Understanding the Control of Plant Development and the Role of Growth Substances

Abstract

The control of development is often viewed as a simple process which can be approached experimentally in an equally simple fashion. However metabolism, cells, tissues and indeed whole plants form networks with a great density of connections. The control of complicated networks is little understood and their behaviour on perturbation is usually counter-intuitive. The notions of 'limiting factors' and 'cause and effect' are commonly used to conceptualise developmental control by growth substances. This article shows that these concepts are incompatible with metabolic network behaviour and it suggests how both can be modified to bring them into line with modern understanding.