Agriculture plays a key role to ensure the food security. But plant diseases hinder the crop production by reducing yield to much extent. To overcome this problem it is crucial to understand plant disease resistance genes which prevent growth of plant pathogens thereby reducing the yield loss.
Gene for gene system in plant fungus interactionVinod Upadhyay
MOLECULAR CHARACTERIZATION OF GENE FOR GENE SYSTEMS IN PLANT- FUNGUS INTERACTION AND THE APPLICATIONS OF AVIRULENCE GENES IN CONTROL OF PLANT PATHOGENS
Gene for gene system in plant fungus interactionVinod Upadhyay
MOLECULAR CHARACTERIZATION OF GENE FOR GENE SYSTEMS IN PLANT- FUNGUS INTERACTION AND THE APPLICATIONS OF AVIRULENCE GENES IN CONTROL OF PLANT PATHOGENS
Plants have array of defense response against biotic stresses which could be either structural reinforcement, release of chemicals, and defense gene expression against invading organisms. The physical barriers are trichoms, waxy cuticle, thick cell wall. Once the pathogen overcomes the first line of defense, basal or innate defense response comes into play. Pathogens secrete some conserved molecules known as Pathogen Associated Molecular Pattern (PAMP/MAMP), which are recognized by transmembrane receptors present in the plasma membrane and initiate a series of signal cascade reaction which ultimately leads to activation of various defense related genes. Apart from inducing the expression of defense related genes, it also triggers a hypersensitive reaction (HR) which cause deliberate cell death at the site of infection and limit the pathogen access to water and nutrient by sacrificing a few cells in order to save the rest of the plant. Once HR is triggered, plant tissue may become highly resistant to a broad range of pathogens for an extended period of time. This phenomenon is called Systemic Acquired Resistance (SAR).
Plants respond to herbivory is a similar manner as described above. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by inducing responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be genetically engineered, so that the defensive compounds are constitutively produced in plants challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production.
The concept of gene for gene hypothesis was first developed by Flor in 1956 based on his studies of host pathogen interaction in flax, for rust caused by Melampsora lini. The gene for gene hypothesis states that for each gene controlling resistance in the host, there is corresponding gene controlling pathogenicity in the pathogen. The resistance of host is governed by dominant genes and virulence of pathogen by recessive genes. The genotype of host and pathogen determine the disease reaction. When genes in host and pathogen match for all loci, then only the host will show susceptible reaction. If some gene loci remain unmatched, the host will show resistant reaction. Now gene – for –gene relationship has been reported in several other crops like potato, sorghum, wheat, etc. The gene for gene hypothesis is also known as “Flor Hypothesis.”
History
Host pathogen interaction
R gene
Molecular techniques for detection of plant pathogens
Role of molecular techniques in resistance breeding Deployment of R genes and linked markers
Transgenic approaches in plant protection
Conclusion
Plants have array of defense response against biotic stresses which could be either structural reinforcement, release of chemicals, and defense gene expression against invading organisms. The physical barriers are trichoms, waxy cuticle, thick cell wall. Once the pathogen overcomes the first line of defense, basal or innate defense response comes into play. Pathogens secrete some conserved molecules known as Pathogen Associated Molecular Pattern (PAMP/MAMP), which are recognized by transmembrane receptors present in the plasma membrane and initiate a series of signal cascade reaction which ultimately leads to activation of various defense related genes. Apart from inducing the expression of defense related genes, it also triggers a hypersensitive reaction (HR) which cause deliberate cell death at the site of infection and limit the pathogen access to water and nutrient by sacrificing a few cells in order to save the rest of the plant. Once HR is triggered, plant tissue may become highly resistant to a broad range of pathogens for an extended period of time. This phenomenon is called Systemic Acquired Resistance (SAR).
Plants respond to herbivory is a similar manner as described above. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by inducing responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be genetically engineered, so that the defensive compounds are constitutively produced in plants challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production.
