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John C. Perez - One of the best experts on this subject based on the ideXlab platform.
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Phylogenetic analysis of serine proteases from Russell's viper (Daboia russelli siamensis) and Agkistrodon piscivorus Leucostoma venom
Toxicon : official journal of the International Society on Toxinology, 2011Co-Authors: Pattadon Sukkapan, Ying Jia, Issarang Nuchprayoon, John C. PerezAbstract:Abstract Serine proteases are widely found in snake venoms. They have variety of functions including contributions to hemostasis. In this study, five serine proteases were cloned and characterized from two different cDNA libraries: factor V activator (RVV-V), alpha fibrinogenase (RVAF) and beta fibrinogenase (RVBF) from Russell’s viper (Daboia russelli siamensis), and plasminogen activator (APL-PA) and protein C activator (APL-C) from Agkistrodon piscivorus Leucostoma. The snake venom serine proteases were clustered in phylogenetic tree according to their functions. KA/KS values suggested that accelerated evolution has occurred in the mature protein coding regions in cDNAs of snake venom serine proteases.
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Molecular cloning and characterization of cDNAs encoding metalloproteinases from snake venom glands.
Toxicon, 2009Co-Authors: Ying Jia, John C. PerezAbstract:Abstract Snake venom metalloproteinases (SVMPs) are a superfamily of zinc-dependent proteases and participate in a number of important biological, physiological and pathophysiological processes. In this work, we simultaneously amplified nine cDNAs encoding different classes of metalloproteinases from glands of four different snake species ( Agkistrodon contortrix laticinctus , Crotalus atrox , Crotalus viridis viridis and Agkistrodon piscivorus Leucostoma ) by RT-PCR with a pair of primers. Among the encoded metalloproteinases, two enzymes ( Acl VMP-I and Apl VMP-I), three enzymes ( Ca VMP-II, Cvv VMP-II and Apl VMP-II) and four enzymes ( Acl VMP-III, Ca VMP-III, Cvv VMP-III and Apl VMP-III) with the characteristic motif (HEXXHXXGXXH) of metalloproteinase belong to type P-I, P-II and P-III enzymes, respectively. Disintegrin domains of Ca VMP-II and Cvv VMP-II from two Crotatus snakes contain RGD-motif whereas Apl VMP-II from Agkistrodon snake has KGD-motif. Instead of R/KGD-motif within disintegrin domain of SVMP-II enzyme, Ca VMP-III, Cvv VMP-III and Apl VMP-III enzymes contain SECD-motif, while Acl VMP-III has DDCD-motif in their corresponding position of disintegrin-like domains. There are 12 Cys amino acids in cysterin-rich domains of each P-III enzyme. Moreover, a disintegrin precursor ( Apl Dis) with RGD-motif also simultaneously amplified from the glands of A.p. Leucostoma while amplifying Apl VMP-II and Apl VMP-III, which indicated that different types of SVMPs and related genes are present in a single species of snake and share a consensus sequence at the 3′ and 5′ untranslated regions. RT-PCR result also showed that P-III is highly expressed in Crotalus snakes than in Agkistrodon snakes. Aligning the deduced amino acid sequence of these enzymes with other SVMPs from GenBank database indicated that this is the first report on the isolation of cDNAs encoding P-II and P-III enzymes from C.v. viridis and A.p. Leucostoma snakes. The availability of these SVMP sequences directly facilitated further studies of structure characterization and diversified function analysis.
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cDNA cloning, expression and fibrin(ogen)olytic activity of two low-molecular weight snake venom metalloproteinases.
