Transcriptome features of stone cell development in weevil-resistant and susceptible Sitka spruce

Area of Science:

• Plant Biology
• Forestry
• Molecular Genetics

Background:

• Stone cells are highly lignified cells offering physical defense in plants.
• In Sitka spruce, stone cell abundance correlates with resistance to the spruce weevil (Pissodes strobi).
• Differences in stone cell distribution are observed between resistant (R) and susceptible (S) trees.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying stone cell formation in conifers.
• To identify genes and pathways involved in constitutive physical defense against insect attack.
• To compare gene expression in developing stone cells of resistant and susceptible Sitka spruce trees.

Main Methods:

• Laser microdissection and RNA sequencing to generate cell-type-specific transcriptomes.
• Microscopy techniques (light, immunohistochemical, fluorescence) to visualize cell wall component deposition.
• Differential gene expression analysis between stone cells and cortical parenchyma.

Main Results:

• 1293 genes showed higher expression in developing stone cells compared to cortical parenchyma.
• Identified genes potentially involved in secondary cell wall (SCW) formation.
• Expression patterns of transcriptional regulators, including NAC and MYB factors, were linked to stone cell development.

Conclusions:

• Stone cell formation involves specific gene expression programs related to SCW synthesis.
• Transcriptional regulators play a key role in mediating stone cell development and insect resistance.
• This study provides a foundation for understanding genetic control of plant physical defenses.