Editorial: Frontiers of Sulfur Metabolism in Plant Growth, Development, and Stress Response.

Abstract

Plants assimilate inorganic sulfur and metabolize it further to organic sulfur compounds essential for plant growth, development, and stress mitigation. Animals including humans in turn depend on plants and microorganisms providing these essential compounds, such as the amino acid methionine, which they cannot synthesize. Furthermore, a number of sulfur-containing metabolites provide the characteristic tastes and smells of our food, and many of them are known to have health promoting and protective properties. Thus, adequate supply of sulfur can be a critical factor affecting crop yield and production of beneficial phytochemicals. However, because of the reduction in anthropogenic emission of sulfur dioxide to the atmosphere, particularly from developed countries, sulfur deficiency has become a problem for agriculture and in many areas sulfur fertilization is required to ensure yield, quality, and health of crops. Such an impact of sulfur has triggered research into mechanisms of sulfur metabolism in plants and its regulation. Indeed great progress has been made over the last decades as summarized in several recent reviews (Takahashi et al., 2011; Sauter et al., 2013; Calderwood and Kopriva, 2014). Starting with identification of genes encoding components of sulfur metabolism, research in molecular biology and molecular genetics has brought us toward finding regulators and signals controlling the pathway (Maruyama-Nakashita et al., 2006; Gigolashvili et al., 2007; Hirai et al., 2007), and describing natural variation in diverse sulfur related traits (Kliebenstein et al., 2001; Loudet et al., 2007; Chao et al., 2014). In addition, questions related to regulation of sulfur metabolism have been on the forefront of systems biology (Maruyama-Nakashita et al., 2003; Hirai et al., 2005; Nikiforova et al., 2005) and quantitative genetics (Loudet et al., 2007). This research topic organized in Frontiers in Plant Science has been an opportunity to present our current understanding and research progress focused on a number of interesting aspects in plant sulfur metabolism. We aimed to cover broad research topics in sulfur nutrition and metabolism by compiling diverse types of articles: original research reports to exemplify new information on questions the sulfur research community is addressing, focused reviews to provide detailed updates to specific topics, and perspectives to review a progress but also to address the questions for the next decade(s) of research. This concept found indeed a great support in the sulfur research community with 34 articles contributed by scholars representing wide disciplinary areas.