The molecular organography of plants

Abstract

In the last 20 years or so, plant molecular biology has become the dominant field of research in botany departments and institutes. The development of powerful techniques for analysis of the genome and the identification of genes has led to a rapid accumulation of data, the collection of which has absorbed much of the research funding available to botanists. There is no doubt that scientists working in more traditional fields are being side-lined as departments move their research emphasis to follow the funding. To these scientists, it can seem that molecular biologists are so involved in the pursuit of the gene that they have lost sight of the plant. This book is particularly welcome, therefore, as it provides a concise and accessible account of how knowledge about gene function and variation are related to anatomical and morphological development. The combination of molecular data with knowledge about plant structure and growth is acquiring increasing importance and has led to the discipline known as the ‘evolution of development’ or ‘evo-devo’. Cronk's excellent book is timely, scholarly and important, bringing together the evolution, anatomy and morphology of the major plant organs and how they develop. As Cronk states in his preface, the book is not a textbook of plant morphology or plant molecular genetics, but it shows what can be achieved if the two subjects are combined. It is aimed at senior undergraduates and graduate students, although I believe that many young postdoctoral scientists working in plant molecular biology would benefit from reading it. It is very readable and gives a welcome overview of evo-devo that botanists new to the area will find extremely accessible, providing an excellent introduction to plant structures and their origins while putting the molecular work into context. As one might expect in a book dealing with a subject that has attracted the attention of so many researchers, there is an extensive 33-page bibliography. The introduction provides an overview of ideas on plant evolution and their development, which sets the scene for what follows: five chapters, each dealing with a particular plant organ. There is a chapter each on stems, roots and leaves, a chapter on sporangia and seeds, and one on sporophylls and flowers. Each chapter includes descriptions of the structure of the organ in question, its evolution and the variations found. Wherever the information is available, the genes involved in the developmental process are described. As a wood anatomist, however, I have one minor criticism: I winced to read that softwoods (by which is meant conifer woods) are soft because they contain relatively more tracheids than fibres, when in fact they contain tracheids and no fibres. It is incorrect to say that this makes the wood soft. Many ‘softwoods’ (or timbers from arborescent gymnosperms) have harder wood than many ‘hardwoods’ (or timbers from arborescent angiosperms), among which may be numbered balsa. ‘Softwood’ and ‘hardwood’ are, of course, industrial terms and not biological ones. As an anatomist, I found the accounts clear and easy to follow, but some recent graduates may find they need to have a well-illustrated anatomy textbook to hand to be able to visualize what is described. I say this because experience has shown that, almost unbelievably in this age of modularized degrees and student choice, a student can graduate in botany without having attended lectures on plant anatomy. However, if this book does not fire up an interest in plant structure and development, then nothing will! I would recommend the book to all botanists who need bringing up to date in this fast-moving area of research. It is an enjoyable read and excellent value at the price.