Decreased amount of reducing sugars in transgenic potato tubers and its influence on yield characteristics

Abstract

This work focuses on the comparison of field characteristics and amounts of reducing sugars in cold-stored tubers of transgenic plants derived from two potato cultivars. The bacterial gene coding for phosphofructokinase under the tuberspecific promoter was used to support the glycolysis in stored tubers. While the tubers from untransformed control plants steadily accumulated reducing sugars during cold storage, the tubers from transformed plants regardless the genotype were characterized by subsequent decrease in the sugar content. After long period of cold storage the greatest reduction in the reducing sugar content was by more than 60 % compared to control. Before the storage, however, the content of reducing sugars was in 80 % of transgenic lines higher than in control ones. The plants evaluated in field trials for their appearance showed any changes in growth characteristics in about 25 % of the transgenic lines. Despite the introduced modification of sugar metabolism the yield of transgenic plants with normal appearance did not differ significantly from the yield of control plants.

Recent Advances in Molecular Improvement for Potato Tuber Traits

“…Scientists have successfully decreased the activity of StvacINV1 by adding two putative inhibitors ( StInvInh2A and StInvInh2B ) to the potato genome, which resulted in reduced accumulation of reducing sugars and acrylamide in cold-stored tubers and thus the CIS [ 78 , 79 ]. Sugar metabolism was significantly modified by inserting bacterial genes encoding phosphofructokinase to decrease CIS, and this addition did not hinder any growth process of the plant [ 80 ].…”

Transgene coding of a key enzyme of the glycolytic pathway helps to decrease sugar content in potato tubers

“…starch synthesis, starch breakdown, glycolysis, hexogenesis and respiration. We decided to solve this problem by an introduction of cold-stable 6-phosphofructokinase from the bacterium Lactobacillus bulgaricus (Navrátil et al 2007). …”

“…Recently we have introduced the Lbpfk gene, the sequence of which was modified to improve its translation, into several Czech potato cultivars (Navrátil et al 2007). The transgenic lines were confirmed by PCR analysis.…”

“…Statistical significance of relative reducing sugar concentrations were calculated using one-paired one-sided Student's t-test at the 5% significance level. We estimated the copy number of the transgene among the C70/2 lines using RT- Previous experiments with two Czech potato varieties Kamyk and Korela and with the original unmodified bacterial gene showed an influence of the transgene on the reducing sugar content in cold-stored tubers (Navrátil et al 2007). For subsequent experiments we modified the transgene in such a way that the gene translation into active protein would be supported.…”