Biochemical Genetics of Metabolic Plasticity

Sulfur (S) metabolism has played a critical role in the evolution of life, serving as an energy source for early biochemical pathways like dissimilatory S reduction and anoxygenic photosynthesis. Across kingdoms, S metabolism displays remarkable diversity. S-containing metabolites like glucosinolates (GLSs) in Brassicaceae and S-alk(en)ylcysteine sulfoxides in Allium species illustrate the ecological and evolutionary significance of Scontaining compounds. These metabolites contribute to defense, homeostasis, and ecological interactions, with mechanisms like enzymatic hydrolysis releasing bioactive molecules such as allicin. Further, advances in transcriptomics and biochemical studies have revealed the genetic underpinnings of S metabolism and specialized pathways in bulb-forming Allium species. The role extends to ecological interactions by modulating S-associated defense pathways. This integrative understanding of S metabolism underscores its evolutionary, physiological, and ecological importance.