DOCSLIB.ORG

Evolution and Diversity of Green Plant Cell Walls Zoe¨ a Popper

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Evolution and Diversity of Green Plant Cell Walls Zoe¨ a Popper Available online at www.sciencedirect.com Evolution and diversity of green plant cell walls Zoe¨ A Popper Plant cells are surrounded by a dynamic cell wall that performs biomass for the emerging biofuel industry. Cell walls have many essential biological roles, including regulation of cell been used as a source of fuel for millennia, for example in expansion, the control of tissue cohesion, ion-exchange and the form of wood, derived from dicotyledonous trees, and defence against microbes. Recent evidence shows that the peat, derived from Sphagnum moss. Algae, while being suite of polysaccharides and wall proteins from which the plant among the most efficient photosynthetic organisms and of cell wall is composed shows variation between monophyletic interest for biofuel generation, will not be specifically plant taxa. This is likely to have been generated during the discussed within this review because their greatest poten- evolution of plant groups in response to environmental stress. tial is as a source of oils (localised in the vacuole) for use in Understanding the natural variation and diversity that exists bio-diesel production, rather than cell wall biomass. This between cell walls from different taxa is key to facilitating their review will focus on the natural variation and diversity future exploitation and manipulation, for example by increasing that exists within land plant cell wall composition that is lignocellulosic content or reducing its recalcitrance for use in associated with land plant phylogeny (Table 1). biofuel generation. Address A more comprehensive investigation of diverse land plant Department of Botany, National University of Ireland Galway, Ireland cell walls not only is essential to facilitate wall modifi- cation enabling production of biomass with improved Corresponding author: Popper, Zoe¨ A([email protected]) qualities, for example an increased cellulose concen- tration; but may also suggest the potential of novel crop Current Opinion in Plant Biology 2008, 11:286–292 plants. This review comes from a themed issue on Types of cell wall Physiology and metabolism Edited by Ken Keegstra and Markus Pauly Cells walls are composed of three types of layers: the middle lamella, the primary cell wall and the secondary Available online 10th April 2008 cell wall. The middle lamella is deposited soon after mitosis creating a boundary between the two daughter 1369-5266/$ – see front matter # 2008 Elsevier Ltd. All rights reserved. nuclei and, once the cell plate is complete, the primary cell wall is deposited and continues to be deposited DOI 10.1016/j.pbi.2008.02.012 throughout cell growth and expansion. Therefore, although the primary cell wall is typically only 0.1– 10 mm thick, its composition is of importance for biomass Introduction accumulation through controlling cell growth. Cellulose-rich cell walls, one of the defining character- istics of plants, are of fundamental importance for normal The secondary cell wall is deposited internally to the plant growth and development. Despite recognition that primary cell wall at the onset of differentiation, once cell distinct differences exist in wall chemistry between growth has ceased. However, secondary cell walls are not Angiosperm taxa [1,2], the main focus of cell wall research present in all cell types, parenchyma and collenchyma has been on Angiosperm, primarily crop, species. frequently have only a primary cell wall, or in all plant Recently, however, there has been increasing interest taxa. In spermatophytes, secondary cell wall composition in the cell wall biochemistry of non-Angiosperm plants is known to vary from one cell type and reflects cell [3,4,5–8,9,10–14], and evidence has emerged to sup- function. For example, many secondary cell walls, port the hypothesis [15] that changes in cell wall com- particularly xylem cells, contain lignin that increases wall position are fundamentally involved with plant evolution strength. and diversification (Figure 1). Primary cell wall polysaccharides Interest in non-Angiosperm cell wall composition is not The majority of research regarding cell wall composition only of intrinsic interest, but the increasing use of Phys- in diverse plant groups