EXPRESSION CONSTRUCT， PLANT CELL， PLANT SEED， OR METHOD FOR PROMOTING A STATE， A METHOD FOR EXPRESSING A POLYPEPTIDE OF RKD

Methods and compositions are provided to increase the activity/level of an RKD polypeptide or an active variant or fragment thereof in an unreduced ovule plant cell that is outside of the embryo sac. In specific embodiments， such modulation of activity/level of the RKD polypeptide promotes an egg cell-like state in an unreduced ovule plant cell that is outside of the embryo sac. Such methods and compositions can employ an expression construct comprising a RKD polypeptide or active variant or fragment thereof operably linked to an ovule tissue-preferred promoter， in particular an ovule tissue-preferred promoter that is active in at least one non-gametophyte tissue in a plant ovule and is active in an unreduced cell that is outside of the embryo sac. Methods and compositions are provided to increase the activity/level of an RKD polypeptide or an active variant or fragment thereof in an unreduced ovule plant cell that is outside of the embryo sac. In specific embodiments， such modulation of activity/level of the RKD polypeptide promotes an egg cell-like state in an unreduced ovule plant cell that is outside of the embryo sac. Such methods and compositions can employ an expression construct comprising a RKD polypeptide or active variant or fragment thereof operably linked to an ovule tissue-preferred promoter， in particular an ovule tissue-preferred promoter that is active in at least one non-gametophyte tissue in a plant ovule and is active in an unreduced cell that is outside of the embryo sac.