Sucrose non-fermenting-1-related protein kinase 2 (SnRK2) plays a key role in the plant stress signalling transduction pathway via phosphorylation. Here, a SnRK2 member of common wheat, TaSnRK2.7, was cloned and characterized. Southern blot analysis suggested that the common wheat genome contains three copies of TaSnRK2.7. Subcellular localization showed the presence of TaSnRK2.7 in the cell membrane, cytoplasm, and nucleus. Expression patterns revealed that TaSnRK2.7 is expressed strongly in roots, and responds to polyethylene glycol, NaCl, and cold stress, but not to abscisic acid (ABA) application, suggesting that TaSnRK2.7 might participate in non-ABA-dependent signal transduction pathways. TaSnRK2.7 was transferred to Arabidopsis under the control of the CaMV-35S promoter. Function analysis showed that TaSnRK2.7 is involved in carbohydrate metabolism, decreasing osmotic potential, enhancing photosystem II activity, and promoting root growth. Its overexpression results in enhanced tolerance to multi-abiotic stress. Therefore, TaSnRK2.7 is a multifunctional regulatory factor in plants, and has the potential to be utilized in transgenic breeding to improve abiotic stress tolerance in crop plants.

Environmental stresses such as drought, salinity, and cold are major adverse factors that significantly affect agricultural productivity. Protein phosphorylation/dephosphorylation is a major signalling event induced by osmotic stress in higher plants. Sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family members play essential roles in the response to hyperosmotic stresses in plants. In this study, the TaSnRK2.3 gene, a novel SnRK2 member was cloned, and three copies located on chromosomes 1A, 1B, and 1D were identified in common wheat. TaSnRK2.3 was strongly expressed in leaves, and responded to polyethylene glycol, NaCl, abscisic acid, and cold stresses. To characterize its function, transgenic Arabidopsis overexpressing TaSnRK2.3–GFP controlled by the cauliflower mosaic virus 35S promoter was generated and subjected to severe abiotic stresses. Overexpression of TaSnRK2.3 resulted in an improved root system and significantly enhanced tolerance to drought, salt, and freezing stresses, simultaneously demonstrated by enhanced expression of abiotic stress-responsive genes and ameliorative physiological indices, including a decreased rate of water loss, enhanced cell membrane stability, improved photosynthetic potential, and significantly increased osmotic potential and free proline content under normal and/or stressed conditions. These results demonstrate that TaSnRK2.3 is a multifunctional regulator, with potential for utilization in transgenic breeding for improved abiotic stress tolerance in crop plants.

Plant responses to stress occur via abscisic acid (ABA) dependent or independent pathways. Sucrose non-fermenting1-related protein kinase 2 (SnRK2) play a key role in plant stress signal transduction pathways. It is known that some SnRK2 members are positive regulators of ABA signal transduction through interaction with group A type 2C protein phosphatases (PP2Cs). Here, 10 SnRK2s were isolated from wheat. Based on phylogenetic analysis using kinase domains or the C-terminus, the 10 SnRK2s were divided into three subclasses. Expression pattern analysis revealed that all TaSnRK2s were involved in the responses to PEG, NaCl, and cold stress. TaSnRK2s in subclass III were strongly induced by ABA. Subclass II TaSnRK2s responded weakly to ABA, whereas TaSnRK2s in subclass I were not activated by ABA treatment. Motif scanning in the C-terminus indicated that motifs 4 and 5 in the C-terminus were unique to subclass III. We further demonstrate the physical and functional interaction between TaSnRK2s and a typical group A PP2C (TaABI1) using Y2H and BiFC assays. The results showed that TaABI1 interacted physically with subclass III TaSnRK2s, while having no interaction with subclasses I and II TaSnRK2s. Together, these findings indicated that subclass III TaSnRK2s were involved in ABA regulated stress responses, whereas subclasses I and II TaSnRK2s responded to various abiotic stressors in an ABA-independent manner.

Transforming growth factor β (TGF-β) is critical for embryonic development, adult tissue homeostasis, and tumor progression. TGF-β suppresses tumors at early stage, but promotes metastasis at later stage through oncogenes such as Twist1. Gamma-synuclein (SNCG) is overexpressed in a variety of invasive and metastatic cancer. Here, we show that TGF-β induces SNCG expression by Smad-Twist1 axis, thus promoting TGF-β- and Twist1-induced cancer cell migration and invasion. We identify multiple Twist1-binding sites (E-boxes) in SNCG promoter. Chromatin immunoprecipitation and luciferase assays confirm the binding of Twist1 to the E-boxes of SNCG promoter sequence (−129/−1026 bp). Importantly, the Twist1-binding site close to the transcription initiation site is critical for the upregulation of SNCG expression by TGF-β and Twist1. Mutations of Twist1 motif on the SNCG promoter constructs markedly reduces the promoter activity. We further show that TGF-β induces Twist1 expression through Smad thereby enhancing the binding of Twist1 to SNCG promoter, upregulating SNCG promoter activity and increasing SNCG expression. SNCG knockdown abrogates TGF-β- or Twist1-induced cancer cell migration and invasion. Finally, SNCG knockdown inhibits the promotion of cancer metastasis by Twist1. Together, our data demonstrate that SNCG is a novel target of TGF-β-Smad-Twist1 axis and a mediator of Twist1-induced cancer metastasis.

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Hydrogen is the most abundant chemical element in the Universe, but is seldom regarded as a therapeutic agent. Recent evidence has shown that hydrogen is a potent antioxidative, antiapoptotic and anti-inflammatory agent and so may have potential medical applications in cells, tissues and organs. There are several methods to administer hydrogen, such as inhalation of hydrogen gas, aerosol inhalation of a hydrogen-rich solution, drinking hydrogen dissolved in water, injecting hydrogen-rich saline (HRS) and taking a hydrogen bath. Drinking hydrogen solution (saline/pure water/other solutions saturated with hydrogen) may be more practical in daily life and more suitable for daily consumption. This review summarizes the findings of recent studies on the use of hydrogen in emergency and critical care medicine using different disease models.

BackgroundHeat shock proteins 90 (HSP90s) are a highly conserved protein family of cellular chaperones widely found in plants; they play a fundamental role in response to biotic and abiotic stresses. The genome-wide analysis of HSP90 gene family has been completed for some species; however, it has been rarely reported for the tobacco HSP90 genes.ResultsIn this study, we systematically conducted genome-wide identification and expression analysis of the tobacco HSP90 gene family, including gene structures, evolutionary relationships, chromosomal locations, conserved domains, and expression patterns. Twenty-one NtHSP90s were identified and classified into eleven categories (NtHSP90–1 to NtHSP90–11) based on phylogenetic analysis. The conserved structures and motifs of NtHSP90 proteins in the same subfamily were highly consistent. Most NtHSP90 proteins contained the ATPase domain, which was closely related to conserved motif 2. Motif 5 was a low complexity sequence and had the function of signal peptide. At least 6 pairs of NtHSP90 genes underwent gene duplication, which arose from segment duplication and tandem duplication events. Phylogenetic analysis showed that most species expanded according to their own species-specific approach during the evolution of HSP90s. Dynamic expression analysis indicated that some NtHSP90 genes may play fundamental roles in regulation of abiotic stress response. The expression of NtHSP90–4, NtHSP90–5, and NtHSP90–9 were up-regulated, while NtHSP90–6, and NtHSP90–7 were not induced by ABA, drought, salt, cold and heat stresses. Among the five treatments, NtHSP90s were most strongly induced by heat stress, and weakly activated by ABA treatment. There was a similar response pattern of NtHSP90s under osmotic stress, or extreme temperature stress.ConclusionsThis is the first genome-wide analysis of Hsp90 in N. tabacum. These results indicate that each NtHSP90 member fulfilled distinct functions in response to various abiotic stresses.Electronic supplementary materialThe online version of this article (10.1186/s12863-019-0738-8) contains supplementary material, which is available to authorized users.

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