PAMP Signals in Plant Innate Immunity

1. Introduction 1.1Classical PAMPs 1.2 Plant pattern recognition receptors (PRRs) 1.3 Second Messengers in PAMP Signaling 1.4 Plant Hormone Signals in Plant Immune Signaling system 1.5 War between Host Plants and Pathogens and the Winner is ...? 2. PAMP signaling in Plant Innate Immunity 2.1 Classical PAMPs as Alarm Signals 2.2 Effector-like PAMPs 2.3 PAMPs found within Effectors 2.4 Toxins acting as PAMPs 2.5 PAMP-induced HAMPs (DAMPs/ MIMPs/ PAMP Amplifiers/ Endogenous Elicitors) 2.6 Bacterial PAMPs 2.7 Fungal PAMPs 2.8 Oomycete PAMPs 2.9 Viral Elicitors 2.10 Host-associated Molecular patterns (HAMPs) as Endogenous Elicitors 2. 11 Pattern Recognition Receptors (PRRs) 2.12 Transmembrane Proteins interacting with PRRs in PAMP-PRR Signaling Complex 2.13 PAMP triggers increased Transcription of PRR gene and Accumulation of PRR Protein 2.14 PAMPs induce Phosphorylation of PRRs 2.15 Negative Regulation of PRR Signaling 2.16 Translocation of PRRs from Plasma Membrane to Endocytic Compartments 2.17 ERQC (for ENDOPLASMIC RETICULUM QUALITY CONTROL) Pathways in Biogenesis of PRRs 2.18 N-glycosylation of PRRs 2.19 Significance of PRRs in Innate Immunity 2.20 PAMPs-induced Early Signaling Events Downstream of PRRs 2.21 Different PAMPs and HAMPs may induce Similar Early Signaling Systems 2.22 Magnitude and Timing of Expression of early Signaling Systems may vary depending on specific PAMPs 2.23 PAMPs may differ in eliciting various Defense Responses 2.24 Synergism and Antagonism in Induction of Plant Immune Responses by PAMPs/HAMPs 2.25 Amount of PAMP/HAMP determines the Intensity of Expression of Defense Signaling Genes 2.26 Amount of PAMP available in the Infection Court may determine the Level of Induction of Immune Responses 2.27 PAMPs may trigger Different Signaling Systems 2.28 PAMPs may function Differently in Different Plants 2.29 Specificity of PAMPs in triggering Immune Responses in Plants 2.30 Role of PAMPs and Effectors in Activation of Plant Innate Immune Responses 2.31 Effectors may suppress PAMP-triggered Immunity 2.32 PAMP-induced Small RNA-mediated RNA Silencing 3. G-proteins as Molecular Switches in Signal Transduction 3.1 G-proteins switch on Plant Innate Immunity Signaling Systems 3.2 Heterotrimeric G-protein Signaling 3.3 Small G-proteins Signaling 3.4 Heterotrimeric G-protein Galpha may act Upstream of Small G-protein in Immune Signaling 3.5 Different G-protein subunits in Heterotrimeric G-proteins play Distinct Roles in Plant Innate Immunity 3.6 Small G-proteins Activate Plant Innate Immunity 3.7 Small G-proteins may be involved in Susceptible Interactions 3.8 RAR1-SGT1-HSP90-HSP70 Molecular Chaperone Complex: a Core Modulator of Small G-protein-triggered Plant Innate Immunity 3.9 PAMP Signal may convert the G-proteins from their Inactive State to their Active State to trigger Immune Responses 3.10 PAMP-activated G-proteins switch on Calcium ion-mediated Immune Signaling System 3.11 G-proteins may trigger Efflux of Vacuolar Protons into Cytoplasm to activate pH-dependent Signaling Pathway 3.12 G-proteins switch on ROS Signaling System 3.13 G-proteins activate Nitric oxide Signaling System 3.14 Close relationship between G-proteins and MAPKs in Signal Transduction 3.15 G-proteins induce biosynthesis of polyamines which act as second messengers triggering early signaling events 3.16 G- proteins modulate Salicylic acid Signaling Pathway 3.17 G-proteins trigger Ethylene Signaling Pathway 3.18 G-proteins switch on Jasmonate Signaling System 3.19 G-proteins switch on Abscisic acid