Toxicon : official journal of the International Society on Toxinology, 2009Co-Authors: Ying Jia, Elda E Sanchez, Sara E. Lucena, Esteban Cantu, John C. PerezAbstract:Abstract Two cDNA clones, AplVMP1 and AplVMP2, were isolated from a snake ( Agkistrodon piscivorus Leucostoma ) venom gland cDNA library. The full-length cDNA sequence of AplVMP1 with a calculated molecular mass of 46.61 kDa is 1233 bp in length. AplVMP1 encodes PI class metalloproteinase with an open reading frame of 411 amino acid residues that includes signal peptide, pro-domain and metalloproteinase domains. The full-length cDNA of the AplVMP2 (1371 bp) has a calculated molecular mass of 51.16 kDa and encodes PII class metalloproteinase. The open reading frame of AplVMP2 with a 457 amino acid residues is composed of signal peptide, pro-domain, metalloproteinase and disintegrin domains. AplVMP1 and AplVMP2 showed 85% and 93% amino acid identical to PI class enzyme Agkistrodon contortrix laticinctus ACLPREF and PII class enzyme Agkistrodon piscivorus piscivorus piscivostatin, respectively. When expressed in Escherichia coli , most of recombinant proteins of AplVMP1 and AplVMP2 were in insoluble inclusion bodies, with soluble yields of 0.7 mg/l and 0.4 mg/l bacterial culture, respectively. Both affinity purified recombinant proteins show proteolytic activity on fibrinogen, although having an activity lower than that of crude A. p. Leucostoma venom. Proteolytic activities of AplVMP1 and AplVMP2 were completely abolished after incubation with a final concentration of 100 μM of EDTA or 1,10-phenanthroline. Both AplVMP1 and AplVMP2 were active in a fibrin–agarose plate but devoid of hemorrhagic activity when injected (up to 50 μg) subcutaneously into mice, and had no capacity to inhibit platelet aggregation.
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complementary dna sequencing and identification of mrnas from the venomous gland of agkistrodon piscivorus Leucostoma
Toxicon, 2008Co-Authors: Ying Jia, Bruno A Cantu, Elda E Sanchez, John C. PerezAbstract:To advance our knowledge on the snake venom composition and transcripts expressed in venom gland at the molecular level, we constructed a cDNA library from the venom gland of Agkistrodon piscivorus Leucostoma for the generation of expressed sequence tags (ESTs) database. From the randomly sequenced 2112 independent clones, we have obtained ESTs for 1309 (62%) cDNAs, which showed significant deduced amino acid sequence similarity (scores >80) to previously characterized proteins in National Center for Biotechnology Information (NCBI) database. Ribosomal proteins make up 47 clones (2%) and the remaining 756 (36%) cDNAs represent either unknown identity or show BLASTX sequence identity scores of <80 with known GenBank accessions. The most highly expressed gene encoding phospholipase A2 (PLA2) accounting for 35% of A. p. Leucostoma venom gland cDNAs was identified and further confirmed by crude venom applied to sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis and protein sequencing. A total of 180 representative genes were obtained from the sequence assemblies and deposited to EST database. Clones showing sequence identity to disintegrins, thrombin-like enzymes, hemorrhagic toxins, fibrinogen clotting inhibitors and plasminogen activators were also identified in our EST database. These data can be used to develop a research program that will help us identify genes encoding proteins that are of medical importance or proteins involved in the mechanisms of the toxin venom.
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Complementary DNA sequencing and identification of mRNAs from the venomous gland of Agkistrodon piscivorus Leucostoma.
Toxicon : official journal of the International Society on Toxinology, 2008Co-Authors: Ying Jia, Bruno A Cantu, Elda E Sanchez, John C. PerezAbstract:To advance our knowledge on the snake venom composition and transcripts expressed in venom gland at the molecular level, we constructed a cDNA library from the venom gland of Agkistrodon piscivorus Leucostoma for the generation of expressed sequence tags (ESTs) database. From the randomly sequenced 2112 independent clones, we have obtained ESTs for 1309 (62%) cDNAs, which showed significant deduced amino acid sequence similarity (scores >80) to previously characterized proteins in National Center for Biotechnology Information (NCBI) database. Ribosomal proteins make up 47 clones (2%) and the remaining 756 (36%) cDNAs represent either unknown identity or show BLASTX sequence identity scores of
Ying Jia - One of the best experts on this subject based on the ideXlab platform.
