Abstract image of a woman sitting on books and studying on a laptop

Unlocking the use OF Functional peptides IN PLANT DISEASE control.pptx

Download as PPTX, PDF
T
TanishDhiman11

Plant disease management

Science
1 of 55
Download to read offline
1
2
Most read
3
4
5
6
7
8
9
Most read
10
11
12
13
14
Most read
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
“UNLOCKING THE USE OF FUNCTIONAL PEPTIDES IN PLANT DISEASE CONTROL” Master’s Seminar on CSK Himachal Pradesh Krishi Vishvavidyalaya Palampur, H.P., India, 176062 Seminar In charge: Dr. Deepika Sud SMS(Plant Pathology) Speaker: Tanish Dhiman (A-2023-30-091) M.Sc. 2nd Year
OUTLINE Importance of Plant Disease Control in Agriculture Need for sustainable alternatives Mechanism of action Types of FP involved in Plant Defence Mechanism Classification of Functional Peptides Sources of Functional Peptides History of Functional Peptides How they differ from other antimicrobial compounds What are Functional Peptides ? Challenges with traditional pesticides Production and Application Formulation Development of Peptides Commercial Products Limitations and Ongoing Challenges Conclusion
Plant diseases pose a significant threat to global food production, leading to reduced crop yields, increased production costs, and food insecurity. Effective disease management is essential to meet the growing food demands of a rising global population while preserving the environment. Importance of Plant Disease Control in Agriculture Outbreaks of plant diseases can have severe economic implications, affecting both local farmers and global agricultural markets Emerging and reemerging plant diseases are exacerbated by climate change, pathogen evolution, and global trade networks.
Challenges with traditional pesticides (resistance, environmental impact) Human Health Impacts Pesticide Treadmill Environmental Risks Cost Escalation Subsidies and Economic incentives Resistance Development
The increasing awareness of the negative effects of synthetic chemical pesticides on human health, the environment, and biodiversity has driven the need for sustainable alternatives. Among these, biopesticides and functional peptides have emerged as promising solutions Need for sustainable alternatives: Biopesticides and functional peptides FUNCTIONAL PEPTIDES BIOPESTICIDES •Microbial agents like Bacillus thuringiensis (Bt) and Trichoderma spp. •Botanical extracts such as Neem oil. •Natural substances like pheromones for pest disruption Purothionins, BP100
What are Functional Peptides ? Functional peptides are polypeptides having 12–50 amino acids sequence and also known as anti- microbial peptides. Part of natural immunity in plants First line of defense against phytopathogens (Tang et al. 2018) Positively charged and are diverse group of plant proteins Amphipathic structure Significantly affect plant growth and development (de Zélicourt et al. 2007).
 Chemical substances (natural, semi-synthetic, or synthetic) that inhibit or kill microorganisms.  Inhibit DNA/RNA synthesis or cell wall synthesis and target specific microbial pathways (e.g., protein synthesis).  Can be broad-spectrum or narrow-spectrum depending on the antibiotic.  High likelihood due to overuse and misuse leading to resistant strains.  E.g. Penicillin, ampicillin  Short chains of amino acids (15- 50) naturally produced by organisms as part of their innate immune system.  Disrupt microbial membranes (e.g., pore formation) and act as immunomodulators to enhance host immunity.  Broad-spectrum: effective against bacteria (Gram-positive and Gram- negative), fungi, viruses, and parasites.  Low likelihood of Resistance Development  E.g. Thionins, Defensins  Biologically active molecules derived from natural sources (plants, microbes, etc.) with diverse effects.  Include antimicrobial, antioxidant, anti- inflammatory, or anticancer properties.  Depends upon the compound  Resistance depends on the target and use; not all bioactive compounds induce resistance  E.g. Polyphenols, Terpenoids Key difference between various compounds involved in Plant Disease Control ANTIBIOTICS FUNCTIONAL PEPTIDES BIOACTIVE COMPOUNDS
Year Milestone 1921 Isolation of insulin by Frederick Banting and Charles Best 1939 Discovery of gramicidins (first antimicrobial peptide) from Bacillus brevis by Dubos 1942 First plant originated Functional Peptide Purothionin was discovered by Balls et al. 1970 Okada and Yoshizumi isolated Hordothionin from endosperm of barley HISTORY
Natural Chemical Biotechnological Platforms • Plants • Animals • Humans • Microorganisms • Solid Phase Peptide Synthesis • Recombinant Peptide Synthesis Sources of Functional Peptides
Classification of Functional Peptides • Non disulfide bridged peptide • Peptides with disulfide group 1. Based on their structure • Synthetic non ribosomal peptides • Synthetic ribosomal/ Natural peptides 2. Based on their nature • Cationic peptides • Non cationic peptides 3. Based on their electrostatic charge 4. Based on their target microorganism • Antifungal • Antibacterial • Antiviral • Antiparasitic
Types of Functional Peptides involved in Plant Defense Mechanism
1. THIONINS Balls et al. (1942) identified thionins for the first time in cereals and classified as plant toxins due to their toxic effect towards microbes Thionins consist of 45-48 amino acids, 6 or 8 cysteine and 3 or 4 disulfide bonds (Stec 2006) Around 100 individual thionin sequences have been identified in more than 15 different plant species  Hydrophobic Mostly Cationic Anti fungal and Antibacterial
Examples
Supportive article When flowers are inoculated with F. graminearum, the Thi2.4 protein had an antifungal effect on F. graminearum.  They purified the Thi2.4 protein, conjugated it with glutathione-S-transferase (GST) . Total protein from F. graminearum was applied to GST-Thi2.4 and the fungal fruit body lectin (FFBL) of F. graminearum was identified as a Thi2.4-interacting protein.  By contrast, FFBL-induced host cell death was effectively suppressed in transgenic plants that over expressed Thi2.4.
Thi2.4 protein was present in flowers and flower buds, but not leaves or inflorescence stems. The molecular mass of the Thi2.4 protein was about 15 kD. 1. 2. 4. 3. F – FFBL M- Control
 In 1990, Mendez et al. isolated from barley and wheat and named as Defensin  Small, cystine rich Functional peptides ranging from 45-54 amino acids  Defensins consist of 3-5 disulfide bonds  Abundantly present in the stomatal and peripheral cells  Expression of plant defensins are also induced by abiotic stress and signaling molecules 2. DEFENSINS
Based on their effect on pathogenic fungi Morphogenic plant defensins Inhibit the growth and branching of hyphae Non- morphogenic plant defensins Inhibit only hyphal growth
Functional Peptides Source Transgenic plant Pathogen tested References BrD1 Brassica rapa Rice Fusarium graminearum Choi et al. (2009) RsAFP2 Raphanus sativus Wheat/Rice Magnaporthe oryzae Rhizoctonia solani Jha and Chattoo et al. (2010) MsDef1 Medicago sativa Tomato Fusarium oxysporum Phytophthora parasitica Abdallah et al. (2010) NmDef02 N. megalosiphon Tobacco/ Potato Phytophthora infestans Alternaria solani Portieles et al. (2010) DEF2 Capsicum annum Tomato Botrytis cinerea Stoz et al. (2009) Examples
Supportive article •Transgenic rice (Oryza sativa L. cv. Pusa basmati 1), overexpressing the Rs-AFP2 defensin gene from the Raphanus sativus was generated by Agrobacterium tumefaciens-mediated transformation. • It was observed that constitutive expression of Rs-AFP2 suppresses the growth of Magnaporthe oryzae and Rhizoctonia solani by 77 and 45%, respectively.
ELISA of T2-transgenic rice plants expressing RsAFP2 Sub-cellular localization of Rs-AFP2 was determined by treating the transgenic leaf and roots functional peptides with anti-Rs-AFP2 Leaf tissue Root tissue Transgenic Control