has concentrated on the primary comitrella patens (Hedw.) B.S.G., a moss, as a tool for cell wall owing to the existence of cell type specific investigating Angiosperm cell wall biochemistry [16] variation between secondary cell walls. demands more complete characterisation of bryophyte walls. The main cell wall components, polysaccharides, The primary cell wall is composed of cellulose microfibrils represent a major and renewable source of photosynthe- embedded in a gel-like matrix of non-cellulosic polysac- tically fixed carbon and are of importance as a source of charides and glycoproteins. The cellulose–hemicellulose Current Opinion in Plant Biology 2008, 11:286–292 www.sciencedirect.com Cell wall diversity Popper 287 Figure 1 Key transitions in cell wall components mapped onto a land plant phylogeny (adapted from references [44,45]). Changes in composition are symbolised as: (+) appearance or substantial increase in occurrence; (#) either a reduction or loss; ( )(1! 3), (1 ! 4)-b-D-glucan [18]; ( ) xyloglucan [13]; ( ) mannose; ( )3-O-Methylgalactose [13]; ( )3-O-Methylrhamnose [13]; ( ) galacturonic acid; ( ) glucuronic acid; ( ) tannins [12]; ( ) branched 4-linked xylan [6]; ( ), rhamnogalacturonan II [11]. Representatives of taxonomic groups shown are (a) Poales, wheat (Triticum aestivum L.); (b) Angiosperms (excluding Poales), Ox-eye Daisy (Leucanthemum vulgare Lam.); (c) Gymnosperms, Larch (Larix decidua L.); (d) Pteridophytes, Tree fern; (e) Lycopodiophytes, Selaginella (Selaginella martensii Spring.); (f) Bryopsida, mosses (Polytrichum sp.); (g) Marchantiopsida, Liverworts (Lunularia cruciata (L.) Lindb.); (h) Anthocerotopsida, hornworts (Phaeoceros carolinanus (Michx.) Prosk.); (i) Charophytes, (Nitella sp.) network co-exists with a network consisting of pectic Although relatively few detailed structural analyses have polysaccharides. A covalent linkage between xyloglucan been performed on cell walls from non-Angiosperm taxa, and pectin, interconnecting the two networks, appears to it appears that seed plants have cell walls with similar, be widespread among Angiosperm taxa [17]. though not identical, compositions. The quantitatively www.sciencedirect.com Current Opinion in Plant Biology 2008, 11:286–292 288 Physiology and metabolism Table 1 Occurrence of cell wall components shown to vary, with phylogenetic significance, between land plant taxa Plant group Monosaccharides Polysaccharides Proteins 3-O- 3-O- Uronic Xylan Mannan Xylo- RGII Pectin (1 ! 3), Expansins Ces/Csl MeRha MeGal acids glucana (1 ! 4)-b- D-glucan Charophytes + À + À + ÀÆ++ À Hornwort + À +++ ++Æ +++ À Liverworts and basal mosses + À + À +++Æ ++ À Advanced mosses + ÀÆ++ ++ Æ ++ À EXPA (conserved CesA, CslA, function) and CslC, CslDb EXPB Homosporous lycopodiophytes + + Æ ++ ++++ À Heterosporous lycopodiophytes + + Æ ++ ++++ À Eusporangiate ferns ÀÆÆ++ ++++ À Leptosporangiate ferns ÀÆÆ+ Æ ++ + + À Gymnosperms ÀÆÆ+ Æ ++ + + À Dicotyledonous Angiosperms ÀÆÆ+ Æ ++ + + À EXLA, EXLB, CesA, CslA, EXPA, EXPB CslB, CslC, CslD, CslE, CslG Poales members of ÀÆÆ+ Æ + + + + CesA, CslA, monocotyledonous CslC, CslD, Angiosperms CslE, CslF, CslH À, not detectable; Æ, trace; +, present at low concentration; ++, present at moderate concentration; +++, present at high concentration. a Xyloglucan shows diversity in glycosyl composition. b CslD is highly represented among P. patens ESTs that may reflect their involvement in tip growth of moss protonemata [16]. predominant monosaccharides present in the walls are D- Rhamnogalacturonan II (RGII) is required for growth and glucose (Glc), D-galactose (Gal), D-mannose (Man), D- development in Angiosperms, and comparable amounts xylose (Xyl), L-arabinose (Ara), L-fucose (Fuc), L-rham- occur in members of the most primitive extant plants nose (Rha) and D-galacturonic acid (GalA). Poales walls lycopodiophytes, equisetophytes, psilotophytes and pter- contain more Xyl and less GalA, Gal and Fuc than other idophytes. By contrast, gametophytes of bryophytes con- Angiosperms and Gymnosperms contain more Man resi- tain only 1% of the amounts present in vascular plants. dues. Differences in cell wall composition are correlated In addition the glycosyl sequence of RGII appears to be with diversification of specific plant taxa. The lycopodio- conserved with the exception that the non-reducing Rha phytes form a distinctive, basal, monophyletic clade