Scientists remotely control plant pores with light

July 9 (UPI) – Scientists have developed a method to remotely control a plant’s stomata, the pores that allow leaves to regulate how much CO2 they absorb and how much water is allowed to transpire.

Each stomatal pore is sandwiched by a pair of guard cells. When the internal pressure in the guard cells drops, they relax and close the pore. As the pressure increases, the guard cells pull away, widening the pore.

Signaling pathways inside guard cells are complex, making intervention difficult, but the authors of a new study – published Friday in the journal Science Advances – have developed a way to manipulate stomata using pulses bright.

To begin with, researchers at Julius Maximilian University in Würzburg, Germany installed a light-sensitive protein switch in the guard cells of tobacco plants – a technology from the field of optogenetics that has already been used. in animal cells.

For the switch, scientists used a light-sensitive protein from algae species Guillardia theta.

When exposed to light pulses, the protein and its anion channel ACR1 scavenge chloride from guard cells, paving the way for potassium release.

This exodus causes the pressure inside the guard cells to drop and the pore to close within 15 minutes.

“The light pulse is like a remote control for the movement of the stomata,” said lead researcher Rainer Hedrich, professor of biophysics at JMU, in a press release.

According to Hedrich, the latest findings provide evidence for the link between anion channels and stomatal regulation.

In the future, botanists and agronomists may be able to design varieties of plants with more anion channels in their guard cells. This would allow them to open and close their pores more effectively to protect themselves from heat waves and prolonged droughts.

“The anion channels in plants are activated during stress; this process is dependent on calcium,” Hedrich said. “In a follow-up optogenetics project, we want to use calcium-conducting channelrhodopsins to specifically allow calcium to flow into guard cells by exposure to light and to understand in detail the mechanism of anion channel activation. . “

Hedrich suggests that their new remote control can be used to conduct a variety of new plant experiments.

“With this, we can gain new knowledge about how plants regulate their water intake and how carbon dioxide uptake and stomatal movements are coupled,” he said.