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Kevin D Hyde - One of the best experts on this subject based on the ideXlab platform.

  • Phyllosticta species from banana musa sp in chongqing and guizhou provinces china
    Phytotaxa, 2014
    Co-Authors: Yongxiang Liu, Kevin D Hyde, Jie Yuan, Yong Wang, Zuoyi Liu
    Abstract:

    Six Phyllosticta strains were isolated from diseased leaves of Musa species in Chongqing and Guizhou provinces, China. Morphological and molecular analysis of LSU and combined ITS, ACT, TEF-1, and GPDH gene sequences, identified these strains as P. capitalensis (3 strains), P. musarum (1 strain) and two isolates were distinct from known Phyllosticta species. The latter is herein introduced as Phyllosticta musaechinensis sp. nov. A description and illustrations are provided, and the new species is compared with other species from Musa in this paper.

  • a phylogenetic re evaluation of Phyllosticta botryosphaeriales
    Studies in Mycology, 2013
    Co-Authors: Saowanee Wikee, Chiharu Nakashima, Keiichi Motohashi, Eric H. C. Mckenzie, Kevin D Hyde, Ekachai Chukeatirote, P W Crous, L Lombard, Ratchadawan Cheewangkoon
    Abstract:

    Abstract Phyllosticta is a geographically widespread genus of plant pathogenic fungi with a diverse host range. This study redefines Phyllosticta , and shows that it clusters sister to the Botryosphaeriaceae ( Botryosphaeriales , Dothideomycetes ), for which the older family name Phyllostictaceae is resurrected. In moving to a unit nomenclature for fungi, the generic name Phyllosticta was chosen over Guignardia in previous studies, an approach that we support here. We use a multigene DNA dataset of the ITS, LSU, ACT, TEF and GPDH gene regions to investigate 129 isolates of Phyllosticta , representing about 170 species names, many of which are shown to be synonyms of the ubiquitous endophyte P. capitalensis . Based on the data generated here, 12 new species are introduced, while epitype and neotype specimens are designated for a further seven species. One species of interest is P. citrimaxima associated with tan spot of Citrus maxima fruit in Thailand, which adds a fifth species to the citrus black spot complex. Previous morphological studies lumped many taxa under single names that represent complexes. In spite of this Phyllosticta is a species-rich genus, and many of these taxa need to be recollected in order to resolve their phylogeny and taxonomy. Taxonomic novelties: New species – Phyllosticta abieticola Wikee & Crous, P. aloeicola Wikee & Crous, P. citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, P. leucothoicola Wikee, Motohashi & Crous, P. mangifera-indica Wikee, Crous, K.D. Hyde & McKenzie, P. neopyrolae Wikee, Motohashi, Crous, K.D. Hyde & McKenzie, P. pachysandricola Wikee, Motohashi & Crous, P. paxistimae Wikee & Crous, P. podocarpicola Wikee, Crous, K.D. Hyde & McKenzie, P. rhaphiolepidis Wikee, C. Nakash. & Crous, P. rubra Wikee & Crous, P. vacciniicola Wikee, Crous, K.D. Hyde & McKenzie; New combinations – P. foliorum (Sacc.) Wikee & Crous, P. philoprina (Berk. & M.A. Curtis) Wikee & Crous; Epitypifications (basionyms) – P. concentrica Sacc., P. cussoniae Cejp, P. owaniana G. Winter; Neotypifications (basionyms) – Phyllosticta cordylinophila P.A. Young, Physalospora gregaria var. foliorum Sacc., Sphaeropsis hypoglossi Mont., Sphaeropsis minima Berk. & M.A. Curtis.

