A pathogen lncRNA secreted into rice sequesters a host miRNA for virulence.

Area of Science:

• Molecular Biology
• Plant Pathology
• Genetics

Background:

• Plants and animals utilize pattern recognition receptor and Nod-like receptor proteins to detect pathogens.
• Pathogens often employ protein effectors to suppress host immunity, but non-protein effectors are less understood.

Purpose of the Study:

• To investigate a novel RNA-RNA recognition mechanism in pathogen-host interactions.
• To elucidate the role of regulatory RNAs in mediating fungal infection in rice.

Main Methods:

• Identification and characterization of a regulatory RNA-encoding DNA sequence in Magnaporthe oryzae.
• Analysis of long non-coding RNA (lncRNA) translocation and microRNA (miRNA) sequestration in host rice cells.
• Gene expression analysis of PKR1 in response to lncRNA-miRNA interaction.

Main Results:

• A fungal lncRNA from Magnaporthe oryzae targets and sequesters a rice-derived miRNA.
• This sequestration releases the repression of PKR1, a negative regulator of host immunity, thereby promoting fungal infection.
• The identified regulatory RNA-encoding DNA sequence appears to be conserved across diverse species.

Conclusions:

• RNA-RNA recognition is a significant mechanism in pathogen-host interactions, extending beyond protein effectors.
• Fungal lncRNAs can manipulate host immunity by interacting with host miRNAs.
• This study reveals a conserved mechanism with potential applications in developing novel disease control strategies using miRNAs.