Sulfur Metabolism in Plants and Related Biotechnologies

Abstract

Plants require sulfur for the production of sulfur-containing compounds that can be either general metabolites or secondary metabolites. Sulfur-containing metabolites are not only essential to growth, as in cysteine (Cys) and methionine, but may also offer selective advantages to the particular plant species, for example, metallothioneins (MTs) and phytochelatins (PCs). The biosyntheses of Cys and methionine in plants and bacteria are generally similar but not without some significant differences. Sulfur-containing secondary metabolites from plants or other sources are very important because their properties can be tuned for several applications. In fact, a better understanding of sulfur metabolism and the specific role of sulfur-containing metabolites has often led to major advances in biotechnology. Several methods based on sulfur metabolism have now been developed for the removal of undesirable gases (e.g., H 2 S and SO 2 ) or volatile organic sulfur compounds from gas stream or industrial waste. Phytoremediation has emerged as an efficient and interesting biotechnology for the removal of heavy metal ions and organic pollutants from soil and water. Significant advances have also been made for the development of new sulfur-metabolism-based biotechnologies in petroleum, mining, beverage, food, and dairy industries. This article is an attempt to provide an understanding of sulfur metabolism from a molecular perspective with a focus on the development of novel biotechnologies.