Glycosylates the amino acid-related molecules isoleucic acid (2-hydroxy-3-methylpentanoic acid) and valic acid (2-hydroxy-3-methylbutyric acid). Acts as a negative regulator of salicylic acid (SA)-dependent plant defense in the absence of pathogens and promotes the jasmonate (JA) response. Negatively influences the onset of senescence. Expressed in roots, leaves, hydathodes, sepals and style. Induced by wounding and the bacterial pathogen Pseudomonas syringae pv. tomato (avirulent avrRpm1 strain). Reduced rosette size, early leaf senescence, enhanced resistance to the biotrophic pathogen Pseudomonas syringae, increased susceptibility toward necrotrophic Alternaria brassicicola and constitutively elevated salicylic acid (SA) levels. Belongs to the UDP-glycosyltransferase family.