The PmRDUF1-PmMYB30-PmLAS Regulatory Module Is Involved in Terpenoid Biosynthesis of Pinus massoniana

Area of Science:

• Plant Molecular Biology
• Biochemistry
• Forestry Science

Background:

• Masson pine (Pinus massoniana L.) resin is economically important, containing diterpenoid resin acids.
• The regulation of key genes in diterpene biosynthesis, such as PmLAS, is not well understood.

Purpose of the Study:

• To identify and characterize transcription factors regulating PmLAS gene expression.
• To elucidate the molecular mechanisms controlling diterpenoid biosynthesis in masson pine.

Main Methods:

• Yeast one-hybrid and two-hybrid screening for protein interactions.
• Dual-luciferase reporter assays for transcriptional activation and suppression.
• Subcellular localization and heterologous expression in tobacco.

Main Results:

• Three PmMYB transcription factors (PmMYB30, PmMYB68, PmMYB74) were identified that activate PmLAS expression.
• These PmMYBs are nuclear-localized and their C-terminal regions mediate transcriptional activation.
• PmMYB transcript levels positively correlate with resin yield.
• Heterologous expression in tobacco increased diterpenoids and glandular trichomes.
• PmRDUF1, a RING-type E3 ubiquitin ligase, interacts with PmMYB30 and suppresses PmLAS activation, forming a regulatory module.

Conclusions:

• A complex transcriptional network involving PmMYBs and PmRDUF1 regulates diterpenoid biosynthesis in masson pine.
• This study provides new insights into the regulation of terpenoid metabolism in plants.