Cluster roots, also known as proteoid roots, are plantroots that form clusters of closely spaced short lateral rootlets. They may form a two- to five-centimetre-thick mat just beneath the leaf litter. They enhance nutrient uptake, possibly by chemically modifying the soil environment to improve nutrient solubilisation.[1] As a result, plants with proteoid roots can grow in soil that is very low in nutrients, such as the phosphorus-deficient native soils of Australia.
Proteoid roots of Leucospermum cordifolium
They were first described by Adolf Engler in 1894, after he discovered them on plants of the family Proteaceae growing in Leipzig Botanic Gardens. In 1960, Helen Purnell examined 44 species from ten Proteaceae genera, finding proteoid roots in every genus except Persoonia; she then coined the name "proteoid roots" in reference to the plant family in which it was known to occur.[2] Proteoid roots are now known to occur in 27 different Proteaceae genera, plus around 30 species from other families, including Betulaceae, Casuarinaceae, Eleagnaceae, Leguminosae, Moraceae and Myricaceae. Similar structures also occur in species of Cyperaceae and Restionaceae, but their physiology is yet to be studied.[3]
Two forms are recognised: simple cluster roots form rootlets only along a root; compound cluster roots form the primary rootlets, and also form secondary rootlets on the primary rootlets.
Some Proteaceae, such as Banksia and Grevillea, are valued by the horticulture and floriculture industries. In cultivation, only slow-release low-phosphorus fertilizers should be used, as higher levels cause phosphorus toxicity and sometimes iron deficiency, leading to plant death. Crop management should minimise root disturbance, and weed control should be via slashing or contact herbicides.
Many plants with proteoid roots have economic value. Cultivated crops with proteoid roots include Lupinus[4] and Macadamia.
Referencesedit
^Grierson, P.F. and P. M. Attiwill (1989). "Chemical characteristics of the proteoid root mat of Banksia integrifolia L. [sic]". Australian Journal of Botany. 37 (2): 137–143. doi:10.1071/BT9890137.
^Purnell, Helen M. (1960). "Studies of the family Proteaceae: I. Anatomy and morphology of the roots of some Victorian species". Australian Journal of Botany. 8 (1): 38–50. doi:10.1071/BT9600038.
^Watt, Michelle and John R. Evans (1999). "Proteoid roots. Physiology and development" (PDF). Plant Physiology. 121 (2): 317–323. doi:10.1104/pp.121.2.317. PMC1539228. PMID 10517822. Retrieved 2006-11-07.
^P.J. Hocking and S. Jeffery (2004). "Cluster-root production and organic anion exudation in a group of old-world lupins and a new-world lupin". Plant and Soil. 258 (1): 135–150. Bibcode:2004PlSoi.258..135H. doi:10.1023/B:PLSO.0000016544.18563.86. S2CID 25635666.
5. Lambers, H. & Poot, P. (eds) 2003. Structure and Functioning of Cluster Roots and Plant Responses to Phosphate Deficiency. Kluwer Academic Publishers, Dordrecht.
7. Lambers, H., Shane, M.W., Cramer, M.D., Pearse, S.J., & Veneklaas, E.J. 2006. Root structure and functioning for efficient acquisition of phosphorus: matching morphological and physiological traits. Ann. Bot. 98: 693–713. http://aob.oxfordjournals.org/cgi/content/abstract/98/4/693
January 01, 1970
cluster, root, also, known, proteoid, roots, plant, roots, that, form, clusters, closely, spaced, short, lateral, rootlets, they, form, five, centimetre, thick, just, beneath, leaf, litter, they, enhance, nutrient, uptake, possibly, chemically, modifying, soil. Cluster roots also known as proteoid roots are plant roots that form clusters of closely spaced short lateral rootlets They may form a two to five centimetre thick mat just beneath the leaf litter They enhance nutrient uptake possibly by chemically modifying the soil environment to improve nutrient solubilisation 1 As a result plants with proteoid roots can grow in soil that is very low in nutrients such as the phosphorus deficient native soils of Australia Proteoid roots of Leucospermum cordifolium They were first described by Adolf Engler in 1894 after he discovered them on plants of the family Proteaceae growing in Leipzig Botanic Gardens In 1960 Helen Purnell examined 44 species from ten Proteaceae genera finding proteoid roots in every genus except Persoonia she then coined the name proteoid roots in reference to the plant family in which it was known to occur 2 Proteoid roots are now known to occur in 27 different Proteaceae genera plus around 30 species from other families including Betulaceae Casuarinaceae Eleagnaceae Leguminosae Moraceae and Myricaceae Similar structures also occur in species of Cyperaceae and Restionaceae but their physiology is yet to be studied 3 Two forms are recognised simple cluster roots form rootlets only along a root compound cluster roots form the primary rootlets and also form secondary rootlets on the primary rootlets Some Proteaceae such as Banksia and Grevillea are valued by the horticulture and floriculture industries In cultivation only slow release low phosphorus fertilizers should be used as higher levels cause phosphorus toxicity and sometimes iron deficiency leading to plant death Crop management should minimise root disturbance and weed control should be via slashing or contact herbicides Many plants with proteoid roots have economic value Cultivated crops with proteoid roots include Lupinus 4 and Macadamia References edit Grierson P F and P M Attiwill 1989 Chemical characteristics of the proteoid root mat of Banksia integrifolia L sic Australian Journal of Botany 37 2 137 143 doi 10 1071 BT9890137 Purnell Helen M 1960 Studies of the family Proteaceae I Anatomy and morphology of the roots of some Victorian species Australian Journal of Botany 8 1 38 50 doi 10 1071 BT9600038 Watt Michelle and John R Evans 1999 Proteoid roots Physiology and development PDF Plant Physiology 121 2 317 323 doi 10 1104 pp 121 2 317 PMC 1539228 PMID 10517822 Retrieved 2006 11 07 P J Hocking and S Jeffery 2004 Cluster root production and organic anion exudation in a group of old world lupins and a new world lupin Plant and Soil 258 1 135 150 Bibcode 2004PlSoi 258 135H doi 10 1023 B PLSO 0000016544 18563 86 S2CID 25635666 5 Lambers H amp Poot P eds 2003 Structure and Functioning of Cluster Roots and Plant Responses to Phosphate Deficiency Kluwer Academic Publishers Dordrecht 6 Shane M W amp Lambers H 2005 Cluster roots A curiosity in context Plant Soil 274 99 123 https doi org 10 1007 2Fs11104 004 2725 77 Lambers H Shane M W Cramer M D Pearse S J amp Veneklaas E J 2006 Root structure and functioning for efficient acquisition of phosphorus matching morphological and physiological traits Ann Bot 98 693 713 http aob oxfordjournals org cgi content abstract 98 4 693 Retrieved from https en wikipedia org w index php title Cluster root amp oldid 1221300261, wikipedia, wiki, book, books, library,