Significant changes in the hyphal morphology Effects of the overexpression of RsAFP2 on resistance of transgenic plants to fungal pathogens. DLA : Diseased leaf area M. oryzae R. solani Rs-AFP2 Transgenic line Control
3. LIPID TRANSFER PROTEINS (LTP)  Small cysteine rich peptides having molecular masses of lower than 10KDa  It consists of 70-100 amino acid  Cationic peptides with a conserved pattern of 4 to 5 disulfide bridges having 8 to 10 cys-cys bonds  LTPs having synergistic activity with thionins against Clavibacter spp.  Expression of lipid transfer proteins can be induced by abiotic stress
Lipid transfer proteins Source Target pathogen Reference Ca-LTP Capsicum annum Candida albicans, Saccaromyces cerevisiae Cruz et al. (2010) Ps-LTP1-3 Pisum sativum Fusarium solani, Fusarium oxysporum Bogdanov et al. (2016) Gt-LTP2 Gentiana triflora Botrytis cinerea Akinori kiba et al. (2011) Ace-Functional Peptides 1 Allium cepa Fusarium oxysporum Cammue et al. (1995) Cc-LTP-1 Coffea canephora seeds Candida albicans Zottich et al. (2011) Examples
4. HEVEIN like peptides •Archer isolated hevein like plant Functional Peptides from rubber tree latex •Heveins are small Functional proteins of 42-45 amino acids and of 4.7 Kda with conserved residues of glycine and aromatic acids •They are cationic proteins having 3-5 disulfide bonds •The N-terminal region contains a chitin binding hevein domain
Hevein Source Against pathogen Reference M-hevein Mulberry Trichoderma viride Zhao et al. (2011) GAFP G. biloba Fusarium graminearum Alternaria alternata Huang et al. (2000) Wj Functional Peptides1 Wasabia japonica Fungi: Botrytis cinerea Fusarium solani Magnaporthe grisea Alternaria alternata Bacteria: Escherichia coli Agrobacterium tumefaciens Kiba et al. (2003) Examples
• Nguyen et al. (1990) isolated it from Mirabilis jalapa • The typical structure of knottins involves conserved disulfde bonds between multiple cysteine pairs, forming a cystine knot • Generally, knottin-type peptides are the smallest in size among plant functional peptides • Promote resistance to biotic and abiotic stresses, stimulating root growth, acting as signaling molecules, and enhancing symbiotic interactions 5. KNOTTIN type peptides ‑
Knottins Source Against pathogen Reference Cy-Functional Peptides1 Cycas revoluta Fungi and bacteria Yokohama et al. (2009) Wr-A11 Wr-A12 Wrightia religiosa Tenebrio molitor Nguyen et al. (2014) Examples
Other Functional Peptides Puroindolines Snakins Cyclopeptides  Contain a unique tryptophan-rich domain  These proteins were isolated from wheat endosperm  Isolated from potato tubers. They comprise the cell wall- associated peptide snakin-1 (StSN1) and snakin-2 (StSN2)  Do not interact with artificial lipid membranes  Cyclic proteins of about 28-37 amino acids  Composed of amino acid residues arranged in a cyclic ring, usually without disulphide bridges
Puroindoline Susceptible species References PinA and PinB from wheat Fungi: Alternaria brassicicola Marino et al. (2009) Botrytis cinerea Verticillium dahliae Cochliobolus heterostrophus Zhang et al. (2011) PinA from wheat Bacteria: Erwinia amylovora Jing et al. (2003) Staphyllococcus aureus Dhaliwal et al. (2009) Examples
Snakins Susceptible species References StSN1 and StSN2 from Solanum tuberosum Fungi: Botrytis cinerea Fusarium solani Fusarium oxysporum f.sp. conglutinans Bacteria Clavibacter michiganensis Ralstonia solanacrarum Berrocal Lobo et al. (2002) Examples
Cyclopeptides Origin Target pathogen Reference Syringomycins and syringopeptins Pseudomonas sp Botrytis cinerea Lavermicocca et al. (1997) Pseudomonas syringae Venturia inaequalis Burr et al. (1996) Tolaasins Pseudomonas sp Rhizoctonia solani, Rhodococcus fascians Bassarello et al. (2004) Pseudophomins Pseudomonas fluorescens BRG100 Sclerotinia sclerotiorum Pedras et al. (2003) Massetolide Pseudomonas fluorescens SS101 Phytium intermedium de Souza et al. (2003) Examples
• PinA and PinB were introduced into corn. • PinA⁄PinB expression–positive transgenic events were evaluated for resistance to Bipolaris maydis, the corn southern leaf blight (SLB) pathogen. • 42.1% reduction in disease symptoms was observed. Supportive article
Positive lines Mo17: Resistant, A188: Susceptible, A679: Moderately resistant, B73: Moderately susceptible,
• BACTERIOCINS  Ribosomal synthesized Functional peptides  Produced by bacteria  Kill or inhibit closely related bacterial strains • PEPTAIBOLS  Non ribosomal synthesized Functional linear peptides  Produced by fungi  Affect fungi and plant pathogenic gram-positive bacteria SYNTHETIC FUNCTIONAL PEPTIDES
Examples Functional Peptides Source Against pathogen 1. Bacteriocins Galtrol Agrobacterium radiobacter Agrobacterium tumefaciens Nogall Agrobacterium radiobacter K1026 Agrobacterium tumefaciens Histick N/T Bacillus subtilis St MB1600 Fusarium, Rhizoctonia, Aspergillus 2. Peptaibols Trichokonins Trichoderma koningii Clavibacter michiganensis,Fusarium, Botrytis, Bipolaris Harzianins and Trichorzins Trichoderma harzianum Sclerotium cepivorum
Mechanisms of Action of Functional Peptides
1. Membrane disruption: Many peptides interact interact with microbial membranes, leading to pore formation or membrane permeabilization. This interaction disrupts the osmotic balance, causing cell lysis and death. These lytic peptides are typically amphipathic and cationic, interacting with the negatively charged membranes of bacteria and fungi.
•Peptides target specific enzymes critical for microbial survival, such as those involved in cell wall synthesis (e.g., lipid II binding) or metabolic pathways •For example, peptides like plectasin inhibit peptidoglycan biosynthesis in bacteria 2. Inhibition of internal cellular processes: A. DNA, RNA and Protein synthesis interference •Peptides bind to DNA or RNA, preventing replication or transcription •They can also inhibit ribosomal activity, halting protein synthesis Some functional peptides penetrate cells and interfere with essential intracellular processes: B. Enzyme inhibition
3. Interaction with external cell structures: A. Binding with chitin B. Binding to Lipopolysaccharides(LPS) C. Binding with fungal membrane Peptides interact with chitin in fungal cell walls, disrupting structural integrity and leading to cell death. In Gram-negative bacteria, peptides bind to LPS on the outer membrane, neutralizing its endotoxin activity and destabilizing the membrane. Peptides target ergosterol or other unique components in fungal membranes, causing selective disruption without harming host cells. Functional peptides can bind to structural components of pathogens' outer layers:
4. Antibiofilm activity and spore germination inhibition: A. Antibiofilm activity B. Spore germination inhibition Certain peptides inhibit spore germination by interfering with enzymatic processes required for spore activation, preventing fungal proliferation. •Functional peptides prevent biofilm formation by disrupting quorum sensing or directly killing biofilm-forming cells. •They can also penetrate existing biofilms and eradicate embedded pathogens.
5. Plant defense elicitation: In plants, functional peptides act as elicitors that trigger immune responses: A. Activation of Pattern Recognition Receptors(PRR’s) Peptides bind to PRRs on plant cell surfaces, initiating signaling cascades that activate defense genes.
B. Reactive oxygen species (ROS) generation •Peptides induce ROS production in plants as an early defense response against pathogens. •ROS can directly damage pathogens or signal further immune responses. C. Hormone pathway Functional peptides modulate plant hormone pathways such as salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), which are critical for systemic acquired resistance (SAR) or induced systemic resistance (ISR).
