Anatomy of the Secondary Phloem in Winteraceae

IAWA Journal ◽  
1984 ◽  
Vol 5 (1) ◽  
pp. 13-43 ◽  
Author(s):  
Katherine Esau ◽  
Vernon I. Cheadle
Keyword(s):  
Protein Body ◽  
Sieve Element ◽  
Secondary Phloem ◽  
Phloem Parenchyma ◽  
The Family ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Evolutionary Level ◽  
Fusiform Initials ◽  
Sieve Plates

The secondary phloem of nine species in five genera of Winteraceae was examined with regard to features that could serve for taxonomic and phylogenetic evaluation of the family. The species examined were as follows: Bubbia pauciflora, B. semecarpoides, Drimys lanceolata, D. winteri, Exospermum stipitatum, Pseudo wintera axillaris, Zygogynum baillonii, Z. bicolor, and Z. vinkii. The nine species showed the following common characteristics: 1) origin from nonstoried vascular cambium with long fusiform initials; 2) ray system consisting of high multiseriate and high uniseriate rays; 3) occurrence of secondary partitioning in the differentiating phloem so that the sieve elements are much shorter than the tracheids; 4) lack of sharp differentiation between lateral sieve areas and those of the sieve plates; 5) predominance of compound sieve plates; 6) short companion cells, often single in a given sieve element; 7) phloem parenchyma cells in strands; 8) lack of specialised fibres (bast fibres) in the secondary phloem; 9) presence of nondispersing protein body in the sieve element protoplast. Features numbered 1, 2, 4-6 are considered to be indications of low evolutionary level. The significance of the other three features (3, 7-9) requires further evaluation. Among these three is the secondary partitioning the occurrence of which seems to imply that in some taxa the well known sequence of evolutionary shortening of cambial initials and their derivatives may be accelerated on the phloem side.

Fine structure of the phloem of Pisum sativum. II. The companion cell and phloem parenchyma

1965 ◽  
Vol 13 (2) ◽  
pp. 185
Author(s):  
MC Wark
Keyword(s):  
Fine Structure ◽  
Sieve Element ◽  
Companion Cell ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Phloem Parenchyma ◽  
Wall Structures ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Vacuolated Cells

The companion cells of the secondary phloem of Pisum contain all the organelles characteristic of cells possessing an active metabolism. The cytoplasm of the companion cells shows little change during ontogeny. Complex plasmodesmata connect the sieve elements and companion cells. These are the only connections observed between the sieve elements and other phloem cells. New wall structures of the companion cells are described. These structures are here tentatively called trabeculae; they intrude into the cytoplasm, but never completely cross the cell. The trabeculae alter in appearance at the time when the sieve element nucleus and tonoplast disappear. The phloem parenchyma cells are large vacuolated cells wider in diameter but shorter in length than the sieve elements. They contain all the organelles found in normal photosynthetic tissue. The cytoplasm of the phloem parenchyma shows little change during ontogeny. Plasmodesmata of well-developed pit fields connect the phloem parenchyma with the companion cells. The phloem parenchyma does not communicate with the sieve elements.

DISTRIBUTION OF VEGETATIVE STORAGE PROTEINS IN ROSACEAE

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 421-428
Author(s):  
Wei-Min Tian ◽  
Zheng-Hai Hu
Keyword(s):  
Seasonal Changes ◽  
Storage Proteins ◽  
Protein Body ◽  
Diagnostic Feature ◽  
Secondary Phloem ◽  
Apple Trees ◽  
Phloem Parenchyma ◽  
Vegetative Storage Proteins ◽  
Parenchyma Cells ◽  
First Time

The distribution pattern of vegetative storage proteins is reported for the first time for 18 species and 2 varieties of twelve genera of Rosaceae. Vegetative storage proteins were present in all the species studied of Prunoideae and absent in Maloideae. Their occurrence in a genus seemed to be either universal or entirely absent. Rosaceae trees were poor in vegetative storage proteins and the form of vegetative storage proteins was not protein body-like. Granular and floccular forms of vegetative storage proteins could be distinguished exclusively in the secondary phloem parenchyma cells and their distribution was cell-specific. Our results suggest that the distribution of vegetative storage proteins in Rosaceae can be considered as a taxonomically diagnostic feature. The nature of the bark proteins with seasonal changes in apple trees is discussed.