The concept of gene for gene hypothesis was first developed by Flor in 1956 based on his studies of host pathogen interaction in flax, for rust caused by Melampsora lini. The gene for gene hypothesis states that for each gene controlling resistance in the host, there is corresponding gene controlling pathogenicity in the pathogen. The resistance of host is governed by dominant genes and virulence of pathogen by recessive genes. The genotype of host and pathogen determine the disease reaction. When genes in host and pathogen match for all loci, then only the host will show susceptible reaction. If some gene loci remain unmatched, the host will show resistant reaction. Now gene – for –gene relationship has been reported in several other crops like potato, sorghum, wheat, etc. The gene for gene hypothesis is also known as “Flor Hypothesis.”
History
Host pathogen interaction
R gene
Molecular techniques for detection of plant pathogens
Role of molecular techniques in resistance breeding Deployment of R genes and linked markers
Transgenic approaches in plant protection
Conclusion
Molecular basis of plant resistance and defense responses to pathogensSenthil Natesan
In response to pathogen attack, plants have evolved sophisticated defense mechanisms to delay or arrest pathogen growth.Unlike animals, plants lack a circulating immune system recognizing microbial pathogens. Plant cells are more autonomous in their defense mechanisms and rely on the innate immune capacity of each cell and systemic signals that disseminate from infection sites (Jones and Dangl, 2006). Plant innate immunity consists of preformed physical and chemical barriers (such as leaf hairs, rigid cell walls, pre-existing antimicrobial compounds) and induced defenses. Should an invading microbe successfully breach the pre-formed barriers, it may be recognized by the plant, resulting in the activation of cellular defense responses that stop or restrict further development of the invader.
Signal transduction in plant defence responsesrkravikirankt
Plant respond to the attack of diseases by triggering various bio-molecules insider their system to combat the infection and establishment of the pathogens. these response operate in specified pathways mediated by many enzymes starting from the infection site to the nucleus which together constitute the signal transduction pathway.
Genetic Engineering in bacteria for resistance.pptxaishnasrivastava
Natural cationic antimicrobial peptides (CAPs) that play a crucial role in enhancing resistance against bacterial diseases.
α-helical peptides β-sheet peptides
CAPs exhibit an amphipathic distribution of polar residues, granting them the capability to interact effectively with phospholipid membranes. This interaction results in the disruption of the lipid bilayer and the collapse of trans-membrane electrochemical gradients, ultimately leading to cell death.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Plant disease resistance genes: current status and future directions.
1. Plant Disease Resistance Genes-
Current Status and Future
Directions
Presented by: Ronika (A-2020-40-017)
(Ph.D. Genetics and Plant Breeding)
Credit Seminar: Pl Path-591
2. *7.90 Billions Population (world)
*1.39 Billions Population (India)
Global trade
Plant pests and
diseases are
responsible for
losses of 20 to
40% of global
food production.
Climate change Abbas et al. 2021
Plant Diseases
• Threat to food security
• Reduces crop quality
Food Security
2
4. What is a Disease
Malfunctioning process that is caused
by continuous irritation which
results in some suffering producing
symptoms.
(Congenial)
(Susceptibility)
(Virulence)
Plants
Exposed to
many
microbes
Only few lead
to disease
development
Why?
4
Host-Pathogen
Interaction
5. Gene for Gene Hypothesis
Pathogen
genotype
Host genotype
R1 r1
Avr1
- +
avr1
+ +
- = Incompatible reaction
+ = Compatible reaction
“for each gene
conditioning
rust reaction
in the host
there is a
specific gene
conditioning
pathogenicity
in the
parasite”- Dr.
H.H. Flor
5
9. 1). Host-Pathogen Recognition
• Elicitor Receptor Model (Albersheim et al. 1981)
• Dimer Model (Ellingboe 1982)
• Ion Channel Model (Gabriel 1984)
• Suppressor Receptor Model (Bushnell & Rowell 1981 and Heath
1982)
Direct Interaction
• Guard Hypothesis
Indirect Interaction
9
10. 2). Signaling
Perception and conveyance of information from outside the
cell to the nucleus or other sites within the cell, leading to a
cellular response.
Signal transduction occurs in response to a signal and
consists of a series of post-translational modifications
that regulate the activity of proteins.
G-Proteins, Calcium ions, Mitogen activated protein
Kinases, Reactive Oxygen Species (H2O2), Nitric Oxide,
Salicylic Acid, Jasmonic Acid, Ethylene.
