Abstract
M.Sc. (Biochemistry)
Plant innate immunity occurs in two interconnected branches, the first being the recognition of pathogen conserved surface structures known as pathogen- or microbe-associated molecular patterns (P/MAMPs) by the plant plasma membrane pathogen recognition receptors (PRRs), leading to activation of P/MAMP-triggered immunity (P/MTI). The second branch involves the recognition of pathogen avirulence (Avr) genes by the corresponding plant disease resistance (R) genes, known as the ‘gene-for-gene‘ interaction, and results in a more efficient or stronger defence response, namely effector-triggered immunity (ETI). Lipopolysaccharide (LPS) acts as a P/MAMP that induces an innate immune response in both plants and animals. LPS, especially the lipid A component, has been shown to play a vital role in activating immune responses in animals. Other LPS components such as lipooligosaccharide (LOS) and the core-oligosaccharide have also been shown to trigger an immune response in plants such as Arabidopsis thaliana. In mammalian cells, LPS binds to the LPS-binding protein (LBP) forming a LPS-LBP complex, which binds to a Toll-like receptor 4/myeloid differentiation-2 (TLR4/MD-2) complex together with the co-receptor CD14, a glycosylphosphatidylinositol (GPI)-linked protein, and activates an immune response. To date, there is still no knowledge about the LPS receptor(s) in plants.....