A Spray Inoculation Technique to Establish Fungal Infection in Rice Plant Leaves

Take a Petri plate with sections of rice plant leaves positioned above a wet filter paper to prevent desiccation.

Take a suspension of conidia  — reproductive spores — of the pathogenic fungus Magnaporthe grisea. Spray on the leaf sections and incubate under dark and humid conditions.

Moisture induces conidia to release mucilage, facilitating attachment to the leaf surface.

The conidia extend germ tubes, the tip of which differentiates into dome-shaped appressorium.

High solute concentration inside the appressorium generates turgor pressure, forming a penetration peg.

The small diameter of the peg focuses turgor-mediated force on a small leaf area, causing penetration into the leaf cell.

The peg differentiates into invasive hyphae to derive nutrition.

Incubate the leaf sections under fluorescent light for fungal growth.

The hyphae ramify within infected cells and invade neighboring cells through plasmodesmata.

The fungus secretes toxins to induce necrosis, resulting in leaf lesions. Score the lesions to assess infection severity.