While plants and humans have little in common, a team of University of Wisconsin Department of Botany researchers were “astonished” after accidentally discovering calcium plays a similar role in each.

A new form of probe technology was used as a constant to study how plants react to stress and surprised a team of researchers led by professor Simon Gilroy when it began displaying rapid calcium transmission waves, similar to calcium’s role in neurotransmission. 

“The microscope we work with is on the other end of the building, and this was one of those times when they came down to this end of the building and said, ‘You’ve gotta come and have a look at this,’” Gilroy said. “Because it was absolutely awesome when we saw it.”

The sensor changes color from green to red when calcium is present, according to a UW statement. When the team applied stress to the plants, the sensor would repeatedly emit a wave of red traveling rapidly from the roots to the top of the plant, Gilroy said.

The research team believes the evidence of calcium waves produced by the new machinery suggests plants use the chemical to transfer sensory information quickly over long distances, for example, from root to shoot or an injured leaf to a healthy leaf, Dirk Spencer, a sophomore studying genetics at UW who has worked on the study for more than a year, said.

“If an insect starts nibbling on one leaf of a plant, very quickly, the whole plant starts switching on defense responses,” Spencer said. “We’ve known about those phenomena for a very long time, but we didn’t really have any of the machinery regarding how that local thing that’s happening to the plant gets transmitted to the rest of the plant.”

Gilroy and his team will study the specifics about which molecules and genes cause these signals, he said. After they establish this, he said they think they will be able to determine how reactionary systems in plants work.

The team hopes to determine what this means in regards to the plant deciding what specific reaction processes to employ after these signals are sent, Gilroy said. However, he said these questions are far from being answered.

Spencer said his procedural responsibility in continuing the study includes inserting sensory protein into plants, identifying the plants exhibit the protein in the most efficient way and then adding different stimuli to the plants and observing the plants reaction.

By determining which genes are active in these reactions, they are trying to connect specific calcium signals to certain stimuli, Spencer said.

As the study progresses, Spencer said the Global Health Institute on campus could benefit from this connection between understanding how plants cope with a stressful environment because it could be helpful in regards to food security around the world.

“[UW] is a hotspot for research. When you have so many types and different levels of research going on, it gives rise to great discoveries and great collaborations,” Spencer said.