Signalling: No plant is an island

Abstract

Plants and animals have much in common in their signal transduction systems - G-proteins, protein kinases, cryptochromes, ion channels, Ca2+/calmodulin, cyclic nucleotides, reactive oxygen species and nitric oxide are all common elements. This may partly reflect a tendency to look in plants for the same intermediates that have been well documented in animals. In other cases there are indirect similarities: jasmonic acid, for example, structurally resembles the prostaglandins from animals. Nevertheless, other components, such as phytochrome, phototropin and salicylate appear to be specific to plants. Moreover, the way in which plants and animals defend themselves from pathogens is fundamentally different. In plants, most of the components mentioned are involved in multiple pathways - there must be considerable cross-talk during the response to environmental factors. This serves to emphasize both the complexity of the transduction networks and the limits to our current understanding. The fact that signal transduction involves linking an environmental signal to a biochemical or genetic response further emphasizes the need for the involvement of scientists from different backgrounds: interdisciplinary meetings will continue to have a vital role in the future.