residue present on the aceric acid containing side-chain of within extant vascular plants whose cell walls uniquely RGII is replaced by 3-O-methylrhamnose (3-O-MeRha) contain the unusual monosaccharide residue 3-O-methyl- in some lycopodiophytes and pteridophytes [11]. RGII is galatose [12] that is likely to be a component of many linked with the ability to form upright stem and formation lycopodiophyte primary cell wall polysaccharides in- of lignified cell walls, which correlates well with its cluding xyloglucan (MA O’Neill, personal communi- increased concentration in vascular plants. cation). Secondary cell wall polysaccharides Additional variation of cell wall composition exists at the Variation in secondary cell wall composition is perhaps polysaccharide level, (1 ! 3), (1 ! 4)-b-D-linked glucans the most pertinent in the context of biomass production. are restricted to the Poales [18] and xyloglucan is present Secondary cell
Load more

Recommended publications
  • Harvest-Aid Efficiency in Guar (Cyamopsis Tetragonoloba (L.) Taub.) in the Texas Plains
    Harvest-aid Efficiency in Guar (Cyamopsis tetragonoloba (L.) Taub.) in the Texas Plains by Jonathan Shockey BS A Thesis In Plant and Soil Sciences Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTERS OF SCIENCE Approved Dr. Peter Dotray Chair of Committee Dr. Calvin Trostle Dr. Noureddine Abidi Mark Sheridan Dean of the Graduate School December, 2016 Copyright 2016, Jonathan Shockey Texas Tech University, Jonathan Shockey, December 2016 Acknowledgements I would like to thank Dr. Calvin Trostle and Texas A&M AgriLife Extension for not only his guidance during this research and for allowing me the time away from my assigned duties to complete these experiments; but also for providing the funding to get it accomplished. Under his direction I learned many things about agricultural research that I will carry with me throughout my career. I would also like to thank Dr. Peter Dotray for his advice and direction both as committee co-chairman and as an instructor for modes and mechanisms of herbicides. Rounding out my committee I would like to thank Dr. Noureddine Abidi for his expert advice in all potential biopolymer aspects of this study, and patient instruction during his biopolymers and bioproducts course. Additionally, I would like to thank Ray White for his assistance in conducting spray applications, harvesting, and other data collection, his time and dedication to this research was without question a major contribution to its completion. I would also like to thank Dr. Katie Lewis for her expert assistance with SAS and other software questions.
    [Show full text]
  • Plant Evolution an Introduction to the History of Life
    Plant Evolution An Introduction to the History of Life KARL J. NIKLAS The University of Chicago Press Chicago and London CONTENTS Preface vii Introduction 1 1 Origins and Early Events 29 2 The Invasion of Land and Air 93 3 Population Genetics, Adaptation, and Evolution 153 4 Development and Evolution 217 5 Speciation and Microevolution 271 6 Macroevolution 325 7 The Evolution of Multicellularity 377 8 Biophysics and Evolution 431 9 Ecology and Evolution 483 Glossary 537 Index 547 v Introduction The unpredictable and the predetermined unfold together to make everything the way it is. It’s how nature creates itself, on every scale, the snowflake and the snowstorm. — TOM STOPPARD, Arcadia, Act 1, Scene 4 (1993) Much has been written about evolution from the perspective of the history and biology of animals, but significantly less has been writ- ten about the evolutionary biology of plants. Zoocentricism in the biological literature is understandable to some extent because we are after all animals and not plants and because our self- interest is not entirely egotistical, since no biologist can deny the fact that animals have played significant and important roles as the actors on the stage of evolution come and go. The nearly romantic fascination with di- nosaurs and what caused their extinction is understandable, even though we should be equally fascinated with the monarchs of the Carboniferous, the tree lycopods and calamites, and with what caused their extinction (fig. 0.1). Yet, it must be understood that plants are as fascinating as animals, and that they are just as important to the study of biology in general and to understanding evolutionary theory in particular.
