Download or read book Physiological Significance of Ethylene in Needle Abscission of Root detached Balsam Fir Abies Balsamea L Mill written by Mason T. (Mason Thane) MacDonald and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'abscission prématurée des aiguilles constitue un problème majeur pour l'industrie de l'arbre de Noël dans les provinces Atlantiques du Canada. Les objectifs de cette étude étaient donc de déterminer: 1) l'effet de l'éthylène endogène et exogène sur l'abscission des aiguilles, 2) l'effet de l'utilisation d'inhibiteurs de l'activité de l'éthylène sur l'abscission des aiguilles, 3) l'activité des cellulases associées à l'éthylène et l'abscission des aiguilles, 4) l'interaction entre l'éthylène et la variabilité génotypique, et 5) l'effet de l'éthylène sous des conditions de perte d'eau réduite. Nos résultats ont démontré que l'éthylène est impliqué comme signal d'abscission pour les aiguilles du sapin baumier. Il a été constaté que l'évolution de l'éthylène endogène a augmenté à des taux variant de 10,5 à 20,0 (j.L-g"lh"' suivie immédiatement de l'abscission complète des aiguilles. Selon la concentration utilisée, l'apport exogène d'ethylene a réduit la durée de rétention des aiguilles de 30 à 70%. En absence d'éthylène exogène, l'inhibition de l'éthylène avec AVG ou 1-MCP a retardé respectivement l'abscission des aiguilles de 113 et 73%. D'autre part, l'éthylène a stimulé l'activité des cellulases. Les branches ne démontrant aucun signe d'abscission ont eu une activité cellulase de 0,4 unité alors que les branches induites par l'éthylène exogène et endogène ont eu une activité respective de 4,6 et 3,1 unités. Les génotypes ayant une faible durée de rétention de leurs aiguilles ont libéré 50% plus d'éthylène et ont réagi à l'éthylène exogène plus tôt que les génotypes possédant une durée de rétention élevée de leurs aiguilles. Enfin, le contrôle de la perte d'eau a significativement retardé l'abscission induite par l'éthylène. Ainsi, l'exposition des branches à 90% d'humidité ou à une température de 5°C a diminué la perte d'eau, l'évolution de l'éthylène et l'abscission des aiguilles. Le stockage des branches à une humidité de 90% a été particulièrement efficace augmentant de plus de 3 fois la durée de rétention des aiguilles. Il est ainsi suggéré que le sapin baumier réagisse à de faibles stress hydriques en libérant de l'éthylène. Une exposition de courte durée à l'éthylène est toutefois bénéfique alors qu'une exposition continuelle stimule les enzymes hydrolytiques qui culminent en l'abscission des aiguilles.
Download or read book Plant Organ Abscission From Models to Crops written by Timothy J. Tranbarger and published by Frontiers Media SA. This book was released on 2017-11-22 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant organ abscission is a developmental process regulated by the environment, stress, pathogens and the physiological status of the plant. In particular, seed and fruit abscission play an important role in seed dispersion and plant reproductive success and are common domestication traits with important agronomic consequences for many crop species. Indeed, in natural populations, shedding of the seed or fruit at the correct time is essential for reproductive success, while for crop species the premature or lack of abscission may be either beneficial or detrimental to crop productivity. The use of model plants, in particular Arabidopsis and tomato, have led to major advances in our understanding of the molecular and cellular mechanisms underlying organ abscission, and now many workers pursue the translation of these advances to crop species. Organ abscission involves specialized cell layers called the abscission zone (AZ), where abscission signals are perceived and cell separation takes place for the organ to be shed. A general model for plant organ abscission includes (1) the differentiation of the AZ, (2) the acquisition of AZ cells to become competent to respond to various abscission signals, (3) response to signals and the activation of the molecular and cellular processes that lead to cell separation in the AZ and (4) the post-abscission events related to protection of exposed cells after the organ has been shed. While this simple four-phase framework is helpful to describe the abscission process, the exact mechanisms of each stage, the differences between organ types and amongst diverse species, and in response to different abscission inducing signals are far from elucidated. For an organ to be shed, AZ cells must transduce a multitude of both endogenous and exogenous signals that lead to transcriptional and cellular and ultimately cell wall modifications necessary for adjacent cells to separate. How these key processes have been adapted during evolution to allow for organ abscission to take place in different locations and under different conditions is unknown. The aim of the current proposal is to present and be able to compare recent results on our understanding of organ abscission from model and crop species, and to provide a basis to understand both the evolution of abscission in plants and the translation of advances with model plants for applications in crop species.
Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 2014-10 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The RELATIONSHIP BETWEEN PECTINASE AND CELLULASE AND POST HARVEST NEEDLE ABSCISSION IN BALSAM FIR Abies Balsamea L written by Jingyi Wang and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Post-harvest needle abscission is a major challenge for the Christmas tree industry in Atlantic Canada. To further elucidate the physiological basis of needle loss in Balsam fir, experiments were conducted to investigate the possible link between certain hydrolytic enzymes and post-harvest needle abscission in balsam fir. This study focussed on the role of enzymes, pectinase and cellulase, in post-harvest needle abscission. Following harvest, cumulative cellulase activity increased over time prior to needle loss on both high and low needle retention duration (NRD) clones. Total cellulase activity of low NRD clone was much higher than that of high NRD clone. Pectinase does not affect needle abscission in this study. If cellulase activity is linked to post-harvest needle abscission, then inhibiting cellulase enzyme would reduce needle loss. Pre-treating branches with 2.5g 1-methylcyclopropene (1-MCP) enhanced needle retention.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1976 with total page 1732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trees in a Changing Environment written by Michael Tausz and published by Springer. This book was released on 2014-08-26 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book delivers current state-of-the-science knowledge of tree ecophysiology, with particular emphasis on adaptation to a novel future physical and chemical environment. Unlike the focus of most books on the topic, this considers air chemistry changes (O3, NOx, and N deposition) in addition to elevated CO2 effects and its secondary effects of elevated temperature. The authors have addressed two systems essential for plant life: water handling capacity from the perspective of water transport; the coupling of xylem and phloem water potential and flow; water and nutrition uptake via likely changes in mycorrhizal relationships; control of water loss via stomata and its retention via cellular regulation; and within plant carbon dynamics from the perspective of environmental limitations to growth, allocation to defences, and changes in partitioning to respiration. The authors offer expert knowledge and insight to develop likely outcomes within the context of many unknowns. We offer this comprehensive analysis of tree responses and their capacity to respond to environmental changes to provide a better insight in understanding likelihood for survival, as well as planning for the future with long-lived, stationary organisms adapted to the past: trees.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1976 with total page 1168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resource Physiology of Conifers written by William K. Smith and published by Gulf Professional Publishing. This book was released on 1995 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coniferous forests are among the most important of ecosystems. These forests are widespread and influence both the financial and biological health of our globe. This book focuses attention on conifers and how these trees acquire, allocate, and utilize the resources that sustain this crucial productivity. An international team of experts has surveyed and synthesized information from an expanding area of inquiry. The first half of the book describes how resources are acquired both by means of photosynthesis and through root systems. The latter half of the volume focuses upon how resources are stored and used. As conifers continue as a resource and ever increasingly important contributor to the regional and global environmental sustainability, this book will help establish how much sustainability can be expected and maintained.
Download or read book Plant Microbiomes for Sustainable Agriculture written by Ajar Nath Yadav and published by Springer Nature. This book was released on 2020-03-06 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book encompasses the current knowledge of plant microbiomes and their potential biotechnological application for plant growth, crop yield and soil health for sustainable agriculture. The plant microbiomes (rhizospheric, endophytic and epiphytic) play an important role in plant growth, development, and soil health. Plant and rhizospheric soil are a valuable natural resource harbouring hotspots of microbes, and it plays critical roles in the maintenance of global nutrient balance and ecosystem function. The diverse group of microbes is key components of soil–plant systems, where they are engaged in an intense network of interactions in the rhizosphere/endophytic/phyllospheric. The rhizospheric microbial diversity present in rhizospheric zones has a sufficient amount of nutrients release by plant root systems in form of root exudates for growth, development and activities of microbes. The endophytic microbes are referred to those microorganisms, which colonize in the interior of the plant parts, viz root, stem or seeds without causing any harmful effect on host plant. Endophytic microbes enter in host plants mainly through wounds, naturally occurring as a result of plant growth, or through root hairs and at epidermal conjunctions. Endophytes may be transmitted either vertically (directly from parent to offspring) or horizontally (among individuals). The phyllosphere is a common niche for synergism between microbes and plant. The leaf surface has been termed as phyllosphere and zone of leaves inhabited by microorganisms as phyllosphere. The plant part, especially leaves, is exposed to dust and air currents resulting in the establishments of typical flora on their surface aided by the cuticles, waxes and appendages, which help in the anchorage of microorganisms. The phyllospheric microbes may survive or proliferate on leaves depending on extent of influences of material in leaf diffuseness or exudates. The