DOCSLIB.ORG

EVIDENCE for AUXIN REGULATION of BORDERED-PIT POSITIONING DURING TRACHEID DIFFERENTIATION in LARIX LARICINA By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
EVIDENCE for AUXIN REGULATION of BORDERED-PIT POSITIONING DURING TRACHEID DIFFERENTIATION in LARIX LARICINA By IAWA Journal, Vol. 16 (3),1995: 289-297 EVIDENCE FOR AUXIN REGULATION OF BORDERED-PIT POSITIONING DURING TRACHEID DIFFERENTIATION IN LARIX LARICINA by Mathew Adam Leitch & Rodney Arthur Savidge 1 Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, E3B 6C2, Canada SUMMARY Chips containing cambium intact between xylem and phloem were cut from 8-year-old stem regions of 20-30-year-old dormant Larix laricina in late spring and cultured under controlled conditions for six weeks on a defined medium containing varied concentrations of I-naphthalene acetic acid (NAA, a synthetic auxin). Microscopy revealed that auxin was essential for cambial growth and tracheid differentiation. Low (0.1 mg/l) and high (10.0 mg/l) auxin concentrations were conducive to bordered pits forming in tangential walls, whereas an intermediate concentration (1.0 mg/l) of NAA favoured positioning of pits in radial walls. INTRODUCTION Two decades ago, Barnett and Harris (1975) pointed out that the processes involved in bordered-pit formation were incompletely understood, in particular the way in which the pit site is determined and how adjoining cells form a perfectly symmetrical bor­ dered-pit pair. Observing that radial walls of enlarging cambial derivatives were vari­ ably thick and thin, Barnett and Harris (1975) advanced the hypothesis that bordered­ pit development occurs at sites where the primary wall is thinned through the process of centrifugal displacement of microfibrils. Others, however, considered that a thick­ ening rather than a thinning of the primary wall was indicative of the site where pit development commenced (FengeI1972; Parham & Baird 1973). It has long been known that the pit border begins to develop before general secondary wall formation occurs (Sachs 1882), but whether primary wall thinning or thickening is associated with bor­ dered-pit development remains to be conclusively demonstrated, and the factor(s) con­ trolling bordered-pit development still remain unknown (Savidge 1985). In most conifer species, bordered pits are produced exclusively within radial walls of developing earlywood tracheids. On the other hand, experimental induction of earlywood formation in young stem cuttings of Pinus spp., by application of auxin, revealed that positioning of bordered pits in the radial walls was not an absolute 1) Author to whom correspondence should be addressed; E-mail: [email protected]. Downloaded from Brill.com09/30/2021 07:43:40PM via free access 290 IAWA Journal, Vol. 16 (3),1995 Downloaded from Brill.com09/30/2021 07:43:40PM via free access Leitch & Savidge - Auxin regulation of pit positioning 291 requirement (Savidge & Wareing 1981; Savidge 1983). Similarly, when earlywood was induced in 'chip' cultures from stems of Pinus contorta and Larix laricina, bor­ dered pits were common in both radial and tangential walls (Savidge 1983, 1993). Auxin was essential for induction of wood formation in the chip cultures; hence, it seemed appropriate to investigate what, if any, effect varied auxin concentration would have on bordered-pit development. As detailed below, the results indicate that auxin is a factor controlling pit placement. MATERIALS AND METHODS Trees Three dormant tamarack trees [Larix laricina (Du Roi) K. Koch] between 20 and 30 years old and 6 to 8 metres in height and having no visible deformities were felled in the University of New Brunswick Forest (Fredericton, N.B., Canada) on March 30th. Following removal of lateral shoots, the 8-year-old section of the main-stem axis from each tree was removed and transferred to the laboratory for in vitro investiga­ tions. Chip preparation and culturing Surface sterilization, tissue explant procedures, culture conditions (under ordinary white fluorescent illumination, 12 Watts m- 2) and visual assessments were done as previously detailed (Savidge 1993). I-Naphthalene acetic acid (NAA, Sigma Chern. Co.), a synthetic auxin, was incorporated at 0.0,0.1,1.0, and 10.0 mg/l to provide four distinct media. The media were adjusted to pH 5.8 with 0.1 N KOH, and agar (0.8% w/v, Difco-Bacto agar) was added before autoclaving (120°C, 140 kPa, 20 min.). Sterilized media were poured into pre-sterilized petri dishes (Fisher Sci., No. 8-757- 14) to a depth of 4-6 mm (approximately 80 ml of medium/dish) and allowed to