Particular aspects provide six novel Ricinus communis cDNA clones,
including cloned sequences of: DGAT (RcDGAT1 and RcDGAT2); RcLPAT; LACS
(RcLACS4), and PDAT (RcPDAT1A and RcPDAT1B). Additional aspects provide
methods for substantially enhanced accumulation of hydroxy fatty acid
(HFA) in transgenic plant tissue (e.g., seeds), comprising expression of
particular novel sequences. For example, expression of RcDGAT2 or RcPDAT1
in castor hydroxylase-expressing Arabidopsis lines resulted in
substantially enhanced accumulation of hydroxy fatty acid (HFA) (e.g., to
over 30%; a 50-70% increase in HFA accumulation) relative to the
hydroxylase-only expressing parental lines. Further aspects provide
methods to increase at least one of total lipid content, percent seed
germination, and seed weight in transgenic plants, comprising expression
of RcDGAT2 in castor hydroxylase-expressing plant lines. Yet further
aspects provide methods for expressing and accumulating hydroxyl fatty
acid in yeast (e.g., TAG biosynthesis from diricinolein), comprising
expression of RcDGAT2 RcDGAT2 coding sequences in yeast.