Plant antimicrobial peptides

Pathogens, like fungi, nematodes, virus and bacterial are responsible for several human and plant diseases. According FAO, around 20 to 40 percent of crops yields are lost, per year, due plant diseases and pest. Besides this, only USA spend 30 billion dollars a year with hospital infections, and the numbers are increasing as the infection are becoming more and more resistant to conventional antibiotics. Antimicrobial peptides (AMPs) are found in different species: insects, mammals, amphibians, fish, birds and plants. Plant antimicrobial peptides have an important action in plants metabolism: defense against pathogens. Some examples of this class of peptides are: defensins, cyclotides, glycine-rich proteins, thionins and lipid transfer proteins. Usually, the target for AMPs are the DNA, RNA and proteins and they should have selectivity against bacterial cells and not been effective against mammal or plant cells. The interest on AMPs is growing, especially on their structure and mechanism of action. The use as medicine of AMPs is limited and still remaining some open questions that need to be answered: the oral bioavailability improvement, peptidase degradation, before they became an antimicrobial drug.