pericycle

enUK

per·i·cy·cle

P0192100 (pĕr′ĭ-sī′kəl)n. A plant tissue characteristic of the roots, located between the endodermis and phloem.

[French péricycle, from Greek perikuklos, spherical : peri-, peri- + kuklos, circle; see cycle.]

per′i·cy′clic (-sī′klĭk, -sĭk′lĭk) adj.

pericycle

(ˈpɛrɪˌsaɪkəl) n (Botany) a layer of plant tissue beneath the endodermis: surrounds the conducting tissue in roots and certain stems[C19: from Greek perikuklos] pericyclic adj

per•i•cy•cle

(ˈpɛr əˌsaɪ kəl)

n. the cell layer of the stele in a plant, bounded by the endodermis and the phloem. [1890–95; < Greek períkyklos. See peri-, cycle]

Translations

Pericycle

enUK

pericycle

[′per·ə‚sī·kəl] (botany) The outer boundary of the stele of plants; may not be present as a distinct layer of cells.

Pericycle

(also pericambium), formative tissue in the roots and the stems of plants, located around the vascular cylinder. The pericycle is represented by one or more (in gymnosperms) layers of parenchymatous cells of the meristem, which are separated from the cells of the primary cortex by the endodermis. All lateral roots develop from the pericycle of the main root. In dicotyledonous plants, action of the pericyclic cells causes the cambial cells to join in a common cylinder in the roots of secondary growth. The pericycle forms broad rays in the root, in whose parenchyma metabolic products are deposited and new adventitious roots and, sometimes, root buds are formed. When the root thickens and the primary cortex atrophies, the phellogen is differentiated in the pericycle, forming the periderm on the surface of the root.

Pericycle in the stems of plants gives rise to both sclerenchyma and parenchyma (some lianas of the families Aristolochiaceae, Cucurbitaceae, and Solanaceae) or to only sclerenchyma (in monocotyledons). In many species of Compositae (viper’s grass, dandelion), segmented latex vessels are formed in the pericycle. In Umbelliferae, essential-oil passages are formed, and in Cucurbitaceae secretory cells. In some plants of the families Liliaceae, Chenopodiaceae, and Caryophyllaceae, secondary thickening of stems and roots occurs owing to the formation from the pericycle of new layers of cambial zones and vascular bundles to the periphery of the vascular cylinder. The thickening is associated with the formative function of pericyclic cells. This type of secondary thickening of axial organs of a plant is usually called anomalous growth.

I. S. MIKHAILOVSKAIA

单词	pericycle
释义	pericycle enUK per·i·cy·cle P0192100 (pĕr′ĭ-sī′kəl)n. A plant tissue characteristic of the roots, located between the endodermis and phloem. [French péricycle, from Greek perikuklos, spherical : peri-, peri- + kuklos, circle; see cycle.] per′i·cy′clic (-sī′klĭk, -sĭk′lĭk) adj. pericycle (ˈpɛrɪˌsaɪkəl) n (Botany) a layer of plant tissue beneath the endodermis: surrounds the conducting tissue in roots and certain stems[C19: from Greek perikuklos] pericyclic adj per•i•cy•cle (ˈpɛr əˌsaɪ kəl) n. the cell layer of the stele in a plant, bounded by the endodermis and the phloem. [1890–95; < Greek períkyklos. See peri-, cycle] Translations Pericycle enUK pericycle [′per·ə‚sī·kəl] (botany) The outer boundary of the stele of plants; may not be present as a distinct layer of cells. Pericycle (also pericambium), formative tissue in the roots and the stems of plants, located around the vascular cylinder. The pericycle is represented by one or more (in gymnosperms) layers of parenchymatous cells of the meristem, which are separated from the cells of the primary cortex by the endodermis. All lateral roots develop from the pericycle of the main root. In dicotyledonous plants, action of the pericyclic cells causes the cambial cells to join in a common cylinder in the roots of secondary growth. The pericycle forms broad rays in the root, in whose parenchyma metabolic products are deposited and new adventitious roots and, sometimes, root buds are formed. When the root thickens and the primary cortex atrophies, the phellogen is differentiated in the pericycle, forming the periderm on the surface of the root. Pericycle in the stems of plants gives rise to both sclerenchyma and parenchyma (some lianas of the families Aristolochiaceae, Cucurbitaceae, and Solanaceae) or to only sclerenchyma (in monocotyledons). In many species of Compositae (viper’s grass, dandelion), segmented latex vessels are formed in the pericycle. In Umbelliferae, essential-oil passages are formed, and in Cucurbitaceae secretory cells. In some plants of the families Liliaceae, Chenopodiaceae, and Caryophyllaceae, secondary thickening of stems and roots occurs owing to the formation from the pericycle of new layers of cambial zones and vascular bundles to the periphery of the vascular cylinder. The thickening is associated with the formative function of pericyclic cells. This type of secondary thickening of axial organs of a plant is usually called anomalous growth. I. S. MIKHAILOVSKAIA pericycle enUK pericycle the layer of plant cells between the ENDODERMIS and the PHLOEM, consisting mainly of PARENCHYMA, which becomes meristematic to form lateral roots. See STEM and ROOT for diagrams.
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