scholarly journals How Do Trees Grow in Girth? Controversy on the Role of Cellular Events in the Vascular Cambium

2021 ◽  
Author(s):  
Anna Wilczek-Ponce ◽  
Wiesław Włoch ◽  
Muhammad Iqbal
Keyword(s):  
Woody Plants ◽  
Radial Growth ◽  
Apical Cell ◽  
Vascular Cambium ◽  
Cell Dynamics ◽  
Cellular Events ◽  
New Concepts ◽  
New Interpretation ◽  
Cambial Cells ◽  
Periclinal Walls

AbstractRadial growth has long been a subject of interest in tree biology research. Recent studies have brought a significant change in the understanding of some basic processes characteristic to the vascular cambium, a meristem that produces secondary vascular tissues (phloem and xylem) in woody plants. A new hypothesis regarding the mechanism of intrusive growth of the cambial initials, which has been ratified by studies of the arrangement of cambial cells, negates the influence of this apical cell growth on the expansion of the cambial circumference. Instead, it suggests that the tip of the elongating cambial initial intrudes between the tangential (periclinal) walls, rather than the radial (anticlinal) walls, of the initial(s) and its(their) derivative(s) lying ahead of the elongating cell tip. The new concept also explains the hitherto obscure mechanism of the cell event called ‘elimination of initials’. This article evaluates these new concepts of the cambial cell dynamics and offers a new interpretation for some curious events occurring in the cambial meristem in relation to the radial growth in woody plants.

scholarly journals The Impact of Changing Climate on the Cambial Activity during Radial Growth in Some Citrus Species

2021 ◽  
Author(s):  
Moin Ahmad Khan ◽  
M. Badruzzaman Siddiqui
Keyword(s):  
Radial Growth ◽  
Cambial Activity ◽  
Age Effects ◽  
Vascular Cambium ◽  
Citrus Species ◽  
The Third ◽  
Changing Climate ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
The Impact

This study on radial growth in the stem of Citrus was carried out with an aim to notice the behavior of vascular cambium with respect to climatic and age effects. The fusiform initials vary in length from 137 to 363 μm in C. limon, 100 to 463 μm in C. paradisi, 137 to 413 μm in C. reticulata var. kinnow, and 137 to 375 μm in C. sinensis. The length rises with age, followed by decline and then again increase in C. limon. In C. paradisi, there is increase up to maximum and after decline is soon followed by constancy. In C. reticulata var. kinnow, increase in length from top to base in C. sinensis, increase up to maximum followed by a decline. Swelling of cambial cells occurs in the third week of March in C. limon, last week of March in C. paradisi, third week of April in C. reticulata var. kinnow, and second week of April in C. sinensis. The cambium turns dormant in early October in C. limon, late December in C. paradisi, early December in C. reticulata var. kinnow, and early November in C. sinensis. Thus, the cambium remains active for about 6 months in C. limon and C. sinensis, 9 months in C. paradisi, and 7 months in C. reticulata var. kinnow.

scholarly journals Nonparallelism of cambium cells in neighboring rows

2014 ◽  
Vol 50 (4) ◽  
pp. 625-636 ◽  
Author(s):  
Wiesław Włoch
Keyword(s):  
Radial Growth ◽  
Longitudinal Direction ◽  
Intrusive Growth ◽  
Continuous Layer ◽  
Mutual Contact ◽  
Cambial Cells ◽  
Periclinal Walls ◽  
Network Pattern

The periclinal walls of cambial cells in neighboring lineages (rows) may not be parallel when viewed in their radial aspect. This lack of longitudinal parallelism may be so extensive that in active cambium pairs of cells from neighboring rows may be in contact only along restricted segments. This means that the initial cells, rather than farming a continuous layer, may be arranged in an irregular network pattern from which some parts project inward or outward from the layer of their mutual cantacts. The longitudinal nonparallelism of cambial cells becomes more pronounced during symplasitic radial growth. Unequal periclinal divisions counteract this, and in initial cells abscission of the parts projecting from the layer of mutual contact occurs. When the cambium passes from a period of activity to a Period of rest a continuous layer of initials is reestabhshed. This involves elongation by intrusive growth of those cells previously shortened as the result of irregular periclinal divisions. The division walls in cambial cells may be warped, that is they change their orientation along the longitudinal direction perhaps even similar to an aircraft propeller. A division wall may thus be periclinal in one part of the cell and anticlinal in another.

Comparative Structure Of Vascular Cambium And Its Derivatives In Some Species Of Sterculia

IAWA Journal ◽  
1996 ◽  
Vol 17 (3) ◽  
pp. 311-318 ◽  
Author(s):  
K. S. Rao ◽  
Kishore S. Rajput ◽  
T. Srinivas
Keyword(s):  
Sieve Tube ◽  
Vascular Cambium ◽  
The South ◽  
Structural Variations ◽  
Axial Parenchyma ◽  
Vessel Elements ◽  
Comparative Structure ◽  
The Mean ◽  
Cambial Cells ◽  
Sheath Cells

Structural variations in cambium, xylem and phloem collected from main trunks of Sterculia colorata, S. alata, S. villosa, S. urens and S. foetida growing in the South Dangs forests were studied. In all five species, the cambium was storied with variations in the length of fusiform cambial cells. Compared to other species S. foetida had the longest and S. urens the shortest fusiform cambial cells. Cambial rays in all the species were compound (tall) and heterocellular with sheath cells. Their height and width were maximal in S. foetida and in S. villosa respectively. In all the species the storied nature of fusiform cambial cells was maintained in derivative cells that developed into sieve tube elements; vessel elements and axial parenchyma of both phloem and xylem. However, fibres of phloem and xylem were nonstoried. The dimensions of elements in phloem and xylem varied among the species. The variation in the mean length of sieve tube elements and vessel members coincided with that of fusiform cambial cells.

Impact of Seasonal Variation on the Structure and Activity of vascular Cambium in ficus Religiosa1

IAWA Journal ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 177-185 ◽  
Author(s):  
T. O. Siddiqi
Keyword(s):  
Seasonal Variation ◽  
Cell Size ◽  
Radial Growth ◽  
Relative Proportion ◽  
Vascular Cambium ◽  
Ficus Religiosa ◽  
Local Climate ◽  
Structure And Activity ◽  
Ray Initials

In Ficus religiosa (Moraceae) extension and radial growth occurs in late July and early August, respectively, under the local climate of Aligarh. The derivative tissue differentiates into xylem and phloem simultaneously in August. The phloem production stops late in August, restarts early October and then continues up to November. The xylogenesis continues up to November without interruption. Formation of the precursor phloem is observed in March. Cell size and the relative proportion of fusiform and ray initials vary with season.

Cellular adjustments in the vascular cambium leading to spiral grain formation in conifers

1984 ◽  
Vol 62 (12) ◽  
pp. 2872-2879 ◽  
Author(s):  
R. A. Savidge ◽  
J. L. Farrar
Keyword(s):  
Picea Glauca ◽  
Pinus Contorta ◽  
Vascular Cambium ◽  
Grain Development ◽  
Primary Event ◽  
Spiral Grain ◽  
Grain Formation ◽  
Cambial Cells

Radial files of tracheids having changing orientations were traced through serial tangential sections to deduce events in fusiform cambial cells (FCCs) associated with spiral grain formation. Within an induction bridge of phloem and cambium sloping diagonally across a stem girdle in Pinus contorta Dougl. ssp. latifolia, repetitive, homologously sloping, pseudo-transverse anticlinal divisions in FCCs were a primary event contributing to FCC orientation changes. Imperfect periclinal divisions (IPDs) in FCCs also contributed. In Picea glauca (Moench.) Voss, IPDs and FCC elongation interacted to change tracheid orientation during natural spiral grain development. In both natural and induced reorientations, small numbers of adjoining FCCs changed their orientation abruptly while the greater population of FCCs changed orientation less rapidly. These sites of abrupt reorientation are termed "microdomains."not available

Phenology and radial stem growth periodicity in evergreen subtropical rainforest trees

