Antifungal Activity against Plant Pathogens of Metabolites from the Endophytic Fungus Cladosporium cladosporioides

Abstract

Bioassay-guided fractionation of Cladosporium cladosporioides (Fresen.) de Vries extracts led to the isolation of four compounds, including cladosporin, 1, isocladosporin, 2, 5′-hydroxyasperentin, 3, and cladosporin-8-methyl ether, 4. An additional compound 5′,6-diacetyl cladosporin, 5, was synthesized by acetylation of compound 3. Compounds 1-5 were evaluated for antifungal activity against plant pathogens. Phomopsis viticola was the most sensitive fungus to the tested compounds. At 30 μM, compound 1 exhibited 92.7%, 90.1%, 95.4% and 79.9% growth inhibition against Colletotrichum acutatum, Co. fragariae, Co. gloeosporioides and Phomopsis viticola, respectively. Compound 2 showed 50.4%, 60.2% and 83.0% growth inhibition at 30 μM against Co. fragariae, Co. gloeosporioides and P. viticola, respectively. Compounds 3 and 4 were isolated for the first time from Cladosporium cladosporioides. Moreover, the identification of essential structural features of the cladosporin nuclei has also been evaluated. These structures provide new templates for the potential treatment and management of plant diseases.

Using direct amplification and next-generation sequencing technology to explore foliar endophyte communities in experimentally inoculated western white pines

“…OTU145 (Davidiella) showed significantly higher abundance in healthy seedlings, compared to those exhibiting stunted growth. Many fungi within this genus produce antifungal compounds that can inhibit plant pathogens (Wang et al, 2013). This correlation is consistent with the theory that some fungi exhibit a mutualistic relationship with their host.…”

“…Of the inoculant fungi, endophytes in the antagonist treatment group were chosen based on their production of secondary compounds and potential fungal antagonism (Ganley et al, 2008;Wang et al, 2013). Seedlings inoculated with these potential pathogen antagonists grew, on average, over twice as much during the first year after planting as seedlings in both the control and established treatment groups.…”

“…The effects of established species on the colonization probability of subsequent fungi (priority effects), along with variation in the time of arrival of different species, influence fungal community assembly (Fukami et al, 2010). Many fungal endophytes produce antimicrobial metabolites that can inhibit the colonization of secondary species (Soman et al, 1999;Yu et al, 2010;Wang et al, 2013), which may provide protection and increase the life span of their host plant (Berube et al, 1998;Ganley et al, 2008). The factors that shape initial fungal assemblages in conifers also play a role in subsequent ecosystem functions.…”

“…NGS was employed to characterize early community assemblage, priority effects and persistence of inoculated fungi. Inoculant treatments were chosen based on their potential for pathogen antagonism (Ganley et al, 2008;Wang et al, 2013), and seedling growth was used as a response variable to assess seedling health over 2 yr. To our knowledge, this is the first attempt to use NGS to explore the effects of experimentally inoculated endophyte communities with any conifer species. With a broader, more inclusive perspective on fungal endophyte biodiversity, we will better understand the interspecific interactions that drive community assemblage and subsequent ecological processes.…”

Discovery and structure activity relationships of 2-pyrazolines derived from chalcones from a pest management perspective

“…Each fungus was grown in 0.3, 3.0, and 30.0 lM solutions of each test compound. Microtiter plates (Nunc MicroWell, untreated; Roskilde, Denmark) were covered with a plastic lid and incubated in a growth chamber as described previously (Wang et al, 2013;Radwan et al, 2014). Fungal growth was then evaluated by measuring the absorbance of each well at 620 nm using a microplate photometer (BioTek Instruments, Winooski, VT, USA).…”