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Management of Host Plant Resistance
through Immunization
Anshul AryaID-38091
Master’s SeminarAPP-600
Introduction
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Host plant resistance
“Those characters that enable a plant to avoid, tolerate or recover from attacks of the pest under the conditions that would cause greater injury to other plants of same species”.
“A plant that has the ability to resist certain types of diseases while other varieties of the same plant are susceptible”.
Painter, 1951
Terry, 2001
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Host resistance
Effect of
genes
Growth stage
Mode of
inheritance
Cytoplas-mic
Epidemeo-
logical
Chaube and Singh, 2004
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Immunization?
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• Beauverie in 1901 published Essais d'immunization des vegetaux contre des maladies cryptogamiques or
• Chester in 1933 published
• Muller and Borger in 1940 found that-
History
“Testing the immunization of plants against fungal diseases”.
“The problem of acquired physiological immunity”.
Plants can be immunized against many fungal diseases.6
Process of activating natural defense system present in plants induced by biotic or abiotic factors
Sensitize plants to respond rapidly after infection.
Regulate genes for defense compounds, effect is systemic and often lasts for the life of annual plants
Kothari, 2004
Kuc and Tuzun, 1990
Kuc, 1990
Facts……..
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Increases the levels of :
Chitinases
β -1,3-glucanases
Peroxidases
Base of immunization :
Expression of potential of resistance
Ye et al., 1989
Tuzun, 1990
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Kuc, 1991
•Demonstrated in 26 diverse plant pathogen interactions including pear, apple, peach, coffee, tomato, potato etc
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Example- The signal for immunization in cucurbits and
tobacco is graft-transmissible
Signals synthesized at the site of infection
Transported in the phloem
Tuzun and Kuc, 1985
Dean and Kuc, 1986
Tuzun and Kuc, 1985
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Methods of Immunization
Immunized plant
Inoculation with
abiotic elicitors
Inoculation with
pathogens
Inoculation with non
pathogens
Inoculation with
attenuated pathogen
Kuc, 1987
Innate immune system
Effectors-triggered immunity (ETI)gene-for-gene
resistance Hypersensitiv
eResponse(HR)
Pattern-triggered immunity (PTI)
PAMPs
Mechanism
Signal transductionpathways Peng et al., 2013
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Salicylic Acid pathway
Production of active oxygen
Thickening of plant cell wall
Production of phenolic esters
PR –proteins, Anti microbial compounds
Salicylic Acid (SA)
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Azelaic Acid Pathway
Sproales, 201214
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16Thakker et al., 2013
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Thakker et al., 2013
S.No. Plant Pathogen Protection against Reference
1.
2.
3.
4.
Muskmelon Watermelon
Cucumber
Potato
Alfalfa
Colletotrichum lagenarium
Colletotrichum lagenarium
Phytophthora infestans
Colletotrichum lindemuthianum
Colletotrichum lagenarium
Colletotrichum lagenarium
Phytophthora infestans
Colletotrichum
Pass, 1987
Kuc and Kearney,
2004
Kolomiests et al., 2000
Sticher et al.,1997
Immunization against microbial diseases
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19Paparu et al,.2007
S.No. Plant Avirulent strain/non pathogen
Protection against
Reference
1. Cucumber Alternaria cucumarina orCladosporium fulvum
Sphaerotheca fuliginea
Moshe and Reuven,
2000
2.
3.
Rice
Bean
Bipolaris sorokiniana Pyricularia Oryzae
Colletotrichum lindemuthianum
Pyricularia oryzae
Colletotrichum lindemuthianum
Colletotrichum lindemuthianum
Manandhar et al., 1998
Claire et al., 2005
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Avirulent and non-pathogenic organisms as inducers
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Priming
transcriptionally active NPR1, MPK3, MPK6
require pathogen or chemical challenge for activation
secondary pathogen attack
Activate signaling components
long-lasting resistance to secondary pathogen attack
Long lasting immunity
Spoel and Dong, 2012
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Chemical Class Elicitor Source Function Effects
Oligo-saccharides
Branched (1,3-1,6) β-glucans
Phytophtora, Pythium
Component of the fungal cell wall
Phytoalexin in soybean, Rice
Peptides andproteins;
Viral coatProtein
Tobacco Mosaic Virus
Structural component
HR In tobacco, tomato
Peptides andproteins;
Peptaibols Trichoderma andEmericellopsis
Cell wall degradingenzymes
Defense response in lima bean
Peptides andproteins;
Elicitins Phytophtora, Pythium
Induction of leaf necrosis
HR in tobacco
Glycolipids Syringolids Pseudomonassyringae
Signal compound for bacterium
HR in soybean
Biotic elicitors and their effect
Montesano et al., 2003
Pathogen-activated induced resistance of cucumber : response of arthropod herbivores to systemically
protected leaves
• Young cucumber plants were immunized by infection of a lower leaf with Tobacco Necrosis Virus
• No effect on population growth of two spotted spider
mites, Tetranychus urticae .
• Not systemically affect mite performance on the virus-
free side of the leaf.
23Potter et al., 1990
• No effects on growth rate, pupal weight, or survival of armyworm larvae .