Fine structure of the primary root phloem of Pisum

1968 ◽  
Vol 16 (1) ◽  
pp. 37 ◽  
Author(s):  
SY Zee ◽  
TC Chambers
Keyword(s):  
Primary Root ◽  
Root Apex ◽  
Sieve Element ◽  
Cross Wall ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Phloem Parenchyma ◽  
Pisum Sativum L ◽  
Companion Cells ◽  
Stem Internode

The morphogenesis of the sieve elements, companion cells, and phloem parenchyma in the region between 0.5 and 2.0 mm from the actively growing root apex of seedlings of Pisum sativum L. cv. Telephone is described. The overall developmental pattern is essentially similar to that already described for the secondary phloem of the young stem internode of the same species, although differences in the development of some organelles do exist between the two types of phloem. The development of the sieve element is traced from the earliest stages of cross wall formation up to the morphologically mature stages. Very few sieve elements reach morphological maturity in this region. The possibility that the functional translocatory sieve elements are those at earlier stages of development is discussed.

Inclusions in nuclei and plastids of Boraginaceae and their possible taxonomic significance

1989 ◽  
Vol 67 (12) ◽  
pp. 3608-3617 ◽  
Author(s):  
Deborah D. Fisher ◽  
Jennifer Thorsch ◽  
Katherine Esau
Keyword(s):  
Proteolytic Enzyme ◽  
Ultrastructural Level ◽  
Sieve Element ◽  
Nuclear Inclusions ◽  
Sieve Elements ◽  
Phloem Parenchyma ◽  
The Family ◽  
Parenchyma Cells ◽  
Parallel Arrangement ◽  
Systematic Character

A survey of 68 species representing 28 genera in the family Boraginaceae was conducted at the ultrastructural level to determine presence of nuclear crystalloids in sieve elements and occurrence of crystalline structures in chloroplasts of phloem parenchyma cells. Nuclear crystalloids were identified in 55 of the species examined, and 25 of the species contained chloroplast crystals. The nuclear crystals were mainly composed of thin rods densely packed in parallel arrangement. Their sizes, shapes, and numbers varied, but they were basically prismatic or possibly cubical. During maturation, the sieve element nuclei disintegrated and the crystalloids were released into the cell lumen where they remained intact. Loosely arranged paracrystalline components associated with the dense nuclear crystalloids were found only in the genus Amsinckia. Crystalline inclusions in the parenchyma chloroplasts were made up of fibers loosely aligned in a herringbone pattern. The lability of the chloroplast crystals to the proteolytic enzyme, protease, was tested on 10 species, and only Onosma stellulatum Waldst. & Kit. chloroplast crystals were routinely digested. The high percentage of nuclear crystalloids found in this family suggests that these inclusions could be valuable as a systematic character. Key words: sieve elements, nuclear inclusions, plastid crystals, Boraginaceae.

Comparative Anatomy of the Secondary Phloem of Ten Species of Rosaceae

IAWA Journal ◽  
1993 ◽  
Vol 14 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Liu Donghua ◽  
Gao Xinzeng
Keyword(s):  
Comparative Anatomy ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Sieve Plates ◽  
Lateral Walls

The anatomy of the secondary phloem of species belonging to four genera in Rosaceae is described. The three genera of the Maloideae studied are more or less similar in their phloem anatomy; tangential bands of fibresclereids alternate with bands of sieve elements, companion cells and parenchyma cells; superficially, the nonconducting and conducting phloem are not distinct from one another; sieve plates are compound and there are conspicuous sieve areas on lateral walls; rays are uniseriate and multiseriate, and homocellular. In the five species of Prunus (Prunoideae) studied, there are no fibre-sclereids in the conducting phloem, end walls bearing simple sieve plates are oblique to nearly horizontal; and rays are uniseriate and multiseriate, homocellular.