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Phospholipases A2 purified from cottonmouth snake venoms display no antibacterial effect against four representative bacterial species.
Toxicon : official journal of the International Society on Toxinology, 2018Co-Authors: Ying Jia, Justin VillarrealAbstract:Abstract Snake venom phospholipase A2 (PLA2) has widely been reported to possess antibacterial effects, and PLA2 is the major component of cottonmouth snake venoms. We assessed the antibacterial activities of crude venoms from Western cottonmouth (Agkistrodon piscivorus Leucostoma), Eastern cottonmouth (Agkistrodon piscivorus piscivorus), and Florida cottonmouth (Agkistrodon piscivorus conanti) snakes against two gram-positive (Bacillus subtilis, Staphylococcus aureus), and two gram-negative (Escherichia coli, Vibrio cholerae) bacteria. Antibacterial activity of PLA2 proteins, AplAsp49 and AplLys49 purified from A. p. Leucostoma venom, was also examined. Disk-diffusion assays revealed that A. p. Leucostoma crude venom is most effective in inhibiting the growth of the bacteria tested, compared to the other two. Surprisingly, AplAsp49 and AplLys49 PLA2s purified from A. p. Leucostoma venom did not display detectable antibacterial activity against any bacteria tested neither by disk-diffusion nor by minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). The lack of antibacterial activity of cottonmouth venom PLA2s is discussed.
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Phylogenetic analysis of serine proteases from Russell's viper (Daboia russelli siamensis) and Agkistrodon piscivorus Leucostoma venom
Toxicon : official journal of the International Society on Toxinology, 2011Co-Authors: Pattadon Sukkapan, Ying Jia, Issarang Nuchprayoon, John C. PerezAbstract:Abstract Serine proteases are widely found in snake venoms. They have variety of functions including contributions to hemostasis. In this study, five serine proteases were cloned and characterized from two different cDNA libraries: factor V activator (RVV-V), alpha fibrinogenase (RVAF) and beta fibrinogenase (RVBF) from Russell’s viper (Daboia russelli siamensis), and plasminogen activator (APL-PA) and protein C activator (APL-C) from Agkistrodon piscivorus Leucostoma. The snake venom serine proteases were clustered in phylogenetic tree according to their functions. KA/KS values suggested that accelerated evolution has occurred in the mature protein coding regions in cDNAs of snake venom serine proteases.
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Molecular cloning and characterization of cDNAs encoding metalloproteinases from snake venom glands.
Toxicon, 2009Co-Authors: Ying Jia, John C. PerezAbstract:Abstract Snake venom metalloproteinases (SVMPs) are a superfamily of zinc-dependent proteases and participate in a number of important biological, physiological and pathophysiological processes. In this work, we simultaneously amplified nine cDNAs encoding different classes of metalloproteinases from glands of four different snake species ( Agkistrodon contortrix laticinctus , Crotalus atrox , Crotalus viridis viridis and Agkistrodon piscivorus Leucostoma ) by RT-PCR with a pair of primers. Among the encoded metalloproteinases, two enzymes ( Acl VMP-I and Apl VMP-I), three enzymes ( Ca VMP-II, Cvv VMP-II and Apl VMP-II) and four enzymes ( Acl VMP-III, Ca VMP-III, Cvv VMP-III and Apl VMP-III) with the characteristic motif (HEXXHXXGXXH) of metalloproteinase belong to type P-I, P-II and P-III enzymes, respectively. Disintegrin domains of Ca VMP-II and Cvv VMP-II from two Crotatus snakes contain RGD-motif whereas Apl VMP-II from Agkistrodon snake has KGD-motif. Instead of R/KGD-motif within disintegrin domain of SVMP-II enzyme, Ca VMP-III, Cvv VMP-III and Apl VMP-III enzymes contain SECD-motif, while Acl VMP-III has DDCD-motif in their corresponding position of disintegrin-like domains. There are 12 Cys amino acids in cysterin-rich domains of each P-III enzyme. Moreover, a disintegrin precursor ( Apl Dis) with RGD-motif also simultaneously amplified from the glands of A.p. Leucostoma while amplifying Apl VMP-II and Apl VMP-III, which indicated that different types of SVMPs and related genes are present in a single species of snake and share a consensus sequence at the 3′ and 5′ untranslated regions. RT-PCR result also showed that P-III is highly expressed in Crotalus snakes than in Agkistrodon snakes. Aligning the deduced amino acid sequence of these enzymes with other SVMPs from GenBank database indicated that this is the first report on the isolation of cDNAs encoding P-II and P-III enzymes from C.v. viridis and A.p. Leucostoma snakes. The availability of these SVMP sequences directly facilitated further studies of structure characterization and diversified function analysis.
