Does intrusive growth of fusiform initials really contribute to circumferential growth of vascular cambium?

Botany ◽  
2009 ◽  
Vol 87 (2) ◽  
pp. 154-163 ◽  
Author(s):  
Wiesław Włoch ◽  
Joanna Jura-Morawiec ◽  
Paweł Kojs ◽  
Muhammad Iqbal ◽  
Józef Krawczyszyn
Keyword(s):  
Tangential Direction ◽  
Vascular Cambium ◽  
Fusiform Cell ◽  
Intrusive Growth ◽  
Laburnum Anagyroides ◽  
Fusiform Initials ◽  
Visible Effect ◽  
Symplastic Growth

Currently it is believed that intrusive growth of fusiform cambial initials adds to the circumference of the cambial cylinder: the initial cells multiplied by anticlinal divisions are produced in excess, and the excess cells are later eliminated from the cambial surface. The present study, dealing with the intrusive growth of fusiform initials in the cambium of Laburnum anagyroides Medik, suggests that addition of a radial file of initials owing to intrusive growth, or elimination of any such file, has no visible effect on the tangential dimensions of a given cambial sector, and that intrusive growth of fusiform initials and the elimination of excess initials occur in unison. The two events complement each other, and the gain in size of the growing fusiform cell is accompanied by a reduction in size of its neighbour cell, thus keeping the tangential dimensions of the cambium unchanged. Our findings on L. anagyroides find support from illustrations of previous studies, which we have re-examined and re-interpreted. Our data suggest that increase in the cambial circumference is largely due to the symplastic growth of the fusiform initials in tangential direction.

Apical intrusive growth of cambial fusiform initials along the tangential walls of adjacent fusiform initials: evidence for a new concept

2006 ◽  
Vol 54 (5) ◽  
pp. 493 ◽  
Author(s):  
Joanna Jura ◽  
Paweł Kojs ◽  
Muhammad Iqbal ◽  
Joanna Szymanowska-Pułka ◽  
Wiesław Włoch
Keyword(s):  
Cell Walls ◽  
Tilia Cordata ◽  
Intrusive Growth ◽  
Radial Wall ◽  
Cambial Cell ◽  
Fusiform Initials ◽  
Periclinal Walls ◽  
Symplastic Growth ◽  
Wisteria Floribunda ◽  
Fusiform Initial

A new study of cambium of Pinus sylvestris L., Tilia cordata Mill. and Wisteria floribunda (Willd.) DC provides fresh clues on the cambial dynamics, rejecting the hitherto held concept that intrusive growth of the fusiform initial occurs between the radial walls of adjacent initials. It demonstrates that intrusion of the elongating initial in fact takes place along tangential walls of adjacent fusiform initials and their immediate derivatives. It also suggests a new mechanism for ‘elimination of initials’. Intrusive growth of the fusiform initial was found to begin with development of characteristic slants, representing a transitional stage of the process of transformation of periclinal walls of fusiform initial cells into radial walls, as observed in transverse sections of active cambium. The gradually progressing event comprised (a) appearance of either a triangular microspace limited by two periclinal walls of a fusiform initial and its derivative and one radial wall of another fusiform initial in the adjacent radial file, or a rhomboidal microspace enclosed by four periclinal walls of two laterally adjacent fusiform initials and their immediate derivatives, (b) intrusion of elongating tip of fusiform initial from neighbouring file into the microspace thus formed, (c) symplastic growth of the cambial cell walls in radial direction, (d) unequal periclinal divisions of fusiform initial cells while growing intrusively, and (e) unequal periclinal divisions of derivative cells not growing intrusively. Intrusive growth between periclinal walls affected rearrangement of the fusiform initials but did not add to the cambial circumference. The existing concepts of (a) intrusion of the fusiform initial between radial walls of neighbouring initials and (b) elimination of fusiform initials from cambial surface have been reassessed and redefined.

Correlation of intrusive growth of cambial initials to rearrangement of rays in the vascular cambium

IAWA Journal ◽  
2011 ◽  
Vol 32 (3) ◽  
pp. 313-331 ◽  
Author(s):  
Anna Wilczek ◽  
Joanna Jura-Morawiec ◽  
Paweł Kojs ◽  
Muhammad Iqbal ◽  
Wiesław Włoch
Keyword(s):  
Pinus Sylvestris ◽  
Vascular Cambium ◽  
Tilia Cordata ◽  
Intrusive Growth ◽  
Hippophaë Rhamnoides ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
The One ◽  
Fusiform Initial ◽  
Ray Initials