solidify. Fifteen chips per treatment (NAA concentration) per tree were investigated. Microscopy Transverse and radial sections, cut by hand with a razor blade, were mounted in glycerin on glass slides. Unstained sections were examined with brightfield or Nomarski interference contrast illumination using a Reichart Polyvar photomicroscope. To avoid Fig. 1. Growth response of a chip on 1.0 mg/l NAA as seen in transverse section cut by hand. c: cambial zone; r: ray; curved arrow: latewood-earlywood boundary; arrowheads: border­ ed pits in tangential walls; arrow: bordered pits in a transverse end wall. Bar = 10 J..IIll. - Fig. 2. Radial hand section showing radial wall pitting in induced earlywood of a chip grown on 1.0 mg/l NAA. c: cambial zone; a: axial parenchyma as the first cells produced adjacent to the latewood boundary (curved arrow); arrowheads: bordered pits in transverse end walls of shortened fusiform cells. Bar = 10 J..IIll. - Fig. 3. Radial hand section showing biseriate radial wall pitting in induced earlywood of a chip grown on 0.1 mg/l NAA. The curved arrow indi­ cates the earlywood-Iatewood boundary. Bar = 10 J..IIll. - Fig. 4. Radial hand section showing tangential wall pitting (arrowhead) in induced earlywood of a chip grown on 0.1 mg/l NAA. a: axial parenchyma adjoining the latewood. Downloaded from Brill.com09/30/2021 07:43:40PM via free access 292 IAWA Journal, Vol. 16 (3), 1995 14 12 ~ 10 03 u 4 2 o NAA concent rat ion (mg /I ) _ CZceli s IZ22 RE ce ll s. xy logen ic chips D TE·s. xy logen ic chips Fig. 5. Response of cultured Larix laricina chips to different concentrations ofNAA. CZ: cambial zone; RE: radial enlarged primary walled cambial derivatives; TE: mature tracheary elements produced during the culture period. Bars are standard errors of means. possible effects of wounding near the chip edges, analyses were done of the earlywood produced only at the mid-point of the chips. Radial and tangential wall numbers of bordered pits were counted in radial sections by variable focussing using a x 40 ob­ jective. For quantitative data, Student's t-test was used to compare responses at the 95 % confidence level (Zar 1984). Standard errors of the means were calculated for the results. RESULTS The cambium was dormant when the cultures were initiated. Cambial cell divisions occurred only in chips that produced a compact, striated type of callus as noted previ­ ously (Savidge 1993). During chip growth, fusiform cambial cells divided periclinally. maintaining radial file continuity (Fig. 1, 2). Pseudotransverse anticlinal divisions oc­ curred occasionally also, resulting in doubling of some radial files (Fig. 1). True trans­ verse divisons in the fusiform cells yielded shortened axial parenchyma and tracheids Downloaded from Brill.com09/30/2021 07:43:40PM via free access Leitch & Savidge - Auxin regulation of pit positioning 293 70 60 ~ '"E E 50 .... a.0) ....or. 40 0) .0 E c:::l '5.. 30 -0 ~ 0) "0.... 0 20 .0 10 0 0.0 0.1 1.0 10.0 NAA concentration (mg/l) o radial wa ll pits ~ tangential wall pits Fig. 6. Distribution of bordered pits between radial and tangential walls in reponse to varied NAA concentration. Bars are standard errors of means. (Fig. 2). The first cells to differentiate adjacent to latewood usually appeared as axial parenchyma (Fig. 1-4). Tracheid production occurred only when NAA was included in the medium (Fig. 5). Controls (0.0 mg/l NAA) showed no cambial growth response, nor did cal­ lus form on these chips. NAA at 1.0 mg/l yielded a stronger cambial response than did NAA at 0.1 and 10 mg/l (Fig. 5). Bordered pits were conspicuously present in both radial (Fig. 3) and tangential (Fig. 4) walls. Bordered pits were also commonly seen in the transverse walls of both axial and ray tracheids (Fig. 1, 2); however, these end-wall pits were not counted in this study. NAA at 0.1 mg/l was associated with the highest number per unit area of bordered pits in tangential walls. On the other hand, NAA at 10.0 mg/l yielded the highest ratio of tangential to radial wall pitting (Fig. 6). In contrast to the low and high NAA treatments, NAA at 1.0 mg/l resulted in bordered pits being produced pri­ marily in the radial walls (Fig. 6). Downloaded from Brill.com09/30/2021 07:43:40PM via free access 294 IAWA Journal, Vol. 16 (3), 1995 DISCUSSION NAA in the medium was essential for both cambial and callus growth to occur, In a previous study with Larix laricina, endogenous auxin (indol-3-ylacetic acid, IAA) concentrations in the dormant cambial region were determined by combined gas chro­ matography-mass spectrometry to be low throughout