The effect of SEM preparation on pit membrane remnants in vessel element end-walls of primitive angiosperms

Flora ◽  
2011 ◽  
Vol 206 (4) ◽  
pp. 310-315 ◽  
Author(s):  
Hong-fang Li ◽  
Yi Ren
Keyword(s):  
Vessel Element ◽  
Primitive Angiosperms ◽  
Pit Membrane

scholarly journals Influence of Cambial Age and Axial Height on the Spatial Patterns of Xylem Traits in Catalpa bungei, a Ring-Porous Tree Species Native to China

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 662 ◽  
Author(s):  
Shan Li ◽  
Xin Li ◽  
Roman Link ◽  
Ren Li ◽  
Liping Deng ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Linear Models ◽  
Axial Position ◽  
Vertical Position ◽  
Vessel Element ◽  
Main Trunk ◽  
Positive Effects ◽  
Cambial Age ◽  
Pit Membrane ◽  
Catalpa Bungei

Studying how cambial age and axial height affects wood anatomical traits may improve our understanding of xylem hydraulics, heartwood formation and axial growth. Radial strips were collected from six different heights (0–11.3 m) along the main trunk of three Manchurian catalpa (Catalpa bungei) trees, yielding 88 samples. In total, thirteen wood anatomical vessel and fiber traits were observed usinglight microscopy (LM) and scanning electron microscopy (SEM), and linear models were used to analyse the combined effect of axial height, cambial age and their interaction. Vessel diameter differed by about one order of magnitude between early- and latewood, and increased significantly with both cambial age and axial height in latewood, while it was positively affected by cambial age and independent of height in earlywood. Vertical position further had a positive effect on earlywood vessel density, and negative effects on fibre wall thickness, wall thickness to diameter ratio and length. Cambial age had positive effects on the pit membrane diameter and vessel element length, while the annual diameter growth decreased with both cambial age and axial position. In contrast, early- and latewood fiber diameter were unaffected by both cambial age and axial height. We further observed an increasing amount of tyloses from sapwood to heartwood, accompanied by an increase of warty layers and amorphous deposits on cell walls, bordered pit membranes and pit apertures. This study highlights the significant effects of cambial age and vertical position on xylem anatomical traits, and confirms earlier work that cautions to take into account xylem spatial position when interpreting wood anatomical structures, and thus, xylem hydraulic functioning.

scholarly journals Effect of Exogenously Applied 24-Epibrassinolide and Brassinazole on Xylogenesis and Microdistribution of Cell Wall Polymers in Leucaena leucocephala (Lam) De Wit

2021 ◽  
Author(s):  
S. Pramod ◽  
M. Anju ◽  
H. Rajesh ◽  
A. Thulaseedharan ◽  
Karumanchi S. Rao
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Leucaena Leucocephala ◽  
Higher Plants ◽  
Lignin Content ◽  
Wood Quality ◽  
Wall Structure ◽  
Vessel Element ◽  
Xylem Differentiation ◽  
Cell Wall Polymers

AbstractPlant growth regulators play a key role in cell wall structure and chemistry of woody plants. Understanding of these regulatory signals is important in advanced research on wood quality improvement in trees. The present study is aimed to investigate the influence of exogenous application of 24-epibrassinolide (EBR) and brassinosteroid inhibitor, brassinazole (BRZ) on wood formation and spatial distribution of cell wall polymers in the xylem tissue of Leucaena leucocephala using light and immuno electron microscopy methods. Brassinazole caused a decrease in cambial activity, xylem differentiation, length and width of fibres, vessel element width and radial extent of xylem suggesting brassinosteroid inhibition has a concomitant impact on cell elongation, expansion and secondary wall deposition. Histochemical studies of 24-epibrassinolide treated plants showed an increase in syringyl lignin content in the xylem cell walls. Fluorescence microscopy and transmission electron microscopy studies revealed the inhomogenous pattern of lignin distribution in the cell corners and middle lamellae region of BRZ treated plants. Immunolocalization studies using LM10 and LM 11 antibodies have shown a drastic change in the micro-distribution pattern of less substituted and highly substituted xylans in the xylem fibres of plants treated with EBR and BRZ. In conclusion, present study demonstrates an important role of brassinosteroid in plant development through regulating xylogenesis and cell wall chemistry in higher plants.

Phenological Comparison of the Onset of Vessel Formation Between Ring-Porous and Diffuse-Porous Deciduous Trees in a Japanese Temperate Forest

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 431-444 ◽  
Author(s):  
Mitsuo Suzuki ◽  
Kiyotsugu Yoda ◽  
Hitoshi Suzuki
Keyword(s):  
Secondary Wall ◽  
Leaf Expansion ◽  
Vessel Element ◽  
Early Maturation ◽  
Vessel Formation ◽  
Wall Deposition ◽  
Water Conduction ◽  
Vessel Elements ◽  
Secondary Wall Deposition ◽  
Diffuse Porous

