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

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