this invention concerns methods for synthesis and accumulation of fructose polymers in seed , tubers or leaves of transgenic plants by selective expression of a bacterial fructosyltransferase gene . selective expression includes coordination of timing , tissue specific expression and especially subcellular location . successful transformants utilize sucrose to synthesize and accumulate fructan in the vacuole of the cell , in established crops , without loss of co - products or concern for yield loss due to degradation during maturation , harvest or storage of the plant . enhanced fructan production will benefit the fructose sweetener industry and add value to grain used for feed .