:"This article discusses protoplasts in the biological sense. For the theological use, see Adam and Eve"

Protoplast, from the ancient Greek "πρῶτον" (first) + verb "πλάθω" or "πλάττω" (to mould: deriv. "plastic"), initially referred to the first organized body of a species. This meaning is similar to the non-biological definition, the first from which all subsequent forms are derived.

Subsequently it has several biological definitions:

*A protoplast is a plant, bacterial or fungal cell that had its cell wall completely or partially removed using either mechanical or enzymatic means.
**Protoplasts - Have their cell wall entirely removed
**Spheroplasts - Have their cell wall only partially removed

*More generally "protoplast" refers to that unit of biology which is composed of a cell's nucleus and the surrounding protoplasmic materials.

Enzymes for the preparation of protoplasts

Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes:During and subsequent digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress. This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent rupture of the plasma membrane.

Uses for protoplasts

Protoplast can be used to study membrane biology, including the uptake of macromolecules and viruses.

Protoplasts are widely used for DNA transformation (for making genetically modified organisms), since the cell wall would otherwise block the passage of DNA into the cell. Protoplasts may be regenerated into whole plants first by growing into a group of plant cells that develops into a callus and then by regeneration of shoots (caulogenesis) from the callus using plant tissue culture methods. Growth of protoplasts into callus and regeneration of shoots requires the proper balance of plant growth regulators in the tissue culture medium that must be customized for each species of plant.

Protoplasts may also be used for plant breeding, using a technique called protoplast fusion. Protoplasts from different species are induced to fuse by using an electric field or a solution of polyethylene glycol. This technique may be used to generate somatic hybrids in tissue culture.

Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • protoplast — PROTOPLÁST, protoplaste, s.n. (biol.) (Parte din) protoplasmă. – Din fr. protoplaste. Trimis de oprocopiuc, 23.04.2004. Sursa: DEX 98  protoplást s. n., pl. protopláste Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  PROTOPLÁST …   Dicționar Român

  • Protoplast — Pro to*plast, n. [L. protoplastus the first man, Gr. ? formed or created first; ? first + ? formed, fr. ? to form.] [1913 Webster] 1. The thing first formed; that of which there are subsequent copies or reproductions; the original. [1913 Webster] …   The Collaborative International Dictionary of English

  • protoplast — protoplast. См. протопласт. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • protoplast — index prototype Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • Protoplast — Protoplast, 1) lebender Zellleib; außen von einer selektiv permeablen Membran (Plasmamembran, Plasmalemma), bei Pflanzen außerdem von einer Zellwand umgeben; er besteht bei Eucyten aus Zellkern und Cytoplasma und entspricht dem Protoplasma; 2)… …   Deutsch wörterbuch der biologie

  • protoplast — [prōt′ə plast΄] n. [Fr protoplaste < LL protoplastus < Gr protoplastos, formed first < protos, first (see PROTO ) + plastos, formed < plassein, to form: see PLASTIC] 1. a thing or being that is the first of its kind 2. Biol. ENERGID 3 …   English World dictionary

  • Protoplast — Protoplasten von Blattzellen der Petunie (Petunia sp.) Als Protoplast bezeichnet man bei mit Zellwänden versehenen Zellen die kleinste selbstständig lebensfähige morphologische Einheit, d. h. den plasmatischen Inhalt einer Zelle. Daher gibt es… …   Deutsch Wikipedia

  • protoplast — protoplastas statusas T sritis augalininkystė apibrėžtis Ląstelės turinys be sienelės. atitikmenys: angl. protoplast rus. протопласт …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • protoplast fusion — protoplast fusion. См. слияние протопластов. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • protoplast — noun Etymology: Middle French protoplaste, from Late Latin protoplastus first human, from Greek prōtoplastos first formed, from prōt prot + plastos formed, from plassein to mold more at plaster Date: 1532 1. one that is formed first ; prototype 2 …   New Collegiate Dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”