Glutathione transferases (GSTs) are a family of enzymes found in Arabidopsis, with 55 members, including one membrane-bound protein. These enzymes are divided into several classes, including phi, tau, theta, zeta, lambda, dehydroascorbate reductase (DHAR), and TCHQD. The phi and tau classes are highly stress-inducible and frequently studied in proteomic and transcriptomic research. While much is known about their roles in xenobiotic detoxification, their natural functions remain unclear, though they are likely involved in defense-related secondary metabolism. The DHAR and lambda classes are likely glutathione-dependent reductases, while the zeta class functions in tyrosine catabolism and the theta class may be involved in detoxifying oxidized lipids. GSTs have diverse functions beyond their traditional role in conjugating xenobiotics. They may also participate in intracellular transport, transient glutathione conjugation, sulfur introduction into secondary metabolites, and isomerization reactions. Functional genomic studies have shown that GSTs have additional GSH-dependent and GSH-independent catalytic and binding functions. These enzymes are expressed in various subcellular compartments and are involved in stress responses, plant development, and secondary metabolism. The Arabidopsis genome contains 55 GST genes, divided into 8 classes. Most classes have few members, but the phi and tau classes have undergone repeated gene duplication events, resulting in 13 and 28 members, respectively. GSTs are found in various subcellular compartments, including the cytosol, chloroplast, mitochondria, and vacuoles. Their structures are similar, with a conserved G-site for GSH binding and an H-site for hydrophobic substrates. GSTs are dimeric, with each monomer having a potential active site. GSTs are involved in various physiological processes, including the detoxification of herbicides, the regulation of secondary metabolism, and the response to stress. The DHAR class is unique as a plant-specific GST class with defined endogenous functions, involved in the ascorbate-glutathione cycle. The lambda class is also plant-specific and may be involved in the reduction of small molecules. The theta class is conserved between plants and animals and has an active site serine residue. The phi and tau classes are plant-specific and have been studied extensively, with some members showing non-essential roles in normal growth. GSTs are involved in various cellular processes, including the transport of flavonoids, the regulation of auxin transport, and the detoxification of oxidatively damaged DNA. The tau class is the most numerous in Arabidopsis and is involved in the transport of fatty acid-derived reactive molecules. GSTs are also involved in the response to stress, with many showing inducible expression under various conditions. Overall, GSTs play a crucial role in plant physiology,Glutathione transferases (GSTs) are a family of enzymes found in Arabidopsis, with 55 members, including one membrane-bound protein. These enzymes are divided into several classes, including phi, tau, theta, zeta, lambda, dehydroascorbate reductase (DHAR), and TCHQD. The phi and tau classes are highly stress-inducible and frequently studied in proteomic and transcriptomic research. While much is known about their roles in xenobiotic detoxification, their natural functions remain unclear, though they are likely involved in defense-related secondary metabolism. The DHAR and lambda classes are likely glutathione-dependent reductases, while the zeta class functions in tyrosine catabolism and the theta class may be involved in detoxifying oxidized lipids. GSTs have diverse functions beyond their traditional role in conjugating xenobiotics. They may also participate in intracellular transport, transient glutathione conjugation, sulfur introduction into secondary metabolites, and isomerization reactions. Functional genomic studies have shown that GSTs have additional GSH-dependent and GSH-independent catalytic and binding functions. These enzymes are expressed in various subcellular compartments and are involved in stress responses, plant development, and secondary metabolism. The Arabidopsis genome contains 55 GST genes, divided into 8 classes. Most classes have few members, but the phi and tau classes have undergone repeated gene duplication events, resulting in 13 and 28 members, respectively. GSTs are found in various subcellular compartments, including the cytosol, chloroplast, mitochondria, and vacuoles. Their structures are similar, with a conserved G-site for GSH binding and an H-site for hydrophobic substrates. GSTs are dimeric, with each monomer having a potential active site. GSTs are involved in various physiological processes, including the detoxification of herbicides, the regulation of secondary metabolism, and the response to stress. The DHAR class is unique as a plant-specific GST class with defined endogenous functions, involved in the ascorbate-glutathione cycle. The lambda class is also plant-specific and may be involved in the reduction of small molecules. The theta class is conserved between plants and animals and has an active site serine residue. The phi and tau classes are plant-specific and have been studied extensively, with some members showing non-essential roles in normal growth. GSTs are involved in various cellular processes, including the transport of flavonoids, the regulation of auxin transport, and the detoxification of oxidatively damaged DNA. The tau class is the most numerous in Arabidopsis and is involved in the transport of fatty acid-derived reactive molecules. GSTs are also involved in the response to stress, with many showing inducible expression under various conditions. Overall, GSTs play a crucial role in plant physiology,