Traits linked to natural variation of sulfur content in A. thaliana leaf.

Sulfur (S) is an essential mineral nutrient for plant growth and development, important for primary and specialized plant metabolites that are crucial for biotic and abiotic interactions. Foliar S content varies up to six-fold under controlled environment, suggesting an adaptive value under certain natural environmental conditions. However, a major quantitative regulator of S content in Arabidopsis thaliana has not been identified yet, pointing to the existence of additional genetic factors controlling sulfate/sulfur content or existence of many minor quantitative regulators. Here, we use overlapping information of two separate ionomics studies to select groups of accessions with low-, mid-, and high- foliar S content. We quantify series of metabolites, including anions (sulfate, phosphate, nitrate), thiols (cysteine, glutathione), seven glucosinolates, gene expression of twenty genes, sulfate uptake and three biotic traits. Our results suggest that S content is tightly connected with sulfate uptake, concentration of sulfate and phosphate anions, glucosinolate and glutathione synthesis. Additionally, our results indicate that the growth of pathogenic bacteria is enhanced in the A. thaliana accessions containing higher S in their leaf, suggesting complex regulation between S homeostasis, primary and secondary metabolism, and biotic pressures.