the winter months (Savidge 1991). The existence of low endogenous IAA agrees with our present observation that neither cambial nor callus growth occurred in explants on the medium lacking auxin. It fol­ lows that the observed in vitro responses required the presence of exogenous auxin in the medium. Nevertheless, the cambial response rarely extended to 20 earlywood tracheids per radial file. Following this initial response, cambial activity and tracheid production ceased. Sub-culturing of chips onto media identical to those on which they had first been explanted did not encourage continuing wood formation. Hence, al­ though the results indicate that auxin is limiting for reactivation and growth of the dormant cambium, they also point to there being one or more additional endogenous factors, present in the stem at the time of explanting, which becomes depleted during in vitro growth (Savidge 1993, 1994).
Load more

Recommended publications
  • How Trees Modify Wood Development to Cope with Drought
    DOI: 10.1002/ppp3.29 REVIEW Wood and water: How trees modify wood development to cope with drought F. Daniela Rodriguez‐Zaccaro | Andrew Groover US Forest Service, Pacific Southwest Research Station; Department of Plant Societal Impact Statement Biology, University of California Davis, Drought plays a conspicuous role in forest mortality, and is expected to become more Davis, California, USA severe in future climate scenarios. Recent surges in drought-associated forest tree Correspondence mortality have been documented worldwide. For example, recent droughts in Andrew Groover, US Forest Service, Pacific Southwest Research Station; Department of California and Texas killed approximately 129 million and 300 million trees, respec- Plant Biology, University of California Davis, tively. Drought has also induced acute pine tree mortality across east-central China, Davis, CA, USA. Email: [email protected], agroover@ and across extensive areas in southwest China. Understanding the biological pro- ucdavis.edu cesses that enable trees to modify wood development to mitigate the adverse effects Funding information of drought will be crucial for the development of successful strategies for future for- USDA AFRI, Grant/Award Number: 2015- est management and conservation. 67013-22891; National Science Foundation, Grant/Award Number: 1650042; DOE Summary Office of Science, Office of Biological and Drought is a recurrent stress to forests, causing periodic forest mortality with enor- Environmental Research, Grant/Award Number: DE-SC0007183 mous economic and environmental costs. Wood is the water-conducting tissue of tree stems, and trees modify wood development to create anatomical features and hydraulic properties that can mitigate drought stress. This modification of wood de- velopment can be seen in tree rings where not only the amount of wood but also the morphology of the water-conducting cells are modified in response to environmental conditions.
    [Show full text]
  • A Physiologically Explicit Morphospace for Tracheid-Based Water Transport in Modern and Extinct Seed Plants
    A Physiologically Explicit Morphospace for Tracheid-based Water Transport in Modern and Extinct Seed Plants The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Wilson, Jonathan P., and Andrew H. Knoll. 2010. A physiologically explicit morphospace for tracheid-based water transport in modern and extinct seed plants. Paleobiology 36(2): 335-355. Published Version doi:10.1666/08071.1 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:4795216 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP Wilson - 1 A Physiologically Explicit Morphospace for Tracheid-Based Water Transport in Modern and Extinct Seed Plants Jonathan P. Wilson* Andrew H. Knoll September 7, 2009 RRH: PHYSIOLOGICALLY EXPLICIT MORPHOSPACE LRH: JONATHAN P. WILSON AND ANDREW H. KNOLL Wilson - 2 Abstract We present a morphometric analysis of water transport cells within a physiologically explicit three-dimensional space. Previous work has shown that cell length, diameter, and pit resistance govern the hydraulic resistance of individual conducting cells; thus, we use these three parameters as axes for our morphospace. We compare living and extinct plants within this space to investigate how patterns of plant conductivity have changed over evolutionary time. Extinct coniferophytes fall within the range of living conifers, despite differences in tracheid-level anatomy. Living cycads, Ginkgo biloba, the Miocene fossil Ginkgo beckii, and extinct cycadeoids overlap with both conifers and vesselless angiosperms.
    [Show full text]
  • University of Michigan University Library
    CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN VOL. XIX, NO.6, pp. 65-88 (7 pls., 1 fig.) SEFTEMBER25, 1964 A FOSSIL DENNSTAEDTIOID FERN FROM THE EOCENE CLARNO FORMATION OF OREGON BY CHESTER A. ARNOLD and LYMAN H. DAUGHERTY MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN ANN ARBOR CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY Director: LEWISB. KELLUM The series of contributions from the Museum of Paleontology is a medium for the publication of papers based chiefly upon the collections in the Museum. When the number of pages issued is sufficient to make a volume, a title page and a table of contents will be sent to libraries on the mailing list, and to individuals upon request. A list of the separate papers may also be obtained. Correspondence should be directed to the Museum of Paleontology, The University of Michigan, Ann Arbor, Michigan. VOLUMEXIX 1. Silicified Trilobites from the Devonian Jeffersonville Limestone at the Falls of the Ohio, by Erwin C. Stumm. Pages 1-14, with 3 plates. 2. Two Gastropods from the Lower Cretaceous (Albian) of Coahuila, Mexico, by Lewis B. Kellum and Kenneth E. Appelt. Pages 15-22, with 2 figures. 3. Corals of the Traverse Group of Michigan, Part XII, The Small-celled Species of Favosites and Emmonsia, by Erwin C. Stumm and John H. Tyler. Pages 23-36, with 7 plates. 4. Redescription of Syntypes of the Bryozoan Species Rhombotrypa quadrata (Rominger), by Roger J. Cuffey and T. G. Perry. Pages 37-45, with 2 plates. 5. Rare Crustaceans from the Upper Devonian Chagrin Shale in Northern Ohio, by Myron T.
    [Show full text]
  • + Complex Tissues
    + Complex Tissues ! Complex tissues are made up of two or more cell types. ! Xylem - Chief conducting tissue for water and minerals absorbed by the roots. ! Vessels - Made of vessel elements. ! Long tubes open at each end. ! Tracheids - Tapered at the ends with pits that allow water passage between cells. ! Rays - Lateral conduction. + Complex Tissues - Xylem ! Tracheids ! Long, thin cells with pointed ends that conduct water vertically ! Line up in columns like pipes by overlapping their tapered ends ! die when reach maturity ! Water conducted through tubes made up of tracheid cell walls ! Wherever two ends join, small holes in the cell wall called pits line up to allow water to flow from one tracheid to another. + Complex Tissues - Xylem ! Pits always occur in pairs so that a pair of pits lines up on either side of the middle lamella, or center layer, of the cell wall. + Complex Tissues - Xylem !Vessel elements !barrel-shaped cells with open ends that conduct water vertically. !line up end to end forming columns, called vessels, that conduct water. !Some have completely open ends, while others have narrow strips of cell wall material that partially covers the ends !Die at maturity, like tracheids. + Complex Tissues - Xylem ! Ray cells………. ! Long lived parenchyma cells that extend laterally like the spokes of a wheel from the center of a woody stem out towards the exterior of the stem ! alive at maturity ! Transport materials horizontally from center outward + Complex Tissues - Xylem ! Xylem fibers – ! long, thin sclerenchyma cells ! Xylem parenchyma cells- that run parallel to the ! Living cells vessel element ! Distributed among tracheids and vessels ! Help strengthen and support xylem ! Store water and nutrients + Complex Tissues - Phloem ! Phloem brings sugar [glucose from photosynthesis] from the leaves to all parts of the plant body.
