microRNAs responsive to ozone-induced oxidative stress in Arabidopsis thaliana

Abstract

Ozone is a model abiotic elicitor of reactive oxygen species (ROS). ROS are important oxidative signaling molecules coordinating plant development and responses to biotic and abiotic stresses. Recently, microRNAs have been described as important players in regulating stress responses in plants. In this research we examined the miRNAs that are differentially expressed early in response to ozone in the Arabidopsis thaliana ecotype Col-0 that is tolerant to this oxidant. We used a plant miRNA array to identify 22 miRNA families that are differentially expressed within one hour of ozone fumigation. Majority of these miRNAs were also reported in response to UV-B stress. Analysis of the miRNA target genes showed a strong negative correlation to the miRNA expression. In silico promoter analysis of miRNA genes identified several stress responsive cis-elements that were enriched in the promoters of ozone responsive genes. Majority of the target genes of ozone responsive miRNAs were associated with developmental processes. Based on these results we suggest that post-transcriptional gene regulation via miRNAs may aid in resource allocation by downregulating developmental processes to cater to the oxidative stress demands on plants.

Genomewide identification of genes involved in the potato response to drought indicates functional evolutionary conservation with Arabidopsis plants

“…Four of the 23 selected genes were involved in oxidation–reduction processes ( AT1G77120 , AT3G11170 , AT4G31940 and AT4G27030 ), and it might be connected with accumulation of reactive oxygen species (ROS) that play a central role in coordinating defence signalling in plants in response to many abiotic stresses (Iyer et al ., ; Mittler, ). Cell membrane composition changes, such as changes in phospholipids and proteins, help to maintain membrane integrity, preserve cell compartmentalization and activate phospholipid signalling pathways in response to drought (Jarzyniak and Jasinski, ; Liu et al ., ; Ruelland et al ., ; Schulz, ).…”

Impact of Climate Change on MicroRNA Expression in Plants

“…A recent study investigated the response of miRNAs in Arabidopsis under ozone stress, which recorded altered response of 22 miRNAs [48]. Most of these miRNAs showed similar expression under UV-B stress, indicating the activation of similar regulating pathways under both types of stressors [48]. Such similarities in miRNA responses during ozone and UV-B stress could be expected, as both stresses lead to the production of reactive oxygen species (ROS) causing oxidative stress.…”

“…Ozone enters the leaves through stomata, causes oxidative stress, decreases photosynthesis, damages DNA, protein, and cell membranes, and thereby negatively affects plant productivity [72À76]. A recent study investigated the response of miRNAs in Arabidopsis under ozone stress, which recorded altered response of 22 miRNAs [48]. Most of these miRNAs showed similar expression under UV-B stress, indicating the activation of similar regulating pathways under both types of stressors [48].…”

“…Under oxidative stress, miR398 mediates the upregulation of CSD gene expression, which is known to decrease ROS accumulation [53]. Therefore, downregulation of miR398 under ozone and UV-B stress [47,48,69] may induce CSD gene expression and thereby protect the plant against oxidative damage. The importance of miR398-mediated upregulation of CSDs can be explained by the fact that miR398 levels accumulate to normal levels immediately after being relieved from ozone treatment [74].…”

Small RNAs in regulating temperature stress response in plants

“…Three miRNAs‐ (miR319, miR396 and miR408) mediated cold tolerance was also involved in the reduced levels of ROS during cold stress (Wang et al 2014a; Ma et al ; Zhang et al ). Moreover, Iyer et al () has identified 12 conserved miRNA families (including miR156, miR159, miR160 and miR166) that are differentially regulated by ozone (a model abiotic elicitor of ROS) in Arabidopsis (Iyer et al ). These conserved miRNAs were demonstrated to be involved in cold or heat stress response in many plant species (Table ).…”