Planta

, Volume 188, Issue 2, pp 238–244

Inorganic pyrophosphate content and metabolites in potato and tobacco plants expressing E. coli pyrophosphatase in their cytosol

  • Till Jelitto
  • Uwe Sonnewald
  • Lothar Willmitzer
  • Mohammad Hajirezeai
  • Mark Stitt
Article

DOI: 10.1007/BF00216819

Cite this article as:
Jelitto, T., Sonnewald, U., Willmitzer, L. et al. Planta (1992) 188: 238. doi:10.1007/BF00216819

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.

Key words

Inorganic pyrophosphateNicotianaSinksourceSolanumSucrose metabolismTransgenic plants

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

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Till Jelitto
    • 1
  • Uwe Sonnewald
    • 2
  • Lothar Willmitzer
    • 2
  • Mohammad Hajirezeai
    • 1
  • Mark Stitt
    • 3
  1. 1.Lehrstuhl für Pflanzenphysiologie, Universität BayreuthBayreuthFederal Republic of Germany
  2. 2.Institut für genbiologische Forschung Berlin GmbHBerlinFederal Republic of Germany
  3. 3.Botanisches InstitutHeidelbergFederal Republic of Germany