Plant disease and defences

• What microorganisms can cause diseases in plants?

  Fungi, bacteria, and viruses
• Besides microorganisms, what larger organisms can cause plant diseases?

  Insects
• What are deficiency diseases in plants?

  Diseases from lack of essential minerals
• Which essential minerals are mentioned as important for plants?

  Nitrates and magnesium ions
• Why are nitrates important for plants?

  They are needed for making proteins
• What happens to plants with insufficient nitrates?

  They often experience stunted growth
• What role do magnesium ions play in plants?

  They are needed for making chlorophyll
• What symptom indicates a magnesium deficiency in plants?

  Chlorosis and yellow leaves
• What are some symptoms of diseased plants?

  Abnormal growths, lumps, and discoloration
• How can you identify the organism responsible for plant disease?

  By observing if they are visible, like aphids
• What is the easiest method to diagnose plant disease?

  Match symptoms to a garden manual
• What can you do if basic observations fail to diagnose a plant disease?

  Send a sample to a plant pathologist
• What is a plant pathologist?

  A specialist in plant diseases
• What detailed testing can a plant pathologist perform?

  Look at tissue samples under a microscope
• What unique method can be used to identify pathogens?

  Using monoclonal antibodies for antigens
• What advanced method can be used to detect pathogens in plants?

  DNA tests for pathogen DNA
• What is a trial and error method in diagnosing plant diseases?

  Trying treatments to see if they work
• What is a benefit of the trial and error method?

  You can try one treatment at a time
• What are the types of plant defenses against diseases?

  • Physical defenses: prevent pathogen entry
  • Chemical defenses: secrete antimicrobial substances
  • Mechanical defenses: deter animals from eating
• What do chemical defenses in plants do?

  They kill bacteria or fungi
• What common drug is derived from plant chemicals?

  Aspirin from willow trees
• What are mechanical defenses in plants?

  Structures that deter animals from eating
• How do some plants respond when insects land on them?

  Leaves curl or droop to deter insects
• What are the three categories of plant defenses?

  • Physical defenses
  • Chemical defenses
  • Mechanical defenses