Preface

Phytohormones are regulatory compounds that play crucial roles in plant development and comprise five main groups, namely, auxins, cytokinins, abscisic acid, gibberellins and ethyl‐ ene. Salicylates, jasmonates, brassinosteroids, strigolactones, polyamines and some peptides were known as new families of phytohormones. Auxins, gibberellins, cytokinins, brassinoste‐ roids, strigolactones and polyamines play a major role in plant growth and development, whereas ethylene, abscisic acid, salicylates and jasmonates have important roles in stress re‐ sponses. Hormone actions form a signaling network and mutually regulate various systems in plants.

This book brings together recent work and progress that has recently been made in the dy‐ namic field of phytohormone regulation in plant development and stress responses. It also provides new insights and sheds new light regarding the exciting hormonal cross talk phe‐ nomenon in plants. This book will provoke interest in many readers and scientists, who can find this information useful for the advancement of their research works.

The book includes seven chapters. The first chapter "Hormonal Regulation in Plant Develop‐ ment and Stress Tolerance" presents an overview and discusses recent progresses of phytohor‐ mones' roles and their cross talk in plant development and stress tolerance. The second chapter "Recent Developments in a Radio-labeling of Brassinosteroids" provides a comprehen‐ sive overview on methodologies used for radio-labeling of brassinosteroids as one of the new‐ est class of phytohormones. The third chapter "Salicylic Acid: An All-Rounder in Regulating Abiotic Stress Responses in Plants" sheds light on the recent progress on the regulatory role of SA in mitigating abiotic stress. The fourth chapter "Seed Dormancy: The Complex Process Regulated by Abscisic Acid, Gibberellins and Other Phytohormones That Makes the Seed Ger‐ mination Work" describes recent advances in understanding the complex process of seed dor‐ mancy, regulated by many phytohormonal pathways and their components. The fifth chapter "Strigolactone Signaling in Plants" summarizes the recent discoveries in the signal transduc‐ tion pathway of SLs and describes the model of SL perception and signaling. The sixth chapter "Cross Talk between Nitric Oxide and Phytohormones Regulates Plant Development During Abiotic Stresses" discusses the current state of knowledge of cross talk between signaling path‐ ways of NO and phytohormones in plants exposed to various abiotic stresses. The seventh chapter "Phytohormonal Control over the Grapevine Berry Development" discusses phytohor‐ mo*nes, their sig*naling pathways and their association to berry development in Vitis vinifera.

The book editor would like to thank Ms. Nina Kalinić, Publishing Process Manager, for her wholehearted cooperation in the publication of this book.

> **Mohamed Ahmed El-Esawi, PhD** Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom

> > Botany Department, Faculty of Science, Tanta University, Egypt
