Inorganic pyrophosphate content and metabolites in potato and tobacco plants expressing E. coli pyrophosphatase in their cytosol |
| |
Authors: | Till Jelitto Uwe Sonnewald Lothar Willmitzer Mohammad Hajirezeai Mark Stitt |
| |
Institution: | (1) Lehrstuhl für Pflanzenphysiologie, Universität Bayreuth, W-8580 Bayreuth, Federal Republic of Germany;(2) Institut für genbiologische Forschung Berlin GmbH, Ihnestrasse 63, 33 Berlin, Federal Republic of Germany;(3) Botanisches Institut, Im Neuenheimer Feld 360, W-6900 Heidelberg, Federal Republic of Germany |
| |
Abstract: | Metabolite levels and carbohydrates were investigated in the leaves of tobacco (Nicotiana tabacum L.) and leaves and tubers of potato (Solanum tuberosum L.) plants which had been transformed with pyrophosphatase from Escherichia coli. In tobacco the leaves contained two- to threefold less pyrophosphate than controls and showed a large increase in UDP-glucose, relative to hexose phosphate. There was a large accumulation of sucrose, hexoses and starch, but the soluble sugars increased more than starch. Growth of the stem and roots was inhibited and starch, sucrose and hexoses accumulated. In potato, the leaves contained two- to threefold less pyrophosphate and an increased UDP-glucose/ hexose-phosphate ratio. Sucrose increased and starch decreased. The plants produced a larger number of smaller tubers which contained more sucrose and less starch. The tubers contained threefold higher UDP-glucose, threefold lower hexose-phosphates, glycerate-3-phosphate and phosphoenolpyruvate, and up to sixfold more fructose-2,6-bisphosphatase than the wild-type tubers. It is concluded that removal of pyrophosphate from the cytosol inhibits plant growth. It is discussed how these results provide evidence that sucrose mobilisation via sucrose synthase provides one key site at which pyrophosphate is needed for plant growth, but is certainly not the only site at which pyrophosphate plays a crucial role.Abbreviations Fru2,6bisP
fructose-2,6-bisphosphate
- Fru6P
fructose 6-phosphate
- FW
fresh weight
- Glc1P
glucose-1-phosphate
- Glc6P
glucose-6-phosphate
- PEP
phosphoenolpyruvate
- 3PGA
glycerate-3-phosphate
- PFK
phosphofructokinase
- PFP
pyrophosphate: fructose-6-phosphate phosphotransferase
- Pi
inorganic phosphate
- PPi
inorganic pyrophosphate
- UDPGlc
UDP-glucose
This research was supported by the Deutsche Forschungsgemein-Schaft (SFB 137) and Sandoz AG (T.J., M.H., M.S.) and by the Bundesminister für Forschung und Technologie (U.S., L.W.). |
| |
Keywords: | Inorganic pyrophosphate Nicotiana Sinksource Solanum Sucrose metabolism Transgenic plants |
本文献已被 SpringerLink 等数据库收录! |
|