Surface target  Interaction of aminoglycans with virus  Blocking of viral entry into the cell  Suppression of cell fusion by interfering with the activity of ATPase protein. Intracellular target  Suppression viral gene expression  Inhibition of peptide chain elongation by inactivating the ribosome. Viral protein targets:  Binding of peptides to viral proteins causing inhibition of adsorption. Antiviral Mechanism of Functional Peptides
1. Natural Extraction Production and Application of Functional Peptides Functional peptides can be extracted from natural sources such as microorganisms, plants, and animal tissues. a. Microbial Fermentation  Microorganisms like Escherichia coli, Bacillus subtilis, and yeast are used as bio-factories to produce peptides naturally. b. Plant Sources  Plants produce bioactive peptides like defensins and cyclotides as part of their innate immune system.  Techniques such as enzymatic hydrolysis of plant proteins (e.g., soy, wheat, or rice) are used to release functional peptides.
2. Chemical Synthesis Chemical synthesis is a widely used method for producing functional peptides with precise sequences. a. Solution-Phase Synthesis  One of the earliest methods for peptide synthesis, where reactions occur in a liquid medium.  Useful for synthesizing short peptides or small molecules. b. Solid-Phase Peptide Synthesis (SPPS)  Developed by Robert Bruce Merrifield, SPPS is the most common method today.  The peptide chain is assembled step-by-step on an insoluble resin support.  Process:  Protecting groups (e.g., Fmoc or Boc) are used to prevent unwanted side reactions.  Cycles of coupling (adding amino acids) and deprotection (removing protecting groups) are repeated until the desired sequence is achieved.  The peptide is cleaved from the resin and purified. c. Hybrid Methods  Combines solution-phase and solid-phase techniques to optimize yield and efficiency for complex peptides.
 AurH1: Derived from aurein 1.2, it is effective against Candida albicans.  Novicidin: A synthetic AMP with broad- spectrum activity against Gram-positive and Gram-negative bacteria. Examples of Synthetic FPs
3. Biotechnological Platforms for Peptide Production 1. Microbial Expression Systems  Hosts: Bacteria (e.g., Escherichia coli), yeast (e.g., Saccharomyces cerevisiae), and other microorganisms are commonly used. a. Bacterial Systems  E. coli is widely used for producing recombinant proteins and peptides due to its well-understood genetics and rapid growth.  Applications: Production of insulin, growth hormone, and other therapeutic peptides. b. Yeast Systems  Yeast offers advantages in terms of PTMs similar to those in mammalian cells.  Applications: Production of complex peptides with glycosylation. 2. Transgenic Plants  Applications: Production of vaccine antigens, diagnostic reagents, and therapeutic peptides like antibodies. 3. Genetic Code Expansion  Principle: Allows the incorporation of non- canonical amino acids into proteins during translation.  Applications: Enhancing peptide stability, bioactivity, or targeting capabilities.
 Principle: Involves the design and construction of new biological systems or the redesign of existing ones to produce specific peptides.  Applications: Production of small peptides through pathway engineering and biosynthetic pathway evolution.  Role: AI can predict peptide structures and functions, facilitating the design of novel peptides with desired properties.  Applications: Used in drug discovery to optimize peptide-based therapeutics for better efficacy and safety. 4. Synthetic Biology Approaches 5. Artificial Intelligence in Peptide Design
Formulation Development of Peptides Formulation development is a critical step in ensuring the stability, efficacy, and delivery of therapeutic peptides. Below is an overview of the key considerations and strategies used in peptide formulation: 1. Stability a. Chemical Instability  Degradation Pathways: o Hydrolysis of amide bonds. o Oxidation of methionine or cysteine residues.  Solutions: o Incorporate stabilizing excipients like antioxidants (e.g., ascorbic acid) or chelating agents (e.g., EDTA). o Modify amino acid sequences to replace labile residues with more stable analogs. b. Physical Instability  Challenges: o Aggregation, precipitation, or denaturation during storage or handling.  Solutions: o Use lyophilization (freeze-drying) to convert peptides into stable solid forms. o Add surfactants (e.g., polysorbates) to prevent aggregation in aqueous solutions. Peptides are inherently prone to degradation due to their chemical and physical instability. Formulation strategies aim to address these issues:
To ensure an adequate shelf life, peptides must be protected from environmental factors such as temperature, light, and moisture.  Lyophilized Formulations: o Lyophilization extends shelf life by removing water, which prevents hydrolytic degradation.  Packaging: o Use moisture-proof and light-resistant containers to protect sensitive peptides. 2. Shelf Life
Excipients play a crucial role in stabilizing peptides and enhancing their delivery:  Buffers: Maintain pH stability (e.g., phosphate buffer).  Cryoprotectants/Lyoprotectants: Protect peptides during freeze-drying (e.g., sucrose, trehalose).  Surfactants: Prevent aggregation (e.g., polysorbate 20 or 80).  Osmolytes: Enhance solubility and stability (e.g., glycine). a. PEGylation  Covalent attachment of polyethylene glycol (PEG) chains to peptides increases their half-life by reducingproteolytic degradation. b. Cyclization  Cyclizing linear peptides enhances their stability by reducing susceptibility to enzymatic cleavage. c. Nanoparticle-Based Delivery  Encapsulation in nanoparticles, liposomes, or hydrogels protects peptides from degradation and enables controlled release. d. Co-formulation with Protease Inhibitors  Protease inhibitors can protect peptides from enzymatic degradation during delivery. 3. Excipients in Peptide Formulation 4. Advanced Strategies for Peptide Formulation
NOGALL ACTINOVATE SERENADE SUBTILE Commercial products of Functional Peptides
 Stability Issues Many natural peptides are prone to enzymatic degradation, limiting their bioavailability and therapeutic efficacy.  Production Costs The synthesis of long or complex peptides remains expensive due to the need for high-purity reagents and advanced purification techniques.  Limited Trial Evidence There is a need for more in vitro and field trials to authenticate the benefits of plant-derived peptides.  Industrial Application The practical or industrial application of plant-derived peptides with bioactive features is still a long way off, despite their potential.  Resistance Development Prolonged use of antimicrobial peptides may lead to microbial resistance, similar to antibiotics. Limitations and Ongoing Challenges
 Functional peptides hold significant promise for plant disease control due to : Conclusion Their targeted action Low environmental impact Versatility  These peptides can be derived from natural sources or synthesized using advanced techniques, allowing for tailored properties such as enhanced stability and specificity.  Their unique mechanisms of action—ranging from direct antimicrobial effects to the elicitation of plant defense responses—position them as powerful tools in modern agriculture.  Functional peptides represent a transformative approach to plant disease control, offering a sustainable alternative to traditional chemical pesticides.  By harnessing the power of these bioactive molecules, we can foster healthier ecosystems, reduce the environmental footprint of agriculture, and ensure a more resilient food system for generations to come.
Unlocking the use OF Functional peptides IN PLANT DISEASE control.pptx

