Biocontrol ability and action mechanism of dihydromaltophilin against Colletotrichum fructicola causing anthracnose of pear fruit

Abstract

BACKGROUND Anthracnose caused by Colletotrichum fructicola is one of the most important diseases in pear fruit, resulting in huge economic losses. Public awareness of protecting the environment and food safety, together with pathogen resistance to many key fungicides have led to an urgent need to develop alternative strategies for controlling fruit diseases. Here, the antifungal activity of a natural product, dihydromaltophilin [heat‐stable antifungal factor (HSAF)], against C. fructicola in vitro and in vivo was investigated to determine its efficacy for anthracnose management. RESULTS HSAF exhibited pronounced antifungal activity against in vitro mycelial growth of C. fructicola, with a half‐inhibition concentration of 0.43 mg L−1. Hyphae treated with HSAF showed defects such as hyperbranching, swelling and depolarized growth. Conidia germination in the pathogen was inhibited by HSAF in a dose‐dependent manner. In the presence of 4 mg L−1 HSAF, conidia germination was significantly delayed, and germ tube growth was inhibited. HSAF at 8 mg L−1 completely blocked conidia germination in C. fructicola. In addition, HSAF disrupted coordination of cytokinesis with growth and nuclear division, induced reactive oxygen species production in conidia, and damaged the integrity of the conidia cell wall. Moreover, an in vivo test confirmed that 50 mg L−1 HSAF significantly reduced the development of anthracnose decay in pear fruit caused by C. fructicola. CONCLUSION HSAF was highly effective in reducing pear anthracnose caused by C. fructicola and has great potential to become a new type of fruit preservative.

Evaluating the Mode of Antifungal Action of Heat-Stable Antifungal Factor (HSAF) in Neurospora crassa

“…Microscopic examination showed that the morphology of mycelium is significantly shortened, twisted and hyper-branched under HSAF treatment ( Figure 1 E). As reported for other crop and clinical fungal pathogens [ 16 , 17 , 18 ], these data suggested that a certain amount of HSAF could inhibit the germination and polarized growth of N. crassa, enabling it to be a reasonable model to investigate the antifungal mechanism of HSAF.…”

“…In C. fructicola , HSAF disrupts the coordination between cytokinesis and nuclear division, induces the production of reactive oxygen species in conidia and destroys the integrity of the conidial cell wall. HSAF specifically targets biological processes required for the formation and elongation of the germ tube but does not affect nuclear division [ 17 ]. In A. alternata , transcriptomics analysis demonstrates that HSAF disrupts the metabolic network, including the adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway, sphingolipid metabolism, carbon metabolism, TCA (tricarboxylic acid) cycle, cell cycle, etc., and ultimately leads to apoptosis [ 15 ].…”

Characterisation of the Antibiotic Profile of Lysobacter capsici AZ78, an Effective Biological Control Agent of Plant Pathogenic Microorganisms

“…The polycyclic tetramic acid macrolactams have shown specific suppressive activity against plant pathogenic fungi and oomycetes. Alteramide B, isolated from L. enzymogenes, was shown to inhibit various plant pathogenic fungi and oomycetes in vitro [ 52 ], while the application of dihydromaltophilin (HSAF) successfully controlled Fusarium head blight in wheat [ 53 ] and post-harvest application of HSAF in pears reduced anthracnose symptoms caused by Colletotrichum fructicola [ 54 ]. Since heat-treated AZ78 extracts showed prophylactic activity against Pl.…”

Evidences of Colletotrichum fructicola Causing Anthracnose on Passiflora edulis Sims in China

“…Previous studies have demonstrated C. fructicola as the causal organism causing anthracnose of fruit, vegetables, and economic crops, including chili [23], pear [24], apple [25], strawberry [26], dragon fruit [27], and tea [28]. Numerous studies have pointed out various ways to control anthracnose caused by Colletotrichum spp., including, but not limited to, the application of biorational pesticides, such as essential oil [29], biocontrol strategies [30], synthetic fungicides, and heat treatments [31].…”