Molecular aspects of plant disease resistance. Annual Plant Reviews, Volume 34

Abstract

Plant disease resistance is one of the most desirable traits in an agricultural context, especially in these times of fear over food security, making it a key topic within plant biology and crop science. This book, which provides an update on a wide variety of important areas within plant pathology, is therefore particularly timely. In the opening chapter, Heath sets the scene and provides a fascinating overview of developments during the last 40 years of plant pathology research from a personal perspective. She places particular emphasis on the hypersensitive response, gene-for-gene resistance and host verses non-host resistance. In concluding, Heath expresses her desire for more cytological and biochemical-based approaches to understand how, in both space and time, given gene products function to establish disease resistance. In the following chapter, Nurnberger and Kemmerling provide an update on pathogen-associated molecular patterns (PAMPs) and PAMP-triggered immunity. Massive strides have been taken in this field in the past few years, which have dramatically increased our appreciation of this defence system, including the isolation of pattern-recognition receptors (PRRs) from potential host plants, the demonstration that PRR function is biologically relevant during the development of disease resistance, and the accumulating evidence that pathogens specifically target this defence mechanism for suppression to aid pathogenesis. Another chapter deals with the type-III secretion system (TTSS) of the bacterial pathogen Pseudomonas syringae. The discovery that bacterial plant pathogens deliver so-called effector proteins directly into the plant cell to aid pathogenesis via this TTSS has primed an explosion of activity in this area over the last few years. Increasing our understanding of the activities and host targets of these effector proteins will likely provide significant insights into exactly how plants repel attempted bacterial infection. Pathogen genomics is another area of plant pathology that has expanded rapidly in recent times. This is particularly true for oomycetes, such as Phytophthora, five species of which have now been sequenced, and the latest advances in this field are discussed in Chapter 5 by Bouwmeester, van Poppel and Govers. Large areas of synteny between these genomes have been found, significantly aiding the gene-calling process. This process can often be difficult because ∼20 % of genes found in these pathogens are thought to be unique to oomycetes. This genomics-based approach identified the RxLR-dEER motif, located adjacent to the signal peptide, which appears to be found in most oomycete effector proteins. This was surprising because no conserved domains have been found to date in fungal avirulence genes. Consequently, candidate oomycete effectors can now be identified rapidly by bioinformatics-based approaches, and their potential function in infection rapidly investigated utilizing high-throughput strategies. The future application of next-generation sequencing approaches such as Roche 454, Illumina-Solexa and Applied Biosystems SOLiD™ will further accelerate the pace of discovery in this research field. Other chapters in the book cover such topics as plant–virus interactions, the role of secondary metabolites at the host–pathogen interface (an old topic that is currently having a renaissance), and lipid signalling in the defence response. A significant strength of this book is that the chapters have been written by experts in their respective fields who have provided up-to-date descriptions of the state-of-the-art. However, perhaps inevitably, there is sometimes redundancy in material between individual contributions. Each chapter is extensively referenced, leading the reader to a potential wealth of further information including research papers and reviews, and the index is extensive. There is generally judicious use of diagrams and tables to complement the text, although some sections would have benefited from more of these. This book is essential reading for final-year undergraduates attending plant pathology courses or undertaking research projects within this area. The collection of updates on key topics also makes this book entirely suitable for graduate students and post-doctoral fellows, or indeed anyone who has a significant interest in this important area of plant science. In sum, this is a well-written and presented book on an exciting and important topic that provides a wealth of up-to-date information suitable for final-year undergraduates, postgraduates and professional researchers.