The intricate world of trichome development: From signaling pathways to transcriptional regulation

Abstract

Trichomes are specialized plant structures that play a fundamental role in plant development and are present in various plant species. Trichomes serve as a protective shield, defending plants from extreme temperatures, UV radiation, and insect attacks. Their development involves complex signaling pathways and cellular adaptability, determining whether cells become trichomes or remain regular epidermal cells. Gene expression, cell cycle regulation, and differentiation determine the initiation and development of trichomes. This review explores trichome development in Arabidopsis, cotton, and other plants, focusing on their structure, function, transcription factors, epigenetic modifications, and regulatory mechanisms. We focused on genes that control the development of glandular trichomes in various plant species and the complex regulatory networks involved. Phytohormones are essential for initiating and developing trichomes. The unicellular and multicellular/glandular trichomes development exhibits distinct regulatory mechanisms. Trichome development in plants is regulated by a complex network of genes and signaling pathways. GLABRA1 (GL1), GLABRA3 (GL3), and ENHANCER OF GLABRA3 (EGL3) are the essential regulators involved in unicellular trichome development, however, MYB transcription factors, terpene synthesis genes, and hormonal signals govern multicellular/glandular trichome development. The integration of phytohormonal and transcriptional networks contributes to the diversity and functional adaptation of trichomes in plants.