Initiation of vessel formation and vessel maturation indicated by secondary wall deposition have been compared in eleven deciduous broadleaved tree species. In ring-porous species the first vessel element formation in the current growth ring was initiated two to six weeks prior to the onset of leaf expansion, and secondary wall deposition on the vessel elements was completed from one week before to three weeks after leaf expansion. In diffuse-porous species, the first vessel element formation was initiated two to seven weeks after the onset of leaf expansion, and secondary wall deposition was completed four to nine weeks after leaf expansion. These results suggest that early maturation of the first vessel elements in the ring-porous species will serve for water conduction in early spring. On the contrary, the late maturation of the first vessel elements in the diffuse-porous species indicates that no new functional vessels exist at the time of the leaf expansion.

scholarly journals Bacterial Biodegradation of Extractives and Patterns of Bordered Pit Membrane Attack in Pine Wood

2000 ◽  
Vol 66 (12) ◽  
pp. 5201-5205 ◽  
Author(s):  
Todd A. Burnes ◽  
Robert A. Blanchette ◽  
Roberta L. Farrell
Keyword(s):  
Xanthomonas Campestris ◽  
Treated Wood ◽  
Wood Chips ◽  
Pulp Mills ◽  
Wood Extractives ◽  
Bordered Pit ◽  
Pine Wood ◽  
Pit Membrane ◽  
Pine Wood Chips ◽  
Ray Parenchyma Cells

ABSTRACT Wood extractives, commonly referred to as pitch, cause major problems in the manufacturing of pulp and paper. Treatment of nonsterile southern yellow pine chips for 14 days withPseudomonas fluorescens, Pseudomonas sp.,Xanthomonas campestris, and Serratia marcescens reduced wood extractives by as much as 40%. Control treatments receiving only water lost 11% of extractives due to the growth of naturally occurring microorganisms. Control treatments were visually discolored after the 14-day incubation, whereas bacterium-treated wood chips were free of dark staining. Investigations using P. fluorescens NRRL B21432 showed that all individual resin and fatty acid components of the pine wood extractives were substantially reduced. Micromorphological observations showed that bacteria were able to colonize resin canals, ray parenchyma cells, and tracheids. Tracheid pit membranes within bordered pit chambers were degraded after treatment with P. fluorescensNRRL B21432. P. fluorescens and the other bacteria tested appear to have the potential for biological processing to substantially reduce wood extractives in pine wood chips prior to the paper making process so that problems associated with pitch in pulp mills can be controlled.

Mass Transfer Through Microwave-Treated Fir Wood (Abies albaL.): A Gymnosperm Species with Torus Margo Pit Membrane

2013 ◽  
Vol 31 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Hadi Dashti ◽  
Asghar Tarmian ◽  
Mehdi Faezipour ◽  
Sahab Hedjazi ◽  
Mahdi Shahverdi
Keyword(s):  
Mass Transfer ◽  
Pit Membrane

INTERVASCULAR PITTING ACROSS THE ANNUAL RING BOUNDARY IN BETULA PLATYPHYLLA VAR. JAPONICA AND FRAXINUS MANDSHURICA VAR. JAPONICA

IAWA Journal ◽  
2004 ◽  
Vol 25 (2) ◽  
pp. 129-140 ◽  
Author(s):  
Yuzou Sano
Keyword(s):  
Annual Ring ◽  
Peripheral Region ◽  
Betula Platyphylla ◽  
Annual Rings ◽  
Fraxinus Mandshurica ◽  
Common Wall ◽  
Pit Membrane ◽  
Perforation Plates ◽  
Soluble Material ◽  
Ring Boundary

The structure of intervascular pits, located at the boundary between the outermost and the second youngest annual rings in Betula platyphylla var. japonica and Fraxinus mandshurica var. japonica was examined by field-emission scanning electron microscopy. Unilaterally compound pits were present in the intervascular common wall at the annual ring boundary in both species. On the outer annual ring side of the unilaterally compound pits, outlines of pit membranes were curved or trifoliate, and each pit aperture was often elongated and curved. The porosity of the intervascular pit membranes differed between the two species. In B. platyphylla var. japonica, microfibrils were loosely packed in the peripheral region of each pit membrane, and openings of up to 300 nm in width were observed. By contrast, microfibrils were densely packed throughout the entire pit membranes in F. mandshurica var. japonica, and no openings perforating the pit membranes entirely were found. In addition, each species exhibited some unique features. In B. platyphylla var. japonica, extensive ethanol-soluble material was detected not only in the intervascular pits but also on scalariform perforation plates. In F. mandshurica var. japonica, we observed fine curly fibrils of unkown chemical composition in the intervascular pit membranes.

