MAMP-Microbe associated molecular pattern / PAMP-Pathogen Associated molecular pattern

MAMP-Microbe associated molecular pattern /

PAMP-Pathogen Associated molecular pattern

1. By using pattern recognition receptors (PRRs) on the cell surface to identify and activate microbe-associated molecular patterns (MAMPs), plants are able to identify microorganisms in apoplasts. signaling in reaction to microorganisms
2. Plants may identify pathogens in the apoplast by recognizing Microbe/Pathogen-Associated Molecular Structures, which are present when microbes enter the apoplast through natural entry points or damaged plant sites.
3. Proteins, carbohydrates, lipids, and nucleic acids are the main types of MAMPs. They all have the following characteristics: highly conserved structures, critical roles in microbe survival, and absence from host plants.

Plant pattern recognition receptors (PRRs) and their recognition of microbial-associated molecular patterns (MAMPs)

1. Structure and function of PRRs:

• PRRs are membrane-bound proteins responsible for detecting MAMPs in the plant's environment.

They come in two forms:

    Receptor-like kinases (RLKs): Have an intracellular kinase domain for signal transduction.

    Receptor-like proteins (RLPs): Lack the kinase domain, but rely on other pathways for signaling.

Both types typically possess extracellular domains containing:

    Leucine-rich repeats (LRRs) Contribute to ligand binding for MAMPs.

    Lysine motifs (LysMs) Recognize specific carbohydrate patterns on MAMPs.

2. MAMP recognition and specificity

MAMPs act as ligands for PRRs, triggering plant immune responses.

Binding specificity is determined by

• MAMP properties- Chemical structure and presentation of relevant features.
• PRR(pattern recognition receptors) properties-Pocket shape and amino acid residues in the ligand-binding domain.

3. Signaling mechanisms:

PRR(pattern recognition receptors)-MAMP binding often leads to receptor oligomerization (clustering).

• This triggers interactions with co-receptors, essential for downstream signaling.

Some MAMPs, like cerebroside, might not require specific short ligands for recognition.

4. Ligand concentration and activity:

• Effective MAMP concentration is crucial for triggering significant biological responses in plants.