title: A novel tomato SUMO E3 ligase, SlSIZ1, confers drought tolerance in transgenic tobacco.
abstract: SUMOylation is an important post-translational modification process that regulates different cellular functions in eukaryotes. SIZ/PIAS-type SAP and Miz1 (SIZ1) proteins exhibit SUMO E3 ligase activity, which modulates SUMOylation. However, SIZ1 in tomato has been rarely investigated. In this study, a tomato SIZ1 gene (SlSIZ1) was isolated and its molecular characteristics and role in tolerance to drought stress are described. SlSIZ1 was up-regulated by cold, sodium chloride (NaCl), polyethylene glycol (PEG), hydrogen peroxide (H2O2) and abscisic acid (ABA), and the corresponding proteins were localized in the nucleus. The expression of SlSIZ1 in Arabidopsis thaliana (Arabidopsis) siz1-2 mutants partially complemented the phenotypes of dwarf, cold sensitivity and ABA hypersensitivity. SlSIZ1 also exhibited the activity of SUMO E3 ligase to promote the accumulation of SUMO conjugates. Under drought stress, the ectopic expression of SlSIZ1 in transgenic tobacco lines enhanced seed germination and reduced the accumulation of reactive oxygen species. SlSIZ1 overexpression conferred the plants with improved growth, high free proline content, minimal malondialdehyde accumulation and increased accumulation of SUMO conjugates. SlSIZ1 is a functional homolog of Arabidopsis SIZ1 with SUMO E3 ligase activity. Therefore, overexpression of SlSIZ1 enhanced the tolerance of transgenic tobacco to drought stress.
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Kunyang
authors.initials: K
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Shiju
authors.initials: S
authors.lastname: Wang
authors.forename: Jinlian
authors.initials: J
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Na'na
authors.initials: N
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Meng
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D019295:Computational Biology; D055864:Droughts; D005816:Genetic Complementation Test; D018525:Germination / Q000187:drug effects; D018869:Heat-Shock Response / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects / Q000201:enzymology*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects; D014026:Nicotiana / Q000235:genetics* / Q000502:physiology*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D025841:Small Ubiquitin-Related Modifier Proteins; D000040:Abscisic Acid; D044767:Ubiquitin-Protein Ligases
keywords: SUMO E3 ligase SlSIZ1; SUMO conjugates; drought stress; tomato; transgenic tobacco