Nectar: Difference between revisions
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[[Image:Nectar.jpg|thumb|250px|Nectar of camellia]] |
[[Image:Nectar.jpg|thumb|250px|Nectar of camellia]] |
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[[Image:Australian painted lady feeding closeup.jpg|thumb|250px|An [[Australian painted lady]] feeding on a flower's nectar]] |
[[Image:Australian painted lady feeding closeup.jpg|thumb|250px|An [[Australian painted lady]] feeding on a flower's nectar]] |
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'''Nectar''' is a [[sugar]]-rich liquid produced by plants. It is produced either by the [[flower]]s, in which it attracts [[pollination|pollinating]] animals, or by '''extrafloral nectaries''', which provide a nutrient source to animal [[Mutualism (biology)|mutualists]] providing [[plant defense against herbivory#Indirect defenses|anti-herbivore protection]]. It is produced in glands called '''nectaries'''. Common nectar-consuming [[pollinator]]s include [[bee]]s, [[butterfly|butterflies]] and [[moth]]s, [[hummingbird]]s and [[Bat#Fruits and flower nectar|bats]]. |
'''Nectar''' is a [[sugar]]-rich liquid produced by plants. It is produced either by the [[flower]]s, in which it attracts [[pollination|pollinating]] animals, or by '''extrafloral nectaries''', which provide a nutrient source to animal [[Mutualism (biology)|mutualists]] providing [[plant defense against herbivory#Indirect defenses|anti-herbivore protection]]. It is produced in glands called '''nectaries'''. Common nectar-consuming [[pollinator]]s include [[bee]]s, [[butterfly|butterflies]] and [[moth]]s, [[hummingbird]]s and [[Bat#Fruits and flower nectar|bats]] Nectar is also a synonym for something being good or cool. |
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Nectar is an ecologically important item, the sugar source for [[honey]]. It is also useful in [[agriculture]] and [[horticulture]] because the adult stages of some predatory insects feed on nectar.<!-- Examples, please -->{{Examples needed|date=June 2010}} |
Nectar is an ecologically important item, the sugar source for [[honey]]. It is also useful in [[agriculture]] and [[horticulture]] because the adult stages of some predatory insects feed on nectar.<!-- Examples, please -->{{Examples needed|date=June 2010}} |
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Revision as of 21:25, 4 October 2011
Nectar is a sugar-rich liquid produced by plants. It is produced either by the flowers, in which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists providing anti-herbivore protection. It is produced in glands called nectaries. Common nectar-consuming pollinators include bees, butterflies and moths, hummingbirds and bats Nectar is also a synonym for something being good or cool.
Nectar is an ecologically important item, the sugar source for honey. It is also useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar.[example needed]
Nectar secretion increases as the flower is visited by pollinators . After pollination, the nectar is frequently reabsorbed into the plant.[1]
Etymology
Nectar is derived from Latin nectar, the favored drink of the gods, which in turn is the Latinized version of Greek νέκταρ, néktar, presumed to be a compound of the PIE roots *nek-, "death", and -*tar, "overcoming", i.e. has a similar etymology to ambrosia, the immortality-conferring food of the gods. The earliest recorded use of its current meaning, "sweet liquid in flowers," is 1609 C.E.[2]
Floral nectaries
Floral nectaries are generally located at the base of the perianth, so that pollinators are made to brush the flower's reproductive structures, the anthers and pistil, while accessing the nectar.
Extrafloral nectaries
Nectar produced outside the flower is generally made to attract predatory insects. These predatory insects will eat both the nectar and any plant-eating insects around, thus functioning as 'bodyguards'.[3] Extrafloral nectaries are generally located on the leaf petioles, mid-rib or leaf margin. They are thought to be modified trichomes and exude nectar from phloem sap. Extrafloral nectaries can be found on species belonging to (amongst others) the genera Salix, Prunus and Gossypium. In many carnivorous plants, nectar serves to attract insect prey.[4]
Natural components of nectar
Although its main ingredient is natural sugar (i.e., sucrose (table sugar), glucose, and fructose),[5] nectar is a brew of many chemicals. For example, the Nicotiana attenuata, a tobacco plant native to the US state of Utah, uses several volatile aromas to attract pollinating birds and moths. The strongest such aroma is benzyl acetone, but the plant also adds bitter nicotine, which is less aromatic and therefore may not be detected by the bird until after taking a drink. Researchers speculate the purpose of this addition is to drive the bird away after only a sip, motivating it to visit other plants to fill its hunger, and therefore maximizing the pollination efficiency gained by the plant for a minimum nectar output.[6] Neurotoxins such as aesculin are present in some nectars such as that of the California Buckeye.[7] All twenty of the normal amino acids found in protein have been identified in various nectars, with alanine, arginine, serine, proline, glycine, isoleucine, threonine, and valine being the most prevalent.[1]
See also
References
- ^ a b Nectar - Amino Acids Robert Thornburg, 04/06/01 , Iowa state University. Accessed April 2011
- ^ Douglas Harper. "Online Etymology Dictionary". Retrieved 2007-09-26.