    [Show full text]
  • Transition Dates from Earlywood to Latewood and Early Phloem to Late Phloem in Norway Spruce
    Article Transition Dates from Earlywood to Latewood and Early Phloem to Late Phloem in Norway Spruce Jožica Griˇcar 1,* , Katarina Cufarˇ 2 , Klemen Eler 3,4 , Vladimír Gryc 5, Hanuš Vavrˇcík 5 , Martin de Luis 6 and Peter Prislan 7 1 Department of Forest Yield and Silviculture, Slovenian Forestry Institute, 1000 Ljubljana, Slovenia 2 Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; [email protected] 3 Department of Agronomy, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; [email protected] 4 Department of Forest Ecology, Slovenian Forestry Institute, 1000 Ljubljana, Slovenia 5 Department of Wood Science and Technology, Faculty of Forestry and Wood Technology, Mendel University in Brno, 61300 Brno, Czech Republic; [email protected] (V.G.); [email protected] (H.V.) 6 Department Geografía y O.T., University of Zaragoza, 50009 Zaragoza, Spain; [email protected] 7 Department of Forest Techniques and Economy, Slovenian Forestry Institute, 1000 Ljubljana, Slovenia; [email protected] * Correspondence: [email protected] Abstract: Climate change will affect radial growth patterns of trees, which will result in different forest productivity, wood properties, and timber quality. While many studies have been published on xylem phenology and anatomy lately, little is known about the phenology of earlywood and latewood formation, also in relation to cambial phenology. Even less information is available for Citation: Griˇcar, J.; Cufar,ˇ K.; Eler, K.; phloem. Here, we examined year-to-year variability of the transition dates from earlywood to Gryc, V.; Vavrˇcík,H.; de Luis, M.; Prislan, P.
    [Show full text]
  • Chaudhary Mahadeo Prasad College (A CONSTITUENT PG COLLEGE of UNIVERSITY of ALLAHABAD)
    e-Learning Modules Chaudhary Mahadeo Prasad College (A CONSTITUENT PG COLLEGE OF UNIVERSITY OF ALLAHABAD) E-Learning Module Subject: Botany (Study material for Post Graduate Students) M.Sc. II Semester COURSE CODE: BOT 514 Plant Morphology and Anatomy Unit: II Topic: Complex tissue: Xylem and Phloem Developed by Name: Dr Alok Kumar Singh Designation: Assistant Prof. DEPARTMENT OF BOTANY Botany Department Chaudhary Mahadeo Prasad Degree College, Prayagraj-U.P. 211002 Page 1 e-Learning Modules Complex Tissues: Xylem and Phloem The complex tissues are heterogeneous in nature, being composed of different types of cell elements. The latter remain contiguous and form a structural part of the plant, adapted to carry on a specialised function. Xylem and phloem are the complex tissues which constitute the component parts of the vascular bundle. They are also called vascular tissues. The vascular system occupies a unique position in the plant body, both from the point of view of prominence and physiological importance. The term ‘vascular plants’ has been in use since a long time. In recent years a new phylum Tracheophyta has been introduced to include all vascular plants; it covers pteridophyta and spermatophyta of old classifications. Vascular bundles form a continuous and interconnected system in the different organs of the plants. They are primarily responsible for transport of water and solutes and elaborated food matters. Xylem: Xylem is a complex tissue forming a part of the vascular bundle. It is primarily ins- trumental for conduction of water and solutes, and also for mechanical support. Primary xylem originates from the procambium of apical meristem, and secondary xylem from the vascular cambium.
    [Show full text]
  • Signals That Control Plant Vascular Cell Differentiation
    REVIEWS SIGNALS THAT CONTROL PLANT VASCULAR CELL DIFFERENTIATION Hiroo Fukuda Plant vascular cells originate from procambial cells, which are vascular stem cells. Recent studies with Zinnia elegans cell culture and Arabidopsis thaliana mutants indicate that intercellular- signalling molecules such as auxin, cytokinin, brassinosteroids and xylogen regulate the maintenance or differentiation of procambial cells through distinct intracellular-signal transduction and gene-expression machineries. This intercellular- and intracellular-signalling system might be involved in determining the continuity and pattern formation of vascular tissues. PLANT CELL BIOLOGY VASCULAR CELLS The body plan of plants is controlled by a combination such as PROCAMBIUM and VASCULAR CAMBIUM.But MONO- Cells that form the plant of clonal fate and positional information that is pro- COTYLEDONOUS PLANTS and ferns, in which secondary vascular tissues, including vided by local signals, as is commonly seen in multicel- thickening growth does not occur, lack cambium. procambial cells, cambial cells, lular organisms. Recent advances in molecular genetics Individual species of vascular plants form distinct radial sieve elements, companion cells, fibre cells, xylem and phloem and genome biology have uncovered unique mecha- patterns of vascular bundles in each organ, which have parenchyma cells, and tracheary nisms of plant-body formation. Vascular cells are been categorized as collateral, bicollateral, amphivasal elements. formed under a well-defined plant-differentiation pro- or amphicribral patterns (FIG. 1a, b). gramme. Although vascular cells usually differentiate at Procambial cells are vascular stem cells that are APICAL MERISTEM predicted positions and at a predicted time to form a derived from the apical meristem and give rise to xylem The meristematic tissue that is located at the tip of the shoot specific vascular pattern, the arrangement of the vascular and phloem precursor cells.
