Sulphur (S) plays a pivotal role in various plant growth and development processes being a constituent of sulphur-containing amino acids, cysteine and methionine, and other metabolites viz., glutathione and phytochelatins, co-factor of enzymes which contribute to stress repair and amelioration of heavy metal toxicity. Besides, a number of S-containing components are biologically active and, thus, a source for use as medicinal value. The basic global issue before the agricultural scientist and world community is to evolve cultivars and develop methodologies for efficient use of inputs to enhance agricultural productivity. This is particularly true of the developing countries which are going to see maximum rise in population with changing food demands and declining availability of land. Amongst the inputs, nutrients play a crucial role. The major requirement is for N, P and K followed by several micro-nutrients. In this context reports of world-wide S deficiency in the agricultural systems are relevant. The reasons are many. Broadly speaking reduction inS emission, use of S-free N, P and K fertilizers and higher biomass production contributed the maximum. Despite the need for sulphur as an essential plant nutrient and the substantial returns expected from its use, very little attention has been given to fill the gap between supply and demand of S.

As an essential nutrient for plant growth and development, sulfur (S) deficiency in productive systems limits yield and quality. This Special Issue hosts a collection of original research articles, focusing on the following topics: (1) The germinative and post-germinative behavior of Brassica napus seeds when severe S limitation is applied to the parent plants; (2) the independence of S-deficiency from the mRNA degradation initiation enzyme PARN in Arabidopsis; (3) the glucosinolate distribution in the aerial parts of sel1-10, a disruption mutant of the sulfate transporter SULTR1;2, in mature Arabidopsis thaliana plants; (4) the accumulation of S-methylcysteine as its γ-glutamyl dipeptide in Phaseolus vulgaris; and (5) the role of ferric iron chelation-strategy components in the leaves and roots of maize, have provided new insights into the effect of S availability on plant functionality. Moreover, the role of S deficiency in root system functionality has been highlighted, focusing on (6) the contribution of root hair development to sulfate uptake in Arabidopsis, and (7) the modulation of lateral root development by the CLE-CLAVATA1 signaling pathway under S deficiency. The role of S in plants grown under drought conditions has been investigated in more detail focusing (8) on the relationship between S-induced stomata closure and the canonical ABA signal transduction machinery. Furthermore, (9) the assessment of S deficiency under field conditions by single measurements of sulfur, chloride, and phosphorus in mature leaves, (10) the effect of fertilizers enriched with elemental S on durum wheat yield, and (11, 12) the impact of elemental S on the rhizospheric bacteria of durum wheat contributed to enhancing the scientific knowledge of S nutrition under field conditions.

This proceedings volume contains the invited and a selection of the contributed papers of the 8th International Workshop on Sulfur Metabolism in Higher Plants, which was held at Department of Forest and Ecosystem Science, University of Melbourne, Water Street, Creswick, Victoria 3363, Australia from November 22-27, 2010. Content of the volume shows that the understanding of sulfur metabolism in plants and the interaction of the environment are rapidly progressing. This volume covers various aspects of the regulation of sulfate uptake and assimilation in plants, from a cellular to a whole plant level, and additionally emphasizes interactions with other minerals. Moreover the significance of sulfur metabolism in biotic and abiotic stress responses, in food security and quality, and in relation to interactions with global change factors is discussed in detail.

