Exploring links between antisense RNAs and pathogenesis in Ustilago maydis through transcript and gene...

Area of Science:

• Plant pathology
• Fungal genetics
• RNA biology

Background:

• Biotrophic basidiomycete fungi, like the corn smut pathogen *Ustilago maydis*, cause significant annual losses in cereal crops.
• Genomic annotation of *U. maydis* revealed antisense RNAs (asRNAs) complementary to over half of its mRNAs, with some asRNAs highly abundant in teliospores.

Purpose of the Study:

• To investigate the role of asRNAs in *U. maydis* pathogenesis.
• To identify genes complementary to asRNAs and assess their involvement in virulence.
• To characterize the function of specific asRNAs in regulating gene expression and impacting pathogenesis.

Main Methods:

• Deletion analysis of genomic regions controlling asRNA expression.
• Assessment of pathogenesis following genetic modifications.
• Identification and functional characterization of asRNAs and their target genes.

Main Results:

• Deletion of specific genomic regions led to increased asRNA transcript levels and attenuated pathogenesis.
• One gene linked to asRNA regulation encodes a putative xylitol dehydrogenase.
• Evidence suggests asRNAs influence pathogenesis by acting on unlinked genetic loci.

Conclusions:

• Antisense RNAs play a crucial role in the pathogenesis of *Ustilago maydis*.
• The regulatory mechanisms involving asRNAs and their targets are complex and can affect virulence.
• Further research into asRNA function can provide insights into fungal-plant interactions and disease control strategies.