It is well documented that apical elongation of fusiform cambial initials through extension of their longitudinal edges, and their intrusion between tangential walls of the neighbouring initials and their closest derivatives cause rearrangement of fusiform cells, without increasing the cambial circumference. However, the concurrent rearrangement of rays is not fully understood. This study deals with Pinus sylvestris L., Tilia cordata Mill. and Hippophaë rhamnoides L., possessing a nonstoreyed, storeyed and double-storeyed type of cambium, respectively, and shows that the mechanism for rearrangement of ray initials is similar to the one proposed for fusiform initials, and includes multiplication of ray initials by anticlinal divisions, intrusive growth of ray initials, elimination of ray initials caused by intrusive growth of neighbouring fusiform initials, and transformation of ray initials into fusiform initials. Intrusive growth of a ray initial does not necessarily lead to the formation of a new fusiform initial, as it is dependent on the extent of the intrusive growth taken place. The extent of rearrangement of cambial cells is determined by the intensity of events occurring among the fusiform as well as ray initials. Intrusive growth of these initials does not influence the size of the cambial circumference.

scholarly journals The formation of heterogeneous storeys in the cambium on the example of Laburnum anagyroides Medik

2012 ◽  
Vol 65 (2) ◽  
pp. 47-56 ◽  
Author(s):  
Anna Wilczek
Keyword(s):  
Cambial Activity ◽  
Relative Increase ◽  
Temperate Climate ◽  
Intrusive Growth ◽  
Laburnum Anagyroides ◽  
Or Groups ◽  
Heterogeneous Nature ◽  
Fusiform Initials ◽  
Fusiform Initial

The formation of the storeyed pattern of cambium in the first two years of cambial activity and the structure of mature cambium was examined in <i>Laburnum anagyroides</i>, a decorative shrub growing in temperate climate. A distinct storeyed pattern was observed in two-year-old stems, despite the presence of tall rays. The heterogeneous nature of storeys was revealed by the analysis of i) the number of fusiform initials forming storeys or groups of packets; and ii) the frequency of anticlinal divisions in the examined years of cambial activity and the calculation of the relative increase of the cambial circumference. The results are discussed on the basis of the recent hypothesis of intrusive growth of fusiform initial, occurring between the tangential walls of its neighbouring initial and its closest derivative.

scholarly journals Desenvolvimento e mudanças celulares na estrutura dos raios xilemáticos de Rollinia emarginata Schlecht. (Annonaceae)

1988 ◽  
Vol 10 (10) ◽  
pp. 131
Author(s):  
Paulo Cesar Botosso
Keyword(s):  
Secondary Xylem ◽  
Intrusive Growth ◽  
Outermost Layer ◽  
Cellular Changes ◽  
Fusiform Initials ◽  
Cellular Transformations ◽  
Ray Initials

Through microscopical observations in serial tangential sctions from cambium to pith the development and the most significant cellular changes in the structure of rays of Rollinia emarginata Schlecht. (Annonaceae) were observed. The ray characteristics of the outermost layer of secondary xylem are described and the major changes in the ray structure in different stages of secondary develooment are considered. The cellular changes observed are extremely variable, occurring isolated or in complex combinations. The most significant cellular changes observed during ray development are the following: origin of ray initials from fusiform initials or from cambial ray initials; changes resulting from the intrusive growth of fusiform initials through a group of ray initials and the loss of ray initials from the cambium. From these cellular transformations the most important changes in the origin of secondary rays, increase in height and width and reduction in the height of multisseriate rays are considered.

Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia

IAWA Journal ◽  
2018 ◽  
Vol 39 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Anna B. Wilczek ◽  
Muhammad Iqbal ◽  
Wieslaw Wloch ◽  
Marcin Klisz
Keyword(s):  
Secondary Xylem ◽  
Robinia Pseudoacacia ◽  
Geometric Analysis ◽  
Cell Types ◽  
Vascular Cambium ◽  
Tangential Plane ◽  
Intrusive Growth ◽  
Thin Sections ◽  
Growing Cell ◽  
Vessel Elements

ABSTRACTAll cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk ofRobinia pseudoacacia.Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular cambium, we assumed that they have similar growth conditions. Dealing with the cylindrical tissue of the vascular cambium in a previous study, we used a circularly symmetrical equation for describing the growth mechanism of cambial initials. Like the cambial initials, some of the cambial derivatives differentiating into the various cell types composing the secondary xylem also exhibit intrusive growth between the tangential walls of adjacent cells. As seen in cross sections of the cambium, intrusively growing initials form slanted walls by a gradual transformation of tangential (periclinal) walls into radial (anticlinal) walls. Similarly, the intrusive growth of xylem fibres manifests initially as slants, which are formed due to axial growth of the growing cell tips along the tangential walls of adjacent cells. During this process, the tangential walls of adjacent cells are partly separated and dislocated from the tangential plane. The final shape of xylem fibres, or that of vessel elements and axial parenchyma cells, depends upon the ratio of their intrusiveversussymplastic growths in the axial, circumferential and radial directions.

