The Superoxide Dismutase Gene Family in Nicotiana tabacum: Genome-Wide Identification, Characterization, Expression Profiling and Functional Analysis in Response to Heavy Metal Stress

Abstract

Superoxide dismutases (SODs) play an important role in protecting plants against ROS toxicity induced by biotic and abiotic stress. Recent studies have shown that the SOD gene family is involved in plant growth and development; however, knowledge of the SOD gene family in tobacco is still limited. In the present study, the SOD gene family was systematically characterized in the tobacco genome. Based on the conserved motif and phylogenetic tree, 15 NtSOD genes were identified and classified into three subgroups, including 5 NtCSDs, 7 NtFSDs and 3 NtMSDs. The predicted results of the transport peptide or signal peptide were consistent with their subcellular localization. Most NtSOD genes showed relatively well-maintained exon-intron and motif structures in the same subgroup. An analysis of cis-acting elements in SOD gene promoters showed that NtSOD expression was regulated by plant hormones, defense and stress responses, and light. In addition, multiple transcription factors and miRNAs are predicted to be involved in the regulation of NtSOD gene expression. The qPCR results indicated specific spatial and temporal expression patterns of the NtSOD gene family in different tissues and developmental stages, and this gene family played an important role in protecting against heavy metal stress. The results of functional complementation tests in the yeast mutant suggested that NtCSD1a, NtFSD1e and NtMSD1b scavenge ROS produced by heavy metal stress. This study represents the first genome-wide analysis of the NtSOD gene family, which lays a foundation for a better understanding of the function of the NtSOD gene family and improving the tolerance of plants to heavy metal toxicity.

Identification and characterization of the critical genes encoding Cd-induced enhancement of SOD isozymes activities in Zhe-Maidong (Ophiopogon japonicus)

“…In accordance with their domains and patterns, they were classified into three subfamilies: Cu/ZnSOD, FeSOD, and MnSOD. This categorization aligns with the classifications in Nicotiana tabacum ( Huo et al., 2022 ), Salvia miltiorrhiza ( Han et al., 2020 ), soybeans ( Aleem et al., 2022 ), Daucus carota ( Zameer et al., 2022 ), potato ( Rudić et al., 2022 ), and wheat ( Tounsi et al., 2023 ). The gene family of SOD in Zhe-Maidong consists of 10 OjCu/ZnSOD , 6 OjMnSOD , and 6 OjFeSOD genes.…”

“…The family of genes encoding SOD isoenzymes has been identified in a variety of plants, including Nicotiana tabacum ( Huo et al., 2022 ), Salvia miltiorrhiza ( Han et al., 2020 ), soybeans ( Aleem et al., 2022 ), Daucus carota ( Zameer et al., 2022 ), potato ( Rudić et al., 2022 ), wheat ( Tounsi et al., 2023 ), barley ( Zhang et al., 2021b ), oilseed rape ( Su et al., 2021 ), watermelon, and melon ( Zhang et al., 2021a ) and others. Based on the bound metal cofactor, SODs can be categorized into three classes: Cu/ZnSOD, FeSOD, and MnSOD ( Li et al., 2021 ).…”

New seed coating containing Trichoderma viride with anti-pathogenic properties

“…This event cannot be regarded as oxidative stress but rather as an oxidative burst because it is closely related to the plan of plant development. Moreover, promoters of genes encoding SOD enzymes harbor cis -elements involved in response to hormones and light ( Feng et al, 2016 ; Wang et al, 2017 ; Huo et al, 2022 ). This implies that the expression of SOD genes might be regulated by developmental-related factors.…”

Characterisation of an ethyl methanesulfonate‐derived drought‐tolerant sugarcane mutant line

“…A mutation in any of the genes involved in the network that protects against ROS damage could have contributed towards the enhanced scavenging capabilities seen in the M9.2 mutant. For example, the P5CS (Δ-1-pyrroline-5-carboxylate synthetase) gene, catalyses the rate-limiting reaction in proline biosynthesis, and several TFs play a role in the enzymatic antioxidant regulations such as AP2, NAC and MYB TFs (Huo et al, 2022;Zhao et al, 2020).…”