Histological Dissection of Fusarium-Banana Interaction Using a GFP-Tagged Subtropical Race 4 Strain of Fusarium oxysporum f. sp. cubense on Banana Cultivars with Differing Levels of Resistance
- Author: mycolabadmin
- 12/1/2024
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Summary
Researchers used fluorescently-labeled fungal strains to visualize how banana wilt disease spreads inside banana plants. They found that resistant banana varieties can slow down the fungus by forming blockages (called tyloses) in their water-conducting vessels, though the fungus can still initially enter the plant. The study showed that the rhizome, an underground stem-like structure, is the key location where resistant plants successfully contain the fungus, which helps explain why some banana varieties are naturally more resistant to this devastating disease.
Background
Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is a significant threat to global banana production. The disease has caused major economic losses, particularly with the emergence of race 4 strains. Understanding pathogen-host interactions at the histological level is crucial for developing resistance strategies.
Objective
This study aimed to track the movement and colonization of GFP-tagged Foc subtropical race 4 (STR4) strain through different banana cultivars with varying resistance levels using confocal and scanning electron microscopy to understand infection mechanisms and defence responses.
Results
GFP-Foc-STR4 successfully infected all cultivars, moving from roots to rhizomes and aerial parts. Tyloses formation in xylem vessels was observed in both susceptible and resistant cultivars, but was more pronounced and effective in restricting fungal spread in resistant cultivars FHIA25 and GCTCV119. The rhizome was identified as the critical site determining resistance versus susceptibility, with limited fungal proliferation in resistant cultivars compared to extensive colonization in susceptible ones.
Conclusion
Tyloses formation and vascular occlusion contribute to host tolerance in FHIA25 and GCTCV119, though these mechanisms do not confer complete immunity. The rhizome plays a crucial role in banana-Fusarium interactions, and understanding these defense mechanisms is essential for developing integrated management strategies for Fusarium wilt of banana.
- Published in:Microorganisms,
- Study Type:Experimental Study,
- Source: 10.3390/microorganisms12122472