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Reactive oxygen species (ROS) are highly controlled signaling species that are involved in regulating gene expression in response to different environmental cues. The production of heat shock proteins (HSPs) is a key strategy that plants use to defend themselves against diverse stresses, including oxidative stress. In this study, expression patterns of the Arabidopsis <i>HSP17.4CI</i> gene, a cytosolic class I small HSP, were systematically profiled under different abiotic, biotic and oxidative stresses. Our data show that <i>HSP17.4CI</i> was early and highly induced by heat, cold, salt, drought and high-light. <i>HSP17.4CI</i> also showed high expression levels in Arabidopsis plants infected with the biotrophic pathogen <i>Pseudomonas syringae</i>, but not in response to the necrotrophic pathogens <i>Alternaria brassicicola</i> and <i>Fusarium oxysporum</i>. Oxidative stress treatments including H₂O₂ and the herbicide methyl viologen led to induction of <i>HSP17.4CI</i>. The plant hormones abscisic acid (ABA) and salicylic acid (SA) induced the expression of <i>HSP17.4CI</i>, whereas methyl jasmonate (MJ) did not affect the expression level of this gene. Furthermore, we found enhanced expression of <i>HSP17.4CI</i> in catalase mutant plants, which are deficient in catalase 2 activity and accumulate intracellular H₂O₂. Taken together, data presented here suggest that <i>HSP17.4CI</i> expression is regulated by various signals that connect biotic and abiotic stresses with ROS and can be used as a molecular marker for oxidative stress.