Pathogen variation and urea influence selection and success of Streptomyces mixtures in biological control.

Success in biological control of plant diseases remains inconsistent in the field. A collection of well-characterized Streptomyces antagonists (n = 19 isolates) was tested for their capacities to inhibit pathogenic Streptomyces scabies (n = 15 isolates). There was significant variation among antagonists in ability to inhibit pathogen isolates and among pathogens in their susceptibility to inhibition. Only one antagonist could inhibit all pathogens, and antagonist-pathogen interactions were highly specific, highlighting the limitations of single-strain inoculum in biological control. However, the collection of pathogens could be inhibited by several combinations of antagonists, suggesting the potential for successful antagonist mixtures. Urea generally increased effectiveness of antagonists at inhibiting pathogens in vitro (increased mean inhibition zones) but its specific effects varied among antagonist-pathogen combinations. In greenhouse trials, urea enhanced the effectiveness of antagonist mixtures relative to individual antagonists in controlling potato scab. Although antagonist mixtures were frequently antagonistic in the absence of urea, all n= 2 and n = 3 antagonist-isolate combinations were synergistic in the presence of urea. This work provides insights into the efficacy of single- versus multiple-strain inocula in biological control and on the potential for nutrients to influence mixture success.

[1]  Xingzhong Liu,et al.  Nutritional requirements of mycelial growth and sporulation of several biocontrol fungi in submerged and on solid culture , 2010, Microbiology.

[2]  Daqun Liu,et al.  Identification of potato scab inducing and suppressive species of Streptomyces. , 1995 .

[3]  L. Kinkel,et al.  Biological Control of Phytophthora Root Rots on Alfalfa and Soybean with Streptomyces , 2002 .

[4]  G. Grondin,et al.  Potato Suberin Induces Differentiation and Secondary Metabolism in the Genus Streptomyces , 2011, Microbes and environments.

[5]  L. Kinkel,et al.  Genetic and phenotypic traits of streptomycetes used to characterize antibiotic activities of field-collected microbes. , 2004, Canadian journal of microbiology.

[6]  Phenotypic and genetic diversity of Erwinia amylovora: the causal agent of fire blight , 2012, Trees.

[7]  Z. Punja,et al.  Factors influencing colonization of cucumber roots by Clonostachys rosea f. catenulata, a biological disease control agent , 2010 .

[8]  Matthew G. Bakker,et al.  Plant community effects on the diversity and pathogen suppressive activity of soil streptomycetes , 2010 .

[9]  S. Santra,et al.  Phylogeny, phenotypic and nutritional characteristics of estuarine soil actinomycetes having broad-spectrum antimicrobial activity derived from an ecologically guided bioprospecting programme , 2011 .

[10]  A. Shirzad,et al.  Antagonistic Potential of Fluorescent Pseudomonads and Control of Crown and Root Rot of Cucumber Caused by Phythophtora drechsleri , 2012 .

[11]  N. Arora,et al.  Dual activity of pyocyanin from Pseudomonas aeruginosa--antibiotic against phytopathogen and signal molecule for biofilm development by rhizobia. , 2011, Canadian journal of microbiology.

[12]  Daqun Liu,et al.  Selection and characterization of strains of Streptomyces suppressive to the potato scab pathogen , 1996 .

[13]  D. Jiāng,et al.  Effects of ambient pH and nutritional factors on antifungal activity of the mycoparasite Coniothyrium minitans , 2008 .

[14]  D. Shtienberg,et al.  Improved Biocontrol of Botrytis cinerea on Detached Strawberry Leaves by Adding Nutritional Supplements to a Mixture of Pichia guilermondii and Bacillus mycoides , 2002 .

[15]  J. Sutton,et al.  Effects of acetic acid, propionic acid and urea on inoculum production by Gibberella zeae in maize and wheat residues , 1991 .

[16]  S. Hobbie,et al.  Resource Amendments Influence Density and Competitive Phenotypes of Streptomyces in Soil , 2009, Microbial Ecology.

[17]  S. Williams,et al.  Selection of Media for Isolation of Streptomycetes , 1964, Nature.