More Related Content

PPTX
Antimicrobial peptides in the management of plant diseases.pptx
TanishDhiman11
 
PPTX
Functional peptide for plant disease management
Shwetha Gulvady Sridhar
 
PPTX
Antimicrobial peptides in plant disease management
Swami53
 
PDF
Role of antimicrobial peptides in plant disease management
N.H. Shankar Reddy
 
PPTX
Defensins: Antimicrobial peptide for the host plant resistance
snehaljikamade
 
PPTX
application of plant transformation for productivity and performance
Ashika Raveendran
 
PDF
Antimicrobial peptides and innate immunity
Springer
 
PPTX
effectors
KiranKumarN24
 
Antimicrobial peptides in the management of plant diseases.pptx
TanishDhiman11
 
Functional peptide for plant disease management
Shwetha Gulvady Sridhar
 
Antimicrobial peptides in plant disease management
Swami53
 
Role of antimicrobial peptides in plant disease management
N.H. Shankar Reddy
 
Defensins: Antimicrobial peptide for the host plant resistance
snehaljikamade
 
application of plant transformation for productivity and performance
Ashika Raveendran
 
Antimicrobial peptides and innate immunity
Springer
 
effectors
KiranKumarN24
 

Similar to Unlocking the use OF Functional peptides IN PLANT DISEASE control.pptx (20)

PDF
Anti microbial peptides.pdf
LakshmiPrasanna317
 
PPTX
Bacterial endophytes: Potential bioagents against plant pathologens
manohargowdabp
 
PPTX
Genetic Engineering in bacteria for resistance.pptx
aishnasrivastava
 
PPTX
Endophytes
VahidasyedVahidha
 
PPTX
Mechanism of disease control by endophytes
Pooja Bhatt
 
PPTX
Pr protein(rakesh 2014 a42d)
Rakesh Punia
 
PDF
Endophytic-endophytes-bacteria and fungi:their role in plant growth promotion...
KrishnaKPramod
 
PPTX
antifungal plantss .HAJIRA CROP PPT.pptx
hajirashami
 
PPTX
Role of endophytes in nematode menagement
Mathi chandhran
 
PPTX
PR proteins in plant disease resistance.pptx
ReddykumarAv
 
PPSX
Saowaluck- fungal endophytes Tibpromma.ppsx
debasishsahu231
 
PPTX
Phytoalexins
Priyengha R.S
 
PPTX
p.sravani endophytic microbes and application in pest management
PashamSravani1
 
DOCX
Niharika
sanjuhotty16potty
 
PPTX
endophyte.pptx
Lavanya943804
 
PPTX
Share_Host_-pathogen interactions-WPS_Office.pptx
ShashiKala434918
 
PPT
Molecular Aspects of Plant Disease Management
KHUSHBOODUBEY12
 
PDF
Microbial endophytes: functional biology and applications Kumar
yujrcjicws8657
 
PPTX
Phytoalexins ptt by AARIF
AARIF MAQBOOL
 
PPTX
Antifungal proteins copy
Dr. sreeremya S
 
Anti microbial peptides.pdf
LakshmiPrasanna317
 
Bacterial endophytes: Potential bioagents against plant pathologens
manohargowdabp
 
Genetic Engineering in bacteria for resistance.pptx
aishnasrivastava
 
Endophytes
VahidasyedVahidha
 
Mechanism of disease control by endophytes
Pooja Bhatt
 
Pr protein(rakesh 2014 a42d)
Rakesh Punia
 
Endophytic-endophytes-bacteria and fungi:their role in plant growth promotion...
KrishnaKPramod
 
antifungal plantss .HAJIRA CROP PPT.pptx
hajirashami
 
Role of endophytes in nematode menagement
Mathi chandhran
 
PR proteins in plant disease resistance.pptx
ReddykumarAv
 
Saowaluck- fungal endophytes Tibpromma.ppsx
debasishsahu231
 
Phytoalexins
Priyengha R.S
 
p.sravani endophytic microbes and application in pest management
PashamSravani1
 
Niharika
sanjuhotty16potty
 
endophyte.pptx
Lavanya943804
 
Share_Host_-pathogen interactions-WPS_Office.pptx
ShashiKala434918
 
Molecular Aspects of Plant Disease Management
KHUSHBOODUBEY12
 
Microbial endophytes: functional biology and applications Kumar
yujrcjicws8657
 
Phytoalexins ptt by AARIF
AARIF MAQBOOL
 
Antifungal proteins copy
Dr. sreeremya S
 
Ad

Recently uploaded (20)

