Described herein are compositions, including RNAi and / or
CRISPR constructs, for modifying one or more Flowering Locus T (FT) genes in a
plant and methods of using the compositions for producing plants having suppressed or delayed
flowering time. In some embodiments, the
plant is a
Saccharum plant. The approach used herein involves methods for decreasing expression of one or more Flowering Locus T (FT) genes by RNAi inhibition or
CRISPR / Cas9 targeted
mutagenesis that results in suppressed or delayed flowering in
Saccharum plants, such as sugarcane or energycane. Target genes were isolated from the sugarcane and energycane
cultivar and a
conserved sequence between these cultivars and closely related species was chosen to design
intron-hairpin
RNA constructs for RNAi suppression or sgRNA expression constructs for targeted
mutagenesis.
Recombinant DNA vectors were introduced into sugarcane by biolistic
gene transfer and transgenic plants were regenerated and selected, vegetatively propagated for replicated field testing. These genetically modified plants produce significantly elevated
biomass and recoverable
sugar yield under replicated
field conditions relative to a similar plant in which the FT4, FT8, and / or FT10
gene have not been disrupted, when grown under the same conditions.