Poster: Transcription Regulation

Abs # 1040: Expression analysis of two genes for cell wall-bound invertase of sweet potato (Ipomoea batatas Lam.)

Presenter:	Sato, Azusa , unos@agr.kyushu-u.ac.jp
Authors	Sato, Azusa  (A)   Saitou, Kazuyuki  (A)   Fukuda, Kenta  (A)   Nakamura, Kazuyo  (A)   Okubo, Hiroyuki  (A)   Fusayasu, Satoshi  (A)
Affiliations:	(A): Kyushu University

To establish the significance of cell wall-bound invertase in developing of tuberous root of sweet potato, we cloned cDNAs for cell wall-bound invertase, designated IbCIN and IbCIN1, from sweet potato. IbCIN shared 95.6% identity with IbCIN1. IbCIN was expressed in young root and root from tuberous root whereas no expression was observed in developing leaf blade, mature leaf blade, petiole, stolon and tuberous root. IbCIN1 was expressed in tuberous root in addition to young root and root from tuberous root. Expression of IbCIN1 decreased during developing of tuberous root. The level of mRNA for IbCIN was decreased by glucose and mannitol, but was not affected by sucrose. The level of mRNA for IbCIN1 was little affected by sugar treatment. The level of mRNAs for IbCIN and IbCIN1 was elevated by 6-benzylaminopurine. In situ localization of the mRNA revealed that IbCIN1 is expressed preferentially in the phelloderm of tuberous root. These results suggest that IbCIN1 is important for supplying a carbon source to developing tuberous roots by cleaving unloaded sucrose in the apoplast.