Structure of Wood and Cambial Variant in the Stem of Dalbergia Paniculata Roxb.

IAWA Journal ◽  
1990 ◽  
Vol 11 (4) ◽  
pp. 379-391 ◽  
Author(s):  
M. N. B. Nair ◽  
H. Y. Mohan Ram
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Sieve Tube ◽  
Secondary Phloem ◽  
Succinate Dehydrogenase Activity ◽  
Successive Cambia ◽  
Phloem Parenchyma ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Cambial Variant

The wood of Dalbergia paniculata is unique as it consists of concentric layers of broad xylem, alternating with bands of narrow phloem. This anomaly results from the periodic formation of successive cambia in the secondary phloem. Some phloem parenchyma cells dedifferentiate to form a discontinuous ring of cambium. Such parenchyma cells have higher succinate dehydrogenase activity than the neighbouring cells of secondary phloem. The newly differentiated cambial layer functions bidirectionally, and its products give rise to xylem internally and phloem externally. The phloem along with cambium present internal to the newly formed xylem becomes included.The wood is diffuse-porous and the intervessel pits are vestured. The phloem has welldifferentiated sieve tube members and companion cells.

An Ultrastructural Study of the Phloem of Drimys (Winteraceae)

IAWA Journal ◽  
1985 ◽  
Vol 6 (3) ◽  
pp. 255-268 ◽  
Author(s):  
Jennifer Thorsch ◽  
Katherine Esau
Keyword(s):  
Endoplasmic Reticulum ◽  
Ultrastructural Study ◽  
Protein Body ◽  
Sieve Element ◽  
Companion Cell ◽  
Young Cell ◽  
P Protein ◽  
Companion Cells ◽  
Protein Granules ◽  
Sieve Plates

The ultrastructural features of mainly primary phloem of three species of Drimys (Winteraceae), D. winteri J. R. ' G. Forst., D. lanceolata (Poiret) Baill. and D. granadensis L. f. var. mexicana (DC.) A. C. Smith are similar to those usually observed in dicotyledons. The sieve element is early discernible by its association with a companion cell, the deposition of callose in nascent sieve areas, and the appearance in the cytoplasm of the nondispersing paracrystalline protein body. Plastids with starch (and in D. lanceolata also with paracrystalline protein granules), mitochondria, sparse endoplasmic reticulum cisternae (ER), dictyosomes, and ribosomes are present in the young cell. Stacking of ER was not conspicuous. The nucleus is moderately chromatic before its breakdown. P-protein occurs in more or less dense aggregates that usually become dispersed after the tonoplast disappears. The subunits of the P-pro tein have tubular structure before the dispersal. The plasmalemma is retained. The sieve areas are combined into sieve plates on long radial walls and on some transverse walls originating during secondary partitioning of sieve element precursors. The numerous lateral sieve areas intergrade with those of the sieve plates. The pores develop from plasmodesmatal connections and may involve the formation of median cavities. The connections between sieve elements alld companion cells consist of the usual combination of a pore embedded in callose and one plasmodesma or several branches of one on the companion cell side.

