Plants are not as touchy-feely as you think

Not everyone is a touchy-feely kind of person. From warm embraces to holding hands to a congratulatory pats-on-the-back – for some it triggers an immediate, internal defense.

A new study recently published in The Plant Journal has discovered that many plants aren’t very touchy-feely either.

“The lightest touch from a human, animal, insect or even plants touching each other in the wind, triggers a huge gene response in the plant,” says Professor Jim Whelan, Research Director of the La Trobe Institute for Agriculture and Food at AgriBio.

“Within 30 minutes of being touched, 10 percent of the plant’s genome is altered. This involves a huge expenditure of energy which is taken away from plant growth. If the touching is repeated, then plant growth is reduced by up to 30 percent.”

Additional research is needed to fully determine why plants react so strongly and defensively to touch. But the hope is to find ways around this phenomenon in order to reduce sensitivity and ultimately optimize growing rates.

Dr. Yan Wang who co-authored the research said, “We know that when an insect lands on a plant, genes are activated preparing the plant to defend itself against being eaten. However, insects are also beneficial, so how do plants distinguish between friend and foe?”

Whelan believes it may be possible, through more targeted genetic testing, to breed plant species that are less sensitive to touch, while still being sensitive to insect attacks and fluctuating temperatures in the environment.
“As we don’t understand why plants display such a strong defense response to touch, if we are to breed less touch-sensitive varieties, we need to first understand what some of the consequences might be,” Professor Whelan said.

“For example, could touch-resistant plants be more susceptible to disease because a crucial defense mechanism has been removed?”

Next steps include testing their touch sensitivity research on crop species.

There’s a scientific reason why sensitivity is part of a plant’s genetics. Researchers must now unravel the possible catastrophic consequences of breeding plants that are desensitized.