Innovative biological approaches to botrytis suppression

Abstract

Research into the mechanisms used by plants to protect themselves against pathogens has expanded considerably in the past few decades, fuelled, in part, by addition of genomic tools to investigators' resources. As a consequence, information about the details of many defence mechanisms and the genes that are responsible for their constitutive or induced expression is now available for utilization in crop improvement. This chapter briefly addresses many aspects of plant defences against Botrytis infection, including considerations of how the pathogen is detected, signalling pathways that activate and coordinate defence responses, and the expression of factors that make mechanistically different contributions to defence. Almost all of these topics are addressed more fully in earlier chapters of this book. The focus here is on use of more recent biochemical and molecular information to enhance crop plant defence against Botrytis. We discuss the potential for 1) introducing the Botrytis defence systems of wild species by cross-breeding into domesticated, genetically compatible crop species, 2) using genetic engineering to introduce into crops genes enabling the synthesis of antifungal metabolites or encoding peptides and proteins shown to have anti-Botrytis activity, 3) employing powerful techniques for gene discovery to identify sequences encoding downstream factors involved in defence signalling, thus offering the possibility of directly linking beneficial plant responses to the plant's perception of the pathogen while eliminating responses that might facilitate infection, and 4) specific possibilities for enhancing the ability of biocontrol microorganisms to limit damage due to Botrytis infection of crop plants. Broader questions that might serve as guiding principles when specific approaches to enhancing crop plant pathogen defences are under consideration are also discussed. © 2007 Springer Science+Business Media B.V.