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cDNA cloning, expression and fibrin(ogen)olytic activity of two low-molecular weight snake venom metalloproteinases.
Toxicon : official journal of the International Society on Toxinology, 2009Co-Authors: Ying Jia, Elda E Sanchez, Sara E. Lucena, Esteban Cantu, John C. PerezAbstract:Abstract Two cDNA clones, AplVMP1 and AplVMP2, were isolated from a snake ( Agkistrodon piscivorus Leucostoma ) venom gland cDNA library. The full-length cDNA sequence of AplVMP1 with a calculated molecular mass of 46.61 kDa is 1233 bp in length. AplVMP1 encodes PI class metalloproteinase with an open reading frame of 411 amino acid residues that includes signal peptide, pro-domain and metalloproteinase domains. The full-length cDNA of the AplVMP2 (1371 bp) has a calculated molecular mass of 51.16 kDa and encodes PII class metalloproteinase. The open reading frame of AplVMP2 with a 457 amino acid residues is composed of signal peptide, pro-domain, metalloproteinase and disintegrin domains. AplVMP1 and AplVMP2 showed 85% and 93% amino acid identical to PI class enzyme Agkistrodon contortrix laticinctus ACLPREF and PII class enzyme Agkistrodon piscivorus piscivorus piscivostatin, respectively. When expressed in Escherichia coli , most of recombinant proteins of AplVMP1 and AplVMP2 were in insoluble inclusion bodies, with soluble yields of 0.7 mg/l and 0.4 mg/l bacterial culture, respectively. Both affinity purified recombinant proteins show proteolytic activity on fibrinogen, although having an activity lower than that of crude A. p. Leucostoma venom. Proteolytic activities of AplVMP1 and AplVMP2 were completely abolished after incubation with a final concentration of 100 μM of EDTA or 1,10-phenanthroline. Both AplVMP1 and AplVMP2 were active in a fibrin–agarose plate but devoid of hemorrhagic activity when injected (up to 50 μg) subcutaneously into mice, and had no capacity to inhibit platelet aggregation.
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complementary dna sequencing and identification of mrnas from the venomous gland of agkistrodon piscivorus Leucostoma
Toxicon, 2008Co-Authors: Ying Jia, Bruno A Cantu, Elda E Sanchez, John C. PerezAbstract:To advance our knowledge on the snake venom composition and transcripts expressed in venom gland at the molecular level, we constructed a cDNA library from the venom gland of Agkistrodon piscivorus Leucostoma for the generation of expressed sequence tags (ESTs) database. From the randomly sequenced 2112 independent clones, we have obtained ESTs for 1309 (62%) cDNAs, which showed significant deduced amino acid sequence similarity (scores >80) to previously characterized proteins in National Center for Biotechnology Information (NCBI) database. Ribosomal proteins make up 47 clones (2%) and the remaining 756 (36%) cDNAs represent either unknown identity or show BLASTX sequence identity scores of <80 with known GenBank accessions. The most highly expressed gene encoding phospholipase A2 (PLA2) accounting for 35% of A. p. Leucostoma venom gland cDNAs was identified and further confirmed by crude venom applied to sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis and protein sequencing. A total of 180 representative genes were obtained from the sequence assemblies and deposited to EST database. Clones showing sequence identity to disintegrins, thrombin-like enzymes, hemorrhagic toxins, fibrinogen clotting inhibitors and plasminogen activators were also identified in our EST database. These data can be used to develop a research program that will help us identify genes encoding proteins that are of medical importance or proteins involved in the mechanisms of the toxin venom.
