Copper‐Zinc Superoxide Dismutases in Plants: Evolution, Enzymatic Properties, and Beyond

Abstract

Superoxide dismutase (SOD) is a primary antioxidant enzyme that can be found in organisms from all kingdoms of life. Its date of origin indicates a pivotal role in the evolution of life on our planet. The SOD family is subdivided into different classes based upon the metal‐cofactor these enzymes use. In this article, we specifically emphasise the role and appearance of the youngest enzyme, copper‐zinc SOD (CuZnSOD). We discuss the evolution of CuZnSODs and the emergence of COPPER CHAPERONE FOR SUPEROXIDE DISMUTASE (CCS) proteins. SODs were initially appreciated for their antioxidant properties and potential to improve plant stress tolerance. However, recent findings indicate a role for SODs in maintaining reactive oxygen species (ROS) gradients to guide plant developmental processes. Moreover, after nearly 50 years of research on SODs, these enzymes still hold many surprises as evidenced by the recent finding that SOD in yeast acts as a transcriptional regulator. In this article, we aim at giving an overview of the current knowledge on SODs in plants and highlight avenues for future research endeavours, as there is still so much to learn.

Greenbug (Schizaphis graminum) herbivory significantly impacts protein and phosphorylation abundance in switchgrass (Panicum virgatum)

“…However, though ROS are important signaling molecules in plants, high abundance can be toxic to the plant and ROS scavenging is critical for plant health. As such, high amounts of ROS can be removed by ROS-scavenging enzymes like catalases 60 , peroxidases 61 , and superoxide dismutases 62 , as well as antioxidants like ascorbate and glutathione 63 . Apart from scavenging, peroxidases are essential players in auxin catabolism, programmed cell death, defenses against pathogens, and cell wall lignification 64 .…”

Microtranscriptome analysis of sugarcane cultivars in response to aluminum stress

“…Reactive oxygen species (ROS) production is increased by several environmental stresses, including exposure to drought and heavy metals [39]. In addition, recent studies indicate that SODs as one of the primary types of antioxidant enzymes and are responsible for maintaining ROS gradients to guide plant developmental processes [40]. miR398 is predicted to regulate copper/zinc superoxide dismutase (Table 2), an isoform of the oxidative stress-response enzyme SOD ( superoxide dismutase ) (S4 Table).…”

The toxic metal stress in two mosses of different growth forms under axenic and controlled conditions

“…45 (1) Cu/Zn-SOD2 due to chemical similarity, the alternation of the enzyme structure and ultimately to its degradation, accounting for much more pronounced effects of cadmium on the chlorophyll contents applied as 700 µM. The presence of chloroplastic Cu/ZnSOD is not ubiquitous in all mosses (Pilon et al 2011;Dreyer & Schippers 2019). In both of the moss species tested here, cadmium led to the significant loss of chl b, reaching almost the same final concentration in the two species.…”

“…The different effects of copper and cadmium on the amounts of chlorophylls, depending on the applied concentration in the media, could additionally be explained by the different interaction of the two metals with the antioxidative system inside chloroplasts, particularly with the enzyme Cu/Zn superoxide dismutase 2 (Cu/ZnSOD2). This isoform is only present in chloroplasts of higher plants including mosses (Dreyer & Schippers 2019) and its expression and function are dependent on the copper availability. When plants suffer oxidative stress due to disruption of the photosynthetic apparatus, the expression of this enzyme is significantly up-regulated (Andersen et al 2018).…”