An Ongoing War

At first glance, plants seem pretty harmless. I mean, what's this Honey Mesquite tree going to do to you if you try to cut it down? Fall on you I guess...

Image Courtesy of Encinalense

Apart from the obvious tactics like poison berries, plants have some really cool defense mechanisms to repel or 'take care of' predators. For instance, corn releases volatile chemical compounds when it is being eaten by worms. These compounds attract parasitic wasps that then lay eggs inside the worms. It's a win-win for the plant and the wasp. Other examples include essential oils that plants release when getting eaten. These oils can deter insects from the bad taste or smell, or even cause the plant to fortify its cell walls in order to make it more difficult to consume. That smell of freshly cut grass some people adore is actually a compound the plant releases to warn neighboring plants that danger is coming. Looking at it from that perspective, you're smelling the screams of your lawn.

Poor Things..
Image Courtesy of Pixabay.org

To combat all of these defense mechanisms, insects will have their own novel chemical compounds in their saliva. These compounds will suppress the defenses before the plant has the ability to activate them. Doctoral candidate Loren Rivera-Vega is investigating how a particular kind of caterpillar, the cabbage looper, avoids the defense systems of the plants it eats. The cabbage looper is quite unique in that it can eat a remarkable range of plants without triggering their defenses.

Cabbage Looper Caterpillar
Image Courtesy of Brittany Dodson

In order to determine what it is about the saliva that makes it unique, Rivera-Vega is letting the caterpillars eat different kinds of food sources, and then seeing what changed in their spit. After letting the insects feast on the different diets, she harvests the leaves and the caterpillar, and then does an analysis on the leaves to see what defense compounds were released by the plant. Then she slices up the caterpillars and harvests their salivary glands. The plants are then placed in a salt solution in order to extract the compounds for identification. She has found that the saliva does in fact change based on diet, increasing or decreasing the levels of certain proteins in order to better deal with the defenses of that particular plant.

Her next step is to better analyze the defense compounds put out by the different plants, in order to see if the caterpillar is really better dealing with the plants by changing their spit. This research could be very useful for agricultural purposes, as by better understanding the tactics that insects will take to prevent plant defenses, we can produce crops that are better suited to protect against insect damage. As farm land is getting more and more precious, the idea of efficiency in farming keeps getting more important.

A New Fingerprint

Dusting for Fingerprints
Image Courtesy of ABC

Crime TV shows love dusting for fingerprints, and for a good reason. It's one of the more common techniques in forensic science, since fingerprints are supposed to be unique from person to person. In 2015, it was found that a fingerprint test can even identify someone's gender! However, when it comes to forensic science, more tests are always better. With new insights into body flora, a new novel identification technique is being looked into here at Penn State. An international team of researchers, led by Moriah L. Szpara, assistance professor of biochemistry and molecular biology, is researching how different strains of viruses present in the body may reveal a person's history.

The man of the hour. Pretty cute, eh?
Image Courtesy of Penn State

This all started with the identification of the genome of two different and distinct strains of the herpes simplex virus type 1 (HSV-1). This virus is mostly asymptomatic, which means that most people have it even if they don't know they do. It is predominately acquired from the mother early in infancy. And once you have it, you have it. Once gotten from your mother, you carry this same strain of virus with you for the rest of your life. Think of it like your childhood friend you never knew you had. Except a lot more spherical than your friends probably were (I hope). As viruses go through a lot of mutation when they reproduce inside your body, the genome of the viruses present inside you can be used to identify you, as well as trace your lineage. For example, a particular individual they studied turned out to have two separate strains of the HSV-1 virus, one was a North American flavor (TM), and the other was an Asian flavor. This made sense, as the individual was a veteran of the Korean War. The fact that this showed up in the genetic makeup of the viruses present in his body is amazing. From just looking at what brand of viruses call your body home, one can determine where you have been.

Another consequence of this is the idea that you can determine a person's origin from what strain of HSV-1 they have. The viruses comes from your mother, so this makes perfect sense. This idea could prove to be very useful, especially in the instances of trying to identify a disfigured body at a crime scene. From the strains of viruses in the victim's body, one would be able to tell where they are from, as well as potentially who they are related to. This second part comes from the implication that people who have identical or close-to-identical strains of the viruses will be more closely related than those who harbor completely different viruses. This viral fingerprinting could go even further for forensic science, as it could be possibly used to "locate perpetrators at the scene of the crime."

Currently one issue with all of this is sample acquisition. The research team is working on trying to be able to sequence viral genomes from smaller and smaller amounts of starting sample, in order to  sequence more and more from smaller samples. This would have the added benefit of being less invasive to test an individual.

This project is a collaboration between scientists from the Universities of Penn State, Lancaster, Pittsburgh, Georgia State, Emory, and Princeton. If you'd like to read more about the project, inducing the paper on this subject published in the May 2016 issue of Virology, you can find it here.