Auxin Signaling, Transport, and Biosynthesis: Orchestrating Plant Development and Adaptation

Bizuayehu Desta
Debre Berhan University

Werke Hailemeskel
Department of Horticulture, College of Agriculture and Natural Resource Sciences, Debre Berhan University

Netsanet Tena
Debre Berhan University

Wondimagegn Atilaw
Debre Berhan, Ethiopia

Abstract

Plant growth regulators (PGRs), also known as phytohormones, are naturally occurring organic compounds that influence plant growth, development, and physiological processes. They regulate cellular activities and coordinate responses within the plant, often exerting their effects in tissues far from their site of synthesis. Scientists discovered that plants can make their own powerful control substances (hormones), and these substances help control almost all plant growth and development. This discovery greatly changed how horticulture science is understood and practiced. The use of both synthetic and natural PGRs has catapulted the productivity, crop quality, and postharvest life. Extensive research has clarified the distinct functions and signaling pathways of the major plant hormones; however, attention is now increasingly directed toward understanding how these hormones interact and coordinate their actions in an integrated manner. Auxin is one of the central hormones in the whole plant development process, controls all main reproductive events including the selection of floral sites, the creation, arrangement, and even the regulation of the flower's main characteristics. Auxin activity is strongly influenced by its uneven distribution within plant tissues, as well as by its interactions with other signaling molecules such as cytokinins and strigolactones. These hormones influence each other in terms of production, transfer, and signaling pathways, and their specific transcriptional regulators often overlap at the same genetic targets. Of all plant hormones that are being used in culture systems, auxins and cytokinins still hold the key role in controlling morphogenesis while synthetic analogs of the mentioned groups often display equal or better effectiveness than the natural ones.

Keywords: Auxin, Auxin signal transduction, Auxin transport, Auxin biosynthesis, Plant development