Transcriptomic Differences Between Two Fusarium oxysporum Formae Speciales During Cucumber Infection

Area of Science:

• Plant Pathology
• Molecular Plant-Microbe Interactions
• Fungal Genomics

Background:

• Fusarium oxysporum f. sp. radicis-cucumerinum (Forc) and Fusarium oxysporum f. sp. radicis-lycopersici (Forl) cause cucumber foot and root rot.
• These strains differ in host range and effector gene presence (Forc has SIX effectors, Forl does not).
• Understanding their distinct infection mechanisms on a shared host is crucial.

Purpose of the Study:

• To compare the transcriptomic responses of cucumber to Forc V03-2g and Forl ZUM2407.
• To elucidate the distinct infection strategies employed by these two Fusarium species on cucumber.
• To investigate the role of accessory and core chromosome genes in pathogen virulence.

Main Methods:

• Comparative transcriptomic analysis of cucumber at 7 and 14 days post-inoculation (dpi).
• Transcriptomic analysis of tomato at 2 dpi for comparative insights.
• Analysis of gene expression patterns related to core and accessory chromosomes.

Main Results:

• Forl ZUM2407 induced a delayed defense response in cucumber compared to Forc V03-2g.
• Forc V03-2g rapidly activated accessory chromosome effectors in cucumber.
• Forl ZUM2407 initially deployed core chromosome genes, activating distinct accessory genes by 14 dpi.

Conclusions:

• Forc V03-2g and Forl ZUM2407 exhibit divergent infection strategies on cucumber.
• Distinct accessory gene repertoires and core gene transcription patterns contribute to virulence.
• The timing of accessory gene activation differs significantly between the two strains.