Symplastic Growth and Symplasmic Transport

The epidermis of a linear leaf, as in Poaceae, is established by parallel files of cells originating from the leaf base. Their feature is symplastic growth where neighboring cell walls adhere and do not slide along each other. We developed a simple mechanical cell-based model for symplastic growth of linear leaf blade. The challenge is to determine what restrictions on cell size symplastic growth creates compared to the free growing cells. We assume an unidirectional growing cell ensemble starting from a meristem-like layer of generative cells and then generating parallel cell rows from every cell of the initial layer. Each cell is characterized by its growth function, and growth of the whole leaf blade is accompanied by mutual adjustment between all the cells. Cells divide once they have reached a threshold area. A mathematical model and its implementation are proposed for computational simulation of 1D symplastic growth of tissues. The question analyzed is how a cell grows in a plant tissue if there is a mechanism for regulating the growth of an isolated growing cell and the behavior of the cell wall matter is elastoplastic. The results of the simulation of linear leaf blade growth are compared to those for a free-growing cell population.

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Conducting tissues and phyletic relationships of bryophytes

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2000.0616 ◽

2000 ◽

Vol 355 (1398) ◽

pp. 795-813 ◽

Cited By ~ 90

Author(s):

R. Ligrone ◽

J. G. Duckett ◽

K. S. Renzaglia

Keyword(s):

Long Distance ◽

Sieve Cells ◽

Parenchyma Cells ◽

Cytoplasmic Organization ◽

Symplasmic Transport ◽

Axial System ◽

Similar Organization

Internal specialized conducting tissues, if present, are restricted to the gametophytic generation in liverworts while they may occur in both generations in mosses. Conducting tissues are unknown in the anthocerotes. Water–conducting cells (WCCs) with walls perforated by plasmodesma–derived pores occur in the Calobryales and Pallaviciniaceae (Metzgeriales) among liverworts and in Takakia among mosses. Imperforate WCCs (hydroids) are present in bryoid mosses. A polarized cytoplasmic organization and a distinctive axial system of microtubules is present in the highly specialized food–conducting cells of polytrichaceous mosses (leptoids) and in less specialized parenchyma cells of the leafy stem and seta in other mosses including Sphagnum . A similar organization, suggested to reflect specialization in long–distance symplasmic transport of nutrients, also occurs in other parts of the plant in mosses, including rhizoids and caulonemata, and may be observed in thallus parenchyma cells of liverworts. Perforate WCCs in the Calobryales, Metzgeriales and Takakia , and hydroids in bryoid mosses, probably evolved independently. Because of fundamental differences in developmental design, homology of any of these cells with tracheids is highly unlikely. Likewise, putative food–conducting of bryophytes present highly distinctive characteristics and cannot be considered homologous with the sieve cells of tracheophytes.

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

Australian Journal of Botany ◽

10.1071/bt05130 ◽

2006 ◽

Vol 54 (5) ◽

pp. 493 ◽

Cited By ~ 7

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.

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De l'utilisation du lanthane comme traceur de la voie apoplastique chez Cystoseira nodicaulis (Fucales, Cystoseiraceae)

Canadian Journal of Botany ◽

10.1139/b91-004 ◽

1991 ◽

Vol 69 (1) ◽

pp. 18-25 ◽

Cited By ~ 4

Author(s):

Liliane Pellegrini ◽

Marie Epiard-Lahaye ◽

Michel Penot

Keyword(s):

Cell Walls ◽

Long Distance ◽

Long Distance Transport ◽

Dense Deposits ◽

Symplasmic Transport ◽

Apoplastic Pathway ◽

Distance Transport ◽

Kinetics Of ◽

Dense Marker ◽

Over Time

Lanthanum was used as an electron-dense marker of apoplastic transport in the brown alga Cystoseira nodicaulis. A lanthanum salt, La(NO3)3, was given in seawater at the base of excised branches for 2–8 days. Lanthanum transport into two regions distant from the point of application, the base and apex of the branches, was followed over time by electron microscopy. Restricted localisation of the deposits confirmed that an apoplastic pathway exists in this alga. The kinetics of transport are slow. Dense deposits were located exclusively in the cell walls of meristoderm and cortex cells. The significance of apoplastic transport in algae is discussed in the context of long-distance transport. The existence of an apoplastic route does not exclude the occurrence of symplasmic transport, which is suggested by the numerous plasmodesmata present in the medulla. Key words: algae, apoplast, Cystoseira, lanthanum, long-distance transport.

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Symplasmic Transport and Ion Release to the Xylem

Transport and Transfer Process in Plants ◽

10.1016/b978-0-12-734850-6.50014-9 ◽

1976 ◽

pp. 101-112 ◽

Cited By ~ 32

Author(s):

A. Läuchli

Keyword(s):

Ion Release ◽

Symplasmic Transport

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A quantitative investigation of symplasmic transport in Chara corallina. I. Ultrastructure of the nodal complex cell walls

Canadian Journal of Botany ◽

10.1139/b74-155 ◽

1974 ◽

Vol 52 (6) ◽

pp. 1209-1214 ◽

Cited By ~ 12

Author(s):

R. A. Fischer ◽

J. Dainty ◽

M. T. Tyree

Keyword(s):

Cell Walls ◽

Pore Diameter ◽

Chara Corallina ◽

Central Cell ◽

Relative Area ◽

Complex Cell ◽

Quantitative Investigation ◽

Peripheral Cell ◽

Internodal Cell ◽

Symplasmic Transport

We present a quantitative ultrastructural study of the size and frequency (density distribution) of plasmodesmata in the cell wall in common between the internodal cell and peripheral cell (and central cell) of Chara corallina. In the wall in common between the central cell and internodal cell the relative area occupied by plasmodesmata is 15.3%; the pore diameter (less the plasmalemma) is 118 nm; the length is 1.54 μm, and the frequency is 1.4 × 109 pores/cm2. In the wall in common between the peripheral cell and internodal cell the relative area occupied by the plasmodesmata is 9.6%; the pore diameter is 100 nm; the length is 1.07 μm; and the frequency is 1.2 × 109 pores/cm2. The plasmodesmata have an anastomosing structure like Nitella translucens but the pore diameter and frequency are much greater.

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