Transcriptomic Analysis Reveals Novel Regulators of the Scots Pine Stilbene Pathway

Area of Science:

• Plant Molecular Biology
• Forest Genetics
• Biochemistry

Background:

• Stilbenes in Scots pine heartwood are vital for fungal decay resistance and active defense.
• Stilbene biosynthesis is induced by various biotic and abiotic stressors.
• The specific enzymes and transcriptional regulators of this pathway remain largely unknown.

Purpose of the Study:

• To identify candidate genes, including a missing CoA ligase and pathway regulators, involved in Scots pine stilbene biosynthesis.
• To investigate the transcriptional activation of the stilbene pathway in response to UV-C radiation and translational inhibitors.
• To compare stilbene pathway regulation between gymnosperms (Scots pine) and angiosperms (grapevine, Arabidopsis).

Main Methods:

• Large-scale transcriptomic analysis of Scots pine needles under UV-C radiation and translational inhibitor treatments.
• Identification of putative candidate genes using transcriptomic data.
• Functional analysis of the stilbene synthase promoter in heterologous systems (Arabidopsis).

Main Results:

• Transcriptomic analysis identified potential candidates for the stilbene pathway's missing CoA ligase and regulatory elements.
• The stilbene pathway genes are transcriptionally activated by UV-C, translational inhibitors, phosphatase inhibitors, ethylene, and jasmonate.
• The Scots pine stilbene synthase promoter shows inducibility in Arabidopsis, suggesting conserved and species-specific regulatory mechanisms.

Conclusions:

• The study elucidates key genetic components controlling stilbene biosynthesis in Scots pine.
• Conserved regulatory pathways and species-specific regulators likely govern stilbene production across different plant species.
• Understanding these genetic controls is essential for breeding Scots pine varieties with improved resistance to wood decay fungi.