Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1988 Nov;88(3):838–844. doi: 10.1104/pp.88.3.838

A Starchless Mutant of Nicotiana sylvestris Containing a Modified Plastid Phosphoglucomutase

Kenneth R Hanson 1, Neil A McHale 1
PMCID: PMC1055671  PMID: 16666394

Abstract

A mutant (NS 458) of Nicotiana sylvestris (Spegazzini and Comes) unable to synthesize leaf starch was isolated in the M2 generation following ethyl methanesulfonate mutagenesis by testing with iodine. Segregation ratios in reciprocal F2 progenies showed that the starchless phenotype resulted from a recessive mutation in a single nuclear gene. DEAE-agarose chromatography showed that the mutant is grossly deficient in plastid phosphoglucomutase (EC 2.1.5.1) activity. The structure of the enzyme is changed, as evidenced by increased Michaelis constants and by the prolonged activation period (>40 minutes) observed when the enzyme is assayed in triethanolamine buffer rather than imidazole buffer. The activity of the wild-type enzyme with saturating glucose 6-P alone was 7% of the activity when saturating glucose 1,6-P2 was also present. The results suggest that glucose 1,6-P2 is both an effector and a dissociable reaction intermediate. The growth rate of mutant and wild-type plants were not significantly different in continuous light and on an 8-hour dark, 16-hour light cycle and the mutants grew normally under greenhouse conditions. The mutant supports growth during diurnal periods of darkness by vacuolar storage of sugars instead of chloroplast storage of starch. The simplification in metabolism achieved by blocking the diversion of plastid fructose-6-P to starch facilitates the induction of oscillations in CO2 fixation.

Full text

PDF
838

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Caspar T., Huber S. C., Somerville C. Alterations in Growth, Photosynthesis, and Respiration in a Starchless Mutant of Arabidopsis thaliana (L.) Deficient in Chloroplast Phosphoglucomutase Activity. Plant Physiol. 1985 Sep;79(1):11–17. doi: 10.1104/pp.79.1.11. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Daugherty J. P., Kraemer W. F., Joshi J. G. Purification and properties of phosphoglucomutase from Fleischmann's yeast. Eur J Biochem. 1975 Sep 1;57(1):115–126. doi: 10.1111/j.1432-1033.1975.tb02282.x. [DOI] [PubMed] [Google Scholar]
  3. Galloway C. M., Dugger W. M., Black C. C. In vitro activation of phosphoglucomutase by fructose 2,6-bisphosphate. Plant Physiol. 1985 Nov;79(3):920–922. doi: 10.1104/pp.79.3.920. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Gerhardt R., Stitt M., Heldt H. W. Subcellular Metabolite Levels in Spinach Leaves : Regulation of Sucrose Synthesis during Diurnal Alterations in Photosynthetic Partitioning. Plant Physiol. 1987 Feb;83(2):399–407. doi: 10.1104/pp.83.2.399. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hanabusa K., Dougherty H. W., Del Río C., Hashimoto T., Handler P. Phosphoglucomutase. II. Preparation and properties of phosphoglucomutases from Micrococcuus lysodeikticus and Bacillus cereus. J Biol Chem. 1966 Sep 10;241(17):3930–3939. [PubMed] [Google Scholar]
  6. Hanson K. R., Ling R., Havir E. A computer program for fitting data to the Michaelis-Menten equation. Biochem Biophys Res Commun. 1967 Oct 26;29(2):194–197. doi: 10.1016/0006-291x(67)90586-4. [DOI] [PubMed] [Google Scholar]
  7. Jones T. W., Gottlieb L. D., Pichersky E. Reduced enzyme activity and starch level in an induced mutant of chloroplast phosphoglucose isomerase. Plant Physiol. 1986 Jun;81(2):367–371. doi: 10.1104/pp.81.2.367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Lin T. P., Caspar T., Somerville C., Preiss J. Isolation and Characterization of a Starchless Mutant of Arabidopsis thaliana (L.) Heynh Lacking ADPglucose Pyrophosphorylase Activity. Plant Physiol. 1988 Apr;86(4):1131–1135. doi: 10.1104/pp.86.4.1131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Lin Z., Konno M., Abad-Zapatero C., Wierenga R., Murthy M. R., Ray W. J., Jr, Rossmann M. G. The structure of rabbit muscle phosphoglucomutase at intermediate resolution. J Biol Chem. 1986 Jan 5;261(1):264–274. [PubMed] [Google Scholar]
  10. RAY W. J., Jr, ROSCELLI G. A. A KINETIC STUDY OF THE PHOSPHOGLUCOMUTASE PATHWAY. J Biol Chem. 1964 Apr;239:1228–1236. [PubMed] [Google Scholar]
  11. Ray W. J., Jr, Hermodson M. A., Puvathingal J. M., Mahoney W. C. The complete amino acid sequence of rabbit muscle phosphoglucomutase. J Biol Chem. 1983 Aug 10;258(15):9166–9174. [PubMed] [Google Scholar]
  12. Redgwell R. J. Fractionation of plant extracts using ion-exchange Sephadex. Anal Biochem. 1980 Sep 1;107(1):44–50. doi: 10.1016/0003-2697(80)90489-3. [DOI] [PubMed] [Google Scholar]
  13. Weeden N. F., Gottlieb L. D. Dissociation, reassociation, and purification of plastid and cytosolic phosphoglucose isomerase isozymes. Plant Physiol. 1982 Mar;69(3):717–723. doi: 10.1104/pp.69.3.717. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES