Methods and compositions using a site-specific integration system are
combined with methods and compositions which deliver compositions via
microinjection directly to the embryo sac of a plant. The methods allow
for various components of the site-specific recombination system to be
introduced into the cellular environment of the embryo sac a composition
comprising at least one component of the site-specific recombination
system is injected into an embryo sac, providing improved efficiency of
expression, recombination, integration, exchange, excision and/or
inversion of a polynucleotide of interest. The polynucleotide of interest
may be stably integrated into the genome of the egg cell, zygote, embryo,
or endosperm, and tissues, plant parts, and/or plants produced therefrom.
Cells, egg cells, zygotes, embryos, endosperm, tissues, seeds, and/or
plants produced by the methods and comprising the polynucleotide(s) of
interest are also provided.