Signaling System 3.20 G-proteins may participate in Gibberellic acid Signaling 3.21 G-proteins participate in Brassinosteroid Signaling 3.22 Interplay between G-proteins and Auxin Signaling Systems 3.23 G-proteins Activate Defense-related Enzymes 4. Calcium Ion Signaling System: Calcium Signatures and Sensors 4.1 Calcium Signature in Plant Immune Signal Transduction System 4.2 Upstream Events leading to Activation of Ca2+ - permeable Channels 4.3 Ca2+ Influx Channels in Plant Cell Plasma Membrane 4.4 Ca2+ release Channels Involved in Releasing Stored Ca2+ in Vacuole and Endoplasmic Reticulum into cytosol 4.5 Ca2+ Efflux from Cytosol to Vacuole and Endoplasmic Reticulum (ER) 4.6 Plasma Membrane H+-ATPases in Ca2+ Signaling 4.7 Anion Channels in Ca2+ Influx and Increase in [Ca2+]cyt 4.8 K+ channels in Ca2+ Influx 4.9 K+/H+ exchange Response in Ca2+ Signaling System 4.10 PAMPs and DAMPs may trigger Calcium Ion Influx/efflux through Different Ca2+ Channels 4.11 Induction of Increases in Concentration, Oscillations and Waves in Cytoplasmic Calcium Ion ([Ca2+]cyt) 4.12 Ca2+ Sensors in Ca2+ Signal Transduction 4.13 Calmodulins as Ca2+ Sensors 4.14 Calmodulin-binding Proteins 4.15 Calmodulin-like proteins as Ca2+ Sensors 4.16 Calcineurin B- like Proteins as Ca2+ sensors 4.17 NADPH Oxidase as Calcium-binding Protein 4.18 Ca2+-binding Proteins without EF-Hands 4.19 Calcium-dependent Protein kinases as Ca2+ Sensors 4.20 Nuclear Free Calcium Ion ([Ca2+]nuc) in Ca2+ Signaling 4.21 Downstream Events in Ca2+ Signaling System 4.22 Importance of Calcium Signaling System in Activation of Plant Innate Immunity 5. Reactive Oxygen Species and Cognate Redox Signaling System in Plant Innate Immunity 5.1 Reactive Oxygen Intermediates Involved in Oxidative burst 5.2 Upstream Events in ROS Signaling System 5.3 ROS-Scavenging systems may be involved in Fine-tuning Accumulation of ROS 5.4 Site of Production of ROS 5.5 Biphasic ROS Production 5.6 ROS Plays a Central Role in Triggering Immune Responses 5.7 Interplay between ROS and Ca2+ Signaling System 5.8 Interplay between ROS and NO Signaling Systems 5.9 Interplay between ROS and MAPK Signaling Systems 5.10 Interplay between ROS and Salicylic acid Signaling Systems 5.11 Interplay between ROS and Ethylene Signaling Systems 5.12 Interplay between ROS and Jasmonate Signaling Systems 5.13 Interplay between ROS and Abscisic acid (ABA) Signaling Systems 5.14 ROS activates Phosphorylation/dephosphorylation Systems 5.15 Function of ROS in Ubiquitin-Proteasome System 5.16 ROS may Regulate Expression of Transcription Factors 5.17 Redox Signaling System 5.18 ROS Signaling System may activate Transcription of Defense Genes 5.19 Pathogens may cause Disease by Interfering with ROS Signaling System in Host Plants 6. Nitric oxide Signaling System in Plant Innate Immunity 6.1 Nitric Oxide as a Component of the Repertoire of Signals involved in Plant Immune Signaling System 6.2 PAMP-induced Biosynthesis of NO in Plants 6.3 Upstream Events in NO Production 6.4 Nitric Oxide-Target Proteins 6.5 Interplay between NO and Ca2+ Signaling Systems 6.6 Interplay between NO and ROS Signaling Systems 6.7 Role of NO in SA, JA, and Ethylene Signaling Systems 6.8 Role of NO in Protein S-Nitrosylation 6.9 Role of NO in Protein Nitration 6.10 Role of NO in Salicylic acid-regulated Systemic Acquired Resistance 7. Mitogen-activated Protein Kinase Cascades in Plant Innate Immunity 7.1 MAPK Signaling Three-Kinase Modules 7.2 MAP Kinases Involved in Plant Immune Responses 7.3 MAPK Kinases (MAPKKs) in Plant Immune Responses 7.4 MAPKK Kinase