- ^ Plant-Provided Food for Carnivorous Insects - Cambridge University Press
- ^ Merbach, M. 2001. Nectaries in Nepenthes. In: C.M. Clarke Nepenthes of Sumatra and Peninsular Malaysia. Natural History Publications (Borneo), Kota Kinabalu.
- ^ Nicolson, Susan W.; Nepi, Massimo; Pacini, Ettore (Eds.), "Nectaries and Nectars", Springer Publications, 2007 p.9)
- ^ Chemical & Engineering News, Vol. 86 No. 35, 1 Sept. 2008, "Two-Faced Flowers", p. 11
- ^ C.Michael Hogan (2008) Aesculus californica, Globaltwitcher.com, ed. N. Stromberg
Bibliography
- Burquez, A. and Corbet, S.A. (1991) Do flowers reabsorb nectar? Funct. Ecol. 5:369-379.
- Smith, L.L., Lanza, J. and Smith, G.C. (1990) Amino acid concentrations in extrafloral nectar of Impatiens sultani increase after simulated herbivory. Ecol. Publ. Ecol. Soc. Am. 71:107-115.
- Baker, H.G. and Baker, I. (1981) Chemical constituents of nectar in relation to pollination mechanisms and phylogeny. In Biochemical aspects of evolutionary biology. 131-171.
- Roshchina, V.V. and Roshchina, V.D. (1993) The excretory function of higher plants. Springer-Verlag, Berlin.
- Esau, K. (1977) Anatomy of seed plants. John Wiley & Sons, New York.
- Frey-Wyssling, A. (1955) The phloem supply to the nectaries. Acta Bot. Neerl. 4:358-369.
- Baker, H.G. and Baker, I. (1973) Amino acids in nectar and their evolutionary significance. Nature 241:543-545.
- Baker, H.G. and Baker, I. (1975) Studies of nectar-constitution and pollinator-plant coevolution. In Coevolution of animals and plants. Gilbert, L.E. and Raven, P.H. ed. Univ. of Texas Press, Austin, 100-140.
- Ecroyd, C.E., Franich, R.A., Kroese, H.W. and Steward, D. (1995) Volatile constituents of Dactylanthus taylorii flower nectar in relation to flower pollination and browsing by animals. Phytochemistry 40:1387-1389.
- Deinzer, M.L.,tomson p.m, Burgett, D.M. and Isaacson, D.L. (1977) Pyrrolizidine alkaloids: Their occurrence in honey from tansy ragwort (Senecio jacobaea L.). Science 195:497-499.
- Rodriguez-Arce, A.L. and Diaz, N. (1992) The stability of beta-carotene in mango nectar. J. Agric. Univ. P.R. Rio Piedras, P.R.76:101-102.
- Griebel, C. and Hess, G. (1940) The vitamin C content of flower nectar of certain Labiatae. Zeit. Untersuch. Lebensmitt. 79:168-171.
- Ferreres, F., Andrade, P., Gil, M.I. and Tomas Barberan, F.A. (1996) Floral nectar phenolics as biochemical markers for the botanical origin of heather honey. Zeitschrift fur Lebensmittel Untersuchung und Forschung. 202:40-44.
- Vogel, S. (1969) Flowers offering fatty oil instead of nectar. Abstracts XIth Internatl. Bot. Congr. Seattle.
- Heinrich, G. (1989) Analysis of cations in nectars by means of a laser microprobe mass analyser (LAMMA). Beitr. Biol. Pflanz64:293-308.
- Beutler, R. (1935) Nectar. Bee World 24:106-116, 128-136, 156-162.
- Scala, J., Iott, K., Schwab, W. and Semersky, F.E. (1969) Digestive secretion of Dionaea muscipula (Venus's-Flytrap). Plant Physiol. 44:367-371.
- Heslop-Harrison, Y. and Knox, R.B. (1971) A cytochemical study of the leaf-gland enzymes of insectivorus plants of the genusPinguicula. Planta 96:183-211.
- Peumans, W.J., Smeets, K., Van Nerum, K., Van Leuven, F. and Van Damme, E.J.M. (1997) Lectin and alliinase are the predominant proteins in nectar from leek (Allium porrum L.) flowers. Planta 201:298-302.
- Carter, C., Graham, R. and Thornburg, R.W. (1999) Nectarin I is a novel, soluble germin-like protein expressed in the nectar of Nicotiana sp. Plant Mol. Biol. 41:207-216.