leaf diffuseness contains the principal nutrients factors (amino acids, glucose, fructose and sucrose), and such specialized habitats may provide niche for nitrogen fixation and secretions of substances capable of promoting the growth of plants. The microbes associated with plant as rhizospheric, endophytic and epiphytic with plant growth promoting (PGP) attributes have emerged as an important and promising tool for sustainable agriculture. PGP microbes promote plant growth directly or indirectly, either by releasing plant growth regulators; solubilization of phosphorus, potassium and zinc; biological nitrogen fixation or by producing siderophore, ammonia, HCN and other secondary metabolites which are antagonistic against pathogenic microbes. The PGP microbes belong to different phylum of archaea (Euryarchaeota); bacteria (Acidobacteria, Actinobacteria, Bacteroidetes, Deinococcus-Thermus, Firmicutes and Proteobacteria) and fungi (Ascomycota and Basidiomycota), which include different genera namely Achromobacter, Arthrobacter, Aspergillus, Azospirillum, Azotobacter, Bacillus, Beijerinckia, Burkholderia, Enterobacter, Erwinia, Flavobacterium, Gluconoacetobacter, Haloarcula, Herbaspirillum, Methylobacterium, Paenibacillus, Pantoea, Penicillium, Piriformospora, Planomonospora, Pseudomonas, Rhizobium, Serratia and Streptomyces. These PGP microbes could be used as biofertilizers/bioinoculants at place of chemical fertilizers for sustainable agriculture. The aim of “Plant Microbiomes for Sustainable Agriculture” is to provide the current developments in the understanding of microbial diversity associated with plant systems in the form of rhizospheric, endophytic and epiphytic. The book is useful to scientist, research and students related to microbiology, biotechnology, agriculture, molecular biology, environmental biology and related subjects.
Download or read book Fir Broom Rust written by Roger S. Peterson and published by . This book was released on 1964 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Woody Plant Seed Manual written by United States. Forest Service and published by Forest Service. This book was released on 2008 with total page 1240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chlorine and Hydrogen Chloride written by Assembly of Life Sciences (U.S.). Committee on Medical and Biologic Effects of Environmental Pollutants and published by . This book was released on 1976 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1 INTRODUCTION. 2 SOURCERS OF CHLORINE AND HYDROGEN CHLORIDE. 3 CONSUMPTION OF CHLORINE AND HYDROGEN CHLORIDE. 4 ATMOSPHERIC CHEMISTRY OF CHLORINE COMPOUNDS. 5 EFFECTS OF CHLORINE AND HYDROGEN CHLORIDE ON MAN AND ANIMALS. 6 EFFECTS OF CHLORINE AND HYDROGEN CHLORIDE ON VEGETATION. 7 PROPERTY DAMAGE AND PUBLIC NUISANCE. 8 SAFETY IN USE AND HANDLING OF CHLORINE AND ANHYDROUS HYDROGEN CHLORIDE.
Download or read book Horticultural Reviews Volume 35 written by Jules Janick and published by John Wiley & Sons. This book was released on 2009-10-16 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: Horticultural Reviews presents state-of-the-art reviews on topics in horticultural science and technology covering both basic and applied research. Topics covered include the horticulture of fruits, vegetables, nut crops, and ornamentals. These review articles, written by world authorities, bridge the gap between the specialized researcher and the broader community of horticultural scientists and teachers. All contributions are anonymously reviewed and edited by Professor Jules Janick of Purdue University, USA, and published in the form of one or two volumes per year. Recently published articles include: Artificial Pollination in Tree Crop Production (v34) Cider Apples and Cider-Making Techniques in Europe and North America (v34) Garlic: Botany and Horticulture (v33) Controlling Biotic Factors That Cause Postharvest Losses of Fresh Market Tomatoes (v33) Taxus spp.: Botany, Horticulture, and Source of Anti-Cancer Compounds (v32) The Invasive Plant Debate: A Horticultural Perspective (v32)
Download or read book The Plant Plasma Membrane written by Angus S. Murphy and published by Springer Science & Business Media. This book was released on 2010-11-11 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: In plant cells, the plasma membrane is a highly elaborated structure that functions as the point of exchange with adjoining cells, cell walls and the external environment. Transactions at the plasma membrane include uptake of water and essential mineral nutrients, gas exchange, movement of metabolites, transport and perception of signaling molecules, and initial responses to external biota. Selective transporters control the rates and direction of small molecule movement across the membrane barrier and manipulate the turgor that maintains plant form and drives plant cell expansion. The plasma membrane provides an environment in which molecular and macromolecular interactions are enhanced by the clustering of proteins in oligimeric complexes for more efficient retention of biosynthetic intermediates, and by the anchoring of protein complexes to promote regulatory interactions. The coupling of signal perception at the membrane surface with intracellular second messengers also involves transduction across the plasma membrane. Finally, the generation and ordering of the external cell walls involves processes mediated at the plant cell surface by the plasma membrane. This volume is divided into three sections. The first section describes the basic mechanisms that regulate all plasma membrane functions. The second describes plasma membrane transport activity. The final section of the book describes signaling interactions at the plasma membrane. These topics are given a unique treatment in this volume, as the discussions are restricted to the plasma membrane itself as much as possible. A more complete knowledge of the plasma membrane’s structure and function is essential to current efforts to increase the sustainability of agricultural production of food, fiber, and fuel crops.