PDF
The Future of Telehealth: Engineering New Platforms for Care (www.kiu.ac.ug)
publication11
 
PDF
Cosmology using numerical relativity - what hapenned before big bang?
Sérgio Sacani
 
PPTX
Introduction to Immunology (Unit-1).pptx
tkgauri1
 
PDF
Sustainable Biology- Scopes, Principles of sustainiability, Sustainable Resou...
Nistarini College, Purulia (W.B) India
 
PPTX
AP CHEM 1.2 Mass spectroscopy of elements
Mohamed Harb
 
PPT
THE CELL THEORY AND ITS FUNDAMENTALS AND USE
nctpcctv
 
PPT
Animal tissues, epithelial, muscle, connective, nervous tissue
jyrusacepampolina
 
PPTX
bone as a tissue presentation micky.pptx
AbelAyele6
 
PDF
Unit 5 Preparations, Reactions, Properties and Isomersim of Organic Compounds...
fliwertyfw154
 
PDF
Integrative Oncology: Merging Conventional and Alternative Approaches (www.k...
publication11
 
PPT
Enhancing Laboratory Quality Through ISO 15189 Compliance
mdsgift
 
PPTX
Introcution to Microbes Burton's Biology for the Health
fliwertyfw154
 
PPTX
SCIENCE 4 Q2W5 PPT.pptx Lesson About Plnts and animals and their habitat
irishjeancui
 
PDF
Communicating Health Policies to Diverse Populations (www.kiu.ac.ug)
publication11
 
PPTX
Understanding the Circulatory System……..
Sibongokuhle1
 
PPTX
GREEN FIELDS SCHOOL PPT ON HOLIDAY HOMEWORK
GandharvaVerma
 
PDF
Metabolic Acidosis. pa,oakw,llwla,wwwwqw
mustafaaltaie980
 
PPTX
2currentelectricity1-201006102815 (1).pptx
faisalahemd13
 
PPTX
A powerpoint on colorectal cancer with brief background
lilmiceman
 
PDF
From Molecular Interactions to Solubility in Deep Eutectic Solvents: Explorin...
Maciej Przybyłek
 
The Future of Telehealth: Engineering New Platforms for Care (www.kiu.ac.ug)
publication11
 
Cosmology using numerical relativity - what hapenned before big bang?
Sérgio Sacani
 
Introduction to Immunology (Unit-1).pptx
tkgauri1
 
Sustainable Biology- Scopes, Principles of sustainiability, Sustainable Resou...
Nistarini College, Purulia (W.B) India
 
AP CHEM 1.2 Mass spectroscopy of elements
Mohamed Harb
 
THE CELL THEORY AND ITS FUNDAMENTALS AND USE
nctpcctv
 
Animal tissues, epithelial, muscle, connective, nervous tissue
jyrusacepampolina
 
bone as a tissue presentation micky.pptx
AbelAyele6
 
Unit 5 Preparations, Reactions, Properties and Isomersim of Organic Compounds...
fliwertyfw154
 
Integrative Oncology: Merging Conventional and Alternative Approaches (www.k...
publication11
 
Enhancing Laboratory Quality Through ISO 15189 Compliance
mdsgift
 
Introcution to Microbes Burton's Biology for the Health
fliwertyfw154
 
SCIENCE 4 Q2W5 PPT.pptx Lesson About Plnts and animals and their habitat
irishjeancui
 
Communicating Health Policies to Diverse Populations (www.kiu.ac.ug)
publication11
 
Understanding the Circulatory System……..
Sibongokuhle1
 
GREEN FIELDS SCHOOL PPT ON HOLIDAY HOMEWORK
GandharvaVerma
 
Metabolic Acidosis. pa,oakw,llwla,wwwwqw
mustafaaltaie980
 
2currentelectricity1-201006102815 (1).pptx
faisalahemd13
 
A powerpoint on colorectal cancer with brief background
lilmiceman
 
From Molecular Interactions to Solubility in Deep Eutectic Solvents: Explorin...
Maciej Przybyłek
 
