Antifungal activity and mechanisms of ε-poly-l-lysine (ε-PL) against Colletotrichum lagenarium in marrow squash
C. M. Liu, Hongru Liu, Chunfang Wang, Fanjun Kong, Hui He, Yongjin Qiao
Abstract
Fungal diseases are major adverse factors leading to quality deterioration and spoilage of postharvest horticultural products. ε-PL is widely recognized as a natural antibacterial agent because of its broad spectrum antimicrobial property. The objective of this study was to investigate the antifungal activity of ε-PL against C.lagenarium, and elucidate the underlying mechanism involved. In vivo were also confirmed that ε-PL treatment showed an obvious inhibitory effect for control of anthracnose caused by C.lagenarium in marrow squash. Moreover, in vitro assay showed that ε-PL exerted strongly antifungal activity against mycelial growth on colony diameter, spore germination and mycelium dry weight of C.lagenarium, with the increase of the concentration of ε-PL. Furthermore, compared with the control, damage the cell membrane of C.lagenarium and increase MDA content, significant leakages of intercellular electrolytes, nucleic acid, protein and sugar, suggested that ε-PL treatment increased the membrane permeability of C.lagenarium. Simultaneously, ε-PL significantly inhibited the activity of enzyme related to energy metabolism in C.lagenarium. The results were observed by SEM and TEM that ε-PL treatment damaged the morphology of C.lagenarium. In conclusion, ε-PL concentration higher than 400 mg L−1 might be used as an antifungal agents to control anthracnose caused by C.lagenarium in marrow squash.