Sulfur forms and cycling processes in soil and their relationship to sulfur fertility / Jeff J. Schoenau and Sukhdev S. Malhi -- Sulfur nutrition of crops in the Indo-Gangetic plains of South Asia / M.P.S. Khurana, U.S. Sandana and Bijay-Singh -- Soil sulfur cycling temperate agricultural systems / Jørgen Eriksen -- History of sulfur deficiency in crops / Silvia Haneklaus, Elke Bloem and Ewald Schnug -- Availability of sulfur to crops from soil and other sources / Warren A. Dick, David Kost and Liming Chen -- Sulfur and cysteine metabolism / Rainer Hoefgen and Holger Hesse -- Sulfur response based on crop, source, and landscape position / Dave Franzen and Cynthia A. Grant -- Sulfur management for soybean production / Kiyoko Hitsuda [and others] -- Sulfur in a fertilizer program for corn / George W. Rehm and John G. Clapp -- Sulfur nutrition and wheat quality / Hamid A. Naeem -- Sulfur and marketable yield of potato / Alexander D. Pavlista -- Sulfur, its role in onion production and related alliums / George E. Boyhan -- Sulfur and the production of rice in wetland and dryland ecosystems / Richard W. Bell -- Evaluation of the relative significance of sulfur and other essential mineral elements in oilseed rape, cereals, and sugar beet production / Ewald Schnug and Silvia Haneklaus -- Improving the sulfur-containing amino acids of soybean to enhance its nutritional value in animal feed / Hari B. Krishnan -- Methionine metabolism in plants / Rachel Amir and Yael Hacham -- Plant sulfur compounds and human health / Joseph M. Jez and Naomi K. Fukagawa -- A future crop biotechnology view of sulfur and selenium / Muhammad Sayyar Khan and Rüdiger Hell.

It has long been recognized that soil organic matter is the key to soil fertility. As a nutrient store it gradually provides essential elements which the soil cannot retain for long in inorganic form. It buffers growing plants against sudden changes in their chemical environment and preserves moisture in times of drought. It keeps the soil in a friable, easily penetrated physical condition, well-aerated and free draining, providing young seedlings with an excellent medium for growth. But it has another property, the nature and extent of which have been the subject of argu ment and controversy ever since scientists began to study the soil, and that is its ability to affect growth directly, other than by providing nutrient elements. Any one wishing to learn about these effects has been faced with a daunting mass of literature, some confusing, often contradictory, and spread through a multitude of journals. Individual aspects have been covered from time to time in reviews but there has obviously been a need for a modern authoritative text book dealing with the many facets of this subject, so the publication of this volume is timely. The editors and authors are all specialists in their fields, fully familiar with the com plex nature of soil organic matter and with the particular difficulties arising in any study of its properties. Where controversies exist they have presented all sides of the argument and have highlighted areas where further work is badly needed.

This book presents the latest findings on how plants respond physiologically to sulfur in their environment. It combines an ecosystems approach with new insights at the molecular and biochemical level. Key areas are explored to assess the functions and implications of this essential plant nutrient in a range of natural, semi-natural and anthropogenic environments. The result is an important new reference on the relationships between plants and sulfur.

This is the second volume in the series Nutrients in Ecosystems. Sulphur as an essential plant nutrient has received little attention. This is explained by the facts that sulphur was obviously in sufficient supply from the atmosphere, from soil and as a by-product in mineral fertilizers. Increases in the yield potential and thus in the nutrient requirement of modern crops, however, as well as remarkable changes in SO2 emissions by private households, power stations and industry, associated with legislative measures to reduce air and water pollution, have altered the situation to a large extent. In particular the public concerns about forest decline and pollution-induced climatic changes have initiated extensive research programs on the physiological functions of sulphur in plants, on the occurrence and plant availability of sulphur in agricultural and forest soils and on the chemistry of sulphur compounds in the tropo- and stratosphere. This book cannot be an encylcopedia of sulphur in all the media mentioned nor in all ecozones of the globe. However, it aims to give an overview of our present knowledge with a special focus on the sulphur situation in agrosystems of industrialised Western Europe. The ecological trends for sulphur observed in this region during recent decades are likely to be mirrored wherever industrialisation and urbanisation take place and where an increasing standard of living demands clean air, good drinking water and nutritious food. Agricultural production systems, therefore, require well-founded information on the actual sulphur nutrition and potential sulphur-fertilizer requirement of crops and soils respectively. It is hoped that this book will provide this information and will encourage further research where open questions still exist.