    [Show full text]
  • Complex Tissue : Phloem: Sieve Elements
    Complex Tissue : Phloem: The other specialised complex tissue forming a part of the vascular bundle is phloem It is composed of sieve elements, companion cells, parenchyma and some fibres. Sclerotic cells may also be present.Phloem is for translocation of organic solutes—the elaborated food materials in solution. The elements of phloem originate from the procambium of apical meristem or the vascular cambium. Phloem tissue consists offour types of cells, namely: sieve tubes, companion cells, phloem fibres and phloem parenchyma Sieve Elements: The most important constituents of phloem are the sieve elements, the sieve tubes and sieve cells. From ontogenetic point of view a sieve tube resembles a vessel and a sieve cell a tracheid. Sieve tubes are long tube-like bodies formed from a row of cells arranged in longitudinal series where the end-walls are perforated in a sieve-like manner. The perforated end-walls are called the sieve plates, through which cytoplasmic connections are established between adjacent cells. A sieve plate is called simple, if it has only one sieve area, whereas the plate may be compound with several sieve areas arranged in scalariform, reticulate or other manners. Though rare, the sieve areas may occur on the side walls as well. Companion Cells: Companion cells remain associated with the sieve tubes of angiosperms, both ontogenetically and physiologically. These are smaller elongate cells, having dense cytoplasm and prominent nuclei. Starch grains are never present.They occur along the lateral walls of the sieve tubes. A companion cell may be equal in length to the accompanying sieve tube element or the mother cell may be divided transversely forming a series of companion cells .
    [Show full text]
  • Observations on Functional Wood Histology of Vines and Lianas Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden
    Aliso: A Journal of Systematic and Evolutionary Botany Volume 11 | Issue 2 Article 3 1985 Observations on Functional Wood Histology of Vines and Lianas Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden Follow this and additional works at: http://scholarship.claremont.edu/aliso Part of the Botany Commons Recommended Citation Carlquist, Sherwin (1985) "Observations on Functional Wood Histology of Vines and Lianas," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 11: Iss. 2, Article 3. Available at: http://scholarship.claremont.edu/aliso/vol11/iss2/3 ALISO 11(2), 1985, pp. 139-157 OBSERVATIONS ON FUNCTIONAL WOOD HISTOLOGY OF VINES AND LlANAS: VESSEL DIMORPHISM, TRACHEIDS, V ASICENTRIC TRACHEIDS, NARROW VESSELS, AND PARENCHYMA SHERWIN CARLQUIST Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711 ABSTRACT Types of xylem histology in vines, rather than types of cambial activity and xylem conformation, form the focus of this survey. Scandent plants are high in conductive capability, but therefore have highly vulnerable hydrosystems; this survey attempts to see what kinds of adaptations exist for safety and in which taxa. A review of scandent dicotyledons reveals that a high proportion possesses vasi­ centric tracheids (22 families) or true tracheids (24 families); the majority of scandent families falls in these categories. Other features for which listings are given include vascular tracheids, fibriform vessel elements, helical sculpture in vessels, starch-rich parenchyma adjacent to vessels, and other parenchyma distributions. The high vulnerability of wide vessels is held to be countered by various mechanisms. True tracheids and vasicentric tracheids potentially safeguard the hydrosystem by serving when large vessels are embolized.
