Red maple (Acer rubrum L.), a tree species native to North America, has been introduced and widely cultivated for timber and ornamental purpose in China. In May 2021, black-brown leaf spots were ...observed on 3-year-old red maple saplings in a sentinel planting garden located in Lishui district, Jiangsu Province, China. This disease reduces not only the growth but also the ornamental value of affected trees. From symptomatic red maple leaves, three fungal isolates were recovered and subjected to pathogenicity tests by inoculating healthy leaves with mycelium plugs. The isolate EL.1 induced leaf disease successfully with symptoms like those observed in the field, and it was subsequently re-isolated from infected leaves. On PDA media, isolate EL.1 produced spherical brown pycnidia, and its colony displayed a transition from white to grayish with reddish-brown diffusible pigments. Ellipsoidal hyaline conidia were observed. The morphological characteristics of this fungus matched those of Epicoccum spp. For accurate identification, partial sequences of the internal transcribed spacer region (ITS), TUB2 and RPB2 genes were amplified and sequenced. Phylogenetic analysis verified the species as Epicoccum latusicollum. This marks the first record of E. latusicollum on red maple and emphasizes the vital role of sentinel gardens in elucidating novel pathogen-plant host relationships.
•Pathogen was identified as Epicoccum latusicollum.•First report of Acer rubrum leaf spot caused by E. latusicollum in China.•Importance of Sentinel Gardens: elucidating novel pathogen-plant host relationships.
Endive (Cichorium endivia L.) is an annual or biennial herbaceous plant which belongs to the Asteraceae family, widely distributed, and grown worldwide. During the March of 2022, a disease with leaf ...spot symptoms was observed on Cichorium endivia L in 35% of the planted area in a farm field in Ding xi city, Gansu Province, China. Disease symptoms were observed in leaves of endives with pinpoint-sized green spots. The entire plant turns yellow and wilts, and becomes dry starting in the center until it splits or cracks. The K1 strain isolated from infected plants was identified as Epicoccum nigrum based on morphological characteristics, culture features, and molecular identification. To our knowledge, this is the first report of E. nigrum causing leaf spots on endive (Cichorium endivia L.) in China.
•The first report of Epicoccum nigrum Causing Leaf Spot of Endive in China.•This can be helpful for the control of bitterchrysanthemum leaf spot.
Very little is known about the impact of climate change on fungi and especially on spore production. Fungal spores can be allergenic, thus being important for human health. The aim of this study was ...to investigate how climate change influences the responsive ability of fungi by simulating differing environmental regimes. Fungal species with high spore allergenic potential and atmospheric abundance were grown and experimentally examined under a variety of temperatures and different nutrient availability. Each represented the average decadal air temperature of the 1980s, 1990s and 2000s in the UK, along with an Intergovernmental Panel on Climate Change (IPCC) climate change scenario for 2100. All tests were run on six fungal species: Alternaria alternata, Aspergillus niger, Botrytis cinerea, Cladosporium cladosporioides, Cladosporium oxysporum and Epicoccum purpurascens. Mycelium growth rate and spore production were examined on each single species and competitive capacity among species combinations in pairs. All fungal species grew faster at higher temperatures, and this was more pronounced for the temperature projection in 2100. Most species grew faster when there was lower nutrient availability. Exceptions were the species with the highest growth rate (E. purpurascens) and with the highest competition capacity (A. alternata). Most species (except for E. purpurascens) produced more spores in the richer nutrient medium but fewer as temperature increased. C. cladosporioides was an exception, exponentially increasing its spore production in the temperature of the 2100 scenario. Regarding competitive capacity, no species displayed any significant alterations within the environmental range checked. It is suggested that in future climates, fungi will display dramatic growth responses, with faster mycelium growth and lower spore production, with questions risen on relevant allergen potential.
