ABSTRACT
Reactive oxygen species (ROS) are byproducts of aerobic metabolism and may cause oxidative damage to biomolecules. Plants have a complex redox system, involving enzymatic and non-enzymatic compounds. The evolutionary origin of enzymatic antioxidant defense in plants is yet unclear. Here, we describe the redox gene network for A. thaliana and investigate the evolutionary origin of this network. We gathered from public repositories 246 A. thaliana genes directly involved with ROS metabolism and proposed an A. thaliana redox gene network. Using orthology information of 238 Eukaryotes from STRINGdb, we inferred the evolutionary root of each gene to reconstruct the evolutionary history of A. thaliana antioxidant gene network. We found two interconnected clusters: one formed by SOD-related, Thiol-redox, peroxidases, and other oxido-reductase; and the other formed entirely by class III peroxidases. Each cluster emerged in different periods of evolution: the cluster formed by SOD-related, Thiol-redox, peroxidases, and other oxido-reductase emerged before opisthokonta-plant divergence; the cluster composed by class III peroxidases emerged after opisthokonta-plant divergence and therefore contained the most recent network components. According to our results, class III peroxidases are in expansion throughout plant evolution, with new orthologs emerging in each evaluated plant clade divergence.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Evolution, Molecular , Gene Regulatory Networks/genetics , Peroxidases/metabolism , Antioxidants/chemistry , Antioxidants/metabolism , Arabidopsis Proteins/genetics , Oxidation-Reduction , Peroxidases/genetics , Reactive Oxygen Species/metabolismABSTRACT
Lead is an important heavy metal used worldwide in several applications, especially in industry. People exposed to lead can develop a wide range of symptoms associated with lead poisoning. Many effects of lead poisoning are reported in the literature, showing a compromising of whole body health, with symptoms related to cardiovascular, immune, bone, reproductive, hematological, renal, gastrointestinal, and nervous system. However, the molecular lead targets as well as the pathways affected by lead poisoning are not completely described. The aim of this study was to construct a map of metabolic pathways impaired in lead poisoning by evaluating which biomolecules are directly affected by lead. Through manual literature curation, we identified proteins which physically interact with lead and subsequently determined the metabolic pathways those proteins are involved with. At total, we identified 23 proteins involved with heme synthesis, calcium metabolism, neurotransmission, among other biological systems, which helps to understand the wide range of lead-poisoning symptoms.
