Endodermis


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Endodermis

The single layer of plant cells that is located between the cortex and the vascular (xylem and phloem) tissues. It has its most obvious development in roots and subaerial stems. The endodermis has many apparent functions: absorption of water, selection of solutes and ions, and production of oils, antibiotic phenols, and acetylenic acids.

The endodermis has been found to have extra sets of chromosomes as compared with cortical and other cells in the plant. In some plants the chromosome numbers may be so high in the endodermis that four sets of chromosomes may occur in each endodermal cell. The larger amount of nuclear material and nucleic acid in the cells of the endodermis may in part account for the great capacity of endodermal cells to produce large amounts of chemical substances, such as acetylenic oils, high in caloric energy. See Cortex (plant)

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Endodermis

 

the innermost single-row layer of compact parenchymatous cells of the primary cortex adjacent to the central cylinder of the axial organs of higher plants. The endodermis is not highly differentiated in stems and usually contains secondary starch. In the roots, the radial and transverse walls of the endodermal cells have bandlike thickenings containing suberin and lignin. The cells involved in the exchange of molecules remain thin-walled. Thus, the endodermis is a physiological barrier that regulates the entry of water and ions from the primary cortex to the central cylinder of the root.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

endodermis

[¦en·dō¦dər·məs]
(botany)
The innermost tissue of the cortex of most plant roots and certain stems consisting of a single layer of at least partly suberized or cutinized cells; functions to control the movement of water and other substances into and out of the stele.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Stem cross-sections, a Stem terminal portion with numerous leaf traces (arrowheads) and a group of sclercids in the pith (circle), b-c Stem portions in secondary growth showing groups of sclercids in the cortex, in the secondary phloem and in the pith; in b, sclcreids of similar size (arrows); in c, sclercids with different shapes and sizes (black arrows = larger cortical sclercids with varying shapes and sizes; white arrows = smaller medullary and phloematic sclercids and with regular shape and size), d Stem section with secretory endodermis, presenting droplets of lipophilic material evidenced by the Sudan IV.
Essential mineral ions move across the endodermis by symplastic transport (dashed blue arrows).
Epicotyl consists of a uniseriate and hairy epidermis, and collenchymatous and parenchymatous cortex, without typical endodermis. Central cylinder is composed of collateral bundles with band of fibers that lies outside the phloem.
The endodermis and exodermis are important as root apoplastic barriers protecting roots to shoots from soil pollutants and pathogen flux (Hameed et al., 2009; Pereira et al., 2011).
Osmundastrum es un genero monotipico, que se caracteriza, anatomicamente, por la presencia de tres conjuntos de fibras esclerenquimaticas en la base del peciolo uno abaxial y dos laterales al haz vascular; una segunda endodermis en la estela del tallo, localizada entre el cilindro xilematico y la medula y por varias capas de parenquima entre la segunda endodermis y el xilema, mientras que el resto de las osmundaceas poseen solo una capa de endodermis en el tallo, localizada entre el periciclo y la corteza interna (Faull, 1901; Hewitson, 1962).
The distribution of the elements in different regions of interest (ROI) of the root, whole root, the epidermis, the cortex, the endodermis, and the vascular tissue, was also determined and the 95% confidence interval of the average elemental concentrations calculated.
Rhizome sections exhibit a large stele separated by a yellowish line, the endodermis from a thick cortex; numerous small, oval, vascular bundles are scattered throughout the section.
The inner limit of the root cell wall is the endodermis, which forms the outer limit of the root vascular system or stele.
Several endophytic bacteria have been reported to originate from the rhizosphere soil, initially entering the host plant during germination and radicle development, through wounds or by colonizing the cracks formed in lateral root junctions when the endodermis and casparian strips are disrupted thus gaining an easy access to the stele [14, 15].