Structure and Expression Analysis of , , , , and Gene Families in Torr. and Gray.

Exogenous nitrogen and carbon can affect plant cell walls, which are composed of structural carbon. Sucrose synthase (SUS), invertase (INV), hexokinase (HXK), phosphoglucomutase (PGM), and UDP-glucose pyrophosphorylase (UGP) are the key enzymes of sucrose metabolism involved in cell wall synthesis. To understand whether these genes are regulated by carbon and nitrogen to participate in structural carbon biosynthesis, we performed genome-wide identification, analyzed their expression patterns under different carbon and nitrogen treatments, and conducted preliminary functional verification. Different concentrations of nitrogen and carbon were applied to poplar ( Torr. and Gray), which caused changes in cellulose, lignin, and hemicellulose contents. In poplar, 6 s, 20 s, 6 s, 4 s, and 2 s were identified. Moreover, the physicochemical properties, collinearity, and tissue specificity were analyzed. The correlation analysis showed that the expression levels of /, ////, , , /, /, and were positively correlated with the cellulose content. Meanwhile, the knockout of significantly reduced the cellulose content. This study could lay the foundation for revealing the functions of s, s, s, , and s, which affected structural carbon synthesis regulated by nitrogen and carbon, proving that is involved in cell wall synthesis.