Sulfur is essential for plants, as it is a nutrient that plays a structural role in several important molecules of metabolism.
For example, molecules from the amino acid group such as methionine, cysteine and cystine, which are necessary for the formation of proteins. In addition, they play a structural role in molecules such as lipids, polysaccharides, flavonoids, alkaloids, among others. Also, flavonoids and alkaloids are representatives of molecules linked to the secondary metabolism of plants.
Deficiency – Young leaves of apple trees deficient in sulfur showed a lighter green color.