The effects of reduced and oxidized glutathione on white spruce somatic embryogenesis
The glutathione-glutathione disulfide redox pair was utilized to improve white spurce somatic embryo development. Mature cotyledonary-stage somatic embryos were divided into two groups (A and B) based on morphological normality and the ability of the mature somatic embryos to convert into plantlets. Group A embryos had four or more cotyledons and converted readily upon germination after a partial drying treatment. Group B embryos had three or fewer cotyledons with a low conversion frequency. The addition of reduced glutathione (GSH) at a concentration of 0.1 mM resulted in an increase in embryo production (total population) with a mean total number of 64 embryos per 100 mg embryogenic tissue as well as an increase in post-embryonic root growth. However, at a higher concentration (1 mM), GSH inhibited embryo formation. The manipulation of the tissue culture environment via the inclusion of glutathione disulfide (GSSG), at concentrations of 0.1 and 1.0 mM, enhanced the development of better-quality embryos. This quality was best exemplified when embryos forming four or more cotyledons increased by at least twofold to 73.9% when treated with 1.0 mM GSSG, compared to 38% in control. Furthermore, this improved quality was reflected by an increased conversion frequency. A 20% increase in the ability of the somatic embryo to produce both root and shoot structures during post-embryonic development was noted when embryos were matured on maturation medium supplemented with 1.0 mM GSSG over the control.
Key wordswhite spruce somatic embryogenesis reduced glutathione glutathione disulfide
Unable to display preview. Download preview PDF.
- Belmonte, M.; Stasolla, C.; Loukanina, N.; Yeung, E. C.; Thorpe, T. A. Glutathione modulation of purine metabolism in cultured white spruce embryogenic tissue. Plant Science (in press); 2003.Google Scholar
- Grossnickle, S. C. Ecophysiology of northern spurce species: the performance of planted seedlings. Ottawa: NRC Research Press; 2000.Google Scholar
- Hakman, I.; Fowke, L. C. Somatic embryogenesis in Picca glauca (white spruce) and Picea mariana (black spruce). Can. J. Bot. 65:656–659; 1987.Google Scholar
- Kong, L.; Attree, S. M.; Evans, D. E.; Binarova, P.; Yeung, E. C.; Fowke, L. C. Somatic embryogenesis in white spruce: studies of embryo development and cell biology. In: Jain, S. M.; Gupta, P. K.; Newton, B. J., eds. Somatic embryogenesis in woody plants vol. 4. Dordrecht: Kluwer Academic Publishers; 1999:1–28.Google Scholar
- Kong, L.; Yeung, E. C. Development of white spruce somatic embryos: II. Continual shoot meristem development during germination. In Vitro Cell. Dev. Biol. Plant 28:125–131; 1992.Google Scholar
- Lu, C.-Y.; Thorpe, T. A. Somatic embryogenesis and plantlet regeneration in cultured immature embryos of Picea glauca. J. Plant Physiol. 128:297–302; 1987.Google Scholar
- Roberts, D. R.; Sutton, B. C. S.; Flinn, B. S. Synchronous and high frequency germination of interior spruce somatic embryos following partial drying at high relative humidity. Can. J. Bot. 68:1086–1090; 1990.Google Scholar
- Sanchez-Fernandez, R.; Fricker, M.; Corben, L. B.; White, N. S.; Sheard, N.; Leaver, C. J.; Van Montagu, M.; Inze, D.; May, M. J. Cell proliferation and hair tip growth in the Arabidopsis root are under mechanistically different forms of redox control. Proc. Natl Acad. Sci. USA 94:2745–2750; 1997.PubMedCrossRefGoogle Scholar
- Stasolla, C.; Yeung, E. C. Ascorbic acid improves conversion of white spruce somatic embryos. In Vitro Cell. Dev. Biol. Plant 35:316–319; 1999.Google Scholar
- Vernoux, T.; Wilson, R. C.; Seeley, K. A.; Reichheld, P.-P.; Muroy, S.; Brown, S.; Maughan, S. C.; Cebbott, C. S.; Van Montagu, M.; Inze, D.; May, M. J.; Sung, Z. R. The ROOT MERISTEMLESS/CADMIUM SENSITIVE2 gene defines a glutathione-dependent pathway involved in initiation and maintenance of cell division during postembryonic root development. Plant Cell 12:97–109; 2000.PubMedCrossRefGoogle Scholar
- Yeung, E. C. Structural and developmental patterns in somatic embryogenesis. In: Thorpe, T. A., ed. In vitro embryogenesis in plants. Dordrecht: Kluwer Academic Publishers; 1995:205–247.Google Scholar
- Yeung, E. C.; Stasolla, C. Somatic embryogenesis—apical meristems and embryo conversion. Korean. J. Plant Tiss. Cult. 27:299–307; 2000.Google Scholar