Effects of drought on water content and photosynthetic parameters in potato plants expressing the trehalose-6-phosphate synthase gene of Saccharomyces cerevisiae

Abstract

Two transgenic potato lines, T1 and T2, expressing the trehalose-6-phosphate synthase (TPS1) gene of yeast were isolated. In our experimental approach, we applied two novelties, namely the fusion of the drought-inducible promoter StDS2 to TPS1 and a marker-free transformation method. In contrast to the expected drought-induced expression, only a very low constitutive TPS1 expression was detected in the transgenic lines, probably due to chromosomal position effects. The observed expression pattern, however, was sufficient to alter the drought response of plants. Detached leaves of T1 and T2 showed an 8 h delay in wilting compared to the non-transformed control. Potted plants of T1 and T2 kept water 6 days longer than control plants and maintained high stomatal conductance and a satisfactory rate of net photosynthesis. During drought treatment, CO2 assimilation rate measured at saturating CO2 level was maintained at maximum level for 6-9 days in transgenic plants while it decreased rapidly after 3 days in the wild type plants. Under optimal growth conditions, lower CO2 fixation was detected in the transgenic than in the control plants. Stomatal densities of T1 and T2 leaves were reduced by 30-40%. This may have contributed to the lower CO2 fixation rate and altered drought response.

Expression of StMYB1R-1, a Novel Potato Single MYB-Like Domain Transcription Factor, Increases Drought Tolerance

“…Despite this, there are a few reports in the literature of molecular engineering to improve or manipulate stress tolerance in potato plants (Stiller et al, 2008;Tang et al, 2008). A limited number of single MYB-like domain TFs have been identified in plants (Penfield and Hall, 2009).…”

“…Therefore, water availability is an important factor in increasing tuber formation and potato crop yields. Several studies in potato were done to overcome crop yield loss under environmental stress conditions through genetic and molecular biological approaches (Jeong et al, 2001;Schafleitner et al, 2007;Stiller et al, 2008;Evers et al, 2010). Recently, drought-related elements in potato are profiled through a combined transcriptomic and targeted metabolite approach (Vasquez-Robinet et al, 2008;Evers et al, 2010).…”

A Tale of Two Sugars: Trehalose 6-Phosphate and Sucrose

“…More targeted interventions have generally been more successful strategies; these include (1) limiting expression to specific subcellular compartments or tissues, (2) use of endogenous plant genes, and (3) placing the introduced genes under the control of stressinducible promoters (Garg, et al, 2002;Lee et al, 2003;Avonce et al, 2004;Miranda, et al, 2007;Stiller et al, 2008;Li et al, 2011;Kondrák et al, 2012). However, in most cases the enhanced stress tolerance did not appear to be linked to increased trehalose accumulation.…”

photosynthesis in the 7H Asakaze komugi/Manas wheat/barley addition line during salt stress

“…To date, various approaches have been used to produce stress-tolerant plants (Stiller et al, 2008). In the case of wheat these include chromosome-mediated gene transfer from stress-tolerant donor species to wheat.…”