FB4eA01 04/12/2005 09:17 AM Page i Fungal Biology FB4eA01 04/12/2005 09:17 AM Page ii FB4eA01 04/12/2005 09:17 AM Page iii Fungal Biology 4th edition Jim Deacon Institute of Cell and Molecular Biology, University of Edinburgh, UK FB4eA01 04/12/2005 09:17 AM Page iv © 2006 by J.W. Deacon © 1980, 1984, 1997 by Blackwell Publishing Ltd BLACKWELL PUBLISHING 350 Main Street, Malden, MA 02148-5020, USA 9600 Garsington Road, Oxford OX4 2DQ, UK 550 Swanston Street, Carlton, Victoria 3053, Australia The right of J.W. Deacon to be identified as the Author of this Work has been asserted in accordance with the UK Copyright, Designs, and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher. First edition published 1980 Second edition published 1984 Third edition published 1997 Fourth edition published 2006 by Blackwell Publishing Ltd 1 2005 Library of Congress Cataloging-in-Publication Data Deacon, J.W. Fungal biology / J.W. Deacon.—4th ed. p. ; cm. Rev. ed. of: Modern mycology. 3rd ed. 1997. Includes bibliographical references and index. ISBN-13: 978-1-4051-3066-0 (pbk. : alk. paper) ISBN-10: 1-4051-3066-0 (pbk. : alk. paper) 1. Mycology. 2. Fungi. [DNLM: 1. Fungi. 2. Mycology. QK 603 D278i 2006] I. Deacon, J.W. Modern mycology. II. Title. QK603.D4 2006 579.5—dc22 2005004137 A catalogue record for this title is available from the British Library. 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For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com FB4eA01 04/12/2005 09:17 AM Page v Contents Preface vii 1 Introduction: the fungi and fungal activities 1 2 The diversity of fungi and fungus-like organisms 16 3 Fungal structure and ultrastructure 48 4 Fungal growth 67 5 Differentiation and development 85 6 Fungal nutrition 110 7 Fungal metabolism and fungal products 122 8 Environmental conditions for growth, and tolerance of extremes 142 9 Fungal genetics, molecular genetics, and genomics 158 10 Fungal spores, spore dormancy, and spore dispersal 184 11 Fungal ecology: saprotrophs 213 12 Fungal interactions: mechanisms and practical exploitation 237 13 Fungal symbiosis 256 14 Fungi as plant pathogens 279 15 Fungal parasites of insects and nematodes 309 16 “The moulds of man” 322 17 Principles and practice of controlling fungal growth 338 Sources 356 Systematic index 361 General index 366 FB4eA01 04/12/2005 09:17 AM Page vi FB4eA01 04/12/2005 09:17 AM Page vii Preface Fungal Biology (4th edition) is the successor to three pre- defense also are covered in depth, using selected vious editions of “Modern Mycology.” The text has been examples of all the major pathosystems. fully updated and expanded to cover many new devel- Two final chapters are devoted to the “moulds of opments in fungal biology. Each of the 17 chapters is man,” covering the biology, pathogenicity, and virulence largely independent, with a clear theme and cross- factors of the major fungal diseases of humans, and the referencing, so that the text can be used to focus on antifungal drugs used to treat these conditions. selected topics. This text is designed to appeal to both undergradu- The early chapters deal with the unique structure ates and postgraduates. The emphasis throughout is on and organization of fungi and fungus-like organisms, the functional biology of fungi, with several examples including modern experimental approaches in fungal from recent research, and many tables and illustrations. biology, and the many ways in which fungi respond The text is supported by a comprehensive website to environmental cues. These chapters also cover the (available via www.blackwellpublishing.com/deacon), diversity of fungi, and fungal products including im- with over 600 images, many in color, including “Spe- munosuppressants, antibiotics, and mycotoxins that cial Focus Topics” and “Profiles of Significant or Inter- contaminate food. esting Fungi.” My own images are identified, and can Recent developments in fungal genetics, molecular be used freely, without restriction. The website also has genetics, and genomics are discussed within the a large interactive (randomized) test bank of multiple- framework of a “biochemical and molecular toolbox,” choice questions, designed to aid self-assessment and using in-depth examples such as the roles of virus- reinforcement of key learning outcomes. like double-stranded RNA for the control of chestnut I wish to thank many colleagues who have con- blight, and the population dynamics of Dutch elm tributed to this book by providing images and disease. Major sections of the text deal with the de- resources. They include many of my doctorate students, velopment of fungi as commercial biological control and Nick Read’s research group at the University of agents of plant pathogens and insect pests. In addition, Edinburgh, who have been supportive throughout. one of the three new chapters deals with the sym- biotic associations of fungi with plants and animals, Jim Deacon and the biology of lichens. Plant pathogens and plant Edinburgh FB4eA01 04/12/2005 09:17 AM Page viii FB4eC01 04/12/2005 12:26PM Page 1 Chapter 1 Introduction: the fungi and fungal activities This chapter is divided into the following major sections: many important roles. To set the scene, we can men- tion just a few examples: • the place of fungi in the “Tree of Life” – setting the scene • Fungi are the most important causes of crop dis- • the characteristic features of fungi: defining the fun- eases, responsible for billions of dollars worth of gal kingdom damage each year, and for periodic devastating • the major activities of fungi as parasites, symbionts disease epidemics. and saprotrophs • Fungi are the main decomposers and recyclers of • fungi in biotechnology organic matter, including the degradation of cellu- lose and wood by the specialized enzyme systems Fungi are a unique group of organisms, different from unique to fungi. all others in their behavior and cellular organization. • Fungi produce some of the most toxic known Fungi also have an enormous range of activities – as metabolites, including the carcinogenic aflatoxins pathogens of crop plants or humans, as decomposer and other mycotoxins in human foods and animal organisms, as experimental “model organisms” for feedstuffs. investigating genetics and cell biology, and as producers • With the advance of the acquired immune of many important metabolites. The uniqueness of fungi deficiency syndrome (AIDS) and the increasing role is a prominent feature of this book, which adopts a of transplant surgery, fungi are becoming one of functional approach, focusing on topics of inherent the most significant causes of death of immuno- interest and broad significance in fungal biology. compromised and immunosuppressed patients. The uniqueness of fungi is reflected in the fact that Fungal diseases that were once extremely rare are they have the status of a kingdom, equivalent to the now commonplace in this sector of the population. plant and animal kingdoms. So, fungi represent one of • Fungi have an enormous range of biochemical the three major evolutionary branches of multicellular activities that are exploited commercially – notably organisms. the production of antibiotics (e.g. penicillins), In terms of biodiversity, there are estimated to steroids (for contraceptives), ciclosporins (used as be at least 1.5 million different species of fungi, but immunosuppressants in transplant surgery), and only about 75,000 species (5% of the total) have been enzymes for food processing and for the soft drinks described to date. For comparison, there are estimated industry. to be 4.9 million arthropod species and about 420,000 • Fungi are major sources of food. They are used seed plants (Hawksworth 2001, 2002). for bread-making, for mushroom production, in sev- If the estimate of the number of fungal species is eral traditional fermented foods, for the production even remotely accurate then we still have much to learn, of Quorn™ mycoprotein – now widely available in because even the fungi that we know about play supermarkets and the only survivor of the many FB4eC01 04/12/2005 12:26PM Page 2 2 CHAPTER 1 Carl Woese of the University of Illinois at Urbana- “single-cell protein” ventures of the late 1900s – and, Champaign, USA, has championed the use of of course, for the production of alcoholic drinks. molecular phylogenetics. The basis of this is to iden- • Fungi can be used as “cellular factories” for producing tify genes that are present in all living organisms and heterologous (foreign) gene products. The first that have an essential role, so they are likely to be highly genetically engineered vaccine approved for human use conserved, accumulating only small changes (mutations was produced by engineering the gene for hepatitis and back mutations) over large spans of evolutionary B surface antigen into the yeast (Saccharomyces time. Comparisons of these sequences can then cerevisiae) genome. In this way the antigen can be indicate the relationships between different organ- produced and exported from the cells, then purified isms. There are limitations and uncertainties in this from the growth medium. approach, because of the potential for lateral gene • The genome sequences of several fungi have now transfer between species and because there are known been determined, and in several cases the genes of to be variable rates of gene evolution between differ- fungi are found to be homologous (equivalent) to ent groups of organisms.