Management of host plant resistance through immunization

1

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