Transformation of the Solanum tuberosum with Saccharomyces cerevisiae Gene Suc2 Encoding Cell- Wall Invertase Influences on Sugars Distribution in Plants

Invertase is the key enzyme of carbohydrate metabolism, which catalyzes the sucrose hydrolysis. In this study, we investigated a functional role of the apoplastic invertase (cell-wall invertase) on sugars distribution in vegetative organs and cell compartments of potato plants in vitro.
Our study was carried out with potato (S. tuberosum L., cv. Désirée) plants and the line which expressed the suc2 gene of S. cerevisiae under control of the tuberspecific patatin B33-promoter of class I with an N-end-connected potato proteinase II inhibitor signal peptide, which provides apoplastic localization of yeast invertase. The suc2 gene expression were shown using RT-PCR. The results of Ds-Na-PAGE of apoplast proteins from leaves and MALDI-TOF MS analysis indicate the presence of the yeast invertase in the apoplastic space of the transgenic potato plants. The content of fructose and sucrose was determined according to Roe. The glucose content was determined by the glucose oxidase method.
The integrated target suc2 gene encodes the invertase of yeast with an N-endconnected potato proteinase II inhibitor signal peptide, which provides apoplastic localization of foreign invertase.
Transformation of potato plants resulted in accumulation of fructose in the apoplast, sucrose and glucose in the leaves, and especially, glucose in roots and microtubers. It is indicative of regulatory function of cell-wall invertase that could be found some application in medical, biological and pharmaceutical engineering.