Emerging Plant Growth Regulators in Agriculture: Roles in Stress Tolerance presents current PGR discoveries and advances for agricultural applications, providing a comprehensive reference for those seeking to apply these tools for improved plant health and crop yield. As demand for agricultural crops and improved nutritional requirement continue to escalate in response to increasing population, plant researchers have focused on identifying scientific approaches to minimize the negative impacts of climate change on agriculture crops. Among the various applied approaches, the application of plant growth regulators (PGRs) have gained significant attention for their ability to enhance stress tolerance mechanisms. This book was developed to provide foundational and emerging information to advance the discovery of novel, cost-competitive, specific and effective PGRs for applications in agriculture. - Highlights the latest developments in stress signaling, cross-talk and PGR mechanisms as applied to agriculture and agronomy - Includes case studies and examples to provide real-world insights - Presents resources for future research and field application

Agriculture faces many challenges to fulfil the growing demand for sustainable food production and ensure high-quality nutrition for a rapidly growing population. To guarantee adequate food production, it is necessary to increase the yield per area of arable land. A method for achieving this goal has been the application of growth regulators to modulate plant growth. Plant growth regulators (PGRs) are substances in specific formulations which, when applied to plants or seeds, have the capacity to promote, inhibit, or modify physiological traits, development and/or stress responses. They maintain proper balance between source and sink for enhancing crop yield. PGRs are used to maximize productivity and quality, improve consistency in production, and overcome genetic and abiotic limitations to plant productivity. Suitable PGRs include hormones such as cytokinins and auxins, and hormone-like compounds such as mepiquat chloride and paclobutrazol. The use of PGRs in mainstream agriculture has steadily increased within the last 20 years as their benefits have become better understood by growers. Unfortunately, the growth of the PGR market may be constrained by a lack of innovation at a time when an increase in demand for new products will require steady innovation and discovery of novel, cost-competitive, specific, and effective PGRs. A plant bio-stimulant is any substance or microorganism applied to plants with the aim to enhance nutrition efficiency, abiotic stress tolerance and/or crop quality traits, regardless of its nutrients content. Apart from traditional PGRs, which are mostly plant hormones, there are a number of substances/molecules such as nitric oxide, methyl jasmonate, brassinosteroids, seaweed extracts, strigolactones, plant growth promoting rhizobacteria etc. which act as PGRs. These novel PGRs or bio-stimulants have been reported to play important roles in stress responses and adaptation. They can protect plants against various stresses, including water deficit, chilling and high temperatures, salinity and flooding. This book includes chapters ranging from sensing and signalling in plants to translational research. In addition, the cross-talk operative in plants in response to varied signals of biotic and abiotic nature is also presented. Ultimately the objective of this book is to present the current scenario and the future plan of action for the management of stresses through traditional as well as novel PGRs. We believe that this book will initiate and introduce readers to state-of-the-art developments and trends in this field of study.

As agriculture becomes more mechanized and science increases the possibilities for using inputs to enhance production, the role of PGRs becomes more vital. Plant Growth Regulators in Agriculture and Horticulture provides agriculture professionals and researchers with the information needed to effectively tap these versatile resources to enhance crop production. Through discussions of the “classical five” phytohormones--gibberellins, cytokinins, ethylene, abscisic acid, and auxins--and the growing number of nontraditional PGRs such as oligosaccharins and brassinosteroids, Plant Growth Regulators in Agriculture and Horticulture reviews past and present uses of PGRs in managing crop yield and offers some speculation on future directions. Detailed discussions on the use of PGRs in, for example, grain, ornamental, and citrus crops, introduce readers to strategies for enhancing crop quantity and quality, for improving the postproduction quality of life of perishable plants, and for crop load management, respectively. The book also includes informative visuals, such as tables of common, chemical, and trade names of different commercially available PGRs; diagrams of various PGR processes; as well as before-and-after pictures illustrating the effects of PGRs. Plant Growth Regulators in Agriculture and Horticulture is a comprehensive text covering the role of plant growth regulators in: root formation manipulating yield potential plant stress protection ornamental horticulture postharvest life of ornamentals manipulating fruit development and storage quality citriculture reducing fruit drop bloom-thinning strategies If the history of agriculture, which is over 10,000 years old, was condensed into a twenty-four-hour span, science-based plant breeding would be only about fifteen minutes old. Still, the role of PGRs in agriculture is modest compared to other agrochemicals, such as fungicides, herbicides, and insecticides. Plant Growth Regulators in Agriculture and Horticulture is an invaluable guide to the varied roles filled by PGRs in the attainment of higher-quality, better-yielding crops.