    [Show full text]
  • A Review on Guar (Cyamopsis Tetragonoloba L.): a Cash Crop
    Muhammad Shakir et al. Int. Res. J. Pharm. 2020, 11 (4) INTERNATIONAL RESEARCH JOURNAL OF PHARMACY www.irjponline.com ISSN 2230 – 8407 Review Article A REVIEW ON GUAR (CYAMOPSIS TETRAGONOLOBA L.): A CASH CROP Muhammad Shakir 1, Hafeez Ahmad Sadaqat 2, Qasim Farooq 1*, Muzamil Shabir 1, Aisha Sodagar 1, Mubashar Nadeem 5, Tooba Zafar 1, Aman Ullah 2, Faiza Rafiq 1, Rida Anwar 4, Azka Rizwi 3, Safa Amjad 1, Areeba Sajida 3, Mushaim Iqbal 4 1 Department of Botany, University of Agriculture, University Main Road, Faisalabad, Punjab 38000, Pakistan 2 Department of Plant Breeding and Genetics, University of Agriculture, University Main Road, Faisalabad, Punjab 38000, Pakistan 3 Department of Botany, The Women University, Multan,Mattital Road, Near New Katchery Multan, Punjab 60000, Pakistan 4 Botany Division, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Bosan Road, Multan, Punjab 60000, Pakistan 5 Department of Agronomy, University of Agriculture, University Main Road,Faisalabad, Punjab 38000, Pakistan *Corresponding Author Email: [email protected] Article Received on: 25/02/20 Approved for publication: 26/03/20 DOI: 10.7897/2230-8407.110433 ABSTRACT Guar is an essential legume domesticated mainly on marginal and sub marginal areas of arid and semi-arid regions. Generally, Pakistan yields around 15% of worldwidetotal guar production. Its area under cultivation is more than 0.181 million hectares in PaKistan. Regarding to its demand in the foreign marKet, it is cultivated in Punjab, Bahawalpur, Mianwali, Bahawalnagar, Layyah, Sargodha, Muzaffargarh, Multan and Sindh province of Pakistan. Additional, its domestication is also being under consideration to taKe up it for irrigated conditions during summer.
    [Show full text]
  • Introduction to the Cell Cell History Cell Structures and Functions
    Introduction to the cell cell history cell structures and functions CK-12 Foundation December 16, 2009 CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the “FlexBook,” CK-12 intends to pioneer the generation and distribution of high quality educational content that will serve both as core text as well as provide an adaptive environment for learning. Copyright ©2009 CK-12 Foundation This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/us/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. Contents 1 Cell structure and function dec 16 5 1.1 Lesson 3.1: Introduction to Cells .................................. 5 3 www.ck12.org www.ck12.org 4 Chapter 1 Cell structure and function dec 16 1.1 Lesson 3.1: Introduction to Cells Lesson Objectives • Identify the scientists that first observed cells. • Outline the importance of microscopes in the discovery of cells. • Summarize what the cell theory proposes. • Identify the limitations on cell size. • Identify the four parts common to all cells. • Compare prokaryotic and eukaryotic cells. Introduction Knowing the make up of cells and how cells work is necessary to all of the biological sciences. Learning about the similarities and differences between cell types is particularly important to the fields of cell biology and molecular biology.