Gerard C. Adams - One of the best experts on this subject based on the ideXlab platform.
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Ribosomal DNA sequence divergence and group I introns within the Leucostoma species L. cinctum, L. persoonii, and L. parapersoonii sp. nov., ascomycetes that cause Cytospora canker of fruit trees.
Mycologia, 2002Co-Authors: Gerard C. Adams, Rupa S. Surve-iyer, Amy F IezzoniAbstract:Leucostoma species that are the causal agents of Cytospora canker of stone and pome fruit trees were studied in detail. DNA sequence of the internal transcribed spacer regions and the 5.8S of the nuclear ribosomal DNA operon (ITS rDNA) supplied sufficient characters to assess the phylogenetic relationships among species of Leucostoma, Valsa, Valsella, and related anamorphs in Cytospora. Parsimony analysis of the aligned sequence divided Cytospora isolates from fruit trees into clades that generally agreed with the morphological species concepts, and with some of the phenetic groupings (PG 1-6) identified previously by isozyme analysis and cultural characteristics. Phylogenetic analysis inferred that isolates of L. persoonii formed two well-resolved clades distinct from isolates of L. cinctum. Phylogenetic analysis of the ITS rDNA, isozyme analysis, and cultural characteristics supported the inference that L. persoonii groups PG 2 and PG 3 were populations of a new species apparently more genetically different from L. persoonii PG 1 than from isolates representative of L. massariana, L. niveum, L. translucens, and Valsella melastoma. The new species, L. parapersoonii, was described. A diverse collection of isolates of L. cinctum, L. persoonii, and L. parapersoonii were examined for genetic variation using restriction fragment length polymorphism (RFLP) analysis of the ITS rDNA and the five prime end of the large subunit of the rDNA (LSU rDNA). HinfI and HpaII endonucleases were each useful in dividing the Leucostoma isolates into RFLP profiles corresponding to the isozyme phenetic groups, PG 1-6. RFLP analysis was more effective than isozyme analysis in uncovering variation among isolates of L. persoonii PG 1, but less effective within L. cinctum populations. Isolates representative of seven of the L. persoonii formae speciales proposed by G. Defago in 1935 were found to be genetically diverse isolates of PG 1. Two large insertions, 415 and 309 nucleotides long, in the small subunit (SSU) of the nuclear rDNA of L. cinctum were identified as Group 1 introns; intron 1 at position 943 and intron 2 at position 1199. The two introns were found to be consistently present in isolates of L. cinctum PG 4 and PG 5 and absent from L. cinctum PG 6 isolates, despite the similarity of the ITS sequence and teleomorph morphology. Intron 1 was of subgroup 1C1 whereas intron 2 was of an unknown subgroup. RFLP patterns and presence/absence of introns were useful characters for expediting the identification of cultures of Leucostoma isolated from stone and pome fruit cankers. RFLP patterns from 13 endonucleases provided an effective method for selecting an array of diverse PG 1 isolates useful in screening plant germplasm for disease-resistance.