    [Show full text]
  • Vascular Tissue in Plants - Xylem
    March 2004 Vascular tissue in plants - Xylem National Biology Support Service Plant tissue types ascular tissue - there are two different types of vascular tissue in the plants from Xylem Tissue the Kingdom Plantae - xylem and phloem. xylem VXylem is composed of two basic types of elongated fibres water-conducting cells: tracheids and vessels which together with fibres and parenchyma cells make up this complex tissue. Xylem functions in the movement xylem of water and salts throughout the plant. tracheids xylem Structure: vessel During the development of the tracheids and the vessels their cell walls become impregnated with lignin, making them woody and impermeable. The walls of these water-conducting cells are perforated by pits, which allow water and salts to pass sideways between the cells. Mature tracheids and vessels are Phloem In contrast to xylem, this consists of living cells dead cells due to the lignin in their walls. Xylem is the called sieve tube elements. An element has two components - wood in a woody plant and so also functions in the a sieve tube cell and a companion cell. These, together with support of the plant. other cell types - fibres, sclereids and parenchyma make up this complex tissue. End to end sieve tube cells form Shape; continuous pathways. The end wall of each cell is perforated Tracheids are long, tapered cells, which have angled by pores through which cytoplasmic strands stream. These end-plates with pits that allow water to pass from cell perforated end walls are called sieve plates (because they to cell. Xylem vessels are wider and usually shorter, do resemble a sieve).
    [Show full text]
  • The Glocal University 14/03/2020 PLANT ANATOMY GBBT/GBMB-202
    The Glocal University 14/03/2020 PLANT ANATOMY GBBT/GBMB-202 Plant Tissue Lower plants are composed of either single cells or colonies of cells which are more or less similar in size, shape and origin. Higher plants are built up of diverse types of cells, varied in shape, size, origin and function. A group of cells more less alike in size and shape, having same origin, same methods of development and same function are called tissue. Study of tissue is called histology. But, sometime distinctly dissimilar cells are often found to be associated in the formation of a tissue, as for example the complex tissue, xylem and phloem. Tissue may be classified on the basis of different characters, like, nature of cells, origin and methods of development, position in the plant body, etc. However, the tissues are put into two main groups on the basis of development: (i) Meristematic tissue (ii) Permanent tissue Meristematic tissue In the early stages of the development of the embryo, all the cells undergo" division, but with further growth and development cell division and multiplication become restricted to special parts of the plant in which the tissues remain embryonic in character and the cells retain the ability to divide. These embryonic tissues in the mature plant body, are called meristems. Cell division can also occur in tissues other than meristems, for instance, in the cortex of the stem and in young, developing vascular tissues. However, in these tissues the number of divisions is limited. On the other hand, the cells of the meristems continue to divide indefinitely and as a result new cells are continually added to the plant body.
    [Show full text]
  • Wood Anatomy of Ascarina (Chloranthaceae) and the Tracheid-Vessel Element Transition Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden
    Aliso: A Journal of Systematic and Evolutionary Botany Volume 12 | Issue 4 Article 3 1990 Wood Anatomy of Ascarina (Chloranthaceae) and the Tracheid-vessel Element Transition Sherwin Carlquist Pomona College; Rancho Santa Ana Botanic Garden Follow this and additional works at: http://scholarship.claremont.edu/aliso Part of the Botany Commons Recommended Citation Carlquist, Sherwin (1990) "Wood Anatomy of Ascarina (Chloranthaceae) and the Tracheid-vessel Element Transition," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 12: Iss. 4, Article 3. Available at: http://scholarship.claremont.edu/aliso/vol12/iss4/3 ALISO ALISO 12(4), 1990, pp. 667-684 WOOD ANATOMY OF ASCARINA (CHLORANTHACEAE) AND THE TRACHEID-VESSEL ELEMENT TRANSITION SHERWIN CARLQUIST Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711 ABSTRACT Quantitative and qualitative features are presented for 13 collections of 8 species ofAscarina. Wood anatomy is maximally primitive in most respects; moderate exception occurs in the imperforate tracheary elements, which range from tracheidlike (A. solmsiana) to fiber-tracheids (septate in two species). Perforation plates are scalariform, average more than 100 bars per plate, and have bordered bars. Even more significantly, portions of the primary walls in perforations characteristically fail to dissolve; these pit membrane portions range from nearly intact (much like the pit membranes in pits on end walls of tracheids of vesselless dicotyledons) to remnant strands or flakes. Dissolution of pit membranes in perforations is apparently inhibited by deposition ofresinlike substances in some species; the rugose surfaces formed by these deposits may account for a report of vesturing on vessel walls of Ascarina.
    [Show full text]