Transcriptomics of temperature-sensitive R gene-mediated resistance identifies a WAKL10 protein interaction network

Area of Science:

• Plant pathology
• Molecular genetics
• Crop science

Background:

• Temperature sensitivity of plant immune responses affects crop yields.
• Understanding R gene function under varying temperatures is crucial for sustainable agriculture.
• Apoplastic pathogens like Leptosphaeria maculans pose significant threats to oilseed rape (Brassica napus).

Purpose of the Study:

• To investigate the temperature-dependent resistance mechanisms of Brassica napus against Leptosphaeria maculans.
• To compare the molecular responses of temperature-sensitive (Rlm7) and temperature-resilient (Rlm4) resistance alleles.
• To identify host genes and pathways involved in temperature-modulated plant defense.

Main Methods:

• Differential gene expression analysis in Brassica napus introgression lines Topas-Rlm7 and Topas-Rlm4 under different temperatures.
• Protein-protein interaction network analysis.
• Gene Ontology enrichment analysis.

Main Results:

• Resistance to Leptosphaeria maculans was temperature-sensitive in Topas-Rlm7 but resilient in Topas-Rlm4.
• 1,646 host genes showed differential expression in response to temperature across both lines.
• A WAKL10 protein interaction network specific to Topas-Rlm7 at 25°C was identified.
• WRKY22 was identified as a potential target of VPS60.1 within the Rlm4 network.
• Vesicle-mediated transport was linked to defense pathways.

Conclusions:

• The Rlm7-1 allele confers temperature-sensitive resistance, while Rlm4 provides resilience.
• Differential gene expression and network interactions highlight temperature's role in R gene function.
• Dysregulation of effector-triggered immunity in Rlm7 compromises vesicle-associated defense against L. maculans.