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Genetic Heterogeneity of Leucostoma Species in Michigan Peach Orchards
Phytopathology, 1998Co-Authors: Dechun Wang, Amy F Iezzoni, Gerard C. AdamsAbstract:ABSTRACT The pathogens causing perennial canker of peach, Leucostoma spp., were characterized in Michigan orchards to identify which species and subgroups (cryptic species) were prevalent on a highly susceptible peach cultivar, Loring, and a less susceptible cultivar, Redhaven. Four hundred and three strains of Leucostoma were isolated from cankers in three southwest Michigan orchards where ‘Loring’ occurred adjacent to ‘Redhaven’ in side-by-side plots. Based on colony morphology and small nuclear rDNA size polymorphisms, three cryptic species were detected; 89% of the isolates were identified as L. persoonii phenetic group 1, 10% were L. cincta group 4, and 1% were L. persoonii group 2. Pathogen profiles differed significantly between cankers on small branches of ‘Loring’ and ‘Redhaven’, and between cankers on small branches and trunks. Of 1,232 random pairings among isolates of L. persoonii group 1, 95% were vegetatively incompatible. A minimum of 11 and a maximum of 17 maternal lines were identified ba...
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Isozyme detection and variation in Leucostoma species from Prunus and Malus
Mycologia, 1995Co-Authors: Rupa S. Surve-iyer, Amy F Iezzoni, Gerard C. Adams, Alan L. JonesAbstract:Isozyme analysis was used to study the vari? ation among isolates of Leucostoma causing canker on fruit trees. Seventy-seven isolates including 17 from teleomorphs were obtained from six Prunus species and Malus domestica in North America. Thirty-one al- leles were resolved at eight putative loci and the dis? tance and maximum parsimony methods of analysis found the two species of Leucostoma, L. persoonii and L. cincta, to be distinct. The two species had no simi? larity as measured by the coefficient of Jaccard. Par? simony analysis separated the species into two clades with a basal branch supported by 99.8% of the boot- strapped data sets. Fifty six isolates of Leucostoma clus? tered into six phenetic groups. Isolates corresponding to L. persoonii were clustered into three distinct groups, PG1, PG2, and PG3. Those corresponding to L. cincta were clustered into two similar groups on Prunus spp., PG4 and PG5, and a third group on Malus, PG6. Isozyme polymorphism was low within each of the three phenetic groups of L. persoonii, including PG1 that was geographically widespread on many host spe? cies. PG1 was distinct in culture morphology, having a lobate colony margin. Polymorphism was low within L. cincta PG6 on Malus but high within PG4 found on Prunus spp. Isolates from Malus were distinct in cul? tural characteristics and clustered in a separate branch from the other members of the L. cincta clade in 89% ofthe bootstrap trees. Leucostoma persoonii isolates were all able to grow at 33 C, a temperature at which growth ceased in L. cincta isolates. Isozyme polymorphism was evident among seven ascospore progeny of an L. cincta
Amy F Iezzoni - One of the best experts on this subject based on the ideXlab platform.
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Ribosomal DNA sequence divergence and group I introns within the Leucostoma species L. cinctum, L. persoonii, and L. parapersoonii sp. nov., ascomycetes that cause Cytospora canker of fruit trees.
Mycologia, 2002Co-Authors: Gerard C. Adams, Rupa S. Surve-iyer, Amy F IezzoniAbstract:Leucostoma species that are the causal agents of Cytospora canker of stone and pome fruit trees were studied in detail. DNA sequence of the internal transcribed spacer regions and the 5.8S of the nuclear ribosomal DNA operon (ITS rDNA) supplied sufficient characters to assess the phylogenetic relationships among species of Leucostoma, Valsa, Valsella, and related anamorphs in Cytospora. Parsimony analysis of the aligned sequence divided Cytospora isolates from fruit trees into clades that generally agreed with the morphological species concepts, and with some of the phenetic groupings (PG 1-6) identified previously by isozyme analysis and cultural characteristics. Phylogenetic analysis inferred that isolates of L. persoonii formed two well-resolved clades distinct from isolates of L. cinctum. Phylogenetic analysis of the ITS rDNA, isozyme analysis, and cultural characteristics supported the inference that L. persoonii groups PG 2 and PG 3 were populations of a new species apparently more genetically different from L. persoonii PG 1 than from isolates representative of L. massariana, L. niveum, L. translucens, and Valsella melastoma. The new species, L. parapersoonii, was described. A diverse collection