Download or read book Lipid signaling in plants written by Xuemin Wang and published by Frontiers E-books. This book was released on 2013-07-30 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cell membranes are the initial and focal sites of stimulus perception and signal transduction. Membrane lipids are rich sources for the production of signaling messengers that mediate plant growth, development, and response to nutrient status and stresses. In recent years, substantial progress has been made toward understanding lipid signaling in plants, but many fundamental questions remain: What lipids are signaling messengers or mediators in plants? How are the signaling lipids produced and metabolized? In what plant cellular and physiological processes are various lipid mediators involved? How do they carry out their signaling functions? How do lipid signaling networks contribute to modulating plant growth, development, and responses to hormones and stresses? In this Research Topic issue, we invite the broad plant community to address the above questions.Cell membranes are the initial and focal sites of stimulus perception and signal transduction. Membrane lipids are rich sources for the production of signaling messengers that mediate plant growth, development, and response to nutrient status and stresses. In recent years, substantial progress has been made toward understanding lipid signaling in plants, but many fundamental questions remain: What lipids are signaling messengers or mediators in plants? How are the signaling lipids produced and metabolized? In what plant cellular and physiological processes are various lipid mediators involved? How do they carry out their signaling functions? How do lipid signaling networks contribute to modulating plant growth, development, and responses to hormones and stresses? In this Research Topic issue, we invite the broad plant community to address the above questions.
Download or read book Cellular Aspects of Wood Formation written by Jörg Fromm and published by Springer Science & Business Media. This book was released on 2013-04-11 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: With today’s ever growing economic and ecological problems, wood as a raw material takes on increasing significance as the most important renewable source of energy and as industrial feedstock for numerous products. Its chemical and anatomical structure and the excellent properties that result allow wood to be processed into the most diverse products; from logs to furniture and veneers, and from wood chippings to wooden composites and paper. The aim of this book is to review advances in research on the cellular aspects of cambial growth and wood formation in trees over recent decades. The book is divided into two major parts. The first part covers the basic process of wood biosynthesis, focusing on five major steps that are involved in this process: cell division, cell expansion, secondary cell wall formation, programmed cell death and heartwood formation. The second part of the book deals with the regulation of wood formation by endogenous and exogenous factors. On the endogenous level the emphasis is placed on two aspects: control of wood formation by phytohormones and by molecular mechanisms. Apart from endogenous factors, various exogenous effects (such as climate factors) are involved in wood formation. Due to modern microscopic as well as molecular techniques, the understanding of wood formation has progressed significantly over the last decade. Emphasizing the cellular aspects, this book first gives an overview of the basic process of wood formation, before it focuses on factors involved in the regulation of this process.
Download or read book Chemically Mediated Interactions Between Plants and Other Organisms written by Gillian A. Cooper-Driver and published by Springer. This book was released on 1985-05-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant detection of pathogens. Biochemical aspects of plant-microbe and microbe-microbe interaction in soil. Biochemical responses of plants to fungal attack. Allelopathy - an overview. Plant allelochemicals: linkages between herbivores and their natural enemies. Brementown revisited: interactions among allelochemicals in plants. Multifaceted chemically based resistance in plants. Pheromonal communication between plants. Adaptation to resource availability as a determinant of chemical defense strategies in woody plants.
