Plants appear dwarfed. Mg Mobile Component of chlorophyll. Enzyme activator - activates 36 known enzymes, more than any other element Interveinal chlorosis, normally appearing first on lower leaves. Chlorotic areas die. S Mobile Component of all proteins, a constituent of several amino acids.
Several vitamins contain sulfur.
Important in enzyme reactions - sulfur linkage is point of attachment of enzyme to substrate. Important in photosynthesis and N fixation. Uniform chlorosis over whole plant. Thin stems - lateral stems affected, not terminal. Exceptions, e.g., crucifereae.