| 翻訳と辞書 |
| Druse (botany) ： ウィキペディア英語版 |
Druse (botany)
A druse is a group of crystals of calcium oxalate,〔Franceschi VR, Nakata PA (2005) Calcium oxalate in plants: formation and function. Annu Rev Plant Biol. 56:41-71.〕 silicates, or carbonates present in plants. Calcium oxalate (Ca(COO)2, CaOx) crystals are found in algae, angiosperms and gymnosperms in a total of more than 215 families. These plants accumulate oxalate in the range of 3%-80% (w/w) of their dry weight 〔Zindler-Frank E (1976) Oxalate biosynthesis in relation to photosynthetic pathways and plant productivity: a survey. Z Pflanzenphysiol. 80:1-13.〕〔Libert B, Franceschi VR (1987) Oxalate in crop plants. J Agric Food Chem. 35:926-938.〕 through a biomineralization process in a variety of shapes.〔McNair JB (1932)The interrelations between substances in plants: essential oils and resins, cyanogen and oxalate. Am J Bot. 19:255-271.〕 ''Araceae'' have numerous druses, multi-crystal druses and needle-shaped raphide crystals of CaOx present in the tissue.〔Prychid CJ, Jabaily RS, Rudall PJ (2008) Cellular ultrastructure and crystal development in Amorphophallus (Araceae). Ann Bot (Lond). 101(7):983-995.〕 Druses are also found in leaves and bud scales of ''Prunus'', ''Roses'',〔Lersten NR, Horner HT (2006) Crystal macropattern development in Prunus serotina (Rosaceae, Prunoideae) leaves. Ann Bot (Lond). 97(5):723-729.〕 Allium, ''Vitis'', ''Morus'' and ''Phaseolus''.〔Jáuregui-Zúñiga D, Reyes-Grajeda JP, Sepúlveda-Sánchez JD, Whitaker JR, Moreno A (2003) Crystallochemical characterization of calcium oxalate crystals isolated from seed coats of Phaseolus vulgaris and leaves of Vitis vinifera. J Plant Physiol. 160(3):239-245.〕〔Katayama H, Fujibayashi Y, Nagaoka S, Sugimura Y (2007) Cell wall sheath surrounding calcium oxalate crystals in mulberry idioblasts. Protoplasma. 231(3-4):245-248.〕 The poisonous substances in druses are thought to be a defense against herbivory.
== How druses are formed ==
A number of biochemical pathways for calcium oxalate biomineralization in plants have been proposed. Among these are the cleavage of isocitrate, the hydrolysis of oxaloacetate, glycolate/glyoxylate oxidation, and/or oxidative cleavage of L-ascorbic acid.〔Hodgkinson A (1977) Oxalic acid metabolism in higher plants. In A Hodgkinson, ed, Oxalic Acid Biology and Medicine. Academic Press, New York, pp 131-158.〕 The cleavage of ascorbic acid appears to be the most studied pathway.〔Yang J, Loewus FA (1975) Metabolic conversion of L-ascorbic acid in oxalate-accumulating plants. Plant Physiol. 56:283-285.〕〔Nuss RF, Loewus FA (1978) Further studies on oxalic acid biosynthesis in oxalate-accumulating plants. Plant Physiol. 61:590-592.〕〔Li XX, Franceschi VR (1990) Distribution of peroxisomes and glycolate metabolism in relation to calcium oxalate formation in Lemna minor L. Eur J Cell Biol. 51:9-16.〕〔Keates SA, Tarlyn N, Loewus FA, Franceschi VR (2000) L-Ascorbic acid and L-galactose are sources of oxalic acid and calcium oxalate in Pistia stratiotes. Phytochemistry. 53:433-440.〕 The specific mechanism controlling this process is unclear but it has been suggested that a number of factors influence crystal shape and growth, such as proteins, polysaccharides, and lipids or macromolecular membrane structures.〔Horner HT, Wagner BL (1980) The association of druse crystals with the developing stomium of Capsicum annuum (Solanaceae) anthers. Am J Bot. 67:1347-1360.〕〔Arnott HJ, Webb MA (1983) Twin crystals of calcium oxalate in the seed coat of the kidney bean. Protoplasma. 114:23-34.〕〔Webb MA (1999) Cell-mediated crystallization of calcium oxalate in plants. Plant Cell. 11:751-761.〕 Druses may also have some purpose in calcium regulation.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Druse (botany)」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|