Freezing behavior of xylem ray parenchyma cells in softwood species with differences in the organization of cell walls

PROTOPLASMA ◽  
1999 ◽  
Vol 206 (1-3) ◽  
pp. 31-40 ◽  
Author(s):  
S. Fujikawa ◽  
K. Kuroda ◽  
Y. Jitsuyama ◽  
Y. Sano ◽  
J. Ohtani
IAWA Journal ◽  
2009 ◽  
Vol 30 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Pat Denne ◽  
Siân Turner

Differences between the ray structure of rootwood and stemwood were analysed in 11 species from 5 families of gymnosperms. Rootwood was consistently found to have fewer ray tracheids, with ray parenchyma cells which were taller axially, wider tangentially, but shorter radially, and had more pits per cross-field than stemwood. A scale for quantifying types of cross-field pitting is proposed, and statistically significant differences in type and diameter of cross-field pitting were found between rootwood and stemwood of most species sampled. These structural differences have practical implications for identification of gymnosperm roots, and for distinguishing between rootwood and stemwood.


IAWA Journal ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 383-401 ◽  
Author(s):  
Jong Sik Kim ◽  
Geoffrey Daniel

Although there is considerable information on anatomy and gross chemistry of oak wood, little is known on the ultrastructure and chemistry at the individual cell wall level. In particular, differences in ultrastructure and chemistry within the same cell type between earlywood (EW) and latewood (LW) are poorly understood. This study investigated the ultrastructure and chemistry of (vasicentric) tracheids, vessels, (libriform) fibers and axial/ray parenchyma cells of English oak xylem (Quercus robur L.) using light-, fluorescence- and transmission electron microscopy combined with histo/cytochemistry and immunohisto/ cytochemistry. EW tracheids showed several differences from LW tracheids including thinner cell walls, wider middle lamella cell corner (MLcc) regions and lesser amounts of mannan epitopes. Fibers showed thicker cell walls and higher amounts of mannan epitopes than tracheids. EW vessels were rich in guaiacyl (G) lignin with a characteristic non-layered cell wall organization (absence of S1–3 layers), whereas LW vessels were rich in syringyl (S) lignin with a three layered cell wall structure (S1–3 layers). Formation of a highly lignified and wide protective layer (PL) inside axial/ray parenchyma cells was detected only in EW. Distribution of mannan epitopes varied greatly between cell types and between EW and LW, whereas distribution of xylan epitopes was almost identical in all cell types within a growth ring. Together, this study demonstrates that there are great variations in ultrastructure and chemistry of cell walls within a single growth ring of English oak xylem.


Cryobiology ◽  
1999 ◽  
Vol 38 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Katsushi Kuroda ◽  
Jun Ohtani ◽  
Masatoshi Kubota ◽  
Seizo Fujikawa

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 251
Author(s):  
Katsushi Kuroda ◽  
Kenichi Yamane ◽  
Yuko Itoh

Although the radial movement of minerals in tree trunks is a widely accepted phenomenon, experimental evidence of their movement in standing trees and underlying mechanisms is very limited. Previously, we clarified that cesium (Cs) artificially injected into the outer part of the sapwood of standing Japanese cedar (Cryptomeria japonica D. Don) trunks moved to the inner part of the sapwood, including the intermediate wood, via active transport by xylem parenchyma cells and diffusion through cell walls and then moved into the heartwood by diffusion. To understand the mechanism underlying the radial movement of minerals in the standing tree trunk, it is necessary to clarify their movement in the opposite direction. Therefore, the present study aimed to determine the radial movement of minerals from inside to outside in the trunks of standing trees at the cellular level. For this, a long hole across the center part of the trunk, which reached the heartwood, intermediate wood, and sapwood, was made in standing Japanese cedar trunks, and a solution of stable isotope Cs was continuously injected into the hole for several days as a tracer. The injected part of the trunk was collected after being freeze-fixed with liquid nitrogen, and the frozen sample was subjected to analysis of Cs distribution at the cellular level using cryo-scanning electron microscopy/energy-dispersive X-ray spectroscopy. The Cs injected into the inner sapwood or intermediate wood rapidly moved toward the outer sapwood via xylem ray parenchyma cells together with diffusion through the cell walls. In contrast, the Cs injected into the heartwood barely moved to the sapwood, although it reached a part of the inner intermediate wood. These results suggest that minerals in xylem ray parenchyma cells in the sapwood are bidirectionally supplied to each other; however, the minerals accumulated in the heartwood may not be supplied to living cells.


2014 ◽  
Vol 64 (3) ◽  
pp. 233-238 ◽  
Author(s):  
Beata Niewęgłowska-Guzik

In areas intensely contaminated with sulphur compounds some pine trees (<i>Pinus sylvestris</i> L.) have deformed branches with numerous short sprouts. In the branches lenticular areas with considerably changed xylem elements are found. In these greatly changed xylem areas (GCXAs) deformed tracheids are almost isodiametric, some form hooks and loops. The tracheids and ray parenchyma cells show a differentiated level of cell walls lignification. A significantly larger number of rays and the so-called pseudorings are observed.


IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Pat Denne ◽  
Peter Gasson

Differences in ray structure between root- and stem-wood of softwoods can cause confusion in identifying roots using keys based on stem-wood anatomy. Comparison of root- and stem-wood rays of Larix decidua showed root-wood had fewer ray tracheids, taller, wider but shorter ray parenchyma cells, and larger cross-field pits than stem-wood. The implications of these differences are considered in relation to the identification and function of roots.


IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Yasuaki Sakamoto ◽  
Yuzou Sano

Water conduction and wood anatomy of Salix sachalinensis attacked by watermark disease were investigated. The internal symptom, the watermark, appeared as a brown to brown-black stained zone in sapwood. Dye injection tests revealed that water conduction did not take place in the watermark. However, soft X-ray photography and cryo-scanning electron microscopy revealed that the watermark had a high moisture level. In the watermark, some of the vessels were plugged with tyloses and masses of bacteria, and some of the ray parenchyma cells caused necrosis. Hence, the non-conductive watermark in sapwood can be considered similar to discoloured wood or wetwood.


1960 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
J Cronshaw

Observstion in the electron microscope of carbon replicas of the pits of vessels, ray parenchyma cells, fibres, and tracheids of Eucalyptus regnans has shown the detailed structure of the pit borders and the pit closing membranes. In all cases in the mature wood the primary wall is left apparently without modification as the pit membrane. Unlike the borders of the pits of fibre tracheids and tracheids, the pit borders of the vessels are not separate; the cellulose microfibrils of a border may be common to several pits. The pit borders of fibre traoheids and tracheids are developed as separate entities and have a structure similar to the pit borders of softwood tracheids. The structure of the secondary wall layers associated with the pits is described and related to the structure of the pits. The fine structural features of the pits, especially of the pit closing membranes, are discussed in relation to the movement of liquids into wood.


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