Jasmonate- and wounding-induced expression of a tobacco gene encoding a BTB domain protein

Nicotine is synthesized in the root of tobacco (Nicotiana tabacum) and transported to aerial parts where this alkaloid functions as an insect repellant. Nicotine biosynthesis is regulated by jasmonate and specific regulatory Nic loci, but molecular components in the jasmonate- or Nic-dependent signaling pathways have not been well characterized. We here identified a tobacco gene encoding a novel protein JEI1 (Jasmonate Early Inducible 1) containing a BTB domain and a WD40-like repeat. The JEI1 expression was regulated by the NIC loci. In the leaf, application of jasmonate or wounding rapidly and transiently induced the JEI1 expression, with an induction pattern distinct from a wound-inducible protein kinase WIPK. This tobacco gene might be involved in wound-elicited signaling pathways.