Profiling methyl jasmonate-responsive transcriptome for understanding induced systemic resistance in whitebark pine...

Area of Science:

• Plant Biology
• Forestry
• Molecular Ecology

Background:

• Whitebark pine populations are declining due to susceptibility to mountain pine beetle and white pine blister rust (WPBR).
• Induced systemic resistance (ISR) mechanisms in whitebark pine are not well understood, limiting restoration and breeding efforts.
• Jasmonates are known to activate plant immune systems, triggering ISR through gene expression.

Purpose of the Study:

• To investigate the effects of methyl jasmonate (MeJA) on whitebark pine needle gene expression.
• To identify differentially expressed genes (DEGs) involved in MeJA-induced defense responses.
• To provide insights into the molecular mechanisms of ISR in whitebark pine.

Main Methods:

• RNA sequencing (RNA-seq) was used to profile whitebark pine needle transcriptomes after MeJA treatment.
• A de novo transcriptome assembly was performed.
• Gene Ontology (GO) analysis was conducted to determine the functions of DEGs.

Main Results:

• MeJA treatment resulted in 1422 up-regulated and 999 down-regulated transcripts in whitebark pine needles (FDR corrected p < 0.05).
• DEGs were enriched in functions related to plant defense signaling, transcription regulation, and secondary metabolite biosynthesis.
• MeJA-induced gene expression patterns showed significant overlap with defense responses against pathogens and insects in related Pinus species.

Conclusions:

• MeJA treatment effectively reprograms the whitebark pine transcriptome, activating defense pathways.
• The findings suggest MeJA can enhance whitebark pine resistance to pests and pathogens, aiding in conservation.
• Identified DEGs serve as candidates for marker-assisted selection in breeding programs for improved tree resilience.