Druse (botany) explained

A druse is a group of crystals of calcium oxalate,[1] silicates, or carbonates present in plants, and are thought to be a defense against herbivory due to their toxicity. Calcium oxalate (Ca(COO)2, CaOx) crystals are found in algae, angiosperms and gymnosperms in more than 215 families. These plants accumulate oxalate in the range of 3–80% (w/w) of their dry weight[2] [3] through a biomineralization process in a variety of shapes.[4] Araceae have numerous druses, multi-crystal druses and needle-shaped raphide crystals of CaOx present in the tissue.[5] Druses are also found in leaves and bud scales of Prunus, Rosa,[6] Allium, Vitis, Morus and Phaseolus.[7] [8]

Formation

A number of biochemical pathways for calcium oxalate biomineralization in plants have been proposed. Among these is the cleavage of isocitrate, the hydrolysis of oxaloacetate, glycolate/glyoxylate oxidation, and/or oxidative cleavage of L-ascorbic acid.[9] The cleavage of ascorbic acid appears to be the most studied pathway.[10] [11] [12] [13] The specific mechanism controlling this process is unclear. Still, it has been suggested that a number of factors influence crystal shapes and growth, such as proteins, polysaccharides, and lipids or macromolecular membrane structures.[14] [15] [16] Druses may also have some purpose in calcium regulation.

See also

Notes and References

  1. Franceschi VR, Nakata PA. 2005. Calcium oxalate in plants: formation and function. Annu Rev Plant Biol. 56. 41–71. 15862089. 10.1146/annurev.arplant.56.032604.144106.
  2. Zindler-Frank E.. 1976. Oxalate biosynthesis in relation to photosynthetic pathways and plant productivity: a survey. Z. Pflanzenphysiol. . 80. 1. 1–13. 10.1016/S0044-328X(76)80044-X.
  3. Libert B, Franceschi VR. 1987. Oxalate in crop plants. J Agric Food Chem. 35. 6. 926–938. 10.1021/jf00078a019.
  4. McNair JB. 1932. The interrelation between substances in plants: essential oils and resins, cyanogen and oxalate. Am J Bot. 19. 3. 255–271. 10.2307/2436337. 2436337.
  5. Prychid CJ, Jabaily RS, Rudall PJ . 2008. Cellular ultrastructure and crystal development in Amorphophallus (Araceae). Ann. Bot.. 101. 7. 983–995. 10.1093/aob/mcn022. 18285357. 2710233 .
  6. Lersten NR, Horner HT. 2006. Crystal macropattern development in Prunus serotina (Rosaceae, Prunoideae) leaves. Ann. Bot.. 97. 5. 723–729. 2803424. 16513655. 10.1093/aob/mcl036.
  7. 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. 12749080. 10.1078/0176-1617-00947. 2003JPPhy.160..239J .
  8. 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. 17922267. 10.1007/s00709-007-0263-x. 29944485.
  9. Book: Hodgkinson A. 1977. Oxalic acid metabolism in higher plants. A Hodgkinson. Oxalic Acid Biology and Medicine. FEBS Letters. 101. 2. Academic Press. New York. 131–158. 9780123517500. 10.1016/0014-5793(79)81066-2.
  10. Yang J, Loewus FA. 1975. Metabolic conversion of L-ascorbic acid in oxalate-accumulating plants. Plant Physiol. 56. 2. 283–285. 16659288. 541805. 10.1104/pp.56.2.283.
  11. Nuss RF, Loewus FA. 1978. Further studies on oxalic acid biosynthesis in oxalate-accumulating plants. Plant Physiol. 61. 4. 590–592. 1091923. 16660342. 10.1104/pp.61.4.590.
  12. 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. 1. 9–16. 2184039.
  13. 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. 4. 433–440. 10731019. 10.1016/S0031-9422(99)00448-3. 2000PChem..53..433K .
  14. Horner HT, Wagner BL. 1980. The association of druse crystals with the developing stomium of Capsicum annuum (Solanaceae) anthers. Am J Bot. 67. 9. 1347–1360. 10.2307/2442137. 2442137.
  15. Arnott HJ, Webb MA. 1983. Twin crystals of calcium oxalate in the seed coat of the kidney bean. Protoplasma. 114. 1. 23–34. 10.1007/BF01279865. 180834.
  16. Webb MA. 1999. Cell-mediated crystallization of calcium oxalate in plants. Plant Cell. 11. 4. 751–761. 144206. 10213791. 10.1105/tpc.11.4.751.

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