Structure of Stem and Cambial Variant in Spatholobus Roxburgii (Leguminosae)

IAWA Journal ◽  
1993 ◽  
Vol 14 (2) ◽  
pp. 191-204 ◽  
Author(s):  
M.N.B. Nair
Keyword(s):  
Vascular Tissue ◽  
Secondary Growth ◽  
Sieve Tube ◽  
Secretory Cells ◽  
Secondary Phloem ◽  
Phloem Parenchyma ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Ray Cells ◽  
Cambial Variant

The stern of Spatholobus roxburghii, a tropicalliana, has alternating layers of xylem and phloem as a result of formation and activity of successive cambia. Successive cambial rings are developed by dedifferentiation of groups of parenchyma cells outside the discontinuous band of sclereid-fibres. The sclereid- fibre band is formed by the development of sclereids between the primary bark fibres. Each successive cambium first produces a layer of sclereid-fibres which separates the vascular tissue produced by one cambial ring from the other. After secondary growth, the epidermis is replaced by periderm. In the older stern phelloderm contributes to the formation of new cambiallayers. Secondary phloem has sieve tube members; companion cells, phloem parenchyma, phloem fibres and secretory cells. The wood shows a tendency towards ring-porosity only in the first xylem layer. The subsequent layers are diffuseporous. The vessels are wide and narrow. Perforated ray cells or radial vessels are frequent in the wood and probably help in vertical conduction by interconnecting vessel endings. In this scandent species parenchyma cells are abundant. It is inferred that they help the vessel segments to remain undamaged when the woody stern twists around supports.

The secondary phloem of Austrobaileya scandens

1970 ◽  
Vol 48 (2) ◽  
pp. 341-359 ◽  
Author(s):  
Lalit M. Srivastava
Keyword(s):  
Tannic Acid ◽  
Cross Sections ◽  
Significant Proportion ◽  
Sieve Tube ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Sieve Cells ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Definition Of

The origin of sieve elements and parenchyma cells in the secondary phloem of Austrobaileya was studied by use of serial cross sections stained with tannic acid – ferric chloride and lacmoid. In three important respects, Austrobaileya phloem recalls gymnospermous features: it has sieve cells rather than sieve-tube members; a significant proportion of sieve elements and companion cells arise independently of each other; and sieve areas occur between sieve elements and companion cells ontogenetically unrelated to each other. The angiospermous feature includes origin of most sieve elements and parenchyma, including companion cells, after divisions in phloic initials. In these instances companion cells show a closer ontogenetic relationship to sieve elements than do other parenchyma cells. The combination of gymnospermous and angiospermous features makes phloem of Austrobaileya unique when compared to that of all those species that have been investigated in detail. It is further suggested that the term albuminous cells is inappropriate and should be replaced by companion cells but that the ontogenetic relationship implicit in the definition of companion cells is too restrictive and should be abandoned.

Early modifications of the internodal anatomy of Glycine max sprayed with 2,4-DB

1979 ◽  
Vol 57 (12) ◽  
pp. 1340-1344 ◽  
Author(s):  
Thompson Demetrio Pizzolato ◽  
David L. Regehr
Keyword(s):  
Cell Division ◽  
Cell Enlargement ◽  
Secondary Phloem ◽  
Anatomical Changes ◽  
Phloem Parenchyma ◽  
Cortical Parenchyma ◽  
Parenchyma Cells ◽  
Radial Cell ◽  
Orderly Fashion ◽  
Stimulation Of

An aqueous spray of 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) induces anatomical changes in young Glycine internodes. Four days after spraying, the first symptoms appear outside the cambium when the interfascicular parenchyma cells and the adjacent cortical parenchyma cells enlarge and divide in several planes. Four days later, the metaphloem parenchyma cells in many of the leaf traces undergo considerable periclinal cell division and extensive radial cell enlargement. The phloem parenchyma cells of the late metaphloem and first secondary phloem enlarge and divide in a less orderly fashion. Fifteen days after treatment, the cortical parenchyma is modified into a band of radially seriate cells above the protophloem fibers. Products of this cambium-like region convert the cortex into a callus-like tissue. The size of starch grains is reduced initially in the phloem and xylem and later in the cortex. It appears that the stimuli produced by 2,4-DB move into the internode via the metaphloem of leaf traces. Despite the rapid obliteration of conducting phloem by the 2,4-DB induced stimulation of phloem parenchyma, an accelerated differentiation of secondary phloem compensates for this loss.

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