  • Antimicrobial activity of crude extracts of Phyllosticta spp.
    Mycology, 2013
    Co-Authors: Saowanee Wikee, Eric H. C. Mckenzie, Kevin D Hyde, Phatcharapa Jaidee, Sakuntala Wongkam, Ekachai Chukeatirote
    Abstract:

    Four strains of Phyllosticta were selected to study their antimicrobial activities. The tested strains were identified as Phyllosticta capitalensis, P. citriasiana, and P. cordylinophila based on the internally transcribed spacer (ITS) sequences and morphologies. Initially, the fungal strains were cultured on the potato dextrose agar (PDA) and cultivated at 27°C for 3 weeks. After incubation, the fungal metabolites were extracted using ethyl acetate. The crude extracts were then concentrated using evaporation and subsequently used in antimicrobial activity assay. Our results showed that these fungal crude extracts could inhibit the growth of Escherichia coli, Bacillus cereus, and Pseudomonas aeruginosa but were not active against Aspergillus niger.

  • Phyllosticta capitalensis a widespread endophyte of plants
    Fungal Diversity, 2013
    Co-Authors: Saowanee Wikee, Chiharu Nakashima, Keiichi Motohashi, Eric H. C. Mckenzie, Ekachai Chukeatirote, P W Crous, Lorenzo Lombard, Siti Aisyah Alias, Kevin D Hyde
    Abstract:

    Phyllosticta capitalensis is an endophyte and weak plant pathogen with a worldwide distribution presently known from 70 plant families. This study isolated P. capitalensis from different host plants in northern Thailand, and determined their different life modes. Thirty strains of P. capitalensis were isolated as endophytes from 20 hosts. An additional 30 strains of P. capitalensis from other hosts and geographic locations were also obtained from established culture collections. Phylogenetic analysis using ITS, ACT and TEF gene data confirmed the identity of all isolates. Pathogenicity tests with five strains of P. capitalensis originating from different hosts were completed on their respective host plants. In all cases there was no infection of healthy leaves, indicating that this endophyte does not cause disease on healthy, unstressed host plants. That P. capitalensis is often isolated as an endophyte has important implications in fungal biology and plant health. Due to its endophytic nature, P. capitalensis is commonly found associated with lesions of plants, and often incorrectly identified as a species of quarantine importance, which again has implications for trade in agricultural and forestry production.

  • Phyllosticta ophiopogonis sp nov from ophiopogon japonicus liliaceae
    Saudi Journal of Biological Sciences, 2012
    Co-Authors: Saowanee Wikee, N F Wulandari, Eric H. C. Mckenzie, Kevin D Hyde
    Abstract:

    A leaf spotting disease of an ornamental variety of Ophiopogon japonicus was discovered at several locations in northern Thailand. In all cases a species of Phyllosticta was associated with the lesions. Phyllosticta ophiopogonis sp. nov. is distinguished from Phyllosticta species from Liliaceae in conidia size, mucilaginous sheath and appendage thus the species is introduced as new in this paper. The new species which causes unsightly lesions on this ornamental plant is described, illustrated and compared with other similar Phyllosticta species.

P W Crous - One of the best experts on this subject based on the ideXlab platform.

  • carbon utilization and growth inhibition of citrus colonizing Phyllosticta species
    Fungal Biology, 2021
    Co-Authors: Valerie A Buijs, J.z. Groenewald, Xander C L Zuijdgeest, P W Crous, Ronald P De Vries
    Abstract:

    Abstract The genus Phyllosticta includes both endophytic and phytopathogenic species that occur on a broad range of plant hosts, including Citrus. Some pathogenic species cause severe disease, such as Phyllosticta citricarpa, the causal agent of Citrus Black Spot (CBS). In contrast, other species, such as Phyllosticta capitalensis, have an endophytic lifestyle in numerous plant hosts. Carbon utilization capabilities are hypothesized to influence both host range and lifestyle, and are in part determined by the set of Carbohydrate Active Enzyme (CAZyme) encoding genes of a species. In this study, carbon utilization capabilities of five Phyllosticta species were determined, as well as the CAZyme repertoire (CAZome) encoded in their genomes. Little variation was found among species in terms of carbon utilization capabilities and CAZome. However, one of the tested carbon sources, sugar beet pulp (SBP), inhibited growth of the plant pathogens, also when combined with another carbon source, while endophytic species remained unaffected.