Ad

Unlocking the use OF Functional peptides IN PLANT DISEASE control.pptx

  • 1. “UNLOCKING THE USE OF FUNCTIONAL PEPTIDES IN PLANT DISEASE CONTROL” Master’s Seminar on CSK Himachal Pradesh Krishi Vishvavidyalaya Palampur, H.P., India, 176062 Seminar In charge: Dr. Deepika Sud SMS(Plant Pathology) Speaker: Tanish Dhiman (A-2023-30-091) M.Sc. 2nd Year
  • 2. OUTLINE Importance of Plant Disease Control in Agriculture Need for sustainable alternatives Mechanism of action Types of FP involved in Plant Defence Mechanism Classification of Functional Peptides Sources of Functional Peptides History of Functional Peptides How they differ from other antimicrobial compounds What are Functional Peptides ? Challenges with traditional pesticides Production and Application Formulation Development of Peptides Commercial Products Limitations and Ongoing Challenges Conclusion
  • 3. Plant diseases pose a significant threat to global food production, leading to reduced crop yields, increased production costs, and food insecurity. Effective disease management is essential to meet the growing food demands of a rising global population while preserving the environment. Importance of Plant Disease Control in Agriculture Outbreaks of plant diseases can have severe economic implications, affecting both local farmers and global agricultural markets Emerging and reemerging plant diseases are exacerbated by climate change, pathogen evolution, and global trade networks.
  • 4. Challenges with traditional pesticides (resistance, environmental impact) Human Health Impacts Pesticide Treadmill Environmental Risks Cost Escalation Subsidies and Economic incentives Resistance Development
  • 5. The increasing awareness of the negative effects of synthetic chemical pesticides on human health, the environment, and biodiversity has driven the need for sustainable alternatives. Among these, biopesticides and functional peptides have emerged as promising solutions Need for sustainable alternatives: Biopesticides and functional peptides FUNCTIONAL PEPTIDES BIOPESTICIDES •Microbial agents like Bacillus thuringiensis (Bt) and Trichoderma spp. •Botanical extracts such as Neem oil. •Natural substances like pheromones for pest disruption Purothionins, BP100
  • 6. What are Functional Peptides ? Functional peptides are polypeptides having 12–50 amino acids sequence and also known as anti- microbial peptides. Part of natural immunity in plants First line of defense against phytopathogens (Tang et al. 2018) Positively charged and are diverse group of plant proteins Amphipathic structure Significantly affect plant growth and development (de Zélicourt et al. 2007).
  • 7.  Chemical substances (natural, semi-synthetic, or synthetic) that inhibit or kill microorganisms.  Inhibit DNA/RNA synthesis or cell wall synthesis and target specific microbial pathways (e.g., protein synthesis).  Can be broad-spectrum or narrow-spectrum depending on the antibiotic.  High likelihood due to overuse and misuse leading to resistant strains.  E.g. Penicillin, ampicillin  Short chains of amino acids (15- 50) naturally produced by organisms as part of their innate immune system.  Disrupt microbial membranes (e.g., pore formation) and act as immunomodulators to enhance host immunity.  Broad-spectrum: effective against bacteria (Gram-positive and Gram- negative), fungi, viruses, and parasites.  Low likelihood of Resistance Development  E.g. Thionins, Defensins  Biologically active molecules derived from natural sources (plants, microbes, etc.) with diverse effects.  Include antimicrobial, antioxidant, anti- inflammatory, or anticancer properties.  Depends upon the compound  Resistance depends on the target and use; not all bioactive compounds induce resistance  E.g. Polyphenols, Terpenoids Key difference between various compounds involved in Plant Disease Control ANTIBIOTICS FUNCTIONAL PEPTIDES BIOACTIVE COMPOUNDS
  • 8. Year Milestone 1921 Isolation of insulin by Frederick Banting and Charles Best 1939 Discovery of gramicidins (first antimicrobial peptide) from Bacillus brevis by Dubos 1942 First plant originated Functional Peptide Purothionin was discovered by Balls et al. 1970 Okada and Yoshizumi isolated Hordothionin from endosperm of barley HISTORY
  • 9. Natural Chemical Biotechnological Platforms • Plants • Animals • Humans • Microorganisms • Solid Phase Peptide Synthesis • Recombinant Peptide Synthesis Sources of Functional Peptides
  • 10. Classification of Functional Peptides • Non disulfide bridged peptide • Peptides with disulfide group 1. Based on their structure • Synthetic non ribosomal peptides • Synthetic ribosomal/ Natural peptides 2. Based on their nature • Cationic peptides • Non cationic peptides 3. Based on their electrostatic charge 4. Based on their target microorganism • Antifungal • Antibacterial • Antiviral • Antiparasitic
  • 11. Types of Functional Peptides involved in Plant Defense Mechanism
  • 12. 1. THIONINS Balls et al. (1942) identified thionins for the first time in cereals and classified as plant toxins due to their toxic effect towards microbes Thionins consist of 45-48 amino acids, 6 or 8 cysteine and 3 or 4 disulfide bonds (Stec 2006) Around 100 individual thionin sequences have been identified in more than 15 different plant species  Hydrophobic Mostly Cationic Anti fungal and Antibacterial
  • 14. Supportive article When flowers are inoculated with F. graminearum, the Thi2.4 protein had an antifungal effect on F. graminearum.  They purified the Thi2.4 protein, conjugated it with glutathione-S-transferase (GST) . Total protein from F. graminearum was applied to GST-Thi2.4 and the fungal fruit body lectin (FFBL) of F. graminearum was identified as a Thi2.4-interacting protein.  By contrast, FFBL-induced host cell death was effectively suppressed in transgenic plants that over expressed Thi2.4.
  • 15. Thi2.4 protein was present in flowers and flower buds, but not leaves or inflorescence stems. The molecular mass of the Thi2.4 protein was about 15 kD. 1. 2. 4. 3. F – FFBL M- Control
  • 16.  In 1990, Mendez et al. isolated from barley and wheat and named as Defensin  Small, cystine rich Functional peptides ranging from 45-54 amino acids  Defensins consist of 3-5 disulfide bonds  Abundantly present in the stomatal and peripheral cells  Expression of plant defensins are also induced by abiotic stress and signaling molecules 2. DEFENSINS
  • 17. Based on their effect on pathogenic fungi Morphogenic plant defensins Inhibit the growth and branching of hyphae Non- morphogenic plant defensins Inhibit only hyphal growth
  • 18. Functional Peptides Source Transgenic plant Pathogen tested References BrD1 Brassica rapa Rice Fusarium graminearum Choi et al. (2009) RsAFP2 Raphanus sativus Wheat/Rice Magnaporthe oryzae Rhizoctonia solani Jha and Chattoo et al. (2010) MsDef1 Medicago sativa Tomato Fusarium oxysporum Phytophthora parasitica Abdallah et al. (2010) NmDef02 N. megalosiphon Tobacco/ Potato Phytophthora infestans Alternaria solani Portieles et al. (2010) DEF2 Capsicum annum Tomato Botrytis cinerea Stoz et al. (2009) Examples
  • 19. Supportive article •Transgenic rice (Oryza sativa L. cv. Pusa basmati 1), overexpressing the Rs-AFP2 defensin gene from the Raphanus sativus was generated by Agrobacterium tumefaciens-mediated transformation. • It was observed that constitutive expression of Rs-AFP2 suppresses the growth of Magnaporthe oryzae and Rhizoctonia solani by 77 and 45%, respectively.
  • 20. ELISA of T2-transgenic rice plants expressing RsAFP2 Sub-cellular localization of Rs-AFP2 was determined by treating the transgenic leaf and roots functional peptides with anti-Rs-AFP2 Leaf tissue Root tissue Transgenic Control
