Naphthalene is of global environmental concern because it is assumed to contribute considerably to human cancer risk. Plants are important in removing naphthalene from the atmosphere and soil. However, there remains insufficient knowledge on plant response to this compound. To determine the mechanism of naphthalene uptake and transduction in plants, as well as plant response to this compound, a microarray system was used to analyze gene expression patterns in Arabidopsis thaliana after irrigation with 2.0 mm naphthalene. A total of 247 differentially expressed genes were identified as upregulated by naphthalene. These genes might specifically contribute to naphthalene uptake, transformation, conjugation, and compartmentalization in the plant. The potential role of upregulated genes in plant defense to naphthalene and the use of phytosensing for naphthalene detection were also discussed. (C) 2011 Elsevier B.V. All rights reserved.