A multi-omics approach reveals functions of Secretory Carrier-Associated Membrane Proteins in wood formation of Populus trees

Secretory Carrier-Associated Membrane Proteins (SCAMPs) are highly conserved proteins that are involved in membrane trafficking. An integrated approach was taken to elucidate function of SCAMPs in wood formation of Populus trees. The metabolomics analyses were performed in woody tissues of transgenic Populus trees carrying an RNAi construct for Populus tremula x tremuloides SCAMP3 (PttSCAMP3; Potri.019G104000). The secondary xylem of the transgenic trees displayed increases in the amounts of polysaccharide derived sugars as well as lignin oligomers, indicating increased deposition of both carbohydrate and lignin polymers in the secondary cell walls. Somewhat surprisingly, the transgenic lines showed significantly increased amounts of suberic acid in the secondary xylem tissues. Populus SCAMP proteins were shown to influence accumulation of secondary cell wall components including polysaccharides, polyphenolics, lipids and suberin in the woody tissues of Populus tree stems.