    [Show full text]
  • The Natural Thickener Inca Tara Gum About Inca Tara Gum
    The Natural Thickener Inca Tara Gum About Inca tara Gum INCA TARA GUM is a vegetal polysaccharide obtained by grinding the endosperm of Caesalpinia spinosa commonly known as TARA (Quechua). Tara is a small leguminous tree or thorny shrub native to Peru and cultivated in the region of Ica. INCA TARA GUM is commonly used as a rheology mo- difier in food and cosmetics. INCA TARA GUM, a sustainable and regenerative plant product, is a perfect thickener in aqueous for- mulations. The sensory profile and good tolerance even in asso- ciation with other thickeners makes INCA TARA GUM a perfect ingredient for modern industry demands: NATURAL – VEGAN – ECOLOGICAL GROWN KEYWORDS > Natural thickener > Natural stabilizer > Increases viscosity and suspension > Improves texture and spreadability > Syneresis reduction and oil stability INCI > INCI Name: Caesalpinia Spinosa Gum > CTFA Name: Caesalpinia Spinosa Gum (Tara) meal > Other Names: Guarango, Leguminosae > CAS No: 39300-88-4 > EINECS/ELINCS No: 254-409-6 > Food Additive: E 417 Inca Oil and Inca Gum Over nearly 20 years INCA OIL has developed to a symbol of quality and trustiness for all major cosmetic or personal care companies worldwide. Our Jojoba shrubs for the precious Jojobaoil grow considering environmental beneficial, con- serving resources, pesticide free culture, social responsibility and stop desertification. With the same philosophy and dedication our Tara trees are cultivated in the farm together with Jojoba. Developing the excellent suitability of Tara gum as thickener and stabilizer for food and cos- metics, we decided to add this plant to our cultivation. Tara is a tree with spreading, grey-barked branches, The leaves are compound, bipinnate, alternate and spirally organized and reach a length of 35 cm.
    [Show full text]
  • Guar Production in Texas & SW Oklahoma
    Guar Production in Texas & SW Oklahoma Calvin Trostle, Ph.D. Extension Agronomy, Texas A&M AgriLife—Lubbock (806) 746-6101, [email protected] Updated April 2020 Why Guar? Why Now? Guar gum is highly valuable and sought after as an ingredient from small quantities in numerous food products to large scale uses in oil field services (e.g., a component of frac fluids) ◉ Desirable viscosity, a carrier for materials into deep wells, “cleans out” relative well (no residues remaining) About this information… The information provided is a collection of field observations, limited research, and the input from several farmers and processor staff It is generally relevant for the Texas South Plains and Rolling plains, but it generally applicable as well in southwest Oklahoma and eastern New Mexico (info. is also generally relevant for the Texas Coastal Bend and Lower Rio Grande Valley where there has been limited production in the past). Guar is not well adapted to humid regions of Central Texas, for example, the I-35 corridor due to higher humidity and rainfall which fosters much more disease pressure than normally observed in the HP & RP. The Value of U.S. Guar Gum Imports According to the USDA Agricultural Marketing Service, in 2011 in the Port of Houston (Texas) guar gum imports were ~225,000 metric tons (80% of U.S. total). At historical guar gum prices of $2 to $3/lb., this translates to an import value of $1.0-1.5 billion This represents about 2.3 million acres of production (at 800 lbs./acre, which is an average yield in the U.S., but double the average yield in India).
    [Show full text]
  • Construct a Plant Evolution Timeline
    Constructing a Timeline of Plant Evolution Use this photo as a guide to creating an interactive timeline. Refer to Geologic Time Scale charts. A good resource is http://www.ucmp.berkeley.edu/help/timeform.php Use the “Plant Timeline Cards” found at the end of this document. Attach pictures with Velcro to allow for manipulation by students, and to “build” the timeline in increments. Teachers will need to find and print photos for “seed ferns” or omit that step in the timeline. Cut and paste the text below under each picture. Cyanobacteria: Also known as blue- Mosses: These have the first identifiable green algae, these are bacteria transport systems for water (xylem), and (prokaryotes – no nucleus) that can reproduce via spores, which encase sex photosynthesize. cells to prevent desiccation. They still need to live near water. First eukaryotes (cell nucleus): Scientist think that eukaryotes evolved via Hornworts: These developed the cuticle symbiosis, with one bacteria engulfing (waxy coating to prevent water loss) and another, but not digesting it. stomata (openings in the cuticle to allow Chloroplasts were originally for gas exchange.) All land plants except cyanobacteria engulfed by another liverworts have these two features. bacterium. Development of a true vascular system Anabaena: These water organisms allowed for better transport of water evolved from being unicellular to more and provided structural support for the complex, multicellular organisms. Their plant to grow taller. specialized cells help with nitrogen fixation. Club mosses: These were the first plants to have true leaves with veins. They also Stoneworts: Scientists think that developed roots as an anchoring system colonization of land occurred only once, to allow plant to grow taller.
