Arabidopsis transcriptional regulation by light stress via hydrogen peroxide‐dependent and ‐independent pathways

Abstract

Background: High (intense) light stress causes the formation of oxygen radicals in chloroplasts and has the potential to damage them. However, plants are able to respond to this stress and protect the chloroplasts by various means, including transcriptional regulation in the nucleus. Although the corresponding signalling pathway is largely unknown, the high light response in the expression of the Arabidopsis APX2 gene is reported to be mediated by hydrogen peroxide.

The Responses of Arabidopsis Early Light-Induced Protein2 to Ultraviolet B, High Light, and Cold Stress Are Regulated by a Transcriptional Regulatory Unit Composed of Two Elements

“…1A). This indicates that the stress responses observed here are independent of H 2 O 2 signaling (Kimura et al, 2001).…”

Genome-Wide Gene Expression Analysis Reveals a Critical Role for CRYPTOCHROME1 in the Response of Arabidopsis to High Irradiance

“…The ELIP1, ELIP2, APX2, and LHCB2.4 genes all demonstrated a robust response to our HL exposure and they all encode key components of photosynthetic light stress response. In addition, the observed response to HL of these genes is well documented in plants exposed to somewhat different experimental, high irradiance conditions (Adamska et al, 1992;Karpinski et al, 1999;Kimura et al, 2001;Rossel et al, 2002;Vanderauwera et al, 2005;Heddad et al, 2006). Thus, these four genes Table I.…”

Modification of reactive oxygen species scavenging capacity of chloroplasts through plastid transformation

“…A signalling role of ROS from the chloroplasts, involving induction of nuclear genes encoding defence related proteins, is well established (reviewed in Nott et al 2006;Pfannschmidt et al 2009), with H 2 O 2 as the prime candidate. Excess H 2 O 2 , produced by stress (or in our case elevated SOD activity) can diffuse from the chloroplast and, probably through mitogen-activated protein kinases (Kovtun et al 2000), trigger expression of nuclear encoded defence-related genes such as cAPX encoding an ascorbate peroxidise (Kimura et al 2001), Cat encoding catalase and Gst1 encoding Glutathione-S-transferase (Polidoros and Scandalios 1999), as well (in the C 3 -CAM transition species Mesembryanthemum crystallinum) as genes encoding Cu/Zn-, Mn-, and Fe-SOD (Slesak et al 2003). The current results suggest that increases in H 2 O 2 levels caused by chloroplastic expression of MnSOD, mimic abiotic and biotic stress responses, leading to a similar MAPK induced expression of nuclear-encoded defence proteins, including several organellar SODs, in these transplastomic tobacco lines.…”