BACKGROUND AND AIMS: The anatomical structure and development of adventitious roots were analysed in the basal monocotyledon, Acorus calamus, to determine to what extent those features are related to phylogenetic position. METHODS: Root specimens were harvested and sectioned, either with a hand microtome or freehand, at varying distances from the root tip and examined under the microscope using a variety of staining techniques. KEY RESULTS: Roots of Acorus calamus possess a unique set of developmental characteristics that produce some traits similar to those of another basal angiosperm group, Nymphaeales. The root apical meristem organization seems to be intermediate between that of a closed and an open monocotyledonous root apical meristem organization. The open-type root apical meristem consists of a curved zone of cortical initials and epidermal initials overlying the vascular cylinder initials; the epidermal part of the meristem varies in its association with the cortical initials and columellar initials of the promeristem. The cortex develops an endodermis with only Casparian bands, a dimorphic exodermis with Casparian bands and suberin lamellae, and a polygonal aerenchyma by differential expansion, as also observed in the Nymphaeales and some dicotyledonous species. The stele has characteristics like those of members of the Nymphaeaceae. CONCLUSIONS: Specific anatomical and developmental attributes of Acorus roots seem to be related to the phylogenetic position of this genus.

Department of Plant Physiology Charles University Vinicná 5 Prague 128 44 Czech Republic

Zobrazit více v PubMed

Angiosperm Phylogeny Group. 1998. An ordinal classification for the families of flowering plants. Annals of the Missouri Botanical Garden 85: 531–553.

Angiosperm Phylogeny Group. 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141: 399–436.

Brundrett MC, Enstone DE, Peterson CA. 1988. A berberine–aniline blue fluorescent staining procedure for suberin, lignin, and callose in plant tissue. Protoplasma 1446: 133–142.

Brundrett MC, Kendrick B, Peterson CA. 1987. Efficient lipid staining in plant material with sudan red 7B or fluorol yellow 088 in polyethylene glycol. Biotechnic & Histochemistry 66: 133–142. PubMed

Carlquist S, Schneider EL. 1997. Origins and nature of vessels in monocotyledons. I. Acorus. International Journal of Plant Sciences 158: 51–56.

Clarkson DT, Robards K. 1975. The endodermis, its structural development and physiological role. In: Torrey JG, Clarkson DT, eds. Structure and function of roots. London: Academic Press, 415–436.

Clowes FAL. 1981. The difference between open and closed meristems. Annals of Botany 48: 761–767.

Clowes FAL. 2000. Pattern in root meristem development in angiosperms. New Phytologist 146: 83–94.

Conard HS. 1905. The waterlilies: a monograph of the genus Nymphaea. Washington, DC: Carnegie Institution of Washington.

Duvall MR. 2001. An anatomical study of anther development in Acorus L.: phylogenetic implications. Plant Systematics and Evolution 228: 143–152.

Eames AJ. 1961.Morphology of the angiosperms. New York, NY: McGraw-Hill.

Fleet van DS. 1961. Histochemistry and function of the endodermis. Botanical Review 27: 165–220.

Floyd SK, Friedman WE. 2001. Evolution of endosperm developmental patterns among basal flowering plants. International Journal of Plant Sciences 161: S57–S81.

Friis EM, Pedersen KR, Crane PR. 2001. Fossil evidence of water lilies (Nymphaeales) in the early cretaceous. Nature 410: 357–360. PubMed

Groot EP, Doyle JA, Nichol SA, Rost TL. 2004. Phylogenetic distribution and evolution of root apical meristem organization in dicotyledonous angiosperms. International Journal of Plant Sciences 165: 97–105.

Guttenberg von H. 1968. Der primäre Bau der Angiospermenwurzel. In: Linsbauer K, Tischler G, Pascher A, eds. Handbuch der Pflanzenanatomie, Vol. VIII. Berlin: Gebrüder Borntraeger, 1–472.

Haas DL, Carothers ZB. 1975. Some ultrastructural observations on endodermal cell development in Zea mays roots. American Journal of Botany 62: 336–348.

Haupt AW. 1953.Plant morphology. New York, NY: McGraw-Hill.

Holle HG. 1876. Über den Vegetationspunkt der Angiospermen Wurzeln, insbesondere die Haubenbildung. Botanische Zeitung 34: 241–255, 257–264.

Janczewski E de. 1874. Recherches sur l'accroissement terminal des racines dans les Phanerogames. Annales des Sciences Naturelles Series 20: 162–201.

Jensen WA. 1962.Botanical histochemistry. San Francisco, CA: W.H. Freeman and Co.

Justin SHFW, Armstrong W. 1987. The anatomical characteristics of roots and plant response to soil flooding. New Phytologist 106: 465–405.

Keating RC. 2003.The anatomy of the monocotyledons. Vol. IX. The Acoraceae and Araceae. Oxford: Oxford University Press.

Kroemer K. 1903. Wurzelhaut Hypodermis und Endodermis der Angiospermwurzel. Bibliotheca Botanica 59: 1–151.

Kroll GH. 1912. Kritische Studie über die Verwertbarkeit der Wurzelhaubentypen für Entwicklungsgeschicte. Beiheft zum Botanisches Zentralblatt 28: 134–158.

Laan P, Berrovoets MJ, Lythe S, Armstrong W, Blom CWPM. 1989. Root morphology and aerenchyma formation as indicators of the flood-tolerance of Rumex species. Journal of Ecology 77: 693–703.

Maillefer A. 1921. Sur la presence d'une assise dans la racine d'Acorus calamus Bulletin de la Societie vaudoise des sciences naturelles 53: 77–79.

Nêmec B. 1907.Anatomie a fyziologie rostlin. Prague, Czech Republic: Nakladatelství České Akademie Císaře Františka Josefa pro Vědy, Slovesnost a Umění.

Schneider EL, Carlquist S, Beamer K, Kohn A. 1995. Vessels in Nymphaeaceae: Nuphar, Nymphaea, and Ondinea International Journal of Plant Sciences 156: 857–862.

Seago Jr JL. 2002. The root cortex of the Nymphaeaceae, Cabombaceae, and Nelumbonaceae. Journal of the Torrey Botanical Society 129: 1–9.

Seago Jr JL, Peterson CA, Kinsley LJ, Broderick J. 2000. Development and structure of the root cortex in Caltha palustris L. and Nymphaea cordata Ait. Annals of Botany 86: 631–640.

Shishkoff N. 1987. Distribution of the dimorphic hypodermis of roots in Angiosperm families. Annals of Botany 60: 1–15.

Soltis DE, Soltis PS, Bennet MD, Leitch IJ. 2003. Evolution of genome size in the angiosperms. American Journal of Botany 90: 1596–1603. PubMed

Soukup A, Votrubova O, Cizkova H. 2002. Development of anatomical structure of roots of Phragmites australis New Phytologist 153: 277–287.

Sun G, Ji Q, Dilcher DL, Zheng S, Nixon KC, Wang X. 2002. Archaefructaceae, a new Basal Angiosperm family. Science 296: 899–904. PubMed