10
14. Plant Defense System
Basal
• 1st line of defense
• Constituent of both non host and host resistance
• Elicitor: cell wall derivatives
• PAMPs: lipopolysaccharides, chitins, glucans, flagilins
• Non pathogen & pathogen can trigger
• Adapted microbes expresses effector protein to
suppress defenses of plants
R-gene
mediated
14
• Effectors encoded by Avr genes
• Race specific
• Associated with HR response
• Signal transduction
17. Resistance genes
R genes convey plant disease
resistance against pathogens
by producing R proteins.
First cloned R-gene was Hm1 from
MAIZE while First Avr specific R-gene
cloned was Pto from tomato.
First cloned Avr gene was Cf9
from Cladosporium fulvum
Signaling of plant stress
hormone
Generation of reactive
oxygen species
Ethylene biosynthesis
Phytoalexin synthesis
Cell wall strengthening by
deposition of callose and HR
response
Functions
17
19. R genes
Reduction of
pathogen growth
Minimal damage to
host plant
Zero input of
pesticides
Environment
friendly
19
Most of R genes are dominant but recessive genes
has also been reported; mlo in barley, rice xa5 and
xa13 etc.
R gene broad range host resistance Mi-1 gene in
tomato confers resistance to root-knot nematodes,
potato aphid, whitefly, viruses, bacteria and fungi.
20. R-GENE STRUCTURE
R-genes consist of different domains. The great majority are
intracellular NBS-LRR. The few members possess extracellular LRR-
domain.
20
Nibblers
21. LRR (Leucine Rich Repeat) DOMAIN
• LRR consists of 2-45 motifs of 20-30 amino acid in length that
generally folds into an arc or horseshoe structure. Each motif contain
leucine residues at regular interval. It is involved in protein-protein
interactions.
• Role for recognition specificity
21
22. NBS (Nucleotide Binding Site) DOMAIN
NBS is present in several protein families including ATPases and
G-proteins and may affect R-protein function through
nucleotide binding or hydrolysis. It may be involved in
regulating programmed cell death.
22
23. CC (Coiled Coil) DOMAIN
The CC-structure is repeated heptads sequence with interspersed
hydrophobic amino acid residues. It consists of two alpha or more
alpha helices that interact to form a supercoil. This domain may be
involved in downstream signalling.
23
24. STK (Serine Threonine Kinase) DOMAIN
Kinases are heterodimer with catalytic and regulatory site. The
most common protein kinases present in plants are CDKs and
MAP Kinases.
24
25. LZ (Leucine Zippers) DOMAIN
These work like molecular switches binding to DNA and switching on or
silencing the genes ability to synthesize a particular protein.
TIR (Toll Interleukin Receptor) DOMAIN
The TIR domain is implicated in signalling by its similarity to the
cytoplasmic domain of Toll and IL-I R. Play role in pathogen recognition.
25
35. Avirulence Genes
A pathogen gene is called an Avr gene if its expression causes the pathogen to produce
a signal that triggers a strong defense response in a plant with the appropriate R gene.
However, expressing an Avr gene does not stop the pathogen from being virulent
on hosts that lack the corresponding R gene.
Thus, Avr gene are the mild genes of the pathogen which are responsible for
activation of certain defense responses of the host plants.
More than 40 bacterial Avr genes have been cloned and sequenced, primarily from the
genera Pseudomonas and Xanthomonas.
35
36. Evolution of genes for virulence, resistance & avirulence
Agrios, 2007 36
37. 37
Variation in R-genes
• Generation of repeated sequences within gene eg. 2 clusters
of Cf 9 gene homologue identified on chromosome 1 of
tomato
• Large duplication (17 kb) in Xa21 multigene family, Pto gene
family has generated alternate recognition capability of
encoded protein
• Reshuffling of existing genes & creation of new, amplify &
reduce number of resistance gene family reported in Cf genes
Gene
duplication&
recombination
• Reconstruction of genome in response to pathogen
infection eg. Hm1 gene-TE (Drone 256bp)- inbred
susceptibility for disease
• Major source of variability in Xa21 gene family- 17 TEs
• Evolution by creating epigenetic variation eg.
Arabidopsis thaliana and RPP resistance gene.
