The regulation of phenylalanine metabolism is important, especially in
conifers, a long-lived species that use large amounts of carbon in wood. In
this study, María Belén Pascual from Universitario de Teatinos in Spain
studied the maritime pine (Pinus pinaster) transcription factor PpNAC1, and
found that it is a main regulator of phenylalanine production.
PpNAC1 was found to be expressed in the secondary xylem and compression wood
of adult maritime pine trees. Silencing of PpNAC1 in P. pinaster resulted in
the alteration of the stem vascular pattern and the downregulation of
several genes associated with cell wall synthesis. Further analysis revealed
that PpNAC1 is able to activate its own expression as well as the PpMyb4
promoter, while the PpMyb4 protein activates the PpMyb8 gene, a regulator of
phenylalanine and lignin synthesis in maritime pine.
Knowledge of the mechanisms of controlling wood formation is of great
importance in tree biology and paves the way for biotechnology applications