  • first report of Phyllosticta citricarpa and description of two new species p paracapitalensis and p paracitricarpa from citrus in europe
    Studies in Mycology, 2017
    Co-Authors: Vladimiro Guarnaccia, Chirlei Glienke, J.z. Groenewald, P H Fourie, P W Crous, Elma Carstens, V Hattingh
    Abstract:

    The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts (Rutaceae), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall climates, but is absent in countries of the European Union (EU). Phyllosticta capitalensis is morphologically similar to P. citricarpa, but is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts, and is known to occur in Europe. To determine which Phyllosticta spp. occur within citrus growing regions of EU countries, several surveys were conducted (2015-2017) in the major citrus production areas of Greece, Italy, Malta, Portugal and Spain to collect both living plant material and leaf litter in commercial nurseries, orchards, gardens, backyards and plant collections. A total of 64 Phyllosticta isolates were obtained from citrus in Europe, of which 52 were included in a multi-locus (ITS, actA, tef1, gapdh, LSU and rpb2 genes) DNA dataset. Two isolates from Florida (USA), three isolates from China, and several reference strains from Australia, South Africa and South America were included in the overall 99 isolate dataset. Based on the data obtained, two known species were identified, namely P. capitalensis (from asymptomatic living leaves of Citrus spp.) in Greece, Italy, Malta, Portugal and Spain, and P. citricarpa (from leaf litter of C. sinensis and C. limon) in Italy, Malta and Portugal. Moreover, two new species were described, namely P. paracapitalensis (from asymptomatic living leaves of Citrus spp.) in Italy and Spain, and P. paracitricarpa (from leaf litter of C. limon) in Greece. On a genotypic level, isolates of P. citricarpa populations from Italy and Malta (MAT1-2-1) represented a single clone, and those from Portugal (MAT1-1-1) another. Isolates of P. citricarpa and P. paracitricarpa were able to induce atypical lesions (necrosis) in artificially inoculated mature sweet orange fruit, while P. capitalensis and P. paracapitalensis induced no lesions. The Phyllosticta species recovered were not found to be widespread, and were not associated with disease symptoms, indicating that the fungi persisted over time, but did not cause disease.

  • a phylogenetic re evaluation of Phyllosticta botryosphaeriales
    Studies in Mycology, 2013
    Co-Authors: Saowanee Wikee, Chiharu Nakashima, Keiichi Motohashi, Eric H. C. Mckenzie, Kevin D Hyde, Ekachai Chukeatirote, P W Crous, L Lombard, Ratchadawan Cheewangkoon
    Abstract:

    Abstract Phyllosticta is a geographically widespread genus of plant pathogenic fungi with a diverse host range. This study redefines Phyllosticta , and shows that it clusters sister to the Botryosphaeriaceae ( Botryosphaeriales , Dothideomycetes ), for which the older family name Phyllostictaceae is resurrected. In moving to a unit nomenclature for fungi, the generic name Phyllosticta was chosen over Guignardia in previous studies, an approach that we support here. We use a multigene DNA dataset of the ITS, LSU, ACT, TEF and GPDH gene regions to investigate 129 isolates of Phyllosticta , representing about 170 species names, many of which are shown to be synonyms of the ubiquitous endophyte P. capitalensis . Based on the data generated here, 12 new species are introduced, while epitype and neotype specimens are designated for a further seven species. One species of interest is P. citrimaxima associated with tan spot of Citrus maxima fruit in Thailand, which adds a fifth species to the citrus black spot complex. Previous morphological studies lumped many taxa under single names that represent complexes. In spite of this Phyllosticta is a species-rich genus, and many of these taxa need to be recollected in order to resolve their phylogeny and taxonomy. Taxonomic novelties: New species – Phyllosticta abieticola Wikee & Crous, P. aloeicola Wikee & Crous, P. citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, P. leucothoicola Wikee, Motohashi & Crous, P. mangifera-indica Wikee, Crous, K.D. Hyde & McKenzie, P. neopyrolae Wikee, Motohashi, Crous, K.D. Hyde & McKenzie, P. pachysandricola Wikee, Motohashi & Crous, P. paxistimae Wikee & Crous, P. podocarpicola Wikee, Crous, K.D. Hyde & McKenzie, P. rhaphiolepidis Wikee, C. Nakash. & Crous, P. rubra Wikee & Crous, P. vacciniicola Wikee, Crous, K.D. Hyde & McKenzie; New combinations – P. foliorum (Sacc.) Wikee & Crous, P. philoprina (Berk. & M.A. Curtis) Wikee & Crous; Epitypifications (basionyms) – P. concentrica Sacc., P. cussoniae Cejp, P. owaniana G. Winter; Neotypifications (basionyms) – Phyllosticta cordylinophila P.A. Young, Physalospora gregaria var. foliorum Sacc., Sphaeropsis hypoglossi Mont., Sphaeropsis minima Berk. & M.A. Curtis.

  • Phyllosticta species on citrus risk estimation of resistance to qoi fungicides and identification of species with cytochrome b gene sequences
    Crop Protection, 2013
    Co-Authors: G Stammler, G C Schutte, J Speakman, S Miessner, P W Crous
    Abstract:

    Isolates of three fungal species associated with citrus, Phyllosticta citricarpa, Phyllosticta citriasiana and Phyllosticta capitalensis, collected from different citrus growing countries of the world, were investigated for their sensitivities to the QoI fungicides pyraclostrobin and azoxystrobin. Isolates were highly sensitive in microtiter tests and EC50 values were in narrow ranges, which indicate no acquired adaptation to QoIs. The resistance risk of P. citricarpa to QoIs is considered low since an intron was found immediately after codon 143 in the cytochrome b gene. The presence of an intron is known to reduce the risk of the G143A mutation, the mutation which causes QoI resistance with high resistance factors. The other two species had no intron and therefore are considered having a higher resistance risk. Impact of these two species is rather low, since P. citriasiana is restricted in its regional and host distribution and P. capitalensis is nonpathogenic. Furthermore, the development of a rapid and reliable assay for species detection and identification was made possible based on an analysis of the cytochrome b gene.

  • Phyllosticta capitalensis a widespread endophyte of plants
    Fungal Diversity, 2013
    Co-Authors: Saowanee Wikee, Chiharu Nakashima, Keiichi Motohashi, Eric H. C. Mckenzie, Ekachai Chukeatirote, P W Crous, Lorenzo Lombard, Siti Aisyah Alias, Kevin D Hyde
    Abstract:

    Phyllosticta capitalensis is an endophyte and weak plant pathogen with a worldwide distribution presently known from 70 plant families. This study isolated P. capitalensis from different host plants in northern Thailand, and determined their different life modes. Thirty strains of P. capitalensis were isolated as endophytes from 20 hosts. An additional 30 strains of P. capitalensis from other hosts and geographic locations were also obtained from established culture collections. Phylogenetic analysis using ITS, ACT and TEF gene data confirmed the identity of all isolates. Pathogenicity tests with five strains of P. capitalensis originating from different hosts were completed on their respective host plants. In all cases there was no infection of healthy leaves, indicating that this endophyte does not cause disease on healthy, unstressed host plants. That P. capitalensis is often isolated as an endophyte has important implications in fungal biology and plant health. Due to its endophytic nature, P. capitalensis is commonly found associated with lesions of plants, and often incorrectly identified as a species of quarantine importance, which again has implications for trade in agricultural and forestry production.

Chirlei Glienke - One of the best experts on this subject based on the ideXlab platform.

