Abstract
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 HSP17.4CI gene, a cytosolic class I small HSP, were systematically profiled under different abiotic, biotic and oxidative stresses. Our data show that HSP17.4CI was early and highly induced by heat, cold, salt, drought and high-light. HSP17.4CI also showed high expression levels in Arabidopsis plants infected with the biotrophic pathogen Pseudomonas syringae, but not in response to the necrotrophic pathogens Alternaria brassicicola and Fusarium oxysporum. Oxidative stress treatments including H2O2 and the herbicide methyl viologen led to induction of HSP17.4CI. The plant hormones abscisic acid (ABA) and salicylic acid (SA) induced the expression of HSP17.4CI, whereas methyl jasmonate (MJ) did not affect the expression level of this gene. Furthermore, we found enhanced expression of HSP17.4CI in catalase mutant plants, which are deficient in catalase 2 activity and accumulate intracellular H2O2. Taken together, data presented here suggest that HSP17.4CI 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.
Highlights
Plants are continuously subjected to a broad range of biotic and abiotic stresses that negatively affect plant productivity
Our results show that exposure to a heat dose of 45 ◦C for 2 h, dramatically induced HSP17.4CI transcript levels (Figure 1A)
The effect of prolonged heat shock at 45 ◦C for 4 or 6 h on HSP17.4CI expression was similar to that observed at 2 h. These results show that HSP17.4CI has very low basal expression levels in unstressed plants, but is strongly induced by heat stress
Summary
Plants are continuously subjected to a broad range of biotic and abiotic stresses that negatively affect plant productivity. Available evidence suggests that reactive oxygen species (ROS) production in plants is a common response to almost all environmental challenges [1,2,3]. ROS work as highly controlled signaling species that are able to deliver different environmental cues to the plant cell transcriptional machinery [4,5,6,7,8,9]. This signaling function of ROS is becoming more operative through their interactions with other various signaling components including phytohormones, G proteins, calcium ions and mitogen-activated protein kinases (MAPKs) [7]. HSFA2 and HSFA4A were reported to be induced by oxidative stress and involved in H2O2 sensing [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