Metabolism of special endophytes and phytopathogens can be induced by the symbiotic interactions with the host. A phytopathogen Epicoccum sorghinum cultured in host mushroom Thelephora ganbajun ...medium exhibited different metabolites compared with that of ordinary medium. An unprecedented scaffold possessing the same substructure as perylenequinone mycotoxin, a first methyl rearrangement product of phytotoxin, epoxydon 6-methylsalicylate ester, three undescribed compounds, and an undescribed natural product were isolated from E. sorghinum cultured in T. ganbajun. Episorin A and epicosorin A were produced from E. sorghinum induced by culturing in host medium. Episorin A was the first example of perylenequinone analogue in the natural products. These induced compounds and other metabolites showed notable antibiosis against endogenous fungi, and insect existing in mushroom. Induced episorin A showed significant inhibitory effects on nitric oxide production in LPS-activated macrophages, and anti-acetylcholinesterase with the IC50 at 5.40 ± 0.25 μM, and 4.32 μM, respectively, and cytotoxicity against HL-60, A-549, SMMC-7721, MCF-7 and SW480 with IC50 at 14.21 ± 0.53, 17.93 ± 0.22, 18.17 ± 0.63, 28.36 ± 0.43, and 18.20 ± 1.03 μM.
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•Six undescribed compounds were found from culture of Epicoccum sorghinum in Thelephora ganbajun medium.•The inducing novel antibiotic, episorin A indicated significant activities.•The interaction of host and endogenous fungi can induce the production of novel antibiotics.
Front Cover. The extreme environment in the deep sea led to the presence of a characteristic thriving world of microbial diversity. With the development of sampling techniques, fungi derived from ...deep sea (> 1000 m) have attracted considerable attention on account of special biological diversity and prolific metabolisms. Epicoccum nigrum SD‐388 is a deep‐sea‐sediment‐derived fungus with characteristic metabolites of thiodiketopiperazine derivatives (TDKPs), which displays a variety of bioactivities. Systematical isolation of the culture extract resulted in the isolation of two new TDKPs, namely 7‐dehydroxyepicoccin H (1) and 7‐hydroxyeutypellazine F (2), along with seven known TDKP analogs. Significant inhibitory activities of these compounds against aquatic pathogens Vibrio vulnificus, V. alginolyticus, and Edwardsiella tarda were observed, as reported by Wang et al. in their full paper at10.1002/cbdv.202000320.
•The bioagents agents enhance potato plants growth and potato tuber production.•AMF and E. nigrum decrease the disease severity of blackleg disease.•The promoting potato plant growth is attributed to ...enhance systemic plant resistance.•These biocontrol agents may have promising prospective strategies in potato crop protection.
This work was aimed to evaluate the efficacy of arbuscular mycorrhizal fungi (AMF) and the endophytic fungal strain Epicoccum nigrum ASU11 (Epi) to control potato blackleg caused by bacterial stain Pectobacterium carotovora subsp. atrosepticum PHY7 (Pca). E. nigrum showed unique colonization frequency properties of potato plants (73.3% colonization frequency). Furthermore, the endophytic fungus exhibited antagonistic capability against pathogenic bacteria with inhibition zone 18 ± 0.5 mm. The AMF and Epi individually or in combination reduced Pca population in vivo experiment. The highest level of reduction was recorded in combination of AMF+ Epi. Also, infected potato plants treated with the two bioagents showed the highest weight of potato tubers in comparison to infected control. The enhancement of potato plants growth and the elevation of blackleg disease symptoms by bioagents (Epi + AMF) could be attributed to promoting the systemic plant resistance through the decrease of reactive oxygen species (ROS), malondialdehyde content (MDA), glutathione-s-transferase (GST), soluble peroxidase (SPO), ionic peroxidase (IPO), polyphenol oxidase (PPO), phenyl alanine ammonialyase (PAL) and lignin content. Moreover, they enhance the content of potato phenolics, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GPX) content. These results detected the potentiality of AMF and E. nigrum to promote potato growth and decrease the disease severity of blackleg disease. These biocontrol agents may have promising prospective strategies in potato crop protection and increase the feasibility of agriculture crop protection. The results reported herein are expected to provide competitive economic outcomes for sustainable cropping protection systems.
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