of isolates of L. cinctum, L. persoonii, and L. parapersoonii were examined for genetic variation using restriction fragment length polymorphism (RFLP) analysis of the ITS rDNA and the five prime end of the large subunit of the rDNA (LSU rDNA). HinfI and HpaII endonucleases were each useful in dividing the Leucostoma isolates into RFLP profiles corresponding to the isozyme phenetic groups, PG 1-6. RFLP analysis was more effective than isozyme analysis in uncovering variation among isolates of L. persoonii PG 1, but less effective within L. cinctum populations. Isolates representative of seven of the L. persoonii formae speciales proposed by G. Defago in 1935 were found to be genetically diverse isolates of PG 1. Two large insertions, 415 and 309 nucleotides long, in the small subunit (SSU) of the nuclear rDNA of L. cinctum were identified as Group 1 introns; intron 1 at position 943 and intron 2 at position 1199. The two introns were found to be consistently present in isolates of L. cinctum PG 4 and PG 5 and absent from L. cinctum PG 6 isolates, despite the similarity of the ITS sequence and teleomorph morphology. Intron 1 was of subgroup 1C1 whereas intron 2 was of an unknown subgroup. RFLP patterns and presence/absence of introns were useful characters for expediting the identification of cultures of Leucostoma isolated from stone and pome fruit cankers. RFLP patterns from 13 endonucleases provided an effective method for selecting an array of diverse PG 1 isolates useful in screening plant germplasm for disease-resistance.
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Genetic Heterogeneity of Leucostoma Species in Michigan Peach Orchards
Phytopathology, 1998Co-Authors: Dechun Wang, Amy F Iezzoni, Gerard C. AdamsAbstract:ABSTRACT The pathogens causing perennial canker of peach, Leucostoma spp., were characterized in Michigan orchards to identify which species and subgroups (cryptic species) were prevalent on a highly susceptible peach cultivar, Loring, and a less susceptible cultivar, Redhaven. Four hundred and three strains of Leucostoma were isolated from cankers in three southwest Michigan orchards where ‘Loring’ occurred adjacent to ‘Redhaven’ in side-by-side plots. Based on colony morphology and small nuclear rDNA size polymorphisms, three cryptic species were detected; 89% of the isolates were identified as L. persoonii phenetic group 1, 10% were L. cincta group 4, and 1% were L. persoonii group 2. Pathogen profiles differed significantly between cankers on small branches of ‘Loring’ and ‘Redhaven’, and between cankers on small branches and trunks. Of 1,232 random pairings among isolates of L. persoonii group 1, 95% were vegetatively incompatible. A minimum of 11 and a maximum of 17 maternal lines were identified ba...
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Isozyme detection and variation in Leucostoma species from Prunus and Malus
Mycologia, 1995Co-Authors: Rupa S. Surve-iyer, Amy F Iezzoni, Gerard C. Adams, Alan L. JonesAbstract:Isozyme analysis was used to study the vari? ation among isolates of Leucostoma causing canker on fruit trees. Seventy-seven isolates including 17 from teleomorphs were obtained from six Prunus species and Malus domestica in North America. Thirty-one al- leles were resolved at eight putative loci and the dis? tance and maximum parsimony methods of analysis found the two species of Leucostoma, L. persoonii and L. cincta, to be distinct. The two species had no simi? larity as measured by the coefficient of Jaccard. Par? simony analysis separated the species into two clades with a basal branch supported by 99.8% of the boot- strapped data sets. Fifty six isolates of Leucostoma clus? tered into six phenetic groups. Isolates corresponding to L. persoonii were clustered into three distinct groups, PG1, PG2, and PG3. Those corresponding to L. cincta were clustered into two similar groups on Prunus spp., PG4 and PG5, and a third group on Malus, PG6. Isozyme polymorphism was low within each of the three phenetic groups of L. persoonii, including PG1 that was geographically widespread on many host spe? cies. PG1 was distinct in culture morphology, having a lobate colony margin. Polymorphism was low within L. cincta PG6 on Malus but high within PG4 found on Prunus spp. Isolates from Malus were distinct in cul? tural characteristics and clustered in a separate branch from the other members of the L. cincta clade in 89% ofthe bootstrap trees. Leucostoma persoonii isolates were all able to grow at 33 C, a temperature at which growth ceased in L. cincta isolates. Isozyme polymorphism was evident among seven ascospore progeny of an L. cincta
Alan R. Biggs - One of the best experts on this subject based on the ideXlab platform.