EDR1 Modulates SA-JA-ET Signaling 7.5 MAPK Pathways involved in Defense Signal Transduction may be interconnected 7.6 14-3-3 Protein Enhances Signaling Ability of MAPKKK in Activating Plant Innate Immune Response 7.7 Role of MAPKs in Priming Plants for Augmented Defense Gene Activation 7.8 PAMP Signals Activate MAP kinases 7.9 Signals and Signaling Systems Activating MAPK Cascades 7.10 MAPKs May Function Downstream of G-proteins, Ca2+, ROS, SA, ABA, and NO Signaling Pathways 7.11 Some MAPKs may act Upstream of SA, JA, and ET Signaling Pathways 7.12 Some MAP Kinases act Downstream of Phosphoinositide (PI) Signal Transduction Pathway 7.13 MAP Kinase Cascades may act either Upstream or Downstream of ROS Signaling System 7.14 MAP Kinases Positively or Negatively Regulate SA Signaling System 7.15 MAP Kinase Cascades activate JA Signaling System 7.16 Some MAP kinase Cascades are involved in Biosynthesis of Ethylene and Ethylene-mediated Signaling Systems 7.17 Involvement of MAP Kinase in Crosstalk between SA and JA/ET Signaling Systems 7.18 MAPK Phosphatases as Negative Regulators of MAP Kinases 7.19 MAP Kinase Cascades Modulate Phosphorylation of Transcription Factors to Trigger Transcription of Defense Genes 7.20 MAPKs Regulate Defense Gene Expression by Releasing Transcription Factors in the Nucleus 7.21 Role of MAPK Signaling Cascade in Triggering Phytoalexin Biosynthesis 8. Phospholipids Signaling System in Plant Innate Immunity 8.1 Biosynthesis of Phospholipids-derived Second Messengers 8.2 Phospholipids in Ca2+ Signaling System 8.3 Phosphatidic acid in G Proteins-mediated Signaling System 8.4 Phosphatidic acid in ROS Signaling System 8.5 Phospholipids in JA Signaling System 8.6 Phospholipid Signaling System in ABA Signaling Network 8.7 Phosphatidic acid in Phosphorylation/dephosphorylation System 9. Protein Phosphorylation and Dephosphorylation in Plant Immune Signaling Systems 9.1 Protein Phosphorylation plays Key Roles in Plant Immune Signal Transduction 9.2 Protein Phosphorylation is an Early PAMP/Elicitor-Triggered Event 9.3 Protein Phosphorylation is carried out by Different Protein Kinases 9.4 PAMPs/Elicitors activate Receptor-like Kinases 9.5 PAMP/Elicitor Induces Phosphorylation of Calcium-dependent Protein Kinases 9.6 PAMP/elicitor Triggers Phosphorylation of MAP Kinases 9.7 Role of 14-3-3 Proteins in Protein Phosphorylation 9.8 PAMP/Elicitor Triggers Phosphorylation of PEN Proteins 9.9 Protein Phosphorylation Involved in Early Defense Signaling Events Triggered by PAMPs/Elicitors 9.10 Phosphorylation of Proteins involved in H+ fluxes induced by PAMP/elicitor 9.11 Phosphorylation of Proteins involved in ROS Signaling System 9.12 Phosphorylation of Proteins Involved in Ethylene-Signaling System 9.13 Phosphorylation of Proteins involved in Salicylic acid Signaling System 9.14 Protein Phosphorylation in ABA Signaling System 9.15 Phosphorylation of Transcription Factors 9.16 Phosphorylation Events Induced by MAP Kinases in Various Signaling systems 9.17 Dephosphorylation induced by Phosphatases may negatively regulate Innate Immune Responses 10. Ubiquitin-Proteasome System-mediated Protein Degradation in Defense Signaling 10.1 Ubiquitin-Proteasome System in Plants 10.2 Ubiquitin-Proteasome in Jasmonate Signaling System 10.3 Ubiquitin-Proteasome in Ethylene Signaling System 10.4 Ubiquitin-Proteasome in SA Signaling System 10.5 Ubiquitin-Proteasome in R-Gene mediated Early Signaling System 10.6 Small Ubiquitin-like Modifier (SUMO) in Plant Immunity 10.7 Pathogens may subvert ubiquitin-proteasome system to cause Disease