Antifungal defensins and their role in plant defense

Abstract

Since the beginning of the 90s lots of cationic plant, cysteine-rich antimicrobial peptides (AMP) have been studied. However, Broekaert et al. (1995) only coined the term “plant defensin,” after comparison of a new class of plant antifungal peptides with known insect defensins. From there, many plant defensins have been reported and studies on this class of peptides encompass its activity toward microorganisms and molecular features of the mechanism of action against bacteria and fungi. Plant defensins also have been tested as biotechnological tools to improve crop production through fungi resistance generation in organisms genetically modified (OGM). Its low effective concentration towards fungi, ranging from 0.1 to 10 μM and its safety to mammals and birds makes them a better choice, in place of chemicals, to control fungi infection on crop fields. Herein, is a review of the history of plant defensins since their discovery at the beginning of 90s, following the advances on its structure conformation and mechanism of action towards microorganisms is reported. This review also points out some important topics, including: (i) the most studied plant defensins and their fungal targets; (ii) the molecular features of plant defensins and their relation with antifungal activity; (iii) the possibility of using plant defensin(s) genes to generate fungi resistant GM crops and biofungicides; and (iv) a brief discussion about the absence of products in the market containing plant antifungal defensins.

Food safety assessment of an antifungal protein from Moringa oleifera seeds in an agricultural biotechnology perspective

“…Despite the importance of this issue, no commercial transgenic plant is available with genes that encode proteins to confer resistance against phytopathogenic fungi. On the other hand, several studies have already described the efficacy of antifungal proteins when processed on different host plants, either in laboratory or greenhouse conditions (Lacerda et al, 2014).…”

Antimicrobial Peptides from Fruits and Their Potential Use as Biotechnological Tools—A Review and Outlook

“…Still, it is expected that in a short time the defensins used in agro-products with antifungal activity will be used as an important instrument for the growth of agricultural production, a fact that should stimulate biotechnological research and the application of bioproducts (Lacerda et al, 2014). …”

Anticancer Peptides: Prospective Innovation in Cancer Therapy

“…They present powerful antifungal activity (Mello et al 2011) and their mode of action is related to membrane destabilization or insertion followed by pore formation and leakage of essential biomolecules (Lacerda et al 2014). Sesquin was the first plant defensin known to be active against breast cancer and leukemia cells (Wong and Ng 2005b).…”