PLANT STEAROYL-ACP THIOESTERASE SEQUENCES AND METHODS TO INCREASE STEARATE CONTENT IN PLANT SEED OILS

摘要

This invention relates to plant thioesterases, specifically plant acyl-ACP thioesterases having significant activity on stearoyl-ACP. DNA constructs useful for the expression of a plant stearoyl-ACP thioesterase in a plant seed cell are described. Such constructs will contain a DNA sequence encoding the plant stearoyl-ACP thioesterase of interest under the control of regulatory elements capable of preferentially directing the expression of the plant stearoyl-ACP thioesterase in seed tissue, as compared with other plant tissues, when such a construct is expressed in a transgenic plant. This invention also relates to methods of using a DNA sequence encoding a plant stearoyl-ACP thioesterase for the modification of the stearate produced in a plant seed cell. A plant thioesterase having significant activity on stearoyl-ACP exemplified herein is from mangosteen. Modified stearate concentration may be obtained by expression of mangosteen thioesterase alone or in combination with antisense constructs for reduction of native stearoyl-ACP desaturase in plant seeds.