Transposable
elements
Gupta et al. 2012
38. Conclusion
• Most resistance genes exhibit exquisite recognition specificity & new resistance genes can be
created in the laboratory through single point mutations. Cloned resistance and effector
genes can be used in combination to promote acquired resistance to ‘trigger’ HR response.
• R-genes have remarkable property of rapid diversification under selective pressure from the
pathogens and are highly polymorphic having common structural domains. The DNA
rearrangements plays a crucial role in R-gene evolution allowing plants to generate novel
resistance specificities to match the changing virulence pattern of the pathogen.
• Several evolutionary patterns can be inferred from the molecular studies of resistance genes.
• PRGdb (http://prgdb.org) has been developed which provides a comprehensive overview of
the resistance genes currently have information of 112 known and 105692 putative R-genes
present in 237 plant species which confers resistance to 124 different pathogens.
• Functional genomics tools for disease resistance could help us better understand the plant
defense signaling, could reveal novel insights on the interactions between these signaling
pathways and other plant processes.
38
39. References
• Abbas U, Khan HM, Faisal M, Ayub I, Shafqat and Tahir T. 2021. Role of
interference RNA (RNAi) in plant disease management. Transactions in Physical
and Biochemical Sciences 1: 57-69
• Agrios GN. 2007. Plant Pathology 5th ed. Academic Press, Inc.: New York. P 125
• Gupta SK, Rai AK, Kanwar SS and Sharma TR. 2012. Comparative analysis of Zinc
Finger proteins involved in plant disease resistance. PLoS ONE 7: e42578
• Gururani MA, Venkatesh J, Upadhyaya CP, Nookaraju A, Pandey SK and Park SW.
2012. Plant disease resistance genes: Current status and future directions.
Physiological and Molecular Plant Pathology 78: 51-65
• Jones JDG and Dangl JL. 2006. The plant immune system. Nature 444: 323-329
• Sharma TR, Das A, Thakur S and Jalali BJ. 2014. Recent understanding on
structure function and evolution of plant disease resistance gene. Proceeding
of the Indian National Science Academy 80: 83-93 39
Diseased state of the plants is an outcome of 3 way interactions among pathogen, host and environment where evry component is presumed to b ein favor of the pathogen.
Hpothesis responsible for race specific resistance
shift
Second diagram explain
As PAMPS as easily available in their cell wall, elicito= singnature molecule
PAMP= conserved pathogen derived molecules
Details of function, recessive in viral
common strategy proposed to achieve broad-range host
resistance is to modify the narrow pathogen specificity of R-gene
mediated resistance. Therefore, elucidation of R protein domains
that control recognition of specific pathogens and subsequent
activation of the downstream defense response has been the
subject of intense research
Most r proteins are multidonain NBSLRR called Nibblers. NB central NB
NB LRR ares structurally diverse varying mainly at N terminal
R protein belongs to NB ARC family of STAND protein
NBARC has sub domains as NB ARC1 ARC2 and STAND stands for Signal Tranduction ATPASES with numerous domains
Which function as molecular switches for regulation of cellular responses
MS= molecules which can reversibly convert in one state into another in response of ph, temperature, microenvironment etc
Present in majority of R proteins.
PR Genes can br broadly divided into eight groups based on amino acid motif organization and membrane spanning domains
eLRR play role in defense
WRKY= 60 AA region having conserved WRKYGQK with nivel zinc finger
Schematic diagram of the structure and cell location of the six types of R-coded receptor proteins.
Three types have transmembranous domains, while the other three are membrane-associated cytoplasmic proteins.
LRR, leucine-rich repeats; NBS, nucleotide-binding site. TIR, Toll–interleukin-1 resistance receptor domain; CC, coiled
coil with leucine zipper domain. Genes listed are tomato Cf-2, -4, -5, -9, rice Xa21, tomato Pto, tobacco N, flax L6,
Arabidopsis RPM1, RPS2, RPP5, and the Arabidopsis broad-spectrum gene RPW8.
The distribution of zinc finger domains across
different crops. The cloned R genes of various crops were found to
have zinc finger domain in their proteins. The number of zinc finger
domains represented by cloned R genes of each crop is shown in pie
chart.
Developed by study on Tomato R protein I2
Gene for gene interaction occur step wise step over time and continues to date and causes evolution of gene