It was big news when a researchers at Emory University showed that mice could pass on specific memories to their offspring. The researchers would expose father mice to a specific smell, accompanied by an electric shock. Sure enough, the mice would get jittery every time they smelled the specific scent, even if no electric shock followed. They feared the smell.
The crazy thing was that the offspring showed the same reaction to the odour as their fathers even when they smelled it the first time and were never exposed to an electric shock.
The findings were published in a paper in Nature magazine last year.
Apparently Ivan Pavlov - the guy that made his dogs salivate by ringing a bell - had already published a paper 91 years ago where he claimed that it took him less time to train each offspring generation of dogs to associate the ringing of a bell with food. He claimed that the dogs were passing on this information genetically. But his findings never received much recognition and he was soon dismissed.
If this mouse story is making you raise your eyebrows, then buckle your seats: you are in for a crazy ride now: apparently, plants have memories as well. And they also pass them on to their offspring!
A team of scientists at the Boyce Thompson Institute for Plant Research in Ithaka, New York had shown in a paper published in 2006 that tomato plants could memorise specific caterpillars eating away at them. The tomato plants would defend themselves by producing a toxin in their leaves that would drive the caterpillars away. What is amazing is that the next time the same tomato plant would be exposed to the caterpillar, it would produce the toxin much faster! The plant did that by turning on some of its genes that were previously muted - an epigentic change of its DNA.
And by now you will not be surprised to hear that tomato plant would pass on this molecular memory to its offspring as well. Even the granddaughter generation would remember to respond to the caterpillar invasion more quickly.
The monkeyflower will produce more hair (trichomes) when the previous generation was exposed to plant eating insects (Holeski, 2007). Tobacco plants that were exposed to a the tobacco mosaic virus passed on a defence mechanism to at least two subsequent generations (Monlinener et al., 2006). Plants exposed to high temperatures passed on a tolerance to heat for at least three generations (Whittle et al., 2009). Salt stressed plants passed on a higher tolerance to salt in the next generation (Boyko et al., 2010).
Laura Galloway and Julie Etterson at the University of Virginia went as far as to shown that wild plants will most likely thrive to their highest potential if they grow up under the same conditions that their parents lived in.
This information is not just interesting, it is actually relevant to agriculture today.
Crazy farmers like my boss will feel vindicated for multiplying their own grain seeds every year instead of buying them from a seed distributer - his wheat is optimally adjusted to the soils, the elevation, the amount of rainfall and all the pests that might be lurking around. No commercial seed could ever compete with that.
Most seeds a conventional farmer will buy from a multinational seed company will never have known anything but a sterile environment. The farmer in India will buy the same sterile seed as the farmer in Poland or Canada. At the first sign of drought or pests, the plants will be helpless. So the farmers will have to "save" these helpless plants by buying pesticides, insecticides and fungicides from the very same companies that sold them the seeds.
I am confident that this kind of research will pave the way for decentralised, local seed production to move out of the realm of the the "alternative-organic-nutjob" farmers to become accepted as one of the pillars of sustainable agriculture. Not genetically engineered, laboratory grown patent seeds.