Nitric oxide in plant growth, development and stress physiology. Plant Cell Monographs, Volume 6.

Abstract

Nitric oxide and its role in biological systems has had an increased prominence in the scientific literature since the 1980s, and really came to light as a signalling molecule in plants in the late 1990s. As discussed in the ‘Preface’ of this book, the number of publications concerning NO in plants has increased dramatically since that time, with little sign of this rise easing off. Therefore, a book that brings together a variety of aspects of NO biology in plants is timely. The book starts with chapters on NO synthesis, from mitochondria and from nitrogen assimilation, and then moves on to a chapter on NO signalling, which is an appropriate way to organize a book such as this. One of the main downstream pathways through which NO signals in animals is through the activation of guanylyl cyclase and the production of cGMP, but NO can also covalently modify proteins through a process referred to as S-nitrosylation. This process is the subject of the next chapter of the book, and highlights how NO can have profound effects on a multitude of proteins. Two subsequent chapters on NO in seed germination are followed by chapters on the role of NO in plant hormone signalling, including discussions on auxin, abscisic acid (ABA), lipid signalling, cytokinins and polyamine signalling. This is followed by a chapter on NO control of plant ion channels. The next few chapters are concerned with the role of NO in physiological events. This includes NO in nitrogen-fixing symbiosis, abioitc stress, the hypersensitive response and how it might function under oxygen deprivation. The book ends with a chapter that has a title indicating that it discusses fluorometric detection of NO, but in fact this chapter has short summaries about many techniques to determine the presence of NO, with a more in-depth discussion on the use of the compound diaminofluorescein (DAF) as a fluorometric probe. The greatest strength of this book is the fact that chapters have been contributed from researchers and groups that have a major prominence in the field, and therefore it has been written by those immersed in this research. Most of the major groups working on NO in plants are represented. However, despite the fact that it is timely to publish such a book there are some major issues to be resolved in NO biology in plants. Firstly, the final chapter of this book discusses how NO can be measured, and highlights several matters that need to be resolved in this area in the future. For most of the methods discussed the authors state problems, not least with the use of DAF and fluorescence, one of the most widely used techniques. Secondly, although a sequence for a nitric oxide synthase (NOS) protein from plants has been published, more recent literature brings into doubt exactly what this protein does. In fairness to the editors, they do have a ‘Note added in Proof’ discussing this in the ‘Preface’, but several of the chapters have not had the chance to be similarly up-dated. Therefore, in several places in the book discussion about the sources of NO in plants will need to be read with care. The book is very well presented, with a good use of diagrams, many with the added advantage of the use of colour. All the chapters are very well referenced and this will give any reader a fantastic place to start a more in-depth reading of the literature. However, the index is rather poor, and quickly trying to find pages for subjects known to be discussed in the book is not easy. Final-year undergraduates undertaking research or literature projects on NO will find this book of value, as would any postgraduates working in the area, and in fact for anyone working on NO in plants it ought to be a book that they should definitely read. Furthermore, as NO has now been implicated in so many functions and responses in plants, for those that are not directly involved in NO research but work on growth, development and stress biology, this is a text that they should be aware of. Overall, this is a book on an exciting topic with what appears to be an ever-increasing growth in interest. It is well written by experts in the field, and an excellent place to begin a reasonably in-depth and yet broad reading of the role of nitric oxide in plants.