Abstract: Auxin and jasmonic acid (JA) are two plant phytohormones that both participate in the regulation of many developmental processes. Jasmonic acid also plays important roles in plant stress response reactions. Although extensive investigations have been undertaken to study the biological functions of auxin and JA, little attention has been paid to the cross-talk between their regulated pathways. In the few available reports examining the effects of auxin on the expression of JA or JA-responsive genes, both synergetic and antagonistic results have been found. To further investigate the relationship between auxin and JA, we adopted an integrative method that combines microarray expression data with pathway information to study the behavior of the JA biosynthesis pathway under auxin treatment. Our results showed an overall downregulation of genes involved in JA biosynthesis, providing the first report of a relationship between auxin and the JA synthesis pathway in Arabidopsis seedlings.(Author for correspondence.Institute of Genetics and Development Biology, the Chinese Academy of Sciences, Beijing 100101, China. Tel: +86 (0)10 6484 0941; Fax: +86 (0)10 6487 3428; E-mail: xjwang@genetics.ac.cn)

Key words: Arabidopsis, auxin, biosynthesis, jasmonic acid, pathway.