Nutrition in Plants

• Mode of Nutrition
  • Autotrophic
    • Definition: Making food themselves
    • Example: Green plants
    • Process: Photosynthesis
  • Heterotrophic
    • Definition: Depending on other organisms for food
    • Example: Animals and non-green plants
• Photosynthesis (Food Making Process)
  • Raw Materials
    • Carbon dioxide (from air via stomata)
    • Water and minerals (absorbed by roots)
    • Sunlight (captured by green pigment)
  • Key Components
    • Chlorophyll: Green pigment in leaves
    • Stomata: Tiny pores for gas exchange
    • Guard cells: Regulate stomata opening/closing
  • End Products
    • Carbohydrates (Food/Glucose)
    • Oxygen (Released into atmosphere)
  • Importance
    • Ultimate source of energy for all living organisms
    • Maintains oxygen-carbon dioxide balance in nature
• Other Modes of Nutrition in Plants
  • Parasitic
    • Definition: Living on or inside another host
    • Example: Cuscuta (Amarbel)
  • Insectivorous
    • Definition: Trap and digest insects for nitrogen
    • Example: Pitcher plant and Venus flytrap
  • Saprotrophic
    • Definition: Feeding on dead and decaying matter
    • Example: Fungi (Mushrooms, bread molds)
    • Digestive juices secreted onto dead matter
  • Symbiotic Relationship
    • Definition: Mutual sharing of shelter and nutrients
    • Example: Lichens (Alga + Fungus partnership)
    • Example: Rhizobium bacteria in legume roots (Nitrogen fixation)
• Replenishing Soil Nutrients
  • Nutrient Depletion
    • Plants absorb minerals and nutrients from soil
  • Ways to Replenish
    • Adding Fertilizers and Manures (contain Nitrogen, Phosphorus, Potassium)
    • Growing Leguminous crops (natural nitrogen replenishment by Rhizobium)