• Greenhouse whiteflies oviposited indiscriminately on induced and control plants.
• Striped cucumber beetles consistently fed more on induced than on control plants.
Potter et al., 1990
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• s
25Salazar et al., 2007
T1-plant inoculated withM11 (virulent), T2-plant inoculated withF7 (avirulent), T3-inoculated with 1:1 mixture, T4-T7-M11 inoculated ,48h, 72h, 96h and 120h after prior inoculation with F7.
F7 may be inducing a defensive response in the plant preventing infective M11 hyphae from penetrating deeply into the plant tissues by inducing a defensive response
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Salazar et al., 2007
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Abiotic elicitors
Elicitors Pathogen/Disease Plant Reference
INA Erysiphe graminis Barley Kogale et al., 1994
Probenazole Bipolaris maydis Maize Yang et al., 2011
BABA Uromyces pisi Pea Barilli et al., 2010
BABA Penicillium expansum
Apple Quaglia et al., 2011
BABA Phytophthora infestans
Tomato Sharma et al., 2012
BTH Colletotrichum gloeosporiodes
Mango Lin et al., 2011
BTH Alternaria alternata Turmeric Radhakrishnan et al., 2011
28Peng et al., 2013
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Jelonek et al,. 2014
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Jelonek et al,. 2014
Immunization against viral diseases
Cross protection Genetically engineered cross protection
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Fulton, 1986; Kuc, 2001
•Plant protection mediated by attenuated viruses was successfully used to control disease in several agricultural systems making plants more resistant to subsequent pathogen attacks.
Traux, 2001 •These defense responses have received different names (SAR, cross-protection) depending mainly on the microorganism involved.
Cross Protection
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Mechanism
• Plant resistance gene (R)
• Pathogen avirulence (Avr) gene
• Protein kinase
• Oxidative burst
• Induction of ion fluxes
1.
2.
3.
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Cross protection modelsCoat Protein (CP)
Transcription
Production of genome length viral RNA inhibited
Cell-to-Cell movement prevented
RNA silencing
Yoon et al., 200635
Immunization in resistant plant
• Increases the level of resistance present
• Increases the number of diseases to which the plant is resistant
Example-
Nuckles and Kuc, 198936
Tobacco cultivar Tennessee 86 is resistant to Etch and Chlorotic Vein Mottling Viruses but is highly susceptible to blue mold
Immunization of this cultivar against blue mold rapidly produces plants which are resistant to above three diseases and resistance is transferred to regenerants via tissue culture
SAR in viral and non viral infection
Azelaic acid
Methyl salicylate (MeSA)
Glycerolipids
Salicylic acid
SAR
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Nagaoka et al., 2009
Number of plants of Vicia faba positive for challenge virus after preinoculation with attenuated isolate BYMV-M11 to cross-protect against isolates of Bean Yellow Mosaic Virus (BYMV), Clover Yellow Vein Virus (Clyvv), Or Watermelon Mosaic Virus (WMV)
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Yoon et al., 2006
Pepper Mild Mottle Virus
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Yoon et al., 2006
Effect of mild strain of TMV pre-inoculation on tobacco and bean
Tobacco
• Resistant to subsequent infection
Tobacco Mosaic Virus
Tobacco Necrosis Virus Tobacco Ringspot Virus
• MeSA appear to perpetuate SAR
Bean
• Resistant to subsequent infection only
Tobacco Mosaic Virus
• MeSA appear to perpetuate SAR
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Ross, 1961
Genetically Engineered Cross Protection
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Hypersensitive and necrotic resistance responses to virus infection
Initiated by Avr/R protein interactions
metabolic changes in defense hormone levels both in the infected and non infected tissues
salicylic acid (SA), jasmonic acid (JA), nitric oxide (NO), accumulation of reactive oxygen species (ROS) -- O2
−
and hydrogen peroxide
Mandadi and Scholthof, 201243
Tumer et al., 198744
Expression of Alfaalfa Mosaic Virus coat protein gene confers cross protection in transgenic tobacco
45You et al., 2004
Papaya Ring Spot Virus
Advantages
• Once plant immunized become resistance until flowering
• Limiting the number of application necessary for defense
• Effective against fungal ,bacterial and viral diseases
• Stable, low risk of pathogen populations developing resistance to SAR.
• It is natural and safe for human and environment46
• Immunization occur only when and where it is needed
• It implies genetic potential of plants for resistance
• Graft transmissible in case of tobacco
• Systemic and persistent
• Broader and long- lasting resistance to diverse pathogen types
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Disadvantages
• The natural chemicals signals for systemic immunization have not been characterized
• It is not economically competitive with our present technology in modern agriculture
• Not received sufficient field testing under high pathogen pressure
• People have difficulty in accepting the reality that plant can be immunized systemically
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Conclusion
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Future prospects
Offers the opportunity to enter in the molecular biology of plant defense
Field trials should be encouraged and should be provided to the farmers
Limited to few crops
Very little knowledge about the immune mechanisms used by roots
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Need of molecular studies
Not for long-lived plants, such as trees
Plant immunity still has many mysteries that remain to be solved
Additional studies of virus-induced homologous recombination frequency
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Thank you52