Dear Colleagues,

Auxin is one of the most important plant hormones and plays a central role in the control of a wide range of physiological and developmental processes in plants. Auxin metabolism and signal transduction are involved in many aspects of plant development and responses of plants to environmental signals. Auxin is involved from the earliest stages of embryogenesis and ensures the growth, organisation and branching of aerial and underground parts. These multiple effects reflect its control of cell division, cell elongation and vascular and floral differentiation. Several studies have also shown that auxin plays essential roles in the response to salt and water stress as well as other biotic and abiotic stresses. In plants, auxin is synthesised at different levels, in particular in meristems, young primordium, vascular tissues and reproductive organs. It then reaches the different parts of the plant through passive and active transport.

Indole 3-acetic acid is the predominant form of auxin in plants. It is present in the form of an indole ring to which an acetic acid chain is added in the 3' position.
This Special Issue deals with the study of natural and synthetic auxin compounds, which are known to have growth-promoting properties. Natural and synthetic auxins are used in agriculture to promote rooting, fruit set, fruit thinning and fruit drop control or as selective herbicides. Understanding the different aspects of auxin metabolism and signalling pathways and its interaction with other signalling mechanisms would lead to a better understanding of plant development mechanisms and their interaction with the environment and to the development of new strategies for crop breeding.

Prof. Dr. Khalid Bougrin
Prof. Dr. Abdelaziz Smouni Smouni
Guest Editors

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• auxin
• auxin biosynthesis
• synthetic auxins
• auxin metabolism
• auxin transport
• auxin signalling pathway
• auxin applications

Title: Research Progress on the Regulation of Root Development by Auxin
Authors: Hao Zhang
Affiliation: Hebei Normal University