Plants are a lot more devious than we once thought. Scientists recently discovered that Dodder, a problematic parasitic plant that causes millions of dollars of damage each year to crops, can basically hack into its host’s genes.

You read that right. A parasitic plant can hack the genes of its host, making the host more vulnerable in the future.

We already knew that there was moss that can remove arsenic from water. We just learned that plants can learn to react to stimuli like an animal would. Plants can heal us. They boost our moods just by existing. But plants that can hack into the genes of other animals is a whole new thing.

This research gets a bit technical, but hang in there – we’ll make it digestible.

Dodder can share RNA with its host plants. RNA essentially acts like a messenger, helping living beings carry instructions from DNA around. MicroRNA is a subset of RNA that specifically helps other types of RNA turn on or off.

 

Recap your college biology knowledge with this video, or just keep in mind that microRNA can turn off genes by interacting with other types of RNA. At least one parasitic plant uses microRNA as a weapon.

 

For a while, researchers didn’t know why Dodder shared RNA with its hosts. 

 

Researchers just found the reason. Dodder’s microRNA was actually shutting off genes in the host plant, rendering the host plant more vulnerable to attack from Dodder.

They still don’t know exactly how this all works.

Jim Westwood, one of the researchers who authored the original research, isn’t shy about the significance of their findings. In an interview with Virginia Tech News, he said, “Host-parasite interaction involves the use of microRNAs as messengers of doom. They are hijacking information from the host… MicroRNAs are a new class of weapon being used in the warfare.”

Researchers have been looking at microRNA for a while as a potential way for plants to communicate with (and mount attacks against) each other. Research in 2016 found that parasitic weeds could steal genes info from their hosts and use that information to attack them further.

Now that researchers know what Dodder is doing to weaken its host plant’s defenses, they’re turning their sights to research on how Dodder does it. Once researchers can understand how Dodder actually pulls this sneak attack off, they’ll be able to mount counter-defenses.  

Since parasitic plants cause so much damage to important crops every year, figuring out how to control Dodder is a high priority for industrial agriculture. Dodder is also what’s known as an obligate parasite, meaning it cannot survive without a host plant.

 

 

How A Parasitic Plant Gets its micro RNA into its Host

 

Dodder uses the same mechanisms for stealing nutrients and sharing microRNA. This parasitic plant taps into the vascular system of its host plants, stealing water and nutrients. Normally, a host plant enacts defenses once it realizes that it’s been “hacked.”

Many plants that are attacked by a parasite will create clumping proteins that staunch the flow of nutrients to an affected site. The researchers showed that Dodder’s microRNA targeted the genes that code for this clumping behavior. These genes are very similar across a wide range of species, meaning that Dodder can knock out many types of plants with a single microRNA attack strategy.

Attacking the genes that code for the proteins that produce clotting seems roundabout. In reality, this attack strategy means that Dodder gets an uninterrupted flow of nutrients from its host. Rather than attempting to deal with a lessened nutrient flow, Didder’s microRNA simply force the host plant to freely share nutrients.

Honestly, it’s a bit freaky.

Researchers also suspect that microRNA-based attacks are more common across plants and fungi than we once thought. Engineering a way for important crops to defend themselves from parasitic plants could save farmers millions of dollars per year.