  • Mating-type locus rearrangements and shifts in thallism states in Citrus-associated Phyllosticta species.
    Fungal genetics and biology : FG & B, 2020
    Co-Authors: Desirrê Alexia Lourenço Petters-vandresen, Bruno Janoski Rossi, Johannes Z. Groenewald, Pedro W. Crous, Marcos Antonio Machado, Eva H. Stukenbrock, Chirlei Glienke
    Abstract:

    Currently, eight Phyllosticta species are known to be associated with several Citrus hosts, incorporating diverse lifestyles: while some of them are endophytic (P. capitalensis and P. citribraziliensis), others are pathogenic (P. citriasiana, P. citricarpa, P. citrichinaensis and P. paracitricarpa). Sexual reproduction plays a key role in the interaction between these Phyllosticta species and their Citrus hosts, especially for the spread and persistence of the pathogenic species in the environment. Given this, differences in sexual reproduction strategies could be related to the differences in lifestyles. To evaluate this hypothesis, we characterized the mating-type loci of six Citrus-associated Phyllosticta species from whole genome assemblies. Mating-type genes in the Citrus-associated Phyllosticta species are highly variable in their sequence content, but the genomic locations and organization of the mating-type loci are conserved. Phyllosticta citriasiana, P. citribraziliensis, P. citricarpa and P. paracitricarpa are heterothallic, while P. capitalensis and P. citrichinaensis are homothallic. In addition, the P. citrichinaensis MAT1-2 idiomorph occurs in a separate location from the mating-type locus. Ancestral state reconstruction suggests that homothallism is the ancestral thallism state in Phyllosticta, with a shift to heterothallism in Phyllosticta species that are pathogenic to Citrus. Moreover, the homothallic strategies of P. capitalensis and P. citrichinaensis result from independent evolutionary events, as P. capitalensis locus likely represents the ancestral state, and P. citrichinaensis homothallism has risen through a reversion in a heterothallic ancestor and underwent remodelling events. As the pathogenic species P. citriasiana, P. citricarpa and P. paracitricarpa are heterothallic and incapable of selfing, disease management practices focused in preventing the occurrence of sexual reproduction could assist in the control of Citrus Black Spot and Citrus Tan Spot diseases. This study emphasizes the importance of studying Citrus-Phyllosticta interactions under evolutionary and genomic perspectives, as these approaches can provide valuable information about the association between Phyllosticta species and their hosts, and also serve as guidance for the improvement of disease management practices.

  • Mating-type locus rearrangement leads to shift from homothallism to heterothallism in Citrus-associated Phyllosticta species
    2020
    Co-Authors: Desirrê Alexia Lourenço Petters-vandresen, Bruno Janoski Rossi, Johannes Z. Groenewald, Pedro W. Crous, Marcos Antonio Machado, Eva H. Stukenbrock, Chirlei Glienke
    Abstract:

    Abstract Currently, eight Phyllosticta species are known to be associated with Citrus hosts, incorporating endophytic and pathogenic lifestyles. As sexual reproduction is a key factor involved in host-interaction, it could be related to the differences in lifestyle. To evaluate this hypothesis, we characterized the mating-type loci of six Citrus-associated Phyllosticta species from whole genome assemblies. Mating-type genes are highly variable in their sequence content, but the genomic locations and organization of the mating-type loci are conserved. Phyllosticta citriasiana, P. citribraziliensis and P. paracitricarpa are heterothallic, and P. citrichinaensis was confirmed to be homothallic. In addition, the P. citrichinaensis MAT1-2 idiomorph occurs in a separate location from the mating-type locus. Ancestral state reconstruction suggests that homothallism is the ancestral thallism state in Phyllosticta, with a shift to heterothallism in Phyllosticta species that are pathogenic to Citrus. Moreover, the homothallic strategies of P. capitalensis and P. citrichinaensis result from independent evolutionary events. As the pathogenic species P. citriasiana, P. citricarpa and P. paracitricarpa are heterothallic and incapable of selfing, disease management practices focused in preventing the occurrence of sexual reproduction could assist in the control of Citrus Black Spot and Citrus Tan Spot diseases. This study emphasizes the importance of studying Citrus-Phyllosticta interactions under evolutionary and genomic perspectives, as these approaches can provide valuable information about the association between Phyllosticta species and their hosts, and also serve as guidance for the improvement of disease management practices.