Plants require essential nutrients (macronutrients and micronutrients) for normal functioning. Sufficiency range is the levels of nutrients necessary to meet the plant’s needs for optimal growth. This range depends on individual plant species and the particular nutrient. Nutrient levels outside of a plant’s sufficiency range cause overall crop growth and health to decline, due either to deficiency or toxicity from over-accumulation. Apart from micronutrients (B, Cl, Mn, Fe, Zn, Cu and Mo), Aluminum (Al), cerium (Ce), cobalt (Co), iodine (I), lanthanum (La), sodium (Na), selenium (Se), silicon (Si), titanium (Ti), and vanadium (V) are emerging as novel biostimulants that may enhance crop productivity and nutritional quality. These beneficial elements are not "essential" but when supplied at low dosages, they augment plant growth, development, and yield by stimulating specific molecular, biochemical, and physiological pathways in responses to challenging environments. The book is the first reference volume that approaches plant micronutrient management with the latest biotechnological and omics tools. Expertly curated chapters highlight working solutions as well as open problems and future challenges in plant micronutrient deficiency or toxicity. We believe this book will introduce readers to state-of-the-art developments and research trends in this field.

The cultivation of rice in Japan has suffered from damage caused by baka nae disease, in which rice seedlings show abnormal growth (elongation) as the result of infection by a plant pathogen. Investigation of the taxonomy of this pathogen led to the commencement of gibberellin (GA) research among Japanese plant pathologists, who later identified it as Gibberella jujikuroi, its other name being Fusarium moniliforme. In 1926, Kurosawa demon strated the occurrence of an active principle in the culture media of fungus that showed the same symptoms as those of the rice disease. In 1938, this finding was followed by the successful isolation of the active principles as crystals from the culture filtrate. This was achieved by the Japanese agri cultural chemists Yabuta and Sumiki, of The University of Tokyo, who named these active principles gibberellins A and B. Following World War II, this discovery attracted the interest of scientists around the world, and research on GA was pursued on a worldwide scale. One of the most outstanding discoveries in GA research after the isolation of GA as the metabolite of the plant pathogen must be the isolation and characterization of GAs from tissues of higher plants by the MacMillan group, West and Phinney, and the Tokyo University group in 1958 and 1959. Thus, GAs have been recognized as one of the most important classes of plant hormones.

The current growing interest of molecular biologists in plant hormone research is undoubtedly the most promising development of recent times. Many papers were presented during the 14th International Conference on Plant Growth Substances illustrating the impact of this new approach on our understanding of hormone-controlled processes. The specific character is the integrated study of plant growth regulation at all levels ranging from single molecules to the entire plant and its functioning in the environment. Hormones play an essential role in the regulation, but not an exclusive one. Other compounds and factors, such as Ca2+, for instance are often of equal relevance, because they may take part in the signal transduction pathway. Moreover, regulation of the regulator by non-hormonal factors is an essential part of any control mechanism. The present volume reflects the change in interest from plant growth substances to plant growth regulation.

"Climatic conditions are key determinants of plant growth, whether at the scale of temperature regulation of the cell cycle, or at the scale of the geographic limits for a particular species. The climate is changing, due to human activities - particularly the emission of greenhouse gases - and therefore the conditions for the establishment, growth, reproduction, survival and distribution of plant species are changing. In contrast to animals, plants can continuously cease and resume growth. This flexibility in their architecture and growth patterns is partly achieved by the action of plant hormones. Still, the role of PGRs in agriculture is modest compared to other agrochemicals, such as fungicides, herbicides, and insecticides. Plant Growth Regulators in agriculture is an invaluable guide to the varied roles filled by PGRs in the attainment of higher-quality, better-yielding crops. Salient Features: Explores the plant growth regulator and anthropogenic climate change. Provides new insights related to hormonal cross-talk in plant development and stress responses. Shed new light on the role of PGRs in agriculture in the attainment of higher-quality, better-yielding crops. Delivers a valuable information on physiological and molecular mechanisms linked to the role of plant growth regulator in stress tolerance. Provides valuable knowledge for the all students of agronomy, plant physiology, molecular biology and environmental sciences"--