This explains how the tree “talks” to invading microbes and triggers resin production.
1. What Is Host–Pathogen Signaling?
- Host: the agarwood tree
- Pathogen: invading microbe (fungus or bacterium)
- Signaling: chemical communication that tells the tree:
“You are under attack — defend yourself!”
- This activates the tree’s immune and wound responses, which leads to resin formation.
2. Steps in Host–Pathogen Interaction
- Microbe enters wound
- Drilled hole, bark removal, insect damage
- Tree detects invasion
- Uses receptors in cells to sense microbe molecules
- Signal molecules released
- Reactive oxygen species (ROS)
- Phytohormones (like jasmonic acid)
- Secondary metabolites (sesquiterpenes, chromones)
- Defense response activated
- Resin production starts
- Vascular blockage occurs
- Microbes are slowed or contained
- Resin zone develops over time
- Dark, aromatic, polymerized resin
3. Why Signaling Determines Resin Quality
| Signaling Strength | Result |
|---|---|
| Weak | Light resin, slow formation |
| Moderate | Dark, aromatic, high-quality resin |
| Overactive / uncontrolled | Tissue necrosis, tree death, poor resin |
4. Farmer Key Message
“The tree produces resin because it senses the invader.
Your job is to guide this process safely — not force it.”
5. Practical Tips for Farmers
✔ Use controlled microbial inoculants
✔ Ensure mechanical wounds are moderate
✔ Combine with mild chemical elicitors if needed
✔ Allow time for resin polymerization
✔ Observe leaf health and resin zone development