    [Show full text]
  • The Big Bloom—How Flowering Plants Changed the World
    The Big Bloom—How Flowering Plants Changed the World Written by Michael Klesius Republished from the pages of National Geographic magazine -- July 2002 In the summer of 1973 sunflowers appeared in my father's vegetable garden. They seemed to sprout overnight in a few rows he had lent that year to new neighbors from California. Only six years old at the time, I was at first put off by these garish plants. Such strange and vibrant flowers seemed out of place among the respectable beans, peppers, spinach, and other vegetables we had always grown. Gradually, however, the brilliance of the sunflowers won me over. Their fiery halos relieved the green monotone that by late summer ruled the garden. I marveled at birds that clung upside down to the shaggy, gold disks, wings fluttering, looting the seeds. Sunflowers defined flowers for me that summer and changed my view of the world. Flowers have a way of doing that. They began changing the way the world looked almost as soon as they appeared on Earth about 130 million years ago, during the Cretaceous period. That's relatively recent in geologic time: If all Earth's history were compressed into an hour, flowering plants would exist for only the last 90 seconds. But once they took firm root about 100 million years ago, they swiftly diversified in an explosion of varieties that established most of the flowering plant families of the modern world. Today flowering plant species outnumber by twenty to one those of ferns and cone-bearing trees, or conifers, which had thrived for 200 million years before the first bloom appeared.
    [Show full text]
  • Chapter 1 Definitions and Classifications for Fruit and Vegetables
    Chapter 1 Definitions and classifications for fruit and vegetables In the broadest sense, the botani- Botanical and culinary cal term vegetable refers to any plant, definitions edible or not, including trees, bushes, vines and vascular plants, and Botanical definitions distinguishes plant material from ani- Broadly, the botanical term fruit refers mal material and from inorganic to the mature ovary of a plant, matter. There are two slightly different including its seeds, covering and botanical definitions for the term any closely connected tissue, without vegetable as it relates to food. any consideration of whether these According to one, a vegetable is a are edible. As related to food, the plant cultivated for its edible part(s); IT botanical term fruit refers to the edible M according to the other, a vegetable is part of a plant that consists of the the edible part(s) of a plant, such as seeds and surrounding tissues. This the stems and stalk (celery), root includes fleshy fruits (such as blue- (carrot), tuber (potato), bulb (onion), berries, cantaloupe, poach, pumpkin, leaves (spinach, lettuce), flower (globe tomato) and dry fruits, where the artichoke), fruit (apple, cucumber, ripened ovary wall becomes papery, pumpkin, strawberries, tomato) or leathery, or woody as with cereal seeds (beans, peas). The latter grains, pulses (mature beans and definition includes fruits as a subset of peas) and nuts. vegetables. Definition of fruit and vegetables applicable in epidemiological studies, Fruit and vegetables Edible plant foods excluding
    [Show full text]
  • Keys to Profitable Guar Production R
    I ~ L-907 KEYS TO PROFITABLE GUAR PRODUCTION R. J. Hodges, Murray L. Kinman, Norman W. Brints, Emory P. Boring "' and James R. Mulkey, Jr.* Guar, Cyamopsis tetragonoloba, is a drouth­ textured and sandy loam soils, with good structure tolerant summer annual legume. It was introduced and well-drained subsoils. Guar has been grown into the United States in 1903 from India, where successfully following flax when moisture is avail­ it is grown for exports, as a vegetable for human able on the heavier soils of South Texas. consumption, as cattle feed and as a green manure crop. MOISTURE REQUIREMENTS The guar seed (called a bean) has a rather large The guar plant is drouth resistant; when endosperm which sets it apart from most other moisture is short, growth stops until moisture be­ legumes, 'which have little or no endosperm. The comes available. Such intermittent growth length­ guar endo perm contains galactomannan gum ens the growing season. Peak water use periods which forms a viscous gel in cold water. Perhaps of guar are not as critical as for grain sorghum. the best-known use of guar gum is as a stiffener Guar responds to irrigation since adequate available in soft ice cream, Whip and chill puddings and soil moisture insures maximum production of forage whipped cream substitutes. Such products use the and beans. It is best adapted to areas of 20 to most highly refined food grade guar gum, and 30 inches of annual rainfall. Excessive rain after account for only a small portion of total production. maturity causes the seed to turn black and shrivel Larger volume uses of guar gum are in cloth and which lowers the quality of the beans.
