Altered plant turns red to warn of environmental pollutants

Checking for pollutants in the environment via soil sampling and other traditional methods can be a laborious process, but what alternatives are there? Well, scientists have now engineered a plant to turn red when exposed to specific toxic chemicals.

The idea behind the technology is that plots of such plants could be grown in areas that are being monitored for pollutants. Instead of having to repeatedly go in and obtain soil samples, scientists could just analyze aerial photos of the plots – if the plants were red, that would mean the targeted pollutant was present.

For the study, researchers from the University of California, Riverside genetically altered receptor proteins in the thale cress plant (Arabidopsis thaliana).

Ordinarily these proteins bind with and react to another protein known as abscisic acid (ABA), which the plant produces in response to drought conditions. When the receptor proteins detect ABA, they prompt the plant to close tiny pores (called stomata) in its leaves and stem – doing so helps keep water already in the plant from evaporating.

The UC Riverside scientists had previously discovered that it was possible to alter the receptor proteins in such a manner that they would bind with chemicals other than ABA, prompting different plant responses. For this study, the receptors were altered to bind with a banned highly toxic pesticide known as azinphos-ethyl. When the receptors do so, they cause the plant's normally green leaves and stem to turn red.

Importantly, the metabolism of the plant isn't adversely affected – for instance, it can still conserve water in dry conditions. Additionally, the technology could likely be adapted to detect other pollutants.

"We’re trying to be able to sense any chemical in an environment," said UC Riverside's Prof. Sean Cutler. "Other pesticides but also drugs like birth control pills or Prozac in the water supply, things people are worried about being exposed to. These are applications within reach now."

A paper on the research was recently published in the journal Nature Chemical Biology.

Source: University of California, Riverside

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