Question

What are the 1st and 2nd line of defence of plant against pathogens?

Answer 1

Answer: These may be:

• physical defenses  (1st line)
• chemical defenses (2nd line)

Explanation:

Plants employ several methods in order to defend themselves from pathogens. These may be physical defenses or chemical ones. Several have adaptations to their surfaces that prevent the entry of pathogens, called physical barriers such as

• thick waxy cuticles
• thorns, which are modified plant branches
• spines, which are modified plant leaves
• gall production at infected sites to prevent pathogenic spread

Chemical defenses include the production or secretion of:

• defensins
• antimicrobials such as tannins or resins
• gum at areas facing pathogenic attacks