  • secondary metabolites produced by the citrus phytopathogen Phyllosticta citricarpa
    The Journal of Antibiotics, 2019
    Co-Authors: Chirlei Glienke, Daiani Cristina Savi, Khaled A Shaaban, Prithiba Mitra, Larissa V Ponomareva, Jon S Thorson, Jurgen Rohr
    Abstract:

    The isolation and structure elucidation of one new fungal metabolite, phenguignardic acid butyl ester (1a), and four previously reported metabolites (1b, 2a, 3-4) from the citrus phytopathogen Phyllosticta citricarpa LGMF06 are described. The new dioxolanone phenguignardic acid butyl ester (1a) had low phytotoxic activity in citrus leaves and fruits (at dose of 100 µg), and its importance as virulence factor in citrus black spot disease needs to be further addressed. Beside the phytotoxic analysis, we also evaluated the antibacterial (against methicillin sensitive and resistant Staphylococcus aureus) and cytotoxic (A549 non-small cell lung cancer, PC3 prostate cancer and HEL 299 normal epithelial lung) activities of the isolated compounds, which revealed that compounds 1a, 1b and 2a were responsible for the antibacterial activity of this strain.

  • first report of Phyllosticta citricarpa and description of two new species p paracapitalensis and p paracitricarpa from citrus in europe
    Studies in Mycology, 2017
    Co-Authors: Vladimiro Guarnaccia, Chirlei Glienke, J.z. Groenewald, P H Fourie, P W Crous, Elma Carstens, V Hattingh
    Abstract:

    The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts (Rutaceae), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall climates, but is absent in countries of the European Union (EU). Phyllosticta capitalensis is morphologically similar to P. citricarpa, but is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts, and is known to occur in Europe. To determine which Phyllosticta spp. occur within citrus growing regions of EU countries, several surveys were conducted (2015-2017) in the major citrus production areas of Greece, Italy, Malta, Portugal and Spain to collect both living plant material and leaf litter in commercial nurseries, orchards, gardens, backyards and plant collections. A total of 64 Phyllosticta isolates were obtained from citrus in Europe, of which 52 were included in a multi-locus (ITS, actA, tef1, gapdh, LSU and rpb2 genes) DNA dataset. Two isolates from Florida (USA), three isolates from China, and several reference strains from Australia, South Africa and South America were included in the overall 99 isolate dataset. Based on the data obtained, two known species were identified, namely P. capitalensis (from asymptomatic living leaves of Citrus spp.) in Greece, Italy, Malta, Portugal and Spain, and P. citricarpa (from leaf litter of C. sinensis and C. limon) in Italy, Malta and Portugal. Moreover, two new species were described, namely P. paracapitalensis (from asymptomatic living leaves of Citrus spp.) in Italy and Spain, and P. paracitricarpa (from leaf litter of C. limon) in Greece. On a genotypic level, isolates of P. citricarpa populations from Italy and Malta (MAT1-2-1) represented a single clone, and those from Portugal (MAT1-1-1) another. Isolates of P. citricarpa and P. paracitricarpa were able to induce atypical lesions (necrosis) in artificially inoculated mature sweet orange fruit, while P. capitalensis and P. paracapitalensis induced no lesions. The Phyllosticta species recovered were not found to be widespread, and were not associated with disease symptoms, indicating that the fungi persisted over time, but did not cause disease.

