Mediates E2-dependent ubiquitination (By similarity). Confers resistance to osmotic stress such as high salinity. Promotes H(2)O(2) production. Negative regulator of some defense-related genes via an salicylic acid (SA)-dependent signaling pathway. Confers susceptibility to the compatible phytopathogen Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000). Mediates resistance to type A trichothecenes (phytotoxins produced by phytopathogenic fungi). Protein modification; protein ubiquitination. Expressed in seedlings, roots, stems, leaves, buds, flowers and siliques. By brassinosteroids, osmotic stress and high salinity. Accumulates in response to SA, ethylene, methyl jasmonate (MeJA), flagellin (e.g. flg22), and type A trichothecenes such as T-2 toxin and diacetoxyscirpenol (DAS), but not in response to type B trichothecenes such as deoxynivalenol (DON). The RING-type zinc finger domain interacts with an ubiquitin-conjugating enzyme (E2) and facilitates ubiquitination. Impaired growth and survival under salt stress. Reduced H(2)O(2) production. Hypersensitivity to T-2 toxin and DAS (but not to DON), accompanied by enhanced SA accumulation and several plant defense gene induction. Less susceptible to Pst DC3000. Belongs to the NFX1 family.