Transcription factor. Interacts specifically with the W box (5'-(T)TGAC[CT]-3'), a frequently occurring elicitor-responsive cis-acting element. Regulates trichome development, production of mucilage and tannin in seed coats, and maybe root hair development. A number of isoforms are produced. According to EST sequences. Leaf promordia, trichomes, atrichoblasts, fertilized eggs, seed coat. Not induced by salicylic acid or wounding. Belongs to the WRKY group I family.