PL EN


Preferences help
enabled [disable] Abstract
Number of results
Journal
2009 | 58 | 1-2 | 211-220
Article title

Drogi rozkładu skrobi w roślinach

Content
Title variants
EN
Starch degradation pathways in plants
Languages of publication
PL EN
Abstracts
EN
Starch is the main storage material in higher plants. It is accumulated both in chloroplasts (transitory starch) and in non-photosynthetic tissues (storage starch), in the form of starch granules composed of amylose and amylopectin. Transitory starch accumulated during the day is almost completely degraded at night, when it serves as the main source of energy for the cell metabolism. The biochemical pathway of starch degradation in chloroplasts has been fully characterized only in Arabidopsis thaliana. This process can be divided into two steps: the release of soluble glucans from the granule by α-amylase and further degradation of these glucans by β-amylase and de-branching enzymes. The main product of this degradation pathway is β-maltose, which is afterwards metabolized in the cytosol. The degradation of transitory starch is a periodic process, regulated by the circadian clock, starch phosphorylation and enzyme activity. Storage starch is accumulated for longer periods of time in non-photosynthetic parts of the plant such as cereal and legume seeds, roots, tubers or rhizomes. In these organs the enzymatic reactions, which lead to storage starch degradation and their regulation are different than in the case of transitory starch, and they vary significantly between species. An interesting pathway of starch degradation control, unknown in other species, has been discovered in the duckweed Spirodela polyrhiza. At the end of the vegetative season this water plant forms turions - resting fronds which sink to the bottom of ponds and lakes, and germinate when conditions become favorable. Turions contain starch as a storage material which helps them survive the period of dormancy and, during germination, provide energy for growth of new fronds. Both germination of turions and starch degradation are induced by light and controlled by phytochrome B. The germination response to light is mediated by a low fluence response (LFR), whereas starch degradation can be controlled by a red light-dependent low fluence response or a far red-dependent high irradiance response (HIR). The processes of germination and starch degradation, although independently controlled, are closely connected. Response to a starch degradation-inducing signal is possible only under condition that germination is sufficiently advanced and the new sprout is ready to receive the degradation products. If this is not the case the light-induced signal can be stored until the sprout is formed.
Keywords
Journal
Year
Volume
58
Issue
1-2
Pages
211-220
Physical description
Dates
published
2009
Contributors
  • Zakład Biochemii i Fizjologii Roślin, Wydział Biochemii, Biofizyki i Biotechnologii, Uniwersytet Jagielloński, Gronostajowa 7, 30-387 Kraków, Polska
References
  • Appenroth K.-J., Bergfeld R., 1993. Photophysiology of turion germination in Spirodela polyrhiza (L.) Schleiden. XI. Structural changes during red light induced responses. Plant Physiol. 141, 583-588.
  • Appenroth K.-J., Gabryś H., 2001. Light-induced starch degradation in non-dormant turions of Spirodela polyrhiza. Photochem. Photobiol. 73, 77-82.
  • Appenroth K.-J., Teller S., Horn M., 1996. Photophysiology of turion formation and germination in Spirodela polyrhiza. Biologia Plantarum 38, 95-106.
  • Dölger K., Tirlapur U. K., Appenroth K.-J., 1997. Phytochrome-regulated starch degradation in germinating turions of Spirodela polyrhiza. Photochem. Photobiol. 66, 124-127.
  • Lu Y., Gehan J. P., Sharkey T. D., 2005. Daylength and circadian effects on starch degradation and maltose metabolism. Plant Physiol. 138, 2280-2291.
  • Kopcewicz J., Lewak S., 2005. Fizjologia roślin. Wydawnictwo Naukowe PWN, Warszawa.
  • McManus M., Plaxton W., 2006. Control of primary metabolism in plants. Ann. Plant Rev. 22, 266-269
  • Reinmann R., Hippler M., Machelett B., Appenroth K.-J., 2004. Light induces phosphorylation of glucan water dikinase, which precedes starch degradation in turions of the duckweed Spirodela polyrhiza. Plant Physiol. 135, 121-128.
  • Reinmann R., Ritte G., Steup M., Appenroth K.-J, 2002. Association of α-amylase and the R1 protein with starch granules precedes the initiation of net starch degradation in turions of Spirodela polyrhiza. Physiologia Plantarum 114, 2-12.
  • Samojedny D., Orzechowski S., 2007. Nowe spojrzenie na proces degradacji ziaren skrobi w chloroplastach Arabidopsis thaliana L. Postępy Biochemii 53, 74-83.
  • Smith A. M., Zeeman S. C., Smith S. M., 2005. Starch degradation. Ann. Rev. Plant Biol. 56, 73-98.
  • Szweykowska A., Szweykowski J., 2007. Botanika. Wydawnictwo Naukowe PWN, Warszawa.
  • Taiz L., Zeiger E., 2006. Plant Physiology. Sinauer Associates, Inc.
  • Tetlow I. J., Morell M. K., Emes M. J., 2004. Recent developments in understanding the regulation of starch metabolism in higher plants. J. Exp. Botan. 55, 2131-2145.
Document Type
Publication order reference
Identifiers
YADDA identifier
bwmeta1.element.bwnjournal-article-ksv58p211kz
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.