Plant–plant signalling, the shade-avoidance response and competition

This is the flow of information between Plant–plant signalling Plants generate and perceive informational signals. individuals. An interaction is considered An interaction (between plants) is considered to be to be informational when it involves the informational when it involves the exchange of an exchange of an insignificant amount of matter or energy, in quantitative terms, insignificant amount of matter or energy, in quantitatbut in spite of this has a profound effect ive terms, but in spite of this has a profound effect on on plants by modulating their plants by modulating their developmental programme. developmental programme. Plasticity Phenotypic plasticity is the expression of This article discusses how plants ‘use’ light signals to variability among individuals of identical detect neighbouring plants and outlines the implicagenotype. Throughout the life of an tions of shade-avoidance responses for the developindividual plant, plastic responses are triggered by a variety of input signals and ment of size and fitness hierarchies in canopies. The are constrained by the possible role of shade avoidance as a stabilizing force in monocombinations of protein synthesis and specific canopies is noted. action specified in the plant’s genotype. Shade avoidance This is the response of plants to shade by