Haustorium

Haustorium

In botany, a "haustorium" (plural "haustoria") is the hyphal tip of a parasitic fungus or of the root of a parasitic plant (such as in the broomrape family), that penetrates the host's tissue, but stays outside the host cell membrane.Fungi in all major divisions form haustoria. Haustoria take several forms. Generally, on penetration, the fungus increases the surface area in contact with host plasma membrane releasing enzymes that break down the cell wall, enabling greater potential movement of organic carbon from host to fungus.

Haustoria arise from intercellular hyphae, appressoria, or external hyphae. The hypha narrows as it passes through the wall of the cell and then expands on invaginating the cell. A thickened, electron-dense collar of material is deposited around the hypha at the point of invagination. Further, the host wall becomes highly modified in the invaginated zone. Inclusions normally present in plasma membrane are absent, and the outer layer contains more polysaccharide. The wall of both partners is severely reduced.

Functional exchange takes place within the haustorial complex. The host supplies organic carbon to the fungus, and the metabolic activity within the complex is considerably greater than outside. Carbon from the host is absorbed by the fungus, and immediately transported to the rest of the thallus. The host plant appears to be functioning according to signals from the fungus and the complex appears to be under the control of the invader. [ [http://bugs.bio.usyd.edu.au/Mycology/StructureFunction/haustoria.shtml Mycology - Structure and Function - Haustoria ] ]

The haustorium may be balloon, spiral, or glove shaped.

References


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  • Haustorium — Haus*to ri*um (h[add]s*t[=o] r[i^]*[u^]m), n.; pl. {Haustoria} (h[add]s*t[=o] r[i^]*[.a]). [LL., a well, fr. L. haurire, haustum, to drink.] (Bot.) One of the suckerlike rootlets of such plants as the dodder and ivy. R. Brown. [1913 Webster] …   The Collaborative International Dictionary of English

  • haustorium — haustorium. См. гаустория. (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.

  • Haustorĭum — (Saugwarze, Ansauger, Bot.), ein warzenförmiges Höckerchen, das eigentlich eine verkümmerte Wurzelfaser ist, vermittelst deren sich der Stängel, wie z.B. bei der Flachsseide auf anderen Gewächsen anheftet u. ansaugt …   Pierer's Universal-Lexikon

  • Haustorium — Haustorium, der Aufnahme von Wasser und Nährstoffen dienendes Saugorgan von Pflanzen. a) Fuß des Sporogons bei Bryophyten. b) Bei Cormophyten dient der Suspensor dem Embryo als H. c) Bei Parasiten: Die sich in Interzellularen des Wirts… …   Deutsch wörterbuch der biologie

  • haustorium — [hôs tôr′ē əm] n. pl. haustoria [hôs tôr′ēə] [ModL < L haustus: see HAUSTELLUM] a rootlike outgrowth in certain parasitic plants, through which food is absorbed from the host haustorial [hôs tôr′ēəl] adj …   English World dictionary

  • Haustorium — Cuscute. Un haustorium est un organe d une plante ou d un champignon parasite, qui s insère dans les tissus de la plante hôte, pour absorber l eau et les nutriments contenus dans les cellules. On emploie aussi le terme de suçoir. Haustorium est… …   Wikipédia en Français

  • Haustorium — Hyaloperonospora parasitica: Hyphen und Haustorien …   Deutsch Wikipedia

  • haustorium — haustorial, adj. /haw stawr ee euhm, stohr /, n., pl. haustoria /haw stawr ee euh, stohr /. 1. a projection from the hypha of a fungus into the organic matter from which it absorbs nutrients. 2. the penetrating feeding organ of certain parasites …   Universalium

  • Haustorium — Haus|to|ri|um 〈n.; s, ri|en; Bot.〉 Saugorgan parasitisch lebender Pflanzen [zu lat. haurire „schöpfen, ausleeren, verzehren“] * * * Haustorium   [lateinisch] das, s/...ri |en, pflanzliches ein oder mehrzelliges Saugorgan, das der Ernährung dient …   Universal-Lexikon

  • haustorium — noun (plural haustoria) Etymology: New Latin, from Latin haurire Date: 1875 a food absorbing outgrowth of a plant organ (as a hypha or stem) …   New Collegiate Dictionary

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