  • biological activity of diaporthe terebinthifolii extracts against Phyllosticta citricarpa
    Fems Microbiology Letters, 2017
    Co-Authors: Fabiana Tonial, Beatriz Helena Lameiro De Noronha Sales Maia, Andrea Michel Sobottka, Daiani Cristina Savi, Vânia Aparecida Vicente, Renata R Gomes, Chirlei Glienke
    Abstract:

    Citrus black spot disease, caused by the phytopathogen Phyllosticta citricarpa, depreciates the market value of citrus fruits and prevents their exportation to disease-free regions. It may also reduce the productivity of citrus fruit orchards. To identify an alternative to conventional disease control measures, isolates of Diaporthe terebinthifolii, active against P. citricarpa, were selected from an endophytic fungal population of Schinus terebinthifolia leaves. Different culture media were screened to identify the culture medium that afforded the most efficient production of biologically active extracts. A particular fraction (fraction VI) of the extract completely protected orange leaves by inhibiting the germination of P. citricarpa conidia with a minimum inhibitory concentration of 0.003 μg.mL-1. The active constituents in D. terebinthifolii extract fractions were identified by gas chromatography coupled to mass spectrometry as verbanol, phenylethyl alcohol, verbenyl acetate and methyl hexadecanoate. The results obtained strongly suggest the existence of a synergistic effect among the metabolites produced. Thus, these fungal metabolites could be used to control the CBS disease. As the asexual spores of P. citricarpa play an important role in fruit lesion development and disease dispersion, fungal extracts that inhibit the spore germination can be used as an effective alternative for directional disease control.

Hao Gao - One of the best experts on this subject based on the ideXlab platform.

  • phenylisotertronic acids from the tcm endophytic fungus Phyllosticta sp
    Fitoterapia, 2018
    Co-Authors: Henggang Yang, Shaomeng Chen, Langming Mou, Jian Zou, Guodong Chen, Shengying Qin, Chuanxi Wang, Xinsheng Yao, Hao Gao
    Abstract:

    Four new phenylisotertronic acids (1a/1b, 2a, and 3a) were isolated from a TCM endophytic fungal strain Phyllosticta sp. J13-2-12Y obtained from the leaves of Acorus tatarinowii, along with two known ones (2b and 3b). Compounds 1-3 all existed as mixtures of enantiomers, and their corresponding optically pure enantiomers were successfully isolated by chiral HPLC. The structures of isolated compounds were determined by comprehensive spectroscopic analyses and X-ray diffraction. Their absolute configurations were determined by ECD experiments and quantum chemical calculations. In addition, the antimicrobial activities and the cytotoxicities of these three pairs of optically pure enantiomers (1a/1b, 2a/2b, and 3a/3b) had been evaluated.

  • phyllomeroterpenoids a c multi biosynthetic pathway derived meroterpenoids from the tcm endophytic fungus Phyllosticta sp and their antimicrobial activities
    Scientific Reports, 2017
    Co-Authors: Henggang Yang, Huan Zhao, Shaomeng Chen, Langming Mou, Jian Zou, Guodong Chen, Shengying Qin, Chuanxi Wang, Xinsheng Yao, Hao Gao
    Abstract:

    Phyllomeroterpenoids A−C (1−3), multi-biosynthetic pathway derived meroterpenoids from amino acid/pentose phosphate/terpenoid pathways, were isolated from the TCM endophytic fungus Phyllosticta sp. J13-2-12Y, together with six biosynthetically related compounds (4−9). All structures were determined by extensive spectroscopic analysis, chemical derivatization, and ECD experiments. A plausible biosynthetic pathway of 1−3 was proposed. In addition, the antimicrobial activities of all isolated compounds were evaluated against Staphylococcus aureus 209P (bacterium) and Candida albicans FIM709 (fungus).

Harvey C Hoch - One of the best experts on this subject based on the ideXlab platform.

