Chemical Ecology and Phytochemistry of Forest Ecosystems (eBook)

Proceedings of the Phytochemical Society of North America

J.T. Romeo (Herausgeber)

eBook Download: PDF

2005 | 1. Auflage
318 Seiten
Elsevier Science (Verlag)
978-0-08-045857-1 (ISBN)

Infos

The Phytochemical Society of North America held its forty-fourth annual meeting in Ottawa, Ontario, Canada from July 24-28, 2004. This year's meeting was hosted by the University of Ottawa and the Canadian Forest Service, Great Lakes Forestry Centre and was held jointly with the International Society of Chemical Ecology. All of the chapters in this volume are based on papers presented in the symposium entitled Chemical Ecology and Phytochemistry of Forest Ecosystems. The Symposium Committee, Mamdouh Abou-Zaid, John T. Arnason, Vincenzo deLuca, Constance Nozzolillo, and Bernard Philogene, assembled an international group of phytochemists and chemical ecologists working primarily in northern forest ecosystems. It was a unique interdisciplinary forum of scientists working on the cutting edge in their respective fields. While most of these scientists defy the traditional labels we are accustomed to, they brought to the symposium expertise in phytochemistry, insect biochemistry, molecular biology, genomics and proteomics, botany, entomology, microbiology, mathematics, and ecological modeling.

* A collection of papers presented at the 44th Annual meeting of the Phytochemical Society of North America
* Representation from a unique interdisciplinary forum of scientists
* Includes discussions on new genomics research in forest health

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The Phytochemical Society of North America held its forty-fourth annual meeting in Ottawa, Ontario, Canada from July 24-28, 2004. This year's meeting was hosted by the University of Ottawa and the Canadian Forest Service, Great Lakes Forestry Centre and was held jointly with the International Society of Chemical Ecology. All of the chapters in this volume are based on papers presented in the symposium entitled "e;Chemical Ecology and Phytochemistry of Forest Ecosystems"e;. The Symposium Committee, Mamdouh Abou-Zaid, John T. Arnason, Vincenzo deLuca, Constance Nozzolillo, and Bernard Philogene, assembled an international group of phytochemists and chemical ecologists working primarily in northern forest ecosystems. It was a unique interdisciplinary forum of scientists working on the cutting edge in their respective fields. While most of these scientists defy the traditional labels we are accustomed to, they brought to the symposium expertise in phytochemistry, insect biochemistry, molecular biology, genomics and proteomics, botany, entomology, microbiology, mathematics, and ecological modeling. - A collection of papers presented at the 44th Annual meeting of the Phytochemical Society of North America- Representation from a unique interdisciplinary forum of scientists- Includes discussions on new genomics research in forest health

Inhalt

Cover 1
CONTENTS 10
Induced Chemical Defenses in Conifers: Biochemical and Molecular Approaches to Studying their Function 12
Molecular Biochemistry and Genomics of Terpenoid Defenses in Conifers... 40
Some Insights into the Remarkable Metabolism of the Bark Beetle Midgut... 68
Interactions among Conifer Terpenoids and Bark Beetles across Multiple Levels of Scale: An Attempt to Understand Links between Population Patterns and Physiological Processes 90
Molecular Biology and Biochemistry of Induced Insect Defenses in Populus. 130
Tropical Forests as Sources of Natural Insecticides 156
High Molecular Weight Plant Polyphenols (Tannins): Prospective 174
Odor Perception and the Variability in Natural Odor Scenes 202
Structure and Function of Insect Odorant and Pheromone-Binding Proteins (OBPs and PBPs) and Chemosensory-Specific Proteins (CSPs) 238
Olfaction and Learning in Moths and Weevils Living on Angiosperm and Gymnosperm Hosts 280
Index 304

Textauszug

Chapter Two

Molecular Biochemistry and Genomics of Terpenoid Defenses in Conifers

Diane Martin; Jörg Bohlmann*    Michael Smith Laboratories, and Departments of Botany and Forest Science, University of British Columbia, Vancouver, B.C., Canada
* Author for correspondence email address: [e-mail]

