Most people think of viruses as nothing more than parasitic organisms looking to kill its host. This limited view doesn’t take into consideration the sustained survival of the pathogen. After all, if the host dies, so will the virus. That’s why these organisms need a large supply of unwitting – and usually unwilling – victims.

Human viruses have it pretty good thanks to all that shedding we do over the course of a day. But the same cannot be said for plant viruses. Plants don’t move and for the most part, don’t share their vital fluids without some help. Without outside assistance from creeping plants or insects, the future can be quite dire.

Which brings me to this interesting pathogen…

cmvIt’s called Cucumber Mosaic Virus (CMV)

You may not have heard about it but you may have seen it in action…

cuke_mosaicThis is what it does to cucumbers

But these plants are not the only host for this virus. The pathogen can infect over one thousand different species of plants including one we all cherish…

cmv-tomatoesTomatoes

The most important route of spread happens to be aphids. These little insects can pick up the virus and spread it to another healthy plant. But there’s a problem. When an aphid sees an infected plant, they tend to say…

nopeCan you blame them?

So the virus has developed an ingenious method to get the aphids to come. They lure the insects by changing the way the plant smells. It’s a rather complicated process so I won’t go into the details. If you are curious, you can read more about it here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2840436/

This game-game changing trait makes CMV even more troublesome than once believed. Yet, there are even more surprises in store. In a study released today, it seems the virus can attract more than just aphids. They also seem to lure in…

bee-tomato Bees…

At first glance, this may seem reasonable as bees are pollinators. They would help to spread the virus. Except bees don’t actually come into contact with the pathogen. Attracting them seems to have no value to virus survival. Which brings up the question…

Start_With_WhyWhy would the virus do this?

There are two trains of thought as to why this phenomenon occurs.

The first is a form of pathogenic philanthropy. When the bees come near a tomato plant, their buzzing wings tend to improve self-pollination. The number of seeds per fruit – yes, tomato is a fruit – increases and the plant population may increase.  The buzzing may also help cross-pollination giving the population an even greater chance for sustained success over the generations.

When you hear this side of the story, you might think…

cat-niceWho doesn’t love a virus that gives back?

As for that second theory, it’s as you might expect, devious domination. The virus needs a sustainable crop of hosts to maintain survival. Bees are the perfect vectors as their activity has no link to the virus itself. As the number of tomato plants increase, the virus has a better chance at survival.

But there’s even more malice to this method. Some tomato plants can resist the virus making survival less likely. By attracting bees to the infected plants, the virus is effectively ensuring resistance is diluted out of the tomato population. This would allow the virus to completely dominate the environment in a dastardly and definitively despicable way. You could say…

pres-snowPresident Snow Approves
(if you don’t know who this is…ask your kids)

While both theories are possible, neither has been proven as interviewing a virus tends to gain few answers (they are always mysterious that way). However, if one is to bet on the reason behind this strange action of the virus, I suggest the latter is correct. Considering self-sustainability drives pretty much all biological life, selfish preservation always, um, trumps, benefiting others.

May the odds be ever in your favour…

PS – if you want to read the article to get a better sense of the work done, you can find it here:
http://journals.plos.org/plospathogens/article?id=10.1371%2Fjournal.ppat.1005790

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