WOOD CHARACTERISTICS OF AMAZON FOREST TYPES

IAWA Journal ◽  
2000 ◽  
Vol 21 (3) ◽  
pp. 277-292 ◽  
Author(s):  
D.W. Woodcock ◽  
G. Dos Santos ◽  
C. Reynel
Keyword(s):  
Specific Gravity ◽  
Vessel Diameter ◽  
Floodplain Forest ◽  
Small Samples ◽  
Vessel Element ◽  
Amazon Forest ◽  
Forest Types ◽  
Swamp Forest ◽  
Climate Controls ◽  
Pattern Of Variation

The Tambopata region of the southern Peruvian Amazon supports a high diversity of both woody plants and forest types. Woods collected from low riverside vegetation, floodplain forest, clay-soil forest on an upper terrace, sandy-soil forest, and swamp forest provide an opportunity to test for significant differences in quantitative anatomical characters among forest types. Vessel-element length in floodplain-forest trees is significantly greater than in the other forest types. Specific gravity is lower in the two early-successional associations (low riverine forest and mature floodplain forest). Vessel diameter and density do not show significant differences among forest types and may be responding to overall climate controls. These two characters, however, show a pattern of variation within a transect extending back from the river along a gradient of increasing substrate and forest age; in addition, sites characterized by frequent flooding or presence of standing water lack vessels in the wider-diameter classes. The six characters analyzed show distributions that are, with the exception of wood specific gravity, significantly nonnormally distributed, a consideration that may be important in representing characteristics of assemblages of taxa. The degree of variability seen in some of the quantitative characters shows the importance of either basing analysis on adequate sample sizes or identifying robust indicators that can be used with small samples.

EARLYWOOD VESSELS IN RING-POROUS TREES BECOME FUNCTIONAL FOR WATER TRANSPORT AFTER BUD BURST AND BEFORE THE MATURATION OF THE CURRENT-YEAR LEAVES

IAWA Journal ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 315-331 ◽  
Author(s):  
Peter Kitin ◽  
Ryo Funada
Keyword(s):  
Water Transport ◽  
Time Course ◽  
Growing Season ◽  
Early Spring ◽  
Vessel Element ◽  
Full Time ◽  
Bud Burst ◽  
Long Time ◽  
Wall Perforation ◽  
Earlywood Vessels

This paper reviews the development of xylem vessels in ring-porous dicots and the corresponding leaf phenology. Also included are our original observations on the time-course of vessel element growth, secondary wall deposition, and end wall perforation in the deciduous hardwood Kalopanax septemlobus. Different patterns of xylem growth and phenology serve different strategies of the species for adaptation to seasonal climates. Trees with ring-porous xylem form wide earlywood vessels (EWV) in spring and narrow latewood vessels in summer. The wide EWV become embolized or blocked with tyloses by the end of the growing season while the narrow vessels may remain functional for many years. The co-occurrence of wide and narrow vessels provides both efficiency and safety of the water transport as well as a potentially longer growing season. It has for a long time been assumed that EWV in ring-porous hardwoods are formed in early spring before bud burst in order to supply sap to growing leaves and shoots.However, the full time-course of development of EWV elements from initiation of growth until maturation for water transport has not been adequately studied until recently. Our observations clarify a crucial relationship between leaf maturation and the maturation of earlywood vessels for sap transport. Accumulated new evidence shows that EWV in branches and upper stem parts develop earlier than EWV lower in the stem. The first EWV elements are fully expanded with differentiated secondary walls by the time of bud burst. In lower stem parts, perforations in vessel end walls are formed after bud burst and before the new leaves have achieved full size. Therefore, the current-year EWV network becomes functional for water transport only by the time when the first new leaves are mature.

Hydraulic consequences of enzymatic breakdown of grapevine pit membranes

2021 ◽  
Author(s):  
Ana Clara Fanton ◽  
Craig Brodersen
Keyword(s):  
Hydraulic Conductivity ◽  
Vascular System ◽  
Membrane Surface ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Biological Response ◽  
Plant Host ◽  
Important Species ◽  
Membrane Area ◽  
Pit Membrane

Abstract Xylella fastidiosa (Xf) is the xylem-dwelling bacterial agent associated with Pierce’s Disease (PD), which leads to significant declines in productivity in agriculturally important species like grapevine (Vitis vinifera). Xf spreads through the xylem network by digesting the pit membranes between adjacent vessels, thereby potentially changing the hydraulic properties of the stem. However, the effects of Xf on water transport varies depending on the plant host and the infection stage, presenting diverse outcomes. Here, we investigated the effects of polygalacturonase, an enzyme known to be secreted by Xf when it produces biofilm on the pit membrane surface, on stem hydraulic conductivity and pit membrane integrity. Experiments were performed on six grapevine genotypes with varying levels of PD resistance, with the expectation that pit membrane resistance to degradation by polygalacturonase may play a role in PD-resistance. Our objective was to study a single component of this pathosystem in isolation to better understand the mechanisms behind reported changes in hydraulics, thereby excluding the biological response of the plant to the presence of Xf in the vascular system. Pit membrane damage only occurred in stems perfused with polygalacturonase. Although the damaged pit membrane area was small (2-9% of the total pit aperture area), membrane digestion led to significant changes in the median air-seeding thresholds, and most importantly, shifted frequency distribution. Finally, enzyme perfusion also resulted in a universal reduction in stem hydraulic conductivity, suggesting the development of tyloses may not be the only contributing factor to reduced hydraulic conductivity in infected grapevine.

Sign in / Sign up

Export Citation Format

Share Document