Unusual Pit Membrane Remnants in Perforation Plates of Cyrillaceae

2003 ◽  
Vol 130 (4) ◽  
pp. 225 ◽  
Author(s):  
Edward L. Schneider ◽  
Sherwin Carlquist
Keyword(s):  
Pit Membrane ◽  
Perforation Plates

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.

Pit membrane remnants in perforation plates and other vessel details of Cornales

Brittonia ◽  
2004 ◽  
Vol 56 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Edward L. Schneider ◽  
Sherwin Carlquist
Keyword(s):  
Pit Membrane ◽  
Perforation Plates

SEM STUDIES ON VESSEL ELEMENTS OF SAURURACEAE

IAWA Journal ◽  
2001 ◽  
Vol 22 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Edward L. Schneider ◽  
Sherwin Carlquist
Keyword(s):  
Light Microscopy ◽  
Tracheary Element ◽  
Lateral Wall ◽  
Seasonally Dry ◽  
Pit Membrane ◽  
Vessel Elements ◽  
Perforation Plates ◽  
Sem Studies

Vessel elements in Anemopsis have simple perforation plates and alternate (sometimes scalariform) lateral wall pitting; Anemopsis has tracheids with large, densely placed pits. These conditions are in contrast with tracheary element features of Gymnotheca, Houttuynia, and Saururus, in which perforation plates are scalariform (many with notably slender bars) and with scalariform lateral wall pitting. Porose pit membrane remnants, which cannot be seen with light microscopy, are newly reported in Houttuynia and Saururus. These porose pit membranes underline the primitive nature of vessels in Gymnotheca, Houttuynia, and Saururus. The highly specialized vessels of Anemopsis may relate to entry into seasonally dry habitats, whereas Gymnotheca, Houttuynia, and Saururus may have experienced unbroken occupancy of mesic habitats.

scholarly journals Similar hydraulic efficiency and safety across vesselless angiosperms and vessel-bearing species with scalariform perforation plates

2019 ◽  
Vol 70 (12) ◽  
pp. 3227-3240 ◽  
Author(s):  
Santiago Trueba ◽  
Sylvain Delzon ◽  
Sandrine Isnard ◽  
Frederic Lens
Keyword(s):  
Hydraulic Conductivity ◽  
Rain Forest ◽  
New Caledonia ◽  
Membrane Thickness ◽  
Hydraulic Efficiency ◽  
Key Innovation ◽  
Pit Membrane ◽  
Conduit Diameter ◽  
Perforation Plates

AbstractThe evolution of xylem vessels from tracheids is put forward as a key innovation that boosted hydraulic conductivity and photosynthetic capacities in angiosperms. Yet, the role of xylem anatomy and interconduit pits in hydraulic performance across vesselless and vessel-bearing angiosperms is incompletely known, and there is a lack of functional comparisons of ultrastructural pits between species with different conduit types. We assessed xylem hydraulic conductivity and vulnerability to drought-induced embolism in 12 rain forest species from New Caledonia, including five vesselless species, and seven vessel-bearing species with scalariform perforation plates. We measured xylem conduit traits, along with ultrastructural features of the interconduit pits, to assess the relationships between conduit traits and hydraulic efficiency and safety. In spite of major differences in conduit diameter, conduit density, and the presence/absence of perforation plates, the species studied showed similar hydraulic conductivity and vulnerability to drought-induced embolism, indicating functional similarity between both types of conduits. Interconduit pit membrane thickness (Tm) was the only measured anatomical feature that showed a relationship to significant vulnerability to embolism. Our results suggest that the incidence of drought in rain forest ecosystems can have similar effects on species bearing water-conducting cells with different morphologies.

Wound Reaction of the Parenchyma in Betula

IAWA Journal ◽  
1990 ◽  
Vol 11 (4) ◽  
pp. 413-420 ◽  
Author(s):  
Uwe Schmitt ◽  
Walter Liese
Keyword(s):  
Betula Pendula ◽  
Structural Changes ◽  
Light And Electron Microscopy ◽  
Protective Layer ◽  
Xylem Parenchyma ◽  
Fibrillar Material ◽  
Pit Membrane ◽  
Wound Reaction ◽  
Simultaneous Loss ◽  
Perforation Plates

Reactions in the xylem parenchyma of Betula pendula Roth following wounding in late spring have been investigated by light and electron microscopy. Structural changes in contact parenchyma cells are described in relation to the formation of plugs in vessels and fibres. Swelling of the Protective Layer (PL) with a simultaneous loss in electron density appears first. Fibrillar material is then synthesised, which accumulates outside the cytoplasm between the plasmalemma and the modified PL. The PL now consists of loosely packed fibrils with a structure similar to the accumulating fibrillar material. After extrusion of fibrils through the pit membrane into the lumina of adjacent vessels a membranous layer on the scalariform perforation plates as well as plugs are formed; the latter are also built up in fibres. These reactions spread axially less extensively in cells near the cambium than in the more centrally located ones.

Pentaphragma: A Unique Wood and its Significance

IAWA Journal ◽  
1997 ◽  
Vol 18 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Sherwin Carlquist
Keyword(s):  
Secondary Xylem ◽  
Lateral Wall ◽  
Qualitative And Quantitative ◽  
Primary Xylem ◽  
Pit Membrane ◽  
Bordered Pits ◽  
Vessel Elements ◽  
Perforation Plates ◽  
Secondary Woodiness ◽  
Basal Position

Qualitative and quantitative data are given for wood anatomy of three species of Pentaphragma (Pentaphragmataceae); the woods of the three species are very similar. Pentaphragma is rayless, but eventually develops rays in at least one of the species studied. This is interpreted as related to secondary woodiness or upright habit within a predominantly herbaceous phylad. The vessel elements of Pentaphragma have features universally interpreted as primitive in dicotyledons: scalariform perforation plates with numerous bars; pit membrane remnants in perforations; scalariform lateral wall pitting; the genus also has fiber-tracheids with prominently bordered pits. These character states accord with the basal position in Campanulales accorded Pentaphragmataceae by Cosner et al. (1992), and suggests that order may have begun with more numerous primitive features than generally recognized. The presence of occasional scalariform perforation plates, often aberrant, in secondary xylem of families of Asterales sensu lato - Campanulaceae, Pentaphragmataceae, Valerianaceae, and even Asteraceae (e.g., certain Lactuceae) - can be attributed to paedomorphosis, extending these plates into secondary xylem from primary xylem. Raylessness in Pentaphragma can be described in terms of secondary woodiness or paedomorphosis. The fact that fiber-tracheids are shorter than vessel elements in Pentaphragma is believed related to raylessness also, because some fiber-tracheids are produced from 'potential' ray areas.

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