Poster: Genomics Resources

Abs # 939: Molecular and biochemical characterization of vacuolar invertases from sweet-potato leaves.

Presenter:	Wang, Li-Ting , spinvertase@yahoo.com.tw
Authors	Wang, Li-Ting  (A)   Wang, Ai-Yu  (A)   Sung, Hsien-Yi  (A)
Affiliations:	(A): Department of Agricultural Chemistry, National Taiwan University

Two cDNAs (Ibbfruct2 and Ibbfruct3) encoding invertase (b-D-fructofuranoside fructohydrolase, EC 3.2.1.26) were cloned from leaves of sweet-potato (Ipomoea batatas cv. Tainong 57). The deduced amino acid sequences of the two clones contained typical features of the plant vacuolar invertase, including the b-fructosidase motif and the WECVD catalytic domain, and had 74 and 73% identity with potato vacuolar invertase, respectively. By expression the coding regions of Ibbfruct2 and Ibbfruct3 in Pichia pastoris, recombinant enzymes with acid invertase activity were obtained. Northern analysis showed that Ibbfruct2 is expressed in stems, buds of germinating tuberous roots and other sink tissues, and Ibbfruct3 is specifically expressed in sink leaves. These results suggest that these two genes have different functions during the development of sweet-potato plant.