Reactive oxygen species mediate Na⁺‐inducedSOS1mRNA stability in Arabidopsis

Abstract

SummarySalt Overly Sensitive 1 (SOS1), a plasma membrane Na + /H + antiporter in Arabidopsis, is a salt tolerance determinant crucial for the maintenance of ion homeostasis in saline stress conditions. SOS1 mRNA is unstable at normal growth conditions, but its stability is substantially increased under salt stress and other ionic and dehydration stresses. In addition, H 2 O 2 treatment increases the stability of SOS1 mRNA. SOS1 mRNA is inherently unstable and rapidly degraded with a half-life of approximately 10 min. Rapid decay of SOS1 mRNA requires new protein synthesis. Stress-induced SOS1 mRNA stability is mediated by reactive oxygen species (ROS). NADPH oxidase is also involved in the upregulation of SOS1 mRNA stability, presumably through the control of extracellular ROS production. The cis-element required for SOS1 mRNA instability resides in the 500-bp region within the 2.2 kb at the 3¢ end of the SOS1 mRNA. Furthermore, mutations in the SOS1 gene render sos1 mutants more tolerant to paraquat, a non-selective herbicide causing oxidative stress, indicating that SOS1 plays negative roles in tolerance of oxidative stress. A hypothetical model for the signaling pathway involving SOS1-mediated pH changes, NADPH oxidase activation, apoplastic ROS production and downstream signaling transduction is proposed, and the biological significance of ROS-mediated induction of SOS1 mRNA stability is discussed.

Posttranscriptional Control of Photosynthetic mRNA Decay under Stress Conditions Requires 3′ and 5′ Untranslated Regions and Correlates with Differential Polysome Association in Rice

“…1C). Similar posttranscriptional stabilization has been observed previously in salt stressregulated genes such as PEPCase (Cushman et al, 1990), AtP5R (Hua et al, 2001), and SOS1 (Shi et al, 2003;Chung et al, 2008) and in abscisic acid-and water stress-regulated genes such as a-amylase/subtilisin inhibitor (BASI; Liu and Hill, 1995), le25, and his1-s (Cohen et al, 1999). Taken together, our results suggest that the SMD of RbcS1 and Cab1 as well as the control of the stress-inducible Dip1 and SalT genes are posttranscriptional events.…”

The Tomato Calcium Sensor Cbl10 and Its Interacting Protein Kinase Cipk6 Define a Signaling Pathway in Plant Immunity

“…SOS1, a Na + / H + antiporter, which is a target of the SOS3/SOS2 complex, has been reported to be posttranscriptionally regulated by ROS and to interact with oxidative responses regulators (Katiyar-Agarwal et al, 2006;Chung et al, 2008). In rice cultured cells treated with PAMPs, CIPK14/15 appear to mediate ROS production (Kurusu et al, 2010), and, more recently, Arabidopsis CIPK26 was shown to interact with RBOHF in planta and positively and negatively regulate its ROS-producing activity in human cultured cells (HEK293T) (Kimura et al, 2012;Drerup et al, 2013).…”

Unraveling the Tapestry of Networks Involving Reactive Oxygen Species in Plants

“…An alternative mode by which H 2 O 2 and probably other ROS mediate abiotic stress responses is stabilization of specific transcripts that encode stress-related proteins. Chung et al (2008) demonstrated that increased ROS levels enhance the stability of the saltinduced SOS1 mRNA. This plasma membrane Na 1 / H 1 antiporter interacts via its cytoplasmic tail domain with runaway cell death 1, revealing a new function for SOS1 within the oxidative stress response (KatiyarAgarwal et al, 2006).…”