Defense from within

Greenhouse Management recently spoke with Elena Baraldi, an assistant professor in the department of agricultural science at the University of Bologna in Italy. Her main area of focus is post-harvest diseases, especially fungal diseases.

Baraldi and her colleagues recently published an article for the British Society for Plant Pathology about VvAMP2, a defense against Botrytis cinerea growth in crops.
 

GM: Can you tell us about the botrytis research you conducted? How did you get started with that?

Elena Baraldi: In this article, we focused on the peptide, VvAMP2. These are proteins that are present ubiquitously in all the plant kingdoms, including humans and animals. The molecules are able to act directly against foodborne pathogens and in some cases, also against bacterial pathogens.

VvAMP stands for Vitis vinifera anti-microbial peptide. We called it VvAMP2 because the VvAMP1 has already been discovered and categorized.

Animals, mammals, humans and plants have this peptide. And this particular one was interesting because it was a little bit different in terms of its physical and biochemical properties. Particular biochemical structural features make VvAMP2 regional. In this paper, we were intrigued by the peptide, we managed to see where these peptides were the most abundant in the grapevine tissue, and we show that it was very much abundant in flowers and also in berries, in the fruit.
 

GM: So berries and flowers also have this peptide?

EB: Yes, flowers and berries were rich in these peptides, whereas this peptide is not as abundant in all the other grapevine tissue. And so we use microscopy technique to [visualize] these molecules inside the flower. And we saw that this was actually very abundant both in the male and female flower components, possibly suggesting a type of function during the flower fertilization. Then we looked at the proteins of these peptides and we tested the activity against different fungi, or fungal pathogens. We saw that it was very active and it was quite specific in the activity against Botrytis.
 

GM: Can the peptides be utilized to protect other crops from botrytis?

EB: Yes. Botrytis is present in all the plant kingdoms. Many other types of defenses have been found in other crops. But this specific one was found only in grapevine and one other source. In our earlier studies, for example, we got a couple of the same things from peach, from peach flower and peach fruit, but these were different. They were structurally different from these VvAMP2.
 

GM: What other crops does Botrytis cinerea affect?

EB: That is a very aggressive fungal strain. It affects over 200 kinds of crops. This is one of the major causes of economic losses in every crop around the world. So that’s why we also study in several research labs and institutes. It’s why all the types of molecules that display this kind of inhibitory activity against this fungal straing are all very interesting for biotechnologies.
 

GM: How will your research play a part in defending crops against botrytis?

EB: This is the very early stages of possible applications in the world of crop protection. When you find these kinds of molecules, then you think, “Is it possible to maybe artificially synthesize these molecules and make in a reasonably cheap way and produce this molecule to be used as a botanical?”

This could be very convenient because [the molecules] are inspired by nature. They are molecules that are present in nature and they are not for humans, for animals and for the environment, and so we basically overcome all the problems of pollution and toxicity. The first important question to be answered is, “Is there any possibility to produce this molecule in an active way and in a cheap way so that this could be used in normal agriculture practices?”

The road is quite long because producing this kind of peptide is very expensive. There aren’t set procedures in the lab that allow the production in large quantities. So the next step would be to [gather] research from a pharmaceutical company then possibly [determine] how to synthesize these peptides in a cheap way. If you apply this kind of molecule instead of the normal chemical, then you have the advantages that I listed above: the pollution, toxicity and the protection of your crops against very important pathogens. The other possibility would be to use this in transgenic crops. This would be, of course, the easiest way because if you take this gene and put it in important agronomic crops and then produce a transgenic plant then these peptides will be much more abundant. Then you have protection from inside because the plant itself is able to produce this too [to rid] itself of the pathogen. But this is not allowed in Italy or in many other countries.
 

GM: Is it mostly in the European Union transgenic crops are not allowed, correct?

EB: Yes.
 

GM: What future research products will you be working on?

EB: At the moment, we are working on the same objective: to find molecules to be exploded for improving crop protection. Presently, we are most focused on other genes which seem to be involved in protection (for example, strawberries), but also other fruits against the same type of pathogens, for Botrytis, but also other fungi which are really destructive fungal pathogens for many, many crops.