    [Show full text]
  • The Structure, Function, and Biosynthesis of Plant Cell Wall Pectic Polysaccharides
    Carbohydrate Research 344 (2009) 1879–1900 Contents lists available at ScienceDirect Carbohydrate Research journal homepage: www.elsevier.com/locate/carres The structure, function, and biosynthesis of plant cell wall pectic polysaccharides Kerry Hosmer Caffall a, Debra Mohnen a,b,* a University of Georgia, Department of Biochemistry and Molecular Biology and Complex Carbohydrate Research Center, 315 Riverbend Road Athens, GA 30602, United States b DOE BioEnergy Science Center (BESC), 315 Riverbend Road Athens, GA 30602, United States article info abstract Article history: Plant cell walls consist of carbohydrate, protein, and aromatic compounds and are essential to the proper Received 18 November 2008 growth and development of plants. The carbohydrate components make up 90% of the primary wall, Received in revised form 4 May 2009 and are critical to wall function. There is a diversity of polysaccharides that make up the wall and that Accepted 6 May 2009 are classified as one of three types: cellulose, hemicellulose, or pectin. The pectins, which are most abun- Available online 2 June 2009 dant in the plant primary cell walls and the middle lamellae, are a class of molecules defined by the pres- ence of galacturonic acid. The pectic polysaccharides include the galacturonans (homogalacturonan, Keywords: substituted galacturonans, and RG-II) and rhamnogalacturonan-I. Galacturonans have a backbone that Cell wall polysaccharides consists of -1,4-linked galacturonic acid. The identification of glycosyltransferases involved in pectin Galacturonan a Glycosyltransferases synthesis is essential to the study of cell wall function in plant growth and development and for maxi- Homogalacturonan mizing the value and use of plant polysaccharides in industry and human health.
    [Show full text]
  • 226 PLANT INVENTORY NO. 162 217918 to 217922. Fabaceae. Guar
    226 PLANT INVENTORY NO. 162 217918 to 217922. From Pakistan. Bulbs collected by H. S. Gentry and E. E. Smith, Agricultural Explorers, Plant Introduction Section, Horticultural Crops Research Branch, Beltsville, Md. Received May 24,1954. 217918. IXIOLIRION sp. Amaryllidaceae. No. 14092. Parichinar, Kurrinam Valley, N. W. F. Province. Apr. 22, 1954. Altitude 5,800 feet. Ten to 15 inches tall, with bright-purple flowers. 217919. TULIPA sp. Liliaceae. Tulip. No. 14075. Four miles southwest of Hungu, Northwest Frontier Prov- ince. Apr. 21,1954. 217920. TULIPA sp. No. 14091. Parichinar, Kurram Valley, Northwest Frontier Province. Apr. 22,1954. 217921. TULIPA sp. No. 14202. Kanjoo, Saidu, Swat. Apr. 30, 1954. Altitude 3,000 feet 217922. (Undetermined.) Liliaceae. No. 14203. Kanjoo, Saidu, Swat. Apr. 30, 1953. 217923 to 217925. CYAMOPSIS TETRAGONOLOBA (L.) Taub. Fabaceae. Guar. From India. Seeds presented by the Division of Botany, Indian Agricultural Research Institute, New Delhi, India, Received May 24, 1954. 217923. E.C. 248A. 217924. I.C. 32. 217925. I.C. 43. 217926 and 217927. CERATONIA SILIQUA L. Fabaceae. Carob. From Italy. Budsticks presented by the Stazione Sperimentale Di Agrumi- coltura E. Frutticoltura, Acireale, Sicily. Received May 25, 1954. 217926. Saccarata. 217927. Tantillo. Hermaphrodite. 217928. PHYLLOSTACHYS NIGRA var. KENONIS f. BORYANA (Mitf.) Makino. Poaceae. Bamboo. From California. Roots presented by Dr. R. J. Seibert, Los Angeles County Arboretum, Arcadia, Calif. Numbered May 25, 1954. Probably originally introduced from China by a missionary family into Altadena, Calif. Culms unusually striking because of large mahogany blotches on inter- nodes. Roots planted at the U. S. Plant Introduction Garden, Savannah, Ga.
    [Show full text]