Vertical migration of rays leads to the development of a double-storied phenotype in the cambium of Aesculus turbinata

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Elżbieta Myśkow ◽  
Beata Zagórska-Marek
Keyword(s):  
Vertical Migration ◽  
Hippophae Rhamnoides ◽  
Vascular Cambium ◽  
Common Descent ◽  
Hippophaë Rhamnoides ◽  
Fusiform Initials ◽  
Hippophae Rhamnoïdes L ◽  
Ray Cell ◽  
Ray Initials

In the vascular cambium of Aesculus turbinata (Blume) the double-storied structure develops slowly. Initially, the arrangement of primary rays is nonstoried. New secondary rays are initiated during cambial expansion. Rays grow by addition of new initials at both ray margins and then split by the intrusive elongation of adjacent fusiform cells. The repetitive splits give rise to groups of several rays of common descent. Initially, the secondary rays are also nonstoried. Later, they become organized into horizontal tiers. This results from the vertical migration of ray initials in the vascular cambium. Controlled polar additions and eliminations of ray-cell initials at the opposite margins of the ray continue until it reaches the appropriate position within the storey of fusiform initials. We postulate that there are at least two mechanisms for the formation and maintenance of ray tiers in cambium. They are unrelated to cell inclination changes, which as described earlier, are known to sometimes induce a double-storied phenotype. The first of these mechanisms, involves initiation of secondary rays exactly within the storeys of fusiform initials, as in Hippophaë rhamnoides L. The second mechanism, present in A. turbinata, is based on the dynamic, controlled migration of rays.

Mathematical Modeling of Intrusive Growth of Fusiform Initials in Relation to Radial Growth and Expanding Cambial Circumference in Pinus sylvestris L.

2009 ◽  
Vol 57 (3) ◽  
pp. 331-348 ◽  
Author(s):  
D. Karczewska ◽  
J. Karczewski ◽  
W. Włoch ◽  
J. Jura-Morawiec ◽  
P. Kojs ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Pinus Sylvestris ◽  
Radial Growth ◽  
Intrusive Growth ◽  
Fusiform Initials

scholarly journals Growth activity of fusiform initials in storeyed cambium

2015 ◽  
Vol 44 (4) ◽  
pp. 537-552 ◽  
Author(s):  
B. Zagórska-Marek
Keyword(s):  
Activity Pattern ◽  
Intrusive Growth ◽  
Fusiform Initials ◽  
Growth Activity ◽  
Time Periods

The intrusive growth of fusiform initials was studied in <i>Entandrophragma</i>, This growth makes possible a change in the position of the cell ends of one storey in respect to those in the neighbouring storey, and this is 'turn leads to changes in the orientation of cambial initials. The growth activities of the oppositely directed ends of the same initial are not the same. Not all cell ends are simultaneously actiye. There are groups of ends distributed alternately in a storey which are active or inactive, so that a pattern of growth activity appears in the cambium. The activity of a particular cell end changes in successive time periods. Owing to this, the rate of creeping of one end past. those of the adjoining storey varies. This phenomenon of changes in the activity of cell ends in time may be referred to the phenomenon of the appearance of the growth activity pattern on the cambium surface under the hypothesis of transverse shifting of the elements of this pattern ("active" and. "inactive" groups) in relation to the cambial initials.

scholarly journals Mechanism of changes in grain inclination in wood produced by storeyed cambium

2015 ◽  
Vol 43 (3) ◽  
pp. 381-398 ◽  
Author(s):  
Z. Hejnowicz ◽  
B. Zagórska-Marek
Keyword(s):  
Cell Orientation ◽  
Fusiform Cell ◽  
Intrusive Growth ◽  
Interlocked Grain

The changes in cell orientation in the cambium of <i>Entandrophragma</i> producing wood with interlocked type of grain, and in the cambium of <i>Tilia</i> in a spirally girdled stem are traced through serial tangential sections of wood. In <i>Entandrophragma</i> the changes result from the intrusive growth of a fusiform cell whih repeatedly produces a new pointed tip from one side of the existing tip which disappears. This causes a sort of creeping of cell ends of one storey past those of the adjoining storey. The oppositely directed ends of the cells belonging to one storey creep in opposite directions so that the position of the cell centres remains constant and only the angle between the cells and the stem axis changes. The stratification of short rays in <i>Entandrophragma</i> represents an adaptation to the changes in celi orientation involved in the formation of interlocked grain. The mechanism of changes in grain inclination in <i>Tilia</i> is intermediate between that based on the creeping of cell ends and that based on pseudotransverse division and intrusive elongation which is known in non-storeyed cambia.

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