[18]  C. Beaulieu,et al.  Genome shuffling enhances biocontrol abilities of Streptomyces strains against two potato pathogens , 2011, Journal of applied microbiology.

[19]  J. Waller,et al.  Biological control of fungal plant pathogens. , 2001 .

[20]  D. Backhouse,et al.  Nutritional constraints on displacement of Fusarium pseudograminearum from cereal straw by antagonists , 2010 .

[21]  L. Kinkel,et al.  Spatial Variation in Frequency and Intensity of Antibiotic Interactions among Streptomycetes from Prairie Soil , 2004, Applied and Environmental Microbiology.

[22]  S. Ranamukhaarachchi,et al.  Soil-borne antagonists for biological control of bacterial wilt disease caused by Ralstonia solanacearum in tomato and pepper. , 2010 .

[23]  L. Kinkel,et al.  Inoculum Density and Population Dynamics of Suppressive and PathogenicStreptomycesStrains and Their Relationship to Biological Control of Potato Scab , 1997 .

[24]  D. Crawford,et al.  Characterization of streptomyces lydicus WYEC108 as a potential biocontrol agent against fungal root and seed rots , 1995, Applied and environmental microbiology.

[25]  J. Y. Kim,et al.  Cephamycin C production is regulated by relA and rsh genes in Streptomyces clavuligerus ATCC27064. , 2004, Journal of biotechnology.

[26]  R. Larkin,et al.  Mechanisms of Action and Dose-Response Relationships Governing Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp. , 1999, Phytopathology.

[27]  L. Kinkel,et al.  Effect of Pathogen Isolate, Potato Cultivar, and Antagonist Strain on Potato Scab Severity and Biological Control , 2004 .

[28]  T. Paulitz,et al.  Biological control in greenhouse systems. , 2003, Annual review of phytopathology.

[29]  S. Shafir,et al.  Trichoderma Biocontrol of Colletotrichum acutatum and Botrytis cinerea and Survival in Strawberry , 2004, European Journal of Plant Pathology.

[30]  D. Shtienberg,et al.  Improving biological control by combining biocontrol agents each with several mechanisms of disease suppression. , 2002, Phytopathology.

[31]  T. Potter,et al.  Streptomyces costaricanus sp. nov., isolated from nematode-suppressive soil. , 1995, International journal of systematic bacteriology.

[32]  N. Rosenzweig,et al.  Culture-Based Assessment of Microbial Communities in Soil Suppressive to Potato Common Scab. , 2012, Plant disease.

[33]  D. Sugar,et al.  Mechanistically compatible mixtures of bacterial antagonists improve biological control of fire blight of pear. , 2011, Phytopathology.

[34]  L. Kinkel,et al.  Competition and antibiosis in the biological control of potato scab. , 2001, Canadian journal of microbiology.

[35]  H. Askari,et al.  Plant growth promoting activity of an auxin and siderophore producing isolate of Streptomyces under saline soil conditions , 2012, World journal of microbiology & biotechnology.

[36]  M. Razavi,et al.  Pathogenic and Genetic Diversity among Iranian Isolates of Macrophomina phaseolina , 2012 .

[37]  J. Graham,et al.  Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum , 2012, European Journal of Plant Pathology.

[38]  G. V. van Wezel,et al.  Functional Analysis of the N-Acetylglucosamine Metabolic Genes of Streptomyces coelicolor and Role in Control of Development and Antibiotic Production , 2011, Journal of bacteriology.

[39]  M. R. Carter,et al.  Variation in antibiosis ability, against potato pathogens, of bacterial communities recovered from the endo- and exoroots of potato crops produced under conventional versus minimum tillage systems. , 2005, Canadian journal of microbiology.

[40]  Z. Punja,et al.  Using fungi and yeasts to manage vegetable crop diseases. , 2003, Trends in biotechnology.

[41]  J. H. Bowers,et al.  Quantitative relationships among thaxtomin A production, potato scab severity, and fatty acid composition in Streptomyces. , 1998, Canadian journal of microbiology.

[42]  D. Shtienberg,et al.  Establishment, Survival and Activity of the Biocontrol Agents Pichia guilermondii and Bacillus mycoides Applied as a Mixture on Strawberry Plants , 2002 .

