Cytokinin Inhibits Fungal Development and Virulence by Targeting the Cytoskeleton and Cellular Trafficking

Area of Science:

• Plant Biology
• Mycology
• Molecular Biology

Background:

• Cytokinins (CKs) are key plant hormones regulating growth, development, and stress responses.
• Phytopathogens can secrete CKs, potentially manipulating host signaling for pathogenesis.
• Previous research suggested CKs induce plant resistance, primarily via salicylic acid pathways.

Purpose of the Study:

• To investigate the direct effect of CK on fungal phytopathogens.
• To elucidate the molecular mechanisms underlying CK's impact on fungal development and virulence.
• To explore the conserved role of CK in eukaryotic cell biology.

Main Methods:

• Fungal growth and development assays with CK treatment.
• RNA next-generation sequencing (RNA-NGS) on CK-treated *Botrytis cinerea*.
• Cell biology experiments (cytoskeleton, endocytosis) and yeast mutant analyses.

Main Results:

• CK directly inhibits the growth, development, and virulence of *Botrytis cinerea* and other fungal phytopathogens.
• CK alters fungal cell cycle, cytoskeleton, and endocytosis, leading to growth retardation.
• Endocytic pathway identified as a CK target in both yeast and *B. cinerea*.

Conclusions:

• CK exhibits a conserved inhibitory role in fungal biology, directly impacting growth and virulence.
• Fungal pathogens likely recognize and respond to CK, leading to cell cycle and growth arrest.
• This study uncovers a novel function of a plant hormone in regulating fundamental eukaryotic cellular processes.