Sporopollenin

Sporopollenin

Sporopollenin is a major component of the tough outer (exine) walls of spores and pollen grains. It is chemically very stable and is usually well preserved in soils and sediments. The exine layer is often intricately sculptured in species-specific patterns (see image at right), allowing material recovered from (for example) lake sediments to provide useful information to palynologists about plant and fungal populations in the past.

The chemical composition of sporopollenin is not exactly known, due to its unusual chemical stability and resistance to degradation by enzymes and strong chemical reagents. Analyses have revealed a mixture of biopolymers, containing mainly long chain fatty acids, phenylpropanoids, phenolics and traces of carotenoids. Tracer experiments have shown that phenylalanine is a major precursor, but other carbon sources also contribute. It is likely that sporopollenin derives from several precursors that are chemically cross-linked to form a rigid structure.

Electron microscopy shows that the tapetal cells that surround the developing pollen grain in the anther have a highly active secretory system containing lipophilic globules. These globules are believed to contain sporopollenin precursors. Chemical inhibitors of pollen development and many male sterile mutants have effects on the secretion of these globules by the tapetal cells.

References

Boavida LC, Becker JD, & Feijó JA. (2005) "The making of gametes in higher plants." Int. J. Dev. Biol. 49: 595-614. [http://www.ijdb.ehu.es/web/contents.php?vol=49&issue=5-6&doi=052019lb]

Guilford WJ, Schneider DM, Labovitz J, Opella SJ (1988) "High-Resolution Solid-State C-13 NMR-Spectroscopy of Sporopollenins from Different Plant Taxa." Plant Physiology 86 (1): 134-136. [http://cel.isiknowledge.com/CIW.cgi?&CustomersID=Highwire&Func=Links&PointOfEntry=FullRecord&PublisherID=Highwire&ServiceName=TransferToWos&ServiceUser=Links&UT=A1988L852100029&e=U8R5mlEjT02j7gb4pil6vrULDsc15PCW1cGaQ7MMJcljD5gPNH4RjeCvV32YW7yZ]


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  • Sporopollenin —   [zu Sporen und lateinisch pollen »Mehlstaub«] das, s, verwitterungsbeständiger Hauptbestandteil (Terpene) der Zellwand pflanzlicher Sporen und Pollenkörner; ermöglicht die Pollenanalyse. * * * Spo|ro|pol|le|nin [ʃp..., sp...], das; s [zu lat.… …   Universal-Lexikon

  • sporopollenin — noun Etymology: International Scientific Vocabulary spor + pollen + 1 in Date: 1931 a relatively chemically inert polymer that makes up the outer layer of pollen grains and some spores …   New Collegiate Dictionary

  • sporopollenin — Polymer of carotenoids, found in the exine of the pollen wall. Extremely resistant to chemical or enzymic degradation …   Dictionary of molecular biology

  • sporopollenin — spo·ro·pol·len·in (spôr ə pŏlʹə nĭn, spōr ) n. A polymer that constitutes the outer wall of spores and pollen grains. * * * …   Universalium

  • Sporopollenin — Spo|ro|pol|le|nin das; s <zu lat. pollen »Mehlstaub« u. ↑...in> verwitterungsbeständiger Hauptbestandteil der Zellwand pflanzlicher Sporen u. Pollenkörner, der die Pollenanalyse ermöglicht (Biol.) …   Das große Fremdwörterbuch

  • sporopollenin — spo·ro·pol·len·in …   English syllables

  • sporopollenin — ˌspōrəˈpälənə̇n, ˌspȯr noun ( s) Etymology: International Scientific Vocabulary spor + pollen + in : a relatively chemically inert polymer that makes up the outer layer of pollen grains and spores …   Useful english dictionary

  • Blütenpollen — Pollenkörner mit unterschiedlichen Oberflächen von unterschiedlichen Pflanzen: Lilium auratum mit monocolpaten Pollenkörnern; die anderen haben tricolpate Pollenkörner: Sonnenblume (Helianthus annuus), Prunkwind …   Deutsch Wikipedia

  • Blütenstaub — Pollenkörner mit unterschiedlichen Oberflächen von unterschiedlichen Pflanzen: Lilium auratum mit monocolpaten Pollenkörnern; die anderen haben tricolpate Pollenkörner: Sonnenblume (Helianthus annuus), Prunkwind …   Deutsch Wikipedia

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