Provided herein are compositions and methods for producing transgenic
plants. In specific embodiments, transgenic plants comprise a construct
comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked
to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is
ectopically overexpressed in the transgenic plants, and wherein the
promoter is optionally a constitutive or inducible promoter. In other
embodiments, transgenic plants in which express a lower level of CCA1,
GLK1 or bZIP1 are provided. Also provided herein are commercial products
(e.g., pulp, paper, paper products, or lumber) derived from the
transgenic plants (e.g., transgenic trees) produced using the methods
provided herein.