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Biological Derivatives for Plant Disease Control

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Maxim Burkholderia cepacia. Aoki et al., 1991 ... Maxim. Burkholderia, Friend or Foe? ... Maxim- fludioxonil (phenylpyrrole) ... – PowerPoint PPT presentation

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Title: Biological Derivatives for Plant Disease Control


1
Biological Derivatives for Plant Disease Control
  • Ent 547 Fundamentals of Biological Control
  • Fall 2005

2
Biological Derivatives
  • Sources of materials
  • Bacteria
  • Fungicides
  • Fungi
  • Fungicides
  • Nematicides
  • Viruses
  • Transgenic Plants
  • Plants
  • Transgenic Plants
  • Compost Teas and Extracts

3
Mode of Action of Biological Derivatives
  • Biocidal Pesticides
  • Maxim
  • Strobilurins
  • Inducers of Plant Resistance
  • Derivatives of the Hrp cluster
  • Transgenic Plants (viral products, chitinase)
  • Compost Teas and Extracts
  • Mixture of site exclusion, antibiosis, and
    induced resistance

4
Biocidal Pesticides
  • Natural or synthetic chemistries that are based
    on naturally occurring bioactive metabolites
  • There are numerous examples but only a few has
    been developed into products
  • Potential for discovery and development of new
    chemistries
  • Standard approach
  • Bioinformatics

5
From http//helios.bto.ed.ac.uk/bto/microbes/pen
icill.htm
  • Streptomyces
  • ?-methylene-?-alanine - slight activity against
    velvet leaf, antibacterial, also found in sponges
  • cis-2-amino-1-hydroxycyclobutane-1-acetic acid -
    chlorosis and growth retardation, antibacterial
  • Herbicidins (A, B, E, F, G) - kills many grasses
    but not rice, A control of Xanthomonas oryzae.
    Many dicots affected
  • hydantocidin - a nitrogen containing herbicide
    of monocots and dicots with no antifungal or
    antibacterial activity

6
Bioactive Metabolites
  • Fusarium
  • 3-hydroxycyclobut-3-ene-1,2-diol F. moniliforme
    - potent herbicide, locks mitosis similar to
    colchicine
  • Food borne toxins
  • Nocardia
  • Soilborne actinomycete that can cause a rare
    disorder of the lungs, brain, or skin in
    immunocompromised individuals
  • formycin - a nucleoside

7
Bioactive Metabolites
  • Salicylic acid - induced resistance
  • 2-fluoroglucinol - Pseudomonas aureofaciens
  • phenazine - Pseudomonas fluorescens
  • Auxigro - gamma amino butyric acid, Fusarium
  • Upcoming new materials from basidiomycetes -
    Abound

8
Disease Sour skin of onions Bacterium
Burkholderia cepacia First described by Walter
Burkholder in 1950
9
Maxim Burkholderia cepacia
  • Aoki et al., 1991
  • Tobacco cultivated on rice paddies lower
    incidence of bacterial wilt (Ralstonia
    solanacearum)
  • Isolated antagonists (B. cepacia)
  • 2-keto-D-gluconic acid - intermediary in
    pectolytic enzyme synthesis
  • Also inhibited P. putida, P. syringae, P.
    lachrymans, and P. aeruginosa (pectolytic)

10
Burkholderia cepacia study
  • Gill and Cole, 1991
  • Mushroom grower in New Zealand switched to
    Agaricus bitorquis from A. bisporus
  • Grow at higher temperatures - less virus disease
  • Cavity rot
  • Isolated B. cepacia
  • McLoughlin et al., 1992
  • Inhibition sunflower wilt caused by Sclerotinia
    sclerotiorum (increased seedling emergence)
  • Pyrrolnitrin, aminopyrrolnitrin,
    monochloroaminopyrrolnitrin
  • UV-light mutants did not suppress disease

11
Burkholderia cepacia story
  • Hebbar et al., 1992
  • efficient root colonizer of maize, need a minimum
    of 30 bacterial cells per seed
  • Parke et al., 1990s
  • control of Aphanomyces and Pythium root rot of
    peas
  • 1992 Patent
  • Maxim

Burkholderia, Friend or Foe? http//www.apsnet.org
/online/feature/BurkholderiaCepacia/Top.html
12
  • Maxim- fludioxonil (phenylpyrrole)
  • Broad-spectrum activity against seed-borne and
    soil-borne diseases (Ascomycetes, Deuteromycetes,
    and Basidiomycetes).
  • Fusarium, Rhizoctonia, and Helminthosporium and
    weakly pathogenic fungi of the genera Penicillium
    and Aspergillus.
  • Registered for corn, sweet corn, sorghum, soybean

13
Strobilurus tenacellusThe Pine Cone Fungus
  • Strong inhibition of many fungi in vitro
  • Greenhouse tests with plant pathogens were
    disappointing
  • The antibiotic Strobilurin A is light sensitive