[43]  H. Schrempf,et al.  Streptomyces lividans inhibits the proliferation of the fungus Verticillium dahliae on seeds and roots of Arabidopsis thaliana , 2010, Microbial biotechnology.

[44]  K. El-Tarabily,et al.  Plant growth promotion and biological control of Pythium aphanidermatum, a pathogen of cucumber, by endophytic actinomycetes , 2009, Journal of applied microbiology.

[45]  W. C. James,et al.  illustrated series of assessment keys for plant diseases, their preparation and usage , 1971 .

[46]  D. Schlatter,et al.  Rapid and Specific Method for Evaluating Streptomyces Competitive Dynamics in Complex Soil Communities , 2010, Applied and Environmental Microbiology.

[47]  A. P. Martin,et al.  Spatial Variation in Streptomyces Genetic Composition and Diversity in a Prairie Soil , 2004, Microbial Ecology.

[48]  M. Pautasso,et al.  Combined use of biocontrol agents to manage plant diseases in theory and practice. , 2011, Phytopathology.

[49]  L. Kinkel,et al.  Biological control of potato scab in the field with antagonistic Streptomyces scabies. , 1995 .

[50]  J. Davies.  Small molecules: the lexicon of biodiversity. , 2007, Journal of biotechnology.

[51]  V. Venturi,et al.  Virulence Attenuation of Pectobacterium carotovorum Using N-Acyl-homoserine Lactone Degrading Bacteria Isolated from Potato Rhizosphere , 2011 .

[52]  J. E. F. Figueiredo,et al.  Efficacy and dose–response relationship in biocontrol of Fusarium disease in maize by Streptomyces spp. , 2008, European Journal of Plant Pathology.

[53]  J. Valkonen,et al.  Interactions and biocontrol of pathogenic Streptomyces strains co‐occurring in potato scab lesions , 2009, Journal of applied microbiology.

[54]  M. Shishido,et al.  Biological Control Efficiency of Fusarium Wilt of Tomato by Nonpathogenic Fusarium oxysporum Fo-B2 in Different Environments. , 2005, Phytopathology.

[55]  H. Kaul,et al.  Populations of Fusarium graminearum on crop residues as affected by incorporation depth, nitrogen and fungicide application , 2002 .

[56]  W. Yuxia,et al.  Isolation and characterization of antifungal lipopeptides produced by endophytic Bacillus amyloliquefaciens TF28 , 2012 .

[57]  B. Mahadevan,et al.  Properties of the chitinase of the antifungal biocontrol agent Streptomyces lydicus WYEC108 , 1997 .

[58]  C. Gilligan,et al.  A theoretical framework for biological control of soil-borne plant pathogens: Identifying effective strategies. , 2011, Journal of theoretical biology.

[59]  G. V. van Wezel,et al.  Feast or famine: the global regulator DasR links nutrient stress to antibiotic production by Streptomyces , 2008, EMBO reports.

[60]  D. Sugar,et al.  Control of fire blight by Pseudomonas fluorescens A506 and Pantoea vagans C9-1 applied as single strains and mixed inocula. , 2010, Phytopathology.

[61]  K. B. Johnson.  Dose-response relationships and inundative biological control , 1994 .

[62]  R. Sharifi,et al.  EVALUATION OF BIOCONTROL EFFICIENCY OF PSEUDOMONAS FLUORESCENS UTPF61 IN DIFFERENT NITROGEN SOURCES , 2011 .

[63]  Renu,et al.  Co-inoculation of Dactylaria brochopaga and Monacrosporium eudermatum affects disease dynamics and biochemical responses in tomato (Lycopersicon esculentum Mill.) to enhance bio-protection against Meloidogyne incognita , 2012 .

[64]  K. Eskridge,et al.  Variation in Sclerotinia sclerotiorum Bean Isolates from Multisite Resistance Screening Locations. , 2011, Plant disease.

[65]  J. Whipps,et al.  Some Nutritional Factors Affecting Production of Biomass and Antifungal Metabolites of Coniothyrium minitans , 2002 .

[66]  A. Stewart,et al.  Ecological studies of the bio-inoculant Trichoderma hamatum LU592 in the root system of Pinus radiata. , 2012, FEMS microbiology ecology.