IAWA Journal ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 293-307 ◽  
Author(s):  
Laura Yáñez-Espinosa ◽  
Teresa Terrazas ◽  
Lauro López-Mata
Keyword(s):  
Radial Growth ◽  
Vascular Tissue ◽  
Stem Growth ◽  
Tissue Differentiation ◽  
Vascular Cambium ◽  
Evergreen Species ◽  
Leaf Initiation ◽  
Close Relationship ◽  
Cambium Activity ◽  
Phenological Event

A close relationship between leafing, flowering, fruiting and radial growth has been conjectured to occur in tropical and subtropical rainforest trees. Radial stem growth, in particular, has been associated with the activity of the two secondary meristems, the vascular cambium and, to a lesser degree, the phellogen. In tropical trees vascular cambium activity may occur either virtually year-round, or it may be restricted to a short season. Phellogen and vascular cambium activities may or may not correspond to each other. In subtropical environments, even evergreens may demonstrate seasonal phenology in leaf initiation, flowering and seed set. In the present study, phenological events were analyzed in the evergreen species Aphananthe monoica, Pleuranthodendron lindenii and Psychotria costivenia. A correlation analysis showed that more than half of the variation is shared by phenological event variables (leafing, flowering and fruiting) and radial growth variables (vascular cambium and phellogen activity, and vascular tissue differentiation). Leaf initiation, flowering and vascular cambium activation were the most closely-related simultaneous events during the summer; whereas fruiting, phellogen activity and vascular tissue differentiation were the most closely-related simultaneous events during the summer and fall. This could explain why the leaf initiation and expansion stages, which produce growth regulators, are directly involved in radial growth.

scholarly journals Practical Divinization in Ecologically Threatened Times

2017 ◽  
Vol 12 ◽  
pp. 102-122
Author(s):  
Nanette M. Walsh
Keyword(s):  
Psychological Development ◽  
Ecological Crisis ◽  
Call To Action ◽  
The Past ◽  
The Earth ◽  
New Concepts ◽  
The Face ◽  
New Interpretation ◽  
Green World

Practical divinization describes the practice of connecting our spiritual and psychological development to conscious participation with the earth. This essay investigates the concept of Christian divinization in dialogue with Jung’s conception of individuation. Historically, the idea of divinization emerged from new concepts of personhood synthesized in the 1st century CE. Examining the ancient roots of personhood illuminates concepts of self and divinization within a contemporary theological and psychological context. Annis Pratt’s analysis of the archetype of “green-world epiphany,” evident in much of the literature written by women in the past three centuries, exemplifies the ethos inherent in practical divinization. A new interpretation of Matthew’s “Worry Not Gospel” imagines a female orientation of the text and further confirms the need for an embodied and fully participatory wisdom in relation to the earth. Practical divinization issues forth a call to action and a cause for hope in the face of ecological crisis.

scholarly journals Live imaging reveals the progenitors and cell dynamics of limb regeneration

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Frederike Alwes ◽  
Camille Enjolras ◽  
Michalis Averof
Keyword(s):  
Cell Fate ◽  
Distal Part ◽  
Wound Closure ◽  
Limb Regeneration ◽  
Cell Types ◽  
Live Imaging ◽  
Cell Dynamics ◽  
Cell Lineages ◽  
Cellular Events ◽  
Long Time

Regeneration is a complex and dynamic process, mobilizing diverse cell types and remodelling tissues over long time periods. Tracking cell fate and behaviour during regeneration in active adult animals is especially challenging. Here, we establish continuous live imaging of leg regeneration at single-cell resolution in the crustacean Parhyale hawaiensis. By live recordings encompassing the first 4-5 days after amputation, we capture the cellular events that contribute to wound closure and morphogenesis of regenerating legs with unprecedented resolution and temporal detail. Using these recordings we are able to track cell lineages, to generate fate maps of the blastema and to identify the progenitors of regenerated epidermis. We find that there are no specialized stem cells for the epidermis. Most epidermal cells in the distal part of the leg stump proliferate, acquire new positional values and contribute to new segments in the regenerating leg.

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