TMT-based comparative proteomic analysis reveals regulatory pathways and protein targets associated with resin biosynthesis in Pinus massoniana

Oleoresin is a natural product widely used in industry and plays an important role in the conifer defense system as a natural anti-insect and anti-pathogen substance. As an important resin resource tree species, masson pine (Pinus massoniana) has high commercial value. Resin yield is an important economic trait of masson pine and varies in different clones. In order to evaluate the biosynthesis mechanism of oleoresin in masson pine, a Tandem Mass Tag (TMT)-based quantitative proteomics analysis was applied to observe the proteome profile changes in masson pine secondary xylem with high (H), medium (M), and low (L) resin-yielding capacities (RYCs). A total of 3,745 proteins were identified and quantified in three groups, 507 of which were differentially expressed proteins (DEPs). Most up-regulated proteins were enriched in H vs. L and H vs. M. KEGG enrichment analysis showed that these DEPs were involved in multiple biological pathways, with a particular enrichment of those participating in biosynthesis of secondary metabolism, metabolic pathways, ABC transporter, plant-pathogen interaction, and brassinosteroid (BR) biosynthesis. Using the integrated proteome and transcriptome data to elucidate proteomic profile changes in masson pines, we identified a series of DEPs related to resin biosynthesis, including cytochrome P450, Leucine-rich repeat (LRR) protein, pathogenesis-related (PR) protein, ABC transporter, and chitinase. Our study provides a comprehensive proteomic analysis to aid in understanding the molecular mechanisms involved in resin generation, representing a potential tool for genetic improvement of masson pine.