The Plant that Panics

‘Do plants have feelings?’ is one of the most frequently asked plant-related questions on google and it isn’t as daft as you might think.

On the subject of plants and consciousness, there’s a simple answer (no) and a more nuanced answer which is yet to be formed. Just this week, the multidisciplinary science journal PNAS published a study detailing a plant’s calculated response to rain water.

Scientists claim that the Arabidopsis thaliana (common name: Thale Cress) has a built-in ‘panic response,’ which makes the species close its leaves and communicate danger to neighbouring vegetation when it’s raining.

Scientists from two Australian institutions and Lund University in Sweden conducted a series of laboratory experiments with the plants, measuring the chemical and physical responses to external stimuli. When hit by water, plants released high levels of Myc2, a protein which in turn triggers the activation of thousands of genes, resulting in the plant curling its leaves inward.

Even more strikingly, the Thale Cress has mechanisms to send messages to other plants of all varieties - like a warning siren. Professor Millar, head of the study in question explains: "One of the chemicals produced is a hormone called jasmonic that is used to send signals between plants."

Jasmonic acid is released into the air by the Arabidopsis thaliana and surrounding plants (particularly those lower down the canopy) respond by activating their own defences.

But why would plants even want to shield themselves from rain?

Plants (or the vast majority of plants) need rain water to live and Thale Cress are no exception. However, rain water is also one of the prime carriers of disease for plants, so it makes sense for more sensitive areas to shield themselves and collect water only through their roots.

Unlike humans and animals, ‘when danger occurs, plants aren’t able to move out of the way so instead they rely on complex signalling systems to protect themselves,’ Professor Millar points out.

What do you think? Does this mean plants have feelings? Let us know by tweeting us or tagging us on Instagram @BloomboxClub.