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Handbook of Cytology, Histology, and Histochemistry of Fruit Tree Diseases
2019Co-Authors: Alan R. BiggsAbstract:Aimed at plant pathologists, botanists, horticulturalists and agriculturalists, this book provides a comprehensive discussion of the relationships between host plant structure and pathological anatomy. Topics include the structure and development of gum ducts, wound reactions, systemic invasion by bacterial pathogens, diseases caused by MLOs, and responses to cold temperatures. The book covers an array of fruit tree diseases, including apple scab, fire blight, Leucostoma canker, pear rust, and citrus blight. Features include more than 270 detailed micrographs.
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Production and Dispersal of Conidia of Leucostoma cinctum in Peach and Cherry Orchards Under Irrigation in Eastern Washington.
Plant disease, 2006Co-Authors: Gary G. Grove, Alan R. BiggsAbstract:Grove, G. G., and Biggs, A. R. 2006. Production and dispersal of conidia of Leucostoma cinctum in peach and cherry orchards under irrigation in eastern Washington. Plant Dis. 90:587-591. The objectives of this study were to determine the seasonal production patterns of Leucostoma cinctum conidia in peach and cherry orchards and the effects of irrigation on dispersal of conidia. Conidia were trapped throughout the year and were present in highest numbers during spring and summer on both cherry and peach. The pathogen was dispersed 1.0 m by water drops that simulated irrigation drops that would impact cankers during over-the-canopy irrigation. Spore production and dispersal also resulted from the use of over-the-canopy and under-tree impact sprinklers. Although the two irrigation methods were not directly compared, the latter mode dispersed propagules of L. cinctum over horizontal distances of about 6 m, a distance sufficient to account for the movement of the pathogen between trees within and across orchard rows. It is concluded that disease management could be improved by alteration of horticultural and irrigation practices.
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Water relations of various peach cultivars in relation to peach canker disease
Hortscience, 1993Co-Authors: Alan R. BiggsAbstract:Whole-shoot water potential, osmotic potential of the xylem fluid, and bark water potential were examined from late winter through early spring for six peach (Prunus persica (L.) Batsch.) cultivars varying in relative susceptibility to Leucostoma canker. There were significant differences among cultivars for whole-shoot water potential on all 11 dates tested in 1986, but not in 1985. The date effect was not consistent among cultivars, although when averaged across dates, the whole-shoot water potential of 'Loring' was significantly more negative than that of 'Candor' or 'Garnet Beauty'. There were significant differences among cultivars for xylem fluid osmotic potential on one of five dates tested in 1985 and three of 11 dates tested in 1986, although cultivar differences were not consistent between years. Cultivars exhibited differences in bark water potential on three of five dates tested in 1985, with 'Loring' exhibiting the least negative values when averaged across dates. There were only occasional significant correlations of the water status characteristics with relative susceptibility to Leucostoma canker or suberin accu- mulation. Measurements of plant water status among cultivars or genotypes in peach do not appear to be reliable indicators of susceptibilit y to Leucostoma spp. or wound response. Peach canker, a fungal disease caused by Leucostoma cincta (Pers. ex Fr.) Hohn. (anamorph = Leucocytospora cincta (Sacc.) Hohn.) and L. persoonii (Nits.) Hohn. (anamorph = L. Leucostoma (Pers.) Hohn.), is a major limiting factor in peach production in northern North America. The disease is initi- ated in wounds created by pruning, leaf abscis- sion, cold injury, and insect damage (Willison,