Two-factor ANOVA of SSH and RNA-seq analysis reveal development-associated Pi-starvation genes in oilseed rape.

MAIN CONCLUSION: The 5-leaf-stage rape seedlings were more insensitive to Pi starvation than that of the 3-leaf-stage plants, which may be attributed to the higher expression levels of ethylene signaling and sugar-metabolism genes in more mature seedlings. Traditional suppression subtractive hybridization (SSH) and RNA-Seq usually screen out thousands of differentially expressed genes. However, identification of the most important regulators has not been performed to date. Here, we employed two methods, namely, a two-round SSH and two-factor transcriptome analysis derived from the two-factor ANOVA that is commonly used in the statistics, to identify development-associated inorganic phosphate (Pi) starvation-induced genes in Brassica napus. Several of these genes are related to ethylene signaling (such as EIN3, ACO3, ACS8, ERF1A, and ERF2) or sugar metabolism (such as ACC2, GH3, LHCB1.4, XTH4, and SUS2). Although sucrose and ethylene may counteract each other at the biosynthetic level, they may also work synergistically on Pi-starvation-induced gene expression (such as PT1, PT2, RNS1, ACP5, AT4, and IPS1) and root acid phosphatase activation. Furthermore, three new transcription factors that are responsive to Pi starvation were identified: the zinc-finger MYND domain-containing protein 15 (MYND), a Magonashi family protein (MAGO), and a B-box zinc-finger family salt-tolerance protein. This study indicates that the two methods are highly efficient for functional gene screening in non-model organisms.

Nitric oxide regulates chlorophyllide biosynthesis and singlet oxygen generation differently between Arabidopsis and barley.

Nitric oxide (NO) has a general inhibitory effects on chlorophyll biosynthesis, especially to the step of 5-aminolevulinic acid (ALA) biosynthesis and protochlorophyllide (Pchlide) to chlorophyllide (Chlide) conversion (responsible by the NADPH:Pchlide oxidoreductase POR). Previous study suggested that barley large POR aggregates may be generated by dithiol oxidation of cysteines of two POR monomers, which can be disconnected by some reducing agents. POR aggregate assembly may be correlated with seedling greening in barley, but not in Arabidopsis. Thus, NO may affect POR activity and seedling greening differently between Arabidopsis and barley. We proved this assumption by non-denaturing gel-analysis and reactive oxygen species (ROS) monitoring during the greening. NO treatments cause S-nitrosylation to POR cysteine residues and disassembly of POR aggregates. This modification reduces POR activity and induces Pchlide accumulation and singlet oxygen generation upon dark-to-high-light shift (and therefore inducing photobleaching lesions) in barley leaf apex, but not in Arabidopsis seedlings. ROS staining and ROS-related-gene expression detection confirmed that superoxide anion and singlet oxygen accumulated in barley etiolated seedlings after the NO treatments, when exposed to a fluctuating light. The data suggest that POR aggregate assembly may be correlated with barley chlorophyll biosynthesis and redox homeostasis during greening. Cysteine S-nitrosylation may be one of the key reasons for the NO-induced inhibition to chlorophyll biosynthetic enzymes.

Retinoic acid can induce mouse embryonic stem cell R1/E to differentiate toward female germ cells while oleanolic acid can induce R1/E to differentiate toward both types of germ cells.

Retinoic acid (RA) and oleanolic acid (OA) were studied about their potential to induce mouse embryonic stem cell R1/E (MESC-R1/E) to differentiate toward germ cells. Embryoid bodies (EBs) first formed from MESC-R1/E and EBs were allowed to attach to the bottoms of normal cell-culturing plate and grow. Then, different compounds including RA, OA and so on were respectively added to induce MESC-R1/E to differentiate. After 72 h, microscopy images were taken for all interventions, then total RNAs were extracted, cDNAs were synthesized and real-time fluorescence quantitative PCR (qPCR) was performed to detect the transcriptional expression patterns of 11 reproductive-differentiation-related genes for different compounds respectively. During the data analysis, it was found RA significantly up-regulated the expression levels of GDF-9, Stra8, SCP3, Mvh, ZP1, ZP2, and ZP3, while significantly down-regulated the levels of Itag6 and Itgb1, and the level of Oct-4 was down-regulated insignificantly, while the level of TP2 was up-regulated insignificantly; OA significantly up-regulated the expression levels of Stra8, SCP3, Mvh, ZP1, ZP2, Itgb1, and TP2, and the levels of Oct-4, GDF-9, ZP3, and Itga6 were up-regulated insignificantly. The data showed that RA can induce MESC-R1/E to differentiate toward female germ cells while OA can induce MESC-R1/E to differentiate toward male and female germ cells.

Synthesis and anti-ovarian cancer effects of benzimidazole-2-substituted pyridine and phenyl propenone derivatives.

Background: Given the benzimidazole derivatives have anti-ovarian cancer effects, the authors aimed to determine whether benzimidazole-2-substituted pyridine and phenyl propenone derivatives exert anti-ovarian cancer activity. Materials & methods: 21 derivatives were synthesized and assayed for their antiproliferative activities. Western blotting in A2780 cells was used to detect the effects of compound A-6 on apoptosis-related proteins. Invasion, migration and apoptosis were assayed in SKOV3 cells treated with A-6. The in vivo activity was also examined. Results: A-6 could inhibit proliferation, invasion and migration and induce apoptosis in SKOV3 cells. Additionally, A-6 had potent inhibitory activity in a xenograft mouse model. Conclusion: A-6 shows potent efficacy in the treatment of ovarian cancer and may be a potential antitumor agent.

Synthesis, structure and selective luminescence sensing for iron(III) ions of a three-dimensional zinc(II) (4,6)-connected coordination network.

Coordination polymers constructed from conjugated organic ligands and metal ions with a d10 electronic configuration exhibit intriguing properties for chemical sensing and photochemistry. A ZnII-based coordination polymer, namely poly[aqua(µ6-biphenyl-3,3',5,5'-tetracarboxylato)(µ2-4,4'-bipyridine)dizinc(II)], [Zn2(C16H6O8)(C10H8N2)(H2O)2]n or [Zn2(m,m-bpta)(4,4'-bipy)(H2O)2]n, was synthesized from a mixture of biphenyl-3,3',5,5'-tetracarboxylic acid [H4(m,m-bpta)], 4,4'-bipyridine (4,4'-bipy) and Zn(NO3)2·6H2O under solvothermal conditions. The title complex has been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis, and features a µ6-coordination mode. The ZnII ions adopt square-pyramidal geometries and are bridged by two syn-syn carboxylate groups to form [Zn2(COO)2] secondary buildding units (SBUs). The SBUs are crosslinked by (m,m-bpta)4- ligands to produce a two-dimensional grid-like layer that exhibits a stair-like structure along the a axis. Adjacent layers are linked by 4,4'-bipy ligands to form a three-dimensional network with a {44.610.8}{44.62} topology. In the solid state, the complex displays a strong photoluminescence and an excellent solvent stability. In addition, the luminescence sensing results indicate a highly selective and sensitive sensing for Fe3+ ions.

Two CoII coordination polymers of biphenyl-2,2',5,5'-tetracarboxylic acid with flexible N-donor ligands: syntheses, structures and magnetic properties.

Two CoII-based coordination polymers, namely poly[(µ4-biphenyl-2,2',5,5'-tetracarboxylato){µ2-1,3-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)], [Co2(C16H6O8)(C14H14N4)2]n or [Co2(o,m-bpta)(1,3-bimb)2]n (I), and poly[[aqua(µ4-biphenyl-2,2',5,5'-tetracarboxylato){1,4-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)] dihydrate], {[Co2(C16H6O8)(C14H14N4)2(H2O)2]·4H2O}n or {[Co2(o,m-bpta)(1,4-bimb)2(H2O)2]·4H2O}n (II), were synthesized from a mixture of biphenyl-2,2',5,5'-tetracarboxylic acid, i.e. [H4(o,m-bpta)], CoCl2·6H2O and N-donor ligands under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis. The bridging (o,m-bpta)4- ligands combine with CoII ions in different µ4-coordination modes, leading to the formation of one-dimensional chains. The central CoII atoms display tetrahedral [CoN2O2] and octahedral [CoN2O4] geometries in I and II, respectively. The bis[(1H-imidazol-1-yl)methyl]benzene (bimb) ligands adopt trans or cis conformations to connect CoII ions, thus forming two three-dimensional (3D) networks. Complex I shows a (2,4)-connected 3D network with left- and right-handed helical chains constructed by (o,m-bpta)4- ligands. Complex II is a (4,4)-connected 3D novel network with ribbon-like chains formed by (o,m-bpta)4- linkers. Magnetic studies indicate an orbital contribution to the magnetic moment of I and II due to the longer Co...Co distances. An attempt has been made to fit the χMT results to the magnetic formulae for mononuclear CoII complexes, the fitting indicating the presence of weak antiferromagnetic interactions between the CoII ions.

Design, synthesis and biological evaluation of novel benzimidazole-2-substituted phenyl or pyridine propyl ketene derivatives as antitumour agents.

A series of novel benzimidazole-2-subsituted phenyl or pyridine propyl ketene derivatives were designed and synthesized. The biological activities of these derivatives were then evaluated as potential antitumour agents. These compounds were assayed for growth-inhibitory activity against HCT116, MCF-7 and HepG2 cell lines in vitro. The IC50 values of compounds A1 and A7 against the cancer cells were 0.06-3.64 µM and 0.04-9.80 µM, respectively. Their antiproliferative activities were significantly better than that of 5-Fluorouracil (IC50: 56.96-174.50 µM) and were close to that of Paclitaxel (IC50: 0.026-1.53 µM). The activity of these derivatives was over 100 times more effective than other reported structures of chalcone analogues (licochalcone A). A preliminary mechanistic study suggested that these compounds inhibit p53-MDM2 binding. Compounds A1, A7 and A9 effectively inhibited tumour growth in BALB/c mice with colon carcinoma HCT116 cells. The group administered 200 mg/kg of compound A7 showed a 74.6% tumour growth inhibition with no signs of toxicity at high doses that was similar to the inhibition achieved with the 12.5 mg/kg irinotecan positive control (70.2%). Therefore, this class of benzimidazole-2-subsituted phenyl or pyridine propyl ketene derivatives represents a promising lead structure for the development of possible p53-MDM2 inhibitors as new antitumour agents.

Design, synthesis and antiproliferative activity of a novel class of indole-2-carboxylate derivatives.

Based on the chemical structure of Pyrroloquinoline