  • generality of the prerequisite of conidium attachment to a hydrophobic substratum as a signal for germination among Phyllosticta species
    Mycologia, 2006
    Co-Authors: Brian D Shaw, George C Carroll, Harvey C Hoch
    Abstract:

    It has been shown that conidia of Phyllosticta ampelicida require attachment to a substratum to initiate germination. Furthermore this attachment occurs only on hydrophobic surfaces. This study was initiated to ascertain the breadth of this phenomenon among other species of the genus Phyllosticta. We tested 23 isolates of Phyllosticta representing at least 14 named species. These isolates were collected from North America, Asia and Africa. For 22 of the 23 isolates tested spore attachment occurred at a rate of 60-100% on hydrophobic polystyrene but at 0-5% on hydrophilic polystyrene. The one exception to the preference for a hydrophobic substratum for attachment was an unnamed species of Phyllosticta from Rhus glauca that attached less than 10% on either surface. A similar response was observed when assaying germination and appressorium formation for 17 isolates. Germination and appressorium formation for these isolates proceeded on hydrophobic polystyrene but not on nutrient agar, which is hydrophilic. In five of the tested isolates germination was high on both hydrophobic polystyrene and hydrophilic nutrient media. The isolate from Rhus glauca did not germinate appreciably on either surface. Taken together these results suggest that the requirement for conidium contact/attachment to trigger germination is pervasive to the genus Phyllosticta.

  • Ca2+ regulation of Phyllosticta ampelicida pycnidiospore germination and appressorium Formation.
    Fungal genetics and biology : FG & B, 2000
    Co-Authors: Brian D Shaw, Harvey C Hoch
    Abstract:

    Abstract Phyllosticta ampelicida conidia germinate only after making contact with and attaching to a substratum. Previous studies suggested a role for Ca 2+ in this process. A Ca 2+ buffering system was used to control the external free Ca 2+ concentration. Both germination and appressorium formation were reduced or abolished with low Ca 2+ (less than or equal to nanomolar levels) but were nearly 100% at millimolar levels of Ca 2+ . Germination initiation required Ca 2+ within 10–25 min after the spore made contact with the substratum. Appressorium initiation required Ca 2+ 90–120 min following initial contact. Ca 2+ channel blockers nicardipine and lanthanum abated spore development. TMB-8, a blocker of internal Ca 2+ channels, reduced both developmental events. Gadolinium, a putative stretch-activated Ca 2+ channel blocker, abolished both developmental events at nanomolar levels. Calmodulin antagonists, compounds R-24751 and 48/80, abated spore development at micromolar levels. Together, these results suggest that Ca 2+ signaling is involved in both germination and appressorium formation in P. ampelicida pycnidiospores.

  • Germination and appressorium development of Phyllosticta ampelicida pycnidiospores
    Mycologia, 1998
    Co-Authors: Brian D Shaw, Kerchung Kuo, Harvey C Hoch
    Abstract:

    Germination of Phyllosticta ampelicida pyc- nidiospores was followed from attachment through development of mature, highly melanized appresso- ria. Using time- lapsed video microscopy, it was de- termined that mature appressoria formed within 6 hours of attachment of the spores on hydrophobic substrata. Pycnidiospores germinated in the presence of tricyclazole did not produce pigmented appresso- ria indicating that the darkening agent is melanin, which in normal appressoria reached maximum lev- els within 6 hours following germination. Pycnidio- spores were binucleate. Prior to development of the septum separating the pycnidiospore and germ tube from the appressorium, the two nuclei divided mi- totically and three of the four resulting nuclei mi- grated into the appressorium. The fourth nucleus re- mained in the pycnidiospore where it degraded ul- timately. Mature appressoria formed penetration pegs capable of penetrating polycarbonate.

  • the parasitic relationship between Phyllosticta ampelicida and vitis vinifera
    Mycologia, 1996
    Co-Authors: Kerchung Kuo, Harvey C Hoch
    Abstract:

    Phyllosticta ampelicida, the causal agent of black rot of grape, is one of the most damaging fungal pathogens in viticulture in North America. The interactions of the pathogen with host leaf tis- sues were studied to better understand the behavior