14
  • Chemical alteration
  • Broad spectrum antifungal agent
  • Quick acting
  • Leaf inhabiting fungi
  • Quickly degraded in soil, water, and plant tissue

15
Strobilurin Fungicides
  • A series of compounds that have cytochrome B
    (Ubiquinol oxidase) binding activity.

Fluoxastrobin
fenamidone
azoxystrobin
picoxystrobin
http//www.verbutin.com/strobilurines_main.htm
16
New Technologies?
17
Induced Plant Resistance
  • Induced Plant Resistance is a phenomenon where
    prior exposure to microorganisms or chemicals
    enables the plant to be resistant to infection by
    similar and dissimilar pathogens
  • Types
  • Cross protection a direct antagonism
    (antibiosis, site and nutrient competition,
    parasitism) by one organism against another in
    the host tissue
  • Systemic Acquired Resistance indirect action
    where an organism stimulates the plants defense
    mechanisms

18
Inducers
  • Organisms that serve as inducers are
  • Nonpathogenic or weakly pathogenic
  • However, for most cases, they are strong
    pathogens in other hosts
  • Four Examples of CP/IR
  • Virus cross protection Citrus tristeza virus,
    Tobacco mosaic virus
  • Fungal cross protection Gaeumannomyces graminis
    var. tritici/Phialophora graminicola in
    grass/wheat rotations in England.
  • Multiline and variety mixtures
  • Mycorrhizae

19
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20
Citrus Tristeza Virus (CTV)
  • First introduced in the 1920s in Brazil
  • Spread to Argentina, Uruguay
  • Search for mild strains in moderate and severely
    infected orchards in 1960s
  • Selected 1 of 45 strains.
  • Inoculated bud wood
  • Graft onto CTV tolerant rootstocks

21
The Hypersensitive Reaction
  • rapid necrosis of plant tissue
  • accumulation of phenolics and phytoalexins
  • rapid death of the invading microorganism
  • associated with avr genes
  • Bacterial determinants
  • may be initiated by hrp genes
  • Type III secretion system

22
Secretory Systems in Bacteria
23
Systemic Acquired Resistance
  • Inoculation of pathogenic bacteria or fungi
    causes lesions
  • Plant becomes increasingly resistant to a wider
    range of pathogens
  • Involves
  • Antimicrobial compounds
  • Enzymes chitinases, glucanases
  • Lignification
  • Pathogenesis related proteins
  • Phytoalexins

24
Examples of Systemic Acquired Resistance (SAR) or
Induced Resistance
  • Viswanathan and Samiyappan. 2002. Induced
    systemic resistance by fluorescent pseudomonads
    against red rot disease of sugarcane caused by
    Colletotrichum falcatum. Crop Protect. 211-10.
  • Spencer, M., et al. 2003. Induced defence in
    tobacco by Pseudomonas chlororaphis strain O6
    involves at least the ethylene pathway. Physiol.
    Molec. Plant Pathol. 6327-34.

25
The Harpin Story
  • Steven V. Beer
  • Cornell University, Ithaca, NY
  • Erwinia amylovora
  • Fireblight disease

26
Pathogenicity Islands
  • Genes for pathogenicity and hypersensitivity are
    linked
  • The hypersensitive reaction is controlled by a
    series of genes
  • One of these genes, cloned into E. coli
  • Messenger, Eden BioSciences, 5 11.5 g/acre.

27
Transgenic Plants
  • Introduction of a new gene
  • Agrobacterium mediated
  • Biolistics
  • Pollen transformation
  • Electroporation
  • Disease resistance genes
  • Coat protein gene from viruses
  • Chitinase gene

28
Compost Teas and Extracts
  • Compost extracts are water extracts of a variety
    of compost materials that can be used as a crop
    protection tool
  • Extraction continuous leaching for hours to days
  • Additives molasses, seaweed extract, algae,
    yeast
  • Microbial enrichment

29
Compost Extracts
30
Compost Extracts Mechanisms
  • Induced resistance
  • Inhibition of spore germination
  • Antagonism
  • Competition

31
Compost Teas
  • Compost teas are fermentations where beneficial
    microorganisms are grown supplemented with food
    sources such as molasses, kelp, rock dust, humic
    and fulvic acids.
  • May be an aerobic or anaerobic process.

32
There are Still Questions
  • Inoculating compost teas with specific organisms?
  • Aerobic or non-aerobic?
  • Human health issues?
  • Reproducibility?

33
Summary
  • Derivatives for organisms for disease control
    include
  • Bioactive metabolites
  • Plant pathogens
  • Non-pathogens
  • Plant resistance metabolites
  • Genes from plant pathogens

34
Microbial Biological Control Summary
  • Use of the biological control organisms directly
    for disease and pest management
  • Use of derivatives of the biological control
    organisms
  • Direct
  • Indirect induced systemic resistance
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