Compositions and methods for suppressing the shade-avoidance response of
plants and improving plant yield are provided. Compositions of the
invention include an early flowering 3 (ELF3) maize gene, the promoter
for this gene, an Arabidopsis basic helix-loop-helix transcription factor
(bHLH-041), and fragments and variants thereof. The ELF3 promoter
sequence is useful for driving expression of polynucleotides of interest
in a plant. The ELF3 and bHLH-041 sequences of the invention, or variants
and fragments thereof, are provided in expression cassettes for use in
manipulating expression of the ELF3 and bHLH-041 genes. By increasing
expression of ELF3 and/or suppressing expression of bHLH-041, the methods
of the invention provide for altered response of a plant to light quality
and suppression of the high-density-invoked survival mode of development.
The invention thus provides methods for growing crop plants at high
population densities for yield enhancement. Transformed plants having the
altered shade-avoidance phenotype of the invention, and seeds of said
plants, are also provided.