Plants breathe with millions of tiny mouths. We used lasers to understand how this skill evolved

Plants breathe with millions of tiny mouths. We used lasers to understand how this skill evolved

Plants breathe with millions of tiny mouths. We used lasers to understand how this skill evolved

HOBART (AUSTRALIA): (Mar 27) Plant behaviour may seem rather boring compared with the frenetic excesses of animals. Yet the lives of our vegetable friends, who tirelessly feed the entire biosphere (including us), are full of exciting action. It just requires a little more effort to appreciate.

One such behaviour is the dynamic opening and closing of millions of tiny mouths (called stomata) located on each leaf, through which plants “breathe”. In this process they let out water extracted from the soil in exchange for precious carbon dioxide from the air, which they need to produce sugar in the sunlight-powered process of photosynthesis.

Opening the stomata at the wrong time can waste valuable water and risk a catastrophic drying-out of the plant’s vascular system. Almost all land plants control their stomata very precisely in response to light and humidity to optimise growth while minimising the damage risk.