1. Introduction
  1.1 Background and significance
  1.2 Research objectives
2. Structure and composition of the plant cell wall
  2.1 Cellulose, hemicellulose, and pectin
  2.2 Modifications and cross-linking
  2.3 Role in plant growth and development
3. Plant cell wall recognition of microbial pathogens
  3.1 Pathogen-associated molecular patterns (PAMPs)
  3.2 Pattern recognition receptors (PRRs)
  3.3 Activation of defense responses
4. Plant cell wall interactions with beneficial symbionts
  4.1 Mycorrhizal fungi and rhizobia
  4.2 Signaling and nutrient exchange
  4.3 Mutualistic benefits and co-evolution
5. Experimental design and methodology
  5.1 Selection of plant species and cell wall mutants
  5.2 Microbial pathogens and symbionts
  5.3 Cell wall analysis techniques