This proceedings volume contains a selection of invited and contributed papers of the 9th International Workshop on Sulfur Metabolism in Plants, which was hosted by the Albert-Ludwigs-University Freiburg and held at Schloss  Reinach, Freiburg-Munzigen, Germany from April 14-17, 2014.

Foreword: The Value of Sulfur for Grapevine.- Partitioning of Sulfur between Primary and Secondary Metabolism.- Significance of Long-Distance Transport.- GSH Partitioning between the Nucleus and Cytosol in Arabidopsis thaliana.- Sulfur Metabolism in Hemiascomycetes Yeast.- Small World: A Plant Perspective on Human Sulfate Activatio.- Auxin Response Factors and AUX/IAA Proteins Potentially Control -S Responsive Expression of SULTR1;1.- SULTR1;2 in S Nutrient-Status Control in Arabidopsis.- Comparison of Nitrite Reductase (AcNiR1) with Sulfite Reductase (AcSiR1) in Allium cepa (L.).- Metabolic Analysis of Sulfur Metabolism During Developmental Leaf Senescence.- Apoplastic Iron Concentration in Maize Roots Grown under Sulfate Deprivation.- Suitability of the Ratio Between Reduced and Oxidized Glutathione as an Indicator for Plant Stress.- OAS Cluster Genes: A Tightly Co-Regulated Network.- More Than a Substrate: The O-Acetylserine Responsive Transcriptome.- The CBL-SNRK3 Network - Connections to Sulfur Metabolism.Hydrogen Sulfide and Its Reactive Friends: The Interplay With Reactive Oxygen Species and Nitric Oxide Signalling.- Investigation of Protein-Protein Interaction of Ferredoxin and Sulfite Reductase under Different Sodium Chloride Concentrations by NMR Spectroscopy and Isothermal Titration Calorimetry.- Prospective Post-Translational Regulation of Plant Sulfite Oxidasem.- Identification of the Genes for Intracellular Glutathione Degradation in Arabidopsis thaliana.- Altered Regulation of Myb Genes changes the Aliphatic Glucosinolate Accumulation under Long-Term Sulfur Deficiency in Arabidopsis.- Identification of Genes Potentially Encoding S-Oxygenation Enzymes for the Biosynthesis of S-Alk(en)yl-L-Cysteine Sulfoxides in Onion.- Determining Sulfur-Limiting Conditions for Studies of Seed Composition in Common Bean (Phaseolus vulgaris).- Effect of an Alfalfa Plant-Derived Biostimulant on Sulfur Nutrition in Tomato Plants.- Effect of Sulfur andNod Factors (LCOs) on Some Physiological Features and Yielding of Pea (Pisum sativum L.).- The Impact of Sulfate Salinity on the Uptake and Metabolism of Sulfur in Chinese Cabbage.- Identification and Distribution of Selenium-Containing Glucosinolate Analogues in Tissues of Three Brassicaceae Species.- Selenate Differentially Alters the Content of Glucosinolates in Eruca Sativa and Diplotaxis Tenuifolia Grown in Soil.- Effects of Glutathione Concentration in Root Zone and Glutathione Treatment Period on Cadmium Behaviors in Oilseed Rape Plants.