Cross-kingdom RNA interference promotes arbuscular mycorrhiza development

Area of Science:

• Plant biology
• Mycology
• Molecular biology

Background:

• Cross-kingdom RNA interference is a known mechanism in plant-pathogen interactions.
• Arbuscular mycorrhiza is a widespread and ancient symbiotic relationship between plants and fungi.
• The molecular mechanisms regulating arbuscular mycorrhiza are not fully understood.

Purpose of the Study:

• To investigate the role of RNA interference in the beneficial symbiosis of arbuscular mycorrhiza.
• To determine if cross-kingdom RNA interference occurs between arbuscular mycorrhizal fungi and host plants.
• To identify the source and function of small RNAs transferred between symbionts.

Main Methods:

• Utilized molecular techniques to detect and analyze small RNA transfer between Rhizophagus irregularis and host plant roots.
• Employed gene silencing assays to assess the functional impact of fungal small RNAs on plant gene expression.
• Performed microscopy to confirm fungal colonization and small RNA localization within plant cells.

Main Results:

• Provided evidence for cross-kingdom RNA interference in arbuscular mycorrhiza.
• Demonstrated that the arbuscular mycorrhizal fungus Rhizophagus irregularis transfers small RNAs into host plant cells.
• Showed that these transferred small RNAs promote the colonization of host roots by the fungus.

Conclusions:

• Inter-organismal RNA communication is a novel regulatory mechanism in arbuscular mycorrhiza.
• Cross-kingdom RNA interference plays a role in establishing and maintaining this beneficial plant-fungus symbiosis.
• This finding opens new avenues for understanding and manipulating plant-microbe interactions.