AHX and AOH are formed in a previously unknown metabolic pathway.


Intriguingly, AOH stimulates rice growth, albeit not as much as AHX. Frustrated haters of fairy rings could perhaps take heart from the thought that both compounds hold promise for horticulture.