INTRODUCTION

Successful chemical defense of long-lived conifers against herbivores and pathogens is largely dependent on the formation, accumulation, and release of oleoresin monoterpenoids, sesquiterpenoids, and diterpenoids. In addition, conifers also produce a large array of phenolic and other defense compounds. The topic of terpenoid defenses in conifers has previously been reviewed.1-7 Oleoresin terpenoids are stored in large quantities in resin canals, resin blisters, or resin cells in stems, roots, or foliage of many conifer species. The development of these specialized anatomical structures can be induced with insect or fungal attack, mechanical wounding, and chemical elicitation. Terpenoids may also be released as constitutive or induced volatiles from the foliage of conifers. These volatiles can act as chemical signals by attracting natural enemies of herbivores. The terpene synthases (TPS) play a central role in the formation of terpenoid chemical diversity, in maintaining phenotypic plasticity in conifer defense, and they are a major part of the genomic hardwiring of conifer resistance.7,8 Recent work has revealed much of the multigenic nature of this successful conifer terpenoid defense system. Application of methyl jasmonate (MeJA) has enabled a detailed characterization of inducible terpenoid defenses in several conifer species, including Norway spruce (Picea abies), Sitka spruce (P. sitchensis), and Douglas fir (Pseudotsuga menziesii).9-15 For example, species of spruce produce copious amounts of oleoresin terpenoids, which are stored in constitutive resin ducts, mainly in the bark, or in inducible traumatic resin ducts (TD) in the xylem. Terpenoid accumulation in traumatic resin ducts is regulated, at least in part, by TPS gene expression and by TPS enzyme activities, which are induced upon MeJA treatment or in response to insect attack. TPS gene expression and TPS enzyme activities are also elevated in foliage following MeJA elicitation. The cDNA cloning, functional characterization, and gene expression analysis of a large family of TPS genes from Norway spruce and Sitka spruce enabled an association of the biochemical function of these TPS genes with the accumulation of oleoresin terpenoids in stems or the release of terpenoid volatiles from needles.8,12,16 Recent work in Sitka spruce compared the MeJA- and insect-induced terpenoid defenses at the molecular, biochemical, and anatomical levels.15 The initial targeted gene characterization of the complex insect- and MeJA-induced terpenoid defense system in spruce has laid the foundation for new genome-scale characterization of insect-induced defenses in conifers (www.treenomix.com).

In this chapter, we emphasize recent research, published and unpublished, of the last five years that has established spruce as one of the best characterized systems for molecular, biochemical, and genomic research of conifer defense against insect pests.8,10-12,15,16 The chapter touches on molecular and biochemical regulation of chemical diversity of conifer defense and provides an outlook towards new genomics research in a forest health context, specifically the genomics of trees interacting with insect pests and insect-associated fungal pathogens. Most of the chapter covers our recent research with two species of spruce, Norway spruce and Sitka spruce, including terpenoid defense responses induced by MeJA and the white pine weevil (Pissodes strobi). Results from our research with spruce terpenoid defenses are relevant to the larger field of secondary metabolite structural diversity in plant defense and the evolution of such defenses and their phenotypic plasticity in long-lived, sessile organisms.7

TERPENOID BIOCHEMISTRY AND MOLECULAR GENETICS IN CONIFERS

The terpenoids represent the largest group of known plant secondary metabolites.17 Three classes, monoterpenoids (10 carbon atoms, C10), sesquiterpenoids (15 carbon atoms, C15), and diterpenoids (20 carbon atoms, C20) are especially prominent among the conifer defenses, as they constitute much of the conifer oleoresin (Fig. 2.1).7,10,15 In contrast to the mono-, sesqui-, and diterpenoids other terpenoids, such as hemiterpenoids and triterpenoids, have not yet been adequately characterized at the biochemical and molecular levels in conifers. Terpenoid biosynthesis begins with the formation of the five carbon building blocks, isopentenyl diphosphate (IDP) and its isomer, dimethylallyl diphosphate (DMADP) (Fig. 2.2). Two pathways exist for the formation of these precursors.17 The mevalonate (MEV) pathway is found in the cytosol and endoplasmic reticulum, and the 2-C-methyl erythritol-4-phosphate (MEP) pathway, which proceeds via 1-deoxyxylulose-5-phosphate, occurs in plastids. Most genes of the MEV and MEP pathways have been identified in the spruce expressed sequence tag (EST) database and full-length cDNA clone collections (www.treenomix.com) and are now being used for gene expression analysis in conifer defense.

Fig. 2.1 Characteristic monoterpenes (A), sesquiterpenes (B) and (C) diterpenes present in conifer oleoresin and conifer volatiles emissions.

Fig. 2.2 Scheme of the terpenoid biosynthetic pathway. Formation of monoterpenes and diterpenes occurs in plastids. Formation of sesquiterpenoids occurs in the cytsol. Secondary transformation of diterpenes to diterpene resin acids involves membrane-associated cytochrome P450 dependent monooxygenases. IPP is isopentenyl disphosphate; DMAPP is dimethylallyl diphosphate; GPP is geranyl disphosphate; FPP is farnesyl disphosphate; GGPP is geranylgeranyl disphosphate; ER is endoplasmatic reticulum; Cyt P450 is cytochrome P450 dependent monooxygenase; TPS is terpene synthase.

Upon the formation of IDP and DMADP, prenyltransferases (PT) perform 1’-4 condensation reactions coupling IDP with an allylic prenyl diphosphate. Geranyl diphosphate (GDP) synthase forms the C10 precursor of monoterpenes, farnesyl diphosphate (FDP) synthase forms the C15 precursor of sesquiterpenes, and geranylgeranyl diphosphate (GGDP) synthase produces the precursor for diterpene biosynthesis. A molecular characterization of conifer PTs was first initiated in grand fir (Abies grandis).18 Recent work with Norway spruce PTs is described elsewhere in this volume (see chapter by Schmidt, et al., this volume). Several Sitka spruce and white spruce PTs have also been discovered in the spruce EST database (www.treenomix.com). PTs of the three classes, GDP synthase, FDP synthase, and GGDP synthase, share many common features including sequence similarities, a divalent metal ion requirement for catalysis, and the catalytically active sequence motif DDXXD. GDP synthase and GGDP synthase are localized to the plastid, and FDP synthase is localized to the cytosol / endoplasmic reticulum. Flux of pathway intermediates between these two compartments has been reported.19 Although PTs are critical components of terpenoid biosynthesis, relatively little is known about the regulation of PTs in induced defense responses in conifers.10

The three prenyl diphosphates GDP, FDP, and GGDP are the substrates of a large family of TPS enzymes that catalyze the formation of an amazing structural diversity of monoterpenoids, sesquiterpenoids, and diterpenoids.20 The TPS utilize an electrophilic reaction mechanism, assisted by divalent metal ion cofactors.21-23 The prenyl diphosphate substrates are ionized or protonated by TPS to produce reactive carbocation intermediates, which can be rearranged and eventually quenched to yield a wide variety of cyclic and acyclic terpenoid products.21-26 TPS enzymes exist as single or multiple product enzymes.27 Class specific TPS, mono-TPS, sesqui-TPS, and di-TPS, are responsible for the formation of the many simple (acyclic or single ring structure) and intricate (two or more ring structures) terpene skeletons of conifer mono-, sesqui-, and diterpenoids.8 While many terpenoids are further modified by an array of secondary transformations, the basic terpenoid skeletal structures are the products of unique catalytic activities of TPS enzymes. TPS also tend to exert tight control over the stereochemistry of products formed, and usually one enantiomer dominates any TPS product profile, both for single- and multiple-product TPS.28A number of conifer TPS have been cloned and characterized from grand fir (Abies grandis),27,29-32 loblolly pine (Pinus taeda),33 Sitka spruce,16 Norway spruce,8,12 and Douglas fir35 (Huber et al., unpublished results), and the enantiomeric specificity and product profiles of these enzymes has been investigated.

The recent cloning and characterization of ten functionally different TPS in Norway spruce provided valuable information concerning the biochemistry of conifer defense and established the necessary tools for TPS...

Produkt-Details

• Erscheint lt. Verlag: 26.7.2005
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Themenwelt: Naturwissenschaften ► Chemie ► Organische Chemie
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Geografie / Kartografie
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Optik
• Themenwelt: Technik
• Themenwelt: Wirtschaft
• Themenwelt: Weitere Fachgebiete ► Land- / Forstwirtschaft / Fischerei
• ISBN-10: 0-08-045857-2 / 0080458572
• ISBN-13: 978-0-08-045857-1 / 9780080458571