  • 21. Significant changes in the hyphal morphology Effects of the overexpression of RsAFP2 on resistance of transgenic plants to fungal pathogens. DLA : Diseased leaf area M. oryzae R. solani Rs-AFP2 Transgenic line Control
  • 22. 3. LIPID TRANSFER PROTEINS (LTP)  Small cysteine rich peptides having molecular masses of lower than 10KDa  It consists of 70-100 amino acid  Cationic peptides with a conserved pattern of 4 to 5 disulfide bridges having 8 to 10 cys-cys bonds  LTPs having synergistic activity with thionins against Clavibacter spp.  Expression of lipid transfer proteins can be induced by abiotic stress
  • 23. Lipid transfer proteins Source Target pathogen Reference Ca-LTP Capsicum annum Candida albicans, Saccaromyces cerevisiae Cruz et al. (2010) Ps-LTP1-3 Pisum sativum Fusarium solani, Fusarium oxysporum Bogdanov et al. (2016) Gt-LTP2 Gentiana triflora Botrytis cinerea Akinori kiba et al. (2011) Ace-Functional Peptides 1 Allium cepa Fusarium oxysporum Cammue et al. (1995) Cc-LTP-1 Coffea canephora seeds Candida albicans Zottich et al. (2011) Examples
  • 24. 4. HEVEIN like peptides •Archer isolated hevein like plant Functional Peptides from rubber tree latex •Heveins are small Functional proteins of 42-45 amino acids and of 4.7 Kda with conserved residues of glycine and aromatic acids •They are cationic proteins having 3-5 disulfide bonds •The N-terminal region contains a chitin binding hevein domain
  • 25. Hevein Source Against pathogen Reference M-hevein Mulberry Trichoderma viride Zhao et al. (2011) GAFP G. biloba Fusarium graminearum Alternaria alternata Huang et al. (2000) Wj Functional Peptides1 Wasabia japonica Fungi: Botrytis cinerea Fusarium solani Magnaporthe grisea Alternaria alternata Bacteria: Escherichia coli Agrobacterium tumefaciens Kiba et al. (2003) Examples
  • 26. • Nguyen et al. (1990) isolated it from Mirabilis jalapa • The typical structure of knottins involves conserved disulfde bonds between multiple cysteine pairs, forming a cystine knot • Generally, knottin-type peptides are the smallest in size among plant functional peptides • Promote resistance to biotic and abiotic stresses, stimulating root growth, acting as signaling molecules, and enhancing symbiotic interactions 5. KNOTTIN type peptides ‑
  • 27. Knottins Source Against pathogen Reference Cy-Functional Peptides1 Cycas revoluta Fungi and bacteria Yokohama et al. (2009) Wr-A11 Wr-A12 Wrightia religiosa Tenebrio molitor Nguyen et al. (2014) Examples
  • 28. Other Functional Peptides Puroindolines Snakins Cyclopeptides  Contain a unique tryptophan-rich domain  These proteins were isolated from wheat endosperm  Isolated from potato tubers. They comprise the cell wall- associated peptide snakin-1 (StSN1) and snakin-2 (StSN2)  Do not interact with artificial lipid membranes  Cyclic proteins of about 28-37 amino acids  Composed of amino acid residues arranged in a cyclic ring, usually without disulphide bridges
  • 29. Puroindoline Susceptible species References PinA and PinB from wheat Fungi: Alternaria brassicicola Marino et al. (2009) Botrytis cinerea Verticillium dahliae Cochliobolus heterostrophus Zhang et al. (2011) PinA from wheat Bacteria: Erwinia amylovora Jing et al. (2003) Staphyllococcus aureus Dhaliwal et al. (2009) Examples
  • 30. Snakins Susceptible species References StSN1 and StSN2 from Solanum tuberosum Fungi: Botrytis cinerea Fusarium solani Fusarium oxysporum f.sp. conglutinans Bacteria Clavibacter michiganensis Ralstonia solanacrarum Berrocal Lobo et al. (2002) Examples
  • 31. Cyclopeptides Origin Target pathogen Reference Syringomycins and syringopeptins Pseudomonas sp Botrytis cinerea Lavermicocca et al. (1997) Pseudomonas syringae Venturia inaequalis Burr et al. (1996) Tolaasins Pseudomonas sp Rhizoctonia solani, Rhodococcus fascians Bassarello et al. (2004) Pseudophomins Pseudomonas fluorescens BRG100 Sclerotinia sclerotiorum Pedras et al. (2003) Massetolide Pseudomonas fluorescens SS101 Phytium intermedium de Souza et al. (2003) Examples
  • 32. • PinA and PinB were introduced into corn. • PinA⁄PinB expression–positive transgenic events were evaluated for resistance to Bipolaris maydis, the corn southern leaf blight (SLB) pathogen. • 42.1% reduction in disease symptoms was observed. Supportive article
  • 33. Positive lines Mo17: Resistant, A188: Susceptible, A679: Moderately resistant, B73: Moderately susceptible,
  • 34. • BACTERIOCINS  Ribosomal synthesized Functional peptides  Produced by bacteria  Kill or inhibit closely related bacterial strains • PEPTAIBOLS  Non ribosomal synthesized Functional linear peptides  Produced by fungi  Affect fungi and plant pathogenic gram-positive bacteria SYNTHETIC FUNCTIONAL PEPTIDES
  • 35. Examples Functional Peptides Source Against pathogen 1. Bacteriocins Galtrol Agrobacterium radiobacter Agrobacterium tumefaciens Nogall Agrobacterium radiobacter K1026 Agrobacterium tumefaciens Histick N/T Bacillus subtilis St MB1600 Fusarium, Rhizoctonia, Aspergillus 2. Peptaibols Trichokonins Trichoderma koningii Clavibacter michiganensis,Fusarium, Botrytis, Bipolaris Harzianins and Trichorzins Trichoderma harzianum Sclerotium cepivorum
  • 36. Mechanisms of Action of Functional Peptides
  • 37. 1. Membrane disruption: Many peptides interact interact with microbial membranes, leading to pore formation or membrane permeabilization. This interaction disrupts the osmotic balance, causing cell lysis and death. These lytic peptides are typically amphipathic and cationic, interacting with the negatively charged membranes of bacteria and fungi.
  • 38. •Peptides target specific enzymes critical for microbial survival, such as those involved in cell wall synthesis (e.g., lipid II binding) or metabolic pathways •For example, peptides like plectasin inhibit peptidoglycan biosynthesis in bacteria 2. Inhibition of internal cellular processes: A. DNA, RNA and Protein synthesis interference •Peptides bind to DNA or RNA, preventing replication or transcription •They can also inhibit ribosomal activity, halting protein synthesis Some functional peptides penetrate cells and interfere with essential intracellular processes: B. Enzyme inhibition
  • 39. 3. Interaction with external cell structures: A. Binding with chitin B. Binding to Lipopolysaccharides(LPS) C. Binding with fungal membrane Peptides interact with chitin in fungal cell walls, disrupting structural integrity and leading to cell death. In Gram-negative bacteria, peptides bind to LPS on the outer membrane, neutralizing its endotoxin activity and destabilizing the membrane. Peptides target ergosterol or other unique components in fungal membranes, causing selective disruption without harming host cells. Functional peptides can bind to structural components of pathogens' outer layers:
  • 40. 4. Antibiofilm activity and spore germination inhibition: A. Antibiofilm activity B. Spore germination inhibition Certain peptides inhibit spore germination by interfering with enzymatic processes required for spore activation, preventing fungal proliferation. •Functional peptides prevent biofilm formation by disrupting quorum sensing or directly killing biofilm-forming cells. •They can also penetrate existing biofilms and eradicate embedded pathogens.
  • 41. 5. Plant defense elicitation: In plants, functional peptides act as elicitors that trigger immune responses: A. Activation of Pattern Recognition Receptors(PRR’s) Peptides bind to PRRs on plant cell surfaces, initiating signaling cascades that activate defense genes.
  • 42. B. Reactive oxygen species (ROS) generation •Peptides induce ROS production in plants as an early defense response against pathogens. •ROS can directly damage pathogens or signal further immune responses. C. Hormone pathway Functional peptides modulate plant hormone pathways such as salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), which are critical for systemic acquired resistance (SAR) or induced systemic resistance (ISR).
