Establishing glucosylglycerol synthesis in potato (Solanum tuberosum l. cv. Albatros) by expression of the ggpPS gene from Azotobacter vinelandii

Abstract

Plants and bacteria synthesize compatible solutes to adapt towards various environmental stress conditions. Moderate halotolerant cyanobacteria and some heterotrophic bacteria accumulate the compatible solute glucosylglycerol (GG), a compound not commonly found in higher plants. We aimed to investigate whether GG can be produced in potato and if it has an improving effect regarding stress tolerance. Potato plants were transformed with the ggpPS gene of Azotobacter vinelandii, which codes the bifunctional enzyme GG-phosphate phosphate/synthase (GgpPS) catalyzing the two-step synthesis of GG. Potato plants were generated expressing ggpPS under control of the constitutive CaMV-35S promoter or the stress-inducible rd29A promoter. The integration of T-DNA in transgenic clones was verified by PCR and transgene expression was detected on mRNA level. Transgenic potatoes with constitutive ggpPS expression accumulated GG up to 19 µmol/g fresh mass (FM) in leaves but no GG in tubers, while plants with rd29A-controlled ggpPS expression contained 10 µmol GG/g FM in leaves and up to 2.6 µmol GG/g FM in tubers. In greenhouse experiments, an increased shoot growth of the GG-accumulating potato plants was observed under salt and drought stress conditions. These results demonstrate that GG synthesis can be achieved in potato plants and might have a protective role on plant metabolism.

Faster Removal of 2-Phosphoglycolate through Photorespiration Improves Abiotic Stress Tolerance of Arabidopsis

“…Starch contents were measured enzymatically as described previously [39] from~50 mg of leaf tissue harvested at EoD (9 h illumination) from at least four biological replicates per genotype. The soluble fraction of the extraction procedure was further subjected to gas chromatography (GC) analysis to quantify sucrose, glucose and fructose as described previously [40]. Amino acids and organic acids were essentially quantified on a high-performance liquid chromatograph mass spectrometer LCMS-8050 system (Shimadzu, Japan) as described recently [41] from 50 mg leaf-tissue harvested at the end of the day (9 h of illumination).…”

Mitochondrial Dihydrolipoyl Dehydrogenase Activity Shapes Photosynthesis and Photorespiration of Arabidopsis thaliana

“…Leaf material was harvested from fully expanded rosette leaves using at least five biological replicates (growth stage 5.1 according to Boyes et al [2001]), immediately frozen in liquid nitrogen, and stored at 280°C until analysis. For gas chromatography analysis of organic acids and soluble sugars (;100 mg leaf tissue), we followed the method described by Sievers et al (2013). Absolute amino acid contents were determined from ;100 mg leaf material by HPCL as described previously (Hagemann et al, 2005).…”

Salt Acclimation of Cyanobacteria and Their Application in Biotechnology

“…It also could be expressed in the model plant Arabidopsis, where it also improved the growth on salt media [ 132 ]. Genes for GG biosynthesis were also transferred into Arabidopsis [ 133 ] and later into potato [ 134 ], which slightly improved the salt tolerance of the transgenic plants. In addition to genes for compatible solutes, those for general stress proteins might also be useful.…”