Plant defensin PgD1 a biotechnological alternative against plant pathogens

Plant defensins are antimicrobial proteins (AMP) with a molecular weight of approximately 5 kDa that participate in the immune defense of plants through their antimicrobial, antiviral and antifungal activities. PgD1 is a defensin from Picea glauca (Canadian Pine) and presents antifungal activity against plant pathogens. This activity positions it as an alternative biotechnological route to pesticides commonly used against these diseases. The present study aimed to recombinantly produce PgD1 in Escherichia coli to report its in vitro antifungal potential against different phytopathogens. To achieve this, the coding gene was amplified and cloned into pET30a(+). Recombinant plasmid was subsequently introduced into E. coli for the soluble expression defensin PgD1. To evaluate the antifungal activity of the expressed protein, the growth inhibition test was used in solid and liquid media for approximately 7 days against significant plant pathogens: Botrytis cinerea , Colletotrichum gloeosporioides , Colletotrichum musae , Colletotrichum graminicola and Fusarium oxysporum . Additionally, stability assessments involved temperature variation experiments and inhibition tests using dithiothreitol (DTT). The results show that there was significant inhibition of the fungal species tested when in the presence of PgD1. Furthermore, defensin proved to be resistant to temperature variations and demonstrated that part of its stability is due to its primary structure rich in cysteine ​​residues through the denaturation test with dithiothreitol (DTT) where the antifungal activity of PgD1 defensin was inhibited.