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The plant-environment interface
update
The plantenvironment interface Plant Cuticles: An Integrated Functional Approach
editedby G. Kerstiens Bios, 1996. £60.00/$120.00 hbk (xiv +337 pages) ISBN 1 85996 130 4 It is almost 16 years since researchers last assembled to swap notes on the unique physicochemical properties of the cuticles of plants. I use this terminology advisedly, as in the classic work of Martin and Juniper 1, because cuticles show such diversity in their structure and chemistry - but all occupy a pivotal position as the interface between the plant and its environment. The present tome comprises 17 contributions from The Society of Experimental Biology meeting held at Lancaster, UK in March 1996 - the proceedings were produced in record time. The format is the same as the last major symposium on this subject organized by The Linnean Society2, being a mixture of state of the art reviews together with more specialized accounts of specific cuticular interactions. Perhaps it is a sign of the times that none of the authors of the 27 papers published from the previous meeting made contributions at Lancaster. What have the new generation got to tell us? For the nuts and bolts, little progress I am afraid. Information in the book about cuticular waxes is disappointing, with more detailed accounts having been recently pubfished elsewhere3'4.Nevertheless, the precise mechanism for wax transport from inside the epidermal cell to the surface of the cuticle still remains elusive, despite some genes responsible for wax biosynthesis having now been cloned. Similarly, chemical and biosynthetic studies on the polyester cutins, which form the structural framework of most cuticles, also appear to have remained static (covered in an encyclopedic review by C.E. Jeffree). One of the few breakthroughs in this area was the discovery, in the late 1980s, of a new highly resistant polymethylene-type cuticular polymer, cutan; I was privileged to participate in this work, which was initiated by the Delft group 5. However, more work is needed to complete the elucidation of the structure of cutan. It is this component that is preserved in the fossil records of cuticles (covered by D. Edwards, G.D. Abbott and J.A. Raven). It is also the major polymeric constituent of the polylamellate cuticle present on sugar-beet leaves. © 1997 ElsevierScience Ltd
A major part of the book is devoted to the permeability of plant surfaces, including the cuticle, to liquids, solids and gases (L. Schreiber, T. Kirsch and M. Riederer; G. Kerstiens; J. Schhnherr and P. Banr; J.N. Cape). It is here that there has been considerable expansion in our knowledge in recent years, especially with regard to atmospheric pollutants and crop protection chemicals. Indeed, the former aspect has also been the subject of a recent NATO workshop6. Much of the new experimental data has been collected using model isolated cuticle and wax systems, which have been subjected to rigorous mathematical and kinetic treatment. Examination in this way allows predictions of cuticular behaviour to be made from a consideration of salient physicochemical factors; unfortunately, few attempts have been made to validate these on intact leaves. Also, 'isolated' cuticle is something of a misnomer - what is detached is that portion of the outer epidermal wall that contains the cuticle - almost certainly an incrustation as opposed to an adcrustation (cf. epicuticular wax) in botanical terms. Other recurrent themes are concerned with cuticle-insect, cuticle-fungus and cuticle-environment interactions, the latter being of particular relevance to stresses induced by impending global warming. For insects, there is an overview (S.D. Eigenbrode), and two fascinating case studies with maize (K.E. Espelie) and tobacco (D.M. Jackson and D.A. Danehover). These serve to highlight the potential for improved pest management in crop species, via manipulation of epicuticular wax composition, and even microstructure, by breeding or biotechnology. The behaviour of fungi on plant surfaces was last reviewed in depth in symposium proceedings in the 1970s (Refs 7 and 8) and the present volume provides a valuable update for both epiphytic and pathogenic organisms (K. Mendgen; T.L.W. Carver, S.M. Ingerson and B.J. Thomas; S. Huttunen). The importance of surface wetness for colonization and infection is dealt with separately (D.R. Butler). Whether specific cutinases are involved in cuticular penetration by fungi is still debatable. Although several species produce esterases, convincing evidence for cutin degradation (liberation of monomers) is still lacking; a reliable assay procedure is needed. Finally, there are two valuable articles having a more ecological flavour. One reviews the effects of various types of electromagnetic radiation on the plant surface, reinforcing the protective role of plant cuticles, and especially their epicuticular waxes (J.D. Barnes and J. Cardoso-Vilhena). The other deals with the cuticle in action under
