Double-Staining Method to Detect Pectin in Plant-Fungus Interaction

Area of Science:

• Plant Pathology
• Plant Cell Biology
• Microscopy Techniques

Background:

• Plant cells possess structural defense mechanisms against fungal pathogens.
• Pectin, a cell wall component, is targeted by fungal enzymes in necrotrophic interactions.
• Encapsulation is an inducible plant defense strategy to isolate fungal haustoria.

Purpose of the Study:

• To develop and present a protocol for detecting pectin and fungal hyphae using optical microscopy.
• To investigate pectin-rich encapsulation in coffee leaves infected by Hemileia vastatrix.
• To examine mesophyll cell wall modifications induced by Cercospora coffeicola.

Main Methods:

• Developed a double-staining protocol using cotton blue for fungi and ruthenium red for pectin.
• Fixed, dehydrated, and embedded coffee leaf samples in glycol methacrylate.
• Sectioned samples and analyzed under optical microscopy to visualize plant-fungi interactions.

Main Results:

• Successfully visualized pectin encapsulation of Hemileia vastatrix haustoria in coffee leaf cells.
• Observed dissolution of mesophyll cell walls in coffee leaves infected with Cercospora coffeicola.
• Detected intercellular hyphae and conidiophores associated with Cercospora coffeicola.

Conclusions:

• The presented microscopy protocol is effective for detecting pectin-associated plant defense responses.
• The study provides insights into structural defense mechanisms in coffee plants against specific fungal pathogens.
• This method aids in understanding plant-fungi interactions at the cellular level.