  • 43. Surface target  Interaction of aminoglycans with virus  Blocking of viral entry into the cell  Suppression of cell fusion by interfering with the activity of ATPase protein. Intracellular target  Suppression viral gene expression  Inhibition of peptide chain elongation by inactivating the ribosome. Viral protein targets:  Binding of peptides to viral proteins causing inhibition of adsorption. Antiviral Mechanism of Functional Peptides
  • 44. 1. Natural Extraction Production and Application of Functional Peptides Functional peptides can be extracted from natural sources such as microorganisms, plants, and animal tissues. a. Microbial Fermentation  Microorganisms like Escherichia coli, Bacillus subtilis, and yeast are used as bio-factories to produce peptides naturally. b. Plant Sources  Plants produce bioactive peptides like defensins and cyclotides as part of their innate immune system.  Techniques such as enzymatic hydrolysis of plant proteins (e.g., soy, wheat, or rice) are used to release functional peptides.
  • 45. 2. Chemical Synthesis Chemical synthesis is a widely used method for producing functional peptides with precise sequences. a. Solution-Phase Synthesis  One of the earliest methods for peptide synthesis, where reactions occur in a liquid medium.  Useful for synthesizing short peptides or small molecules. b. Solid-Phase Peptide Synthesis (SPPS)  Developed by Robert Bruce Merrifield, SPPS is the most common method today.  The peptide chain is assembled step-by-step on an insoluble resin support.  Process:  Protecting groups (e.g., Fmoc or Boc) are used to prevent unwanted side reactions.  Cycles of coupling (adding amino acids) and deprotection (removing protecting groups) are repeated until the desired sequence is achieved.  The peptide is cleaved from the resin and purified. c. Hybrid Methods  Combines solution-phase and solid-phase techniques to optimize yield and efficiency for complex peptides.
  • 46.  AurH1: Derived from aurein 1.2, it is effective against Candida albicans.  Novicidin: A synthetic AMP with broad- spectrum activity against Gram-positive and Gram-negative bacteria. Examples of Synthetic FPs
  • 47. 3. Biotechnological Platforms for Peptide Production 1. Microbial Expression Systems  Hosts: Bacteria (e.g., Escherichia coli), yeast (e.g., Saccharomyces cerevisiae), and other microorganisms are commonly used. a. Bacterial Systems  E. coli is widely used for producing recombinant proteins and peptides due to its well-understood genetics and rapid growth.  Applications: Production of insulin, growth hormone, and other therapeutic peptides. b. Yeast Systems  Yeast offers advantages in terms of PTMs similar to those in mammalian cells.  Applications: Production of complex peptides with glycosylation. 2. Transgenic Plants  Applications: Production of vaccine antigens, diagnostic reagents, and therapeutic peptides like antibodies. 3. Genetic Code Expansion  Principle: Allows the incorporation of non- canonical amino acids into proteins during translation.  Applications: Enhancing peptide stability, bioactivity, or targeting capabilities.
  • 48.  Principle: Involves the design and construction of new biological systems or the redesign of existing ones to produce specific peptides.  Applications: Production of small peptides through pathway engineering and biosynthetic pathway evolution.  Role: AI can predict peptide structures and functions, facilitating the design of novel peptides with desired properties.  Applications: Used in drug discovery to optimize peptide-based therapeutics for better efficacy and safety. 4. Synthetic Biology Approaches 5. Artificial Intelligence in Peptide Design
  • 49. Formulation Development of Peptides Formulation development is a critical step in ensuring the stability, efficacy, and delivery of therapeutic peptides. Below is an overview of the key considerations and strategies used in peptide formulation: 1. Stability a. Chemical Instability  Degradation Pathways: o Hydrolysis of amide bonds. o Oxidation of methionine or cysteine residues.  Solutions: o Incorporate stabilizing excipients like antioxidants (e.g., ascorbic acid) or chelating agents (e.g., EDTA). o Modify amino acid sequences to replace labile residues with more stable analogs. b. Physical Instability  Challenges: o Aggregation, precipitation, or denaturation during storage or handling.  Solutions: o Use lyophilization (freeze-drying) to convert peptides into stable solid forms. o Add surfactants (e.g., polysorbates) to prevent aggregation in aqueous solutions. Peptides are inherently prone to degradation due to their chemical and physical instability. Formulation strategies aim to address these issues:
  • 50. To ensure an adequate shelf life, peptides must be protected from environmental factors such as temperature, light, and moisture.  Lyophilized Formulations: o Lyophilization extends shelf life by removing water, which prevents hydrolytic degradation.  Packaging: o Use moisture-proof and light-resistant containers to protect sensitive peptides. 2. Shelf Life
  • 51. Excipients play a crucial role in stabilizing peptides and enhancing their delivery:  Buffers: Maintain pH stability (e.g., phosphate buffer).  Cryoprotectants/Lyoprotectants: Protect peptides during freeze-drying (e.g., sucrose, trehalose).  Surfactants: Prevent aggregation (e.g., polysorbate 20 or 80).  Osmolytes: Enhance solubility and stability (e.g., glycine). a. PEGylation  Covalent attachment of polyethylene glycol (PEG) chains to peptides increases their half-life by reducingproteolytic degradation. b. Cyclization  Cyclizing linear peptides enhances their stability by reducing susceptibility to enzymatic cleavage. c. Nanoparticle-Based Delivery  Encapsulation in nanoparticles, liposomes, or hydrogels protects peptides from degradation and enables controlled release. d. Co-formulation with Protease Inhibitors  Protease inhibitors can protect peptides from enzymatic degradation during delivery. 3. Excipients in Peptide Formulation 4. Advanced Strategies for Peptide Formulation
  • 53.  Stability Issues Many natural peptides are prone to enzymatic degradation, limiting their bioavailability and therapeutic efficacy.  Production Costs The synthesis of long or complex peptides remains expensive due to the need for high-purity reagents and advanced purification techniques.  Limited Trial Evidence There is a need for more in vitro and field trials to authenticate the benefits of plant-derived peptides.  Industrial Application The practical or industrial application of plant-derived peptides with bioactive features is still a long way off, despite their potential.  Resistance Development Prolonged use of antimicrobial peptides may lead to microbial resistance, similar to antibiotics. Limitations and Ongoing Challenges
  • 54.  Functional peptides hold significant promise for plant disease control due to : Conclusion Their targeted action Low environmental impact Versatility  These peptides can be derived from natural sources or synthesized using advanced techniques, allowing for tailored properties such as enhanced stability and specificity.  Their unique mechanisms of action—ranging from direct antimicrobial effects to the elicitation of plant defense responses—position them as powerful tools in modern agriculture.  Functional peptides represent a transformative approach to plant disease control, offering a sustainable alternative to traditional chemical pesticides.  By harnessing the power of these bioactive molecules, we can foster healthier ecosystems, reduce the environmental footprint of agriculture, and ensure a more resilient food system for generations to come.