Lesson 2: Reproduction in Flowering Plants (Angiosperms)

Plant Immunity Architecture ├── 1. Structural Defenses (Physical Barriers) │ ├── Pre-existing Structural Defenses: │ │ ├── Epidermal Cuticle (Waxy layer preventing water retention + Epidermal Hairs & Thorns) │ │ └── Rigid Cellulose Cell Wall (Impregnated with Lignin for structural rigidity) │ └── Induced Structural Defenses (Post-infection Responses): │ ├── Cork Formation (Isolates severed or damaged tissues) │ ├── Tyloses Formation (Overgrowth of parenchyma cells plugging xylem vessels to halt spread) │ ├── Gum Deposition around wounds │ ├── Cellular Structural Defenses (Swelling of cell walls & enclosing fungal hyphae) │ └── Hypersensitive Response (Controlled death of infected tissue to starve pathogens) └── 2. Biochemical Defenses (Chemical Warfare) ├── Pathogen Recognition Receptors (Recognize pathogen molecules & trigger internal cascade) ├── Antimicrobial Chemicals: │ ├── Phenols and Glucosides (Inhibit bacterial and fungal growth) │ └── Non-Protein Amino Acids (Canavanine and Cephalosporin acting as protective toxins) └── Antimicrobial Proteins: ├── Detoxifying Enzymes (Neutralize and decompose microbial toxins) └── Systemic Acquired Resistance (SAR) reinforcing future immunity