Disclosed herein are antisense DNA of a sweetpotato expansin (IbExpansin)
cDNA, a plant transformation vector carrying the same, and a method for
increasing storage root production using the same. The transgenic
sweetpotatoes prepared using the antisense DNA of IbExpansin cDNA have
storage root production increased by up to one and half times. Thus, the
gene is useful in the generation of highly productive transgenic storage
roots for the increase of bioethanol production.