even more drastic conditions, and examines the influences of weathering on its structure and permeability (J. Grace and P.R. van Gardingen). The information content of this book is extremely high and timely. I thoroughly enjoyed reading it, despite a sense of d~j& vu for the perennial chestnuts. Both the humble undergraduate and the dedicated researcher will find it an essential source book. I will end with one conundrum, which has perplexed me for years: there must be a microorganism out there somewhere whose favourite repast is cuticle - otherwise, we would be permanently buried up to our necks in leaves. But what is it? Peter Holloway IACR - Long Ashton ResearchStation, Dept of AgriculturalSciences, Un}versityof Bristol, Long Ashton, Bristol, UK BS18 9AF (tel +44 1275 549274; fax +44 1275 394007; e-mail peter. [email protected]) References 1 Martin, J.T. and Juniper, B.E. (1970) The Cuticle of Plants, Edward Arnold 2 Cutler, D.F., Alvin,K.L. and Price, C.E., eds (1982) The Plant Cuticle, AcademicPress 3 Hamilton, R.J., ed. (1995) Waxes: Chemistry, Molecular Biology and Function, The Oily Press 4 Post-Beittenmiller,D. (1996) Biochemistryand MolecularBiologyofWax Productionin Plants, Annu. Roy. Plant Physiol. Plant Mol. Biol. 47, 405-430 5 Nip, M. et al. (1986)A new non-saponifiable highly aliphatic and resistant biopolymerin plant cuticles. Evidence from pyrolysis and 13C-NMRanalysis from present-day and fossil plants, Naturwissenschaflen 73, 579-585 6 Percy, K.E. et aI., eds (1994)AirPollutants and the Leaf Cuticle, Springer 7 Preece, T.F. and Dickinson,C.H., eds (1971) Ecology of Leaf Surface Micro-organisms, AcademicPress 8 Dickinson,C.H. and Preece, T.F., eds (1976) Microbiology of Aerial Plant Surfaces, AcademicPress
Serene landscapes and football pitches The Biology of Grasses
by G.P. Chapman CAB International, 1996. £45.00/$85,50 hbk (xiv + 273 pages) ISBN 0 85199 111 4 Chapman brings a unique perspective to the biology of grasses, one that emphasizes the taxonomy, growth form, genetic associations and evolution of this important group May1997,Vol,2, No,5
201
The plantenvironment interface Plant Cuticles: An Integrated Functional Approach
editedby G. Kerstiens Bios, 1996. £60.00/$120.00 hbk (xiv +337 pages) ISBN 1 85996 130 4 It is almost 16 years since researchers last assembled to swap notes on the unique physicochemical properties of the cuticles of plants. I use this terminology advisedly, as in the classic work of Martin and Juniper 1, because cuticles show such diversity in their structure and chemistry - but all occupy a pivotal position as the interface between the plant and its environment. The present tome comprises 17 contributions from The Society of Experimental Biology meeting held at Lancaster, UK in March 1996 - the proceedings were produced in record time. The format is the same as the last major symposium on this subject organized by The Linnean Society2, being a mixture of state of the art reviews together with more specialized accounts of specific cuticular interactions. Perhaps it is a sign of the times that none of the authors of the 27 papers published from the previous meeting made contributions at Lancaster. What have the new generation got to tell us? For the nuts and bolts, little progress I am afraid. Information in the book about cuticular waxes is disappointing, with more detailed accounts having been recently pubfished elsewhere3'4.Nevertheless, the precise mechanism for wax transport from inside the epidermal cell to the surface of the cuticle still remains elusive, despite some genes responsible for wax biosynthesis having now been cloned. Similarly, chemical and biosynthetic studies on the polyester cutins, which form the structural framework of most cuticles, also appear to have remained static (covered in an encyclopedic review by C.E. Jeffree). One of the few breakthroughs in this area was the discovery, in the late 1980s, of a new highly resistant polymethylene-type cuticular polymer, cutan; I was privileged to participate in this work, which was initiated by the Delft group 5. However, more work is needed to complete the elucidation of the structure of cutan. It is this component that is preserved in the fossil records of cuticles (covered by D. Edwards, G.D. Abbott and J.A. Raven). It is also the major polymeric constituent of the polylamellate cuticle present on sugar-beet leaves. © 1997 ElsevierScience Ltd
A major part of the book is devoted to the permeability of plant surfaces, including the cuticle, to liquids, solids and gases (L. Schreiber, T. Kirsch and M. Riederer; G. Kerstiens; J. Schhnherr and P. Banr; J.N. Cape). It is here that there has been considerable expansion in our knowledge in recent years, especially with regard to atmospheric pollutants and crop protection chemicals. Indeed, the former aspect has also been the subject of a recent NATO workshop6. Much of the new experimental data has been collected using model isolated cuticle and wax systems, which have been subjected to rigorous mathematical and kinetic treatment. Examination in this way allows predictions of cuticular behaviour to be made from a consideration of salient physicochemical factors; unfortunately, few attempts have been made to validate these on intact leaves. Also, 'isolated' cuticle is something of a misnomer - what is detached is that portion of the outer epidermal wall that contains the cuticle - almost certainly an incrustation as opposed to an adcrustation (cf. epicuticular wax) in botanical terms. Other recurrent themes are concerned with cuticle-insect, cuticle-fungus and cuticle-environment interactions, the latter being of particular relevance to stresses induced by impending global warming. For insects, there is an overview (S.D. Eigenbrode), and two fascinating case studies with maize (K.E. Espelie) and tobacco (D.M. Jackson and D.A. Danehover). These serve to highlight the potential for improved pest management in crop species, via manipulation of epicuticular wax composition, and even microstructure, by breeding or biotechnology. The behaviour of fungi on plant surfaces was last reviewed in depth in symposium proceedings in the 1970s (Refs 7 and 8) and the present volume provides a valuable update for both epiphytic and pathogenic organisms (K. Mendgen; T.L.W. Carver, S.M. Ingerson and B.J. Thomas; S. Huttunen). The importance of surface wetness for colonization and infection is dealt with separately (D.R. Butler). Whether specific cutinases are involved in cuticular penetration by fungi is still debatable. Although several species produce esterases, convincing evidence for cutin degradation (liberation of monomers) is still lacking; a reliable assay procedure is needed. Finally, there are two valuable articles having a more ecological flavour. One reviews the effects of various types of electromagnetic radiation on the plant surface, reinforcing the protective role of plant cuticles, and especially their epicuticular waxes (J.D. Barnes and J. Cardoso-Vilhena). The other deals with the cuticle in action under
even more drastic conditions, and examines the influences of weathering on its structure and permeability (J. Grace and P.R. van Gardingen). The information content of this book is extremely high and timely. I thoroughly enjoyed reading it, despite a sense of d~j& vu for the perennial chestnuts. Both the humble undergraduate and the dedicated researcher will find it an essential source book. I will end with one conundrum, which has perplexed me for years: there must be a microorganism out there somewhere whose favourite repast is cuticle - otherwise, we would be permanently buried up to our necks in leaves. But what is it? Peter Holloway IACR - Long Ashton ResearchStation, Dept of AgriculturalSciences, Un}versityof Bristol, Long Ashton, Bristol, UK BS18 9AF (tel +44 1275 549274; fax +44 1275 394007; e-mail peter. [email protected]) References 1 Martin, J.T. and Juniper, B.E. (1970) The Cuticle of Plants, Edward Arnold 2 Cutler, D.F., Alvin,K.L. and Price, C.E., eds (1982) The Plant Cuticle, AcademicPress 3 Hamilton, R.J., ed. (1995) Waxes: Chemistry, Molecular Biology and Function, The Oily Press 4 Post-Beittenmiller,D. (1996) Biochemistryand MolecularBiologyofWax Productionin Plants, Annu. Roy. Plant Physiol. Plant Mol. Biol. 47, 405-430 5 Nip, M. et al. (1986)A new non-saponifiable highly aliphatic and resistant biopolymerin plant cuticles. Evidence from pyrolysis and 13C-NMRanalysis from present-day and fossil plants, Naturwissenschaflen 73, 579-585 6 Percy, K.E. et aI., eds (1994)AirPollutants and the Leaf Cuticle, Springer 7 Preece, T.F. and Dickinson,C.H., eds (1971) Ecology of Leaf Surface Micro-organisms, AcademicPress 8 Dickinson,C.H. and Preece, T.F., eds (1976) Microbiology of Aerial Plant Surfaces, AcademicPress
Serene landscapes and football pitches The Biology of Grasses
by G.P. Chapman CAB International, 1996. £45.00/$85,50 hbk (xiv + 273 pages) ISBN 0 85199 111 4 Chapman brings a unique perspective to the biology of grasses, one that emphasizes the taxonomy, growth form, genetic associations and evolution of this important group May1997,Vol,2, No,5
201