Internet of tomatoes: how nature’s IT network could help agtech

Tomato plant signaling secrets revealed by nature's IT network could improve crop monitoring, and yes, it's another win for fungal machines.
25 January 2024
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IT networks have grown increasingly sophisticated over time, but – when it comes to efficiency and performance – plants and fungi remain leaders in the field of advanced communications. Not only that, nature’s IT network is self-assembling and fully biodegradable, and there are plenty of lessons to be learned for developers.

Researchers have been delving into the mechanisms at work, which allow crops to communicate with each other, and even recruit other living creatures to come to their aid when covered in predators. Literally rooted to the ground, plants have to face up to their attackers with no option of fleeing and seeking cover.

Nature’s IT network in action

Recently, entomologists have shown how tomato plants seek help using the transmission of volatile organic compounds (VOCs). “When a caterpillar chews on a leaf, the plant sends out a signal that calls out to the caterpillar’s predators,” said Erinn Dady – first author in a study that reveals some tomato varieties to be more capable communicators than others. “It’s like a billboard that tells them where lunch is.”

In the late 1990s, workers at the US Department of Agriculture discovered that corn seedlings could recruit parasitic wasps – capable of laying deadly eggs inside caterpillars attacking the maize – on demand. But that’s not all, as distress signals can be deciphered by multiple crops such as tobacco, chili peppers, beans, and cucumbers – to list just a few examples.

Plants can warn their neighbors if they become threatened, giving other plants more time to react. Electrical signals within an individual plant can propagate internally – a process that’s been found to be linked to an increase in calcium levels – so that connected leaves can release chemicals to deter unwanted bugs.

What’s more, when leaves in adjacent canopies touch, electrical signals can flow from one plant to another – particularly if there is water in the air and leaves are moist. The phenomenon has been dubbed network acquired acclimation and is just one example of plant connectivity.

Below the soil, plants strike a deal with mycelium – a fungal root network that can extend for kilometres – and receive a stream of nutrients in exchange for sugars derived from photosynthesis. The combination is a powerful one and has been shown to help stabilize heavy metals such as lead, which may otherwise pollute groundwater – a process known as phytoremediation.

Plus, there’s evidence that plants sharing common mycorrhizal (a term combining the Greek words for fungal and root) networks can eavesdrop on defence signals sent by their pathogen-challenged neighbours. Again, this buys plants more time to mount defenses before being attacked themselves.

Fungal computing

Mycelium has other properties too – arguably the most fascinating of which is being able to generate bursts of electrical spikes resembling neural signaling in the brain – which have captured the imagination of unconventional computing experts such as Andrew Adamatzky in the UK. And fungi are by no means the only ones transmitting within nature’s IT network, which also supports wireless broadcasts.

In 2023, using microphones capable of detecting frequencies beyond human hearing, agtech experts in Israel and the US discovered that plants emit ultrasonic airbourne sounds when stressed. And those sounds tell a story. “We developed machine learning models that succeeded in identifying the condition of the plants, including dehydration level and injury, based solely on the emitted sounds,” writes the team in the journal Cell.

And, if you are curious to hear what talking tomatoes sound like, there’s a sound clip available here (via CNN), which has been sped up and treated to make it audible to the human ear.

Being able to listen and respond to plants – for example, when they are demanding more water – has obvious appeal in food production and could avoid the use of excess nutrients, saving resources. Also, monitoring the release of VOCs could signal when it’s time to apply pesticides or even distribute natural predators.

There’s a vast amount that we can learn from nature’s IT and those solutions will be a breath of fresh air given how much energy conventional computing infrastructure consumes and the difficulty in neutralizing the environmental impact of such technology.