June’s issue of CSH Protocols brings a set of articles detailing the use of hormone response in the phenotypic analysis of mutants in plants. The protocols, Phenotypic Analysis of Arabidopsis Mutants: Auxin Hormone Response, Ethylene Hormone Response and Brassinosteroid Hormone Response, are part of a larger set of methods for phenotypic analysis of Arabidopsis mutants which have been published over the last few months (with more on the way soon). Previous articles cover growth parameters in phenotypic analysis, including hypocotyl length and root growth. Next month we’ll add a protocol for using flowering time, and future issues will address the response to the abiotic environment, bacterial pathogens, and oomycete pathogens. Histological and imaging techniques for phenotypic analysis are also part of our growing collection, and include sectioning of fixed material, scanning electron microscopy (SEM) and vital stain for cytoplasm. For information about obtaining mutants in Arabidopsis, please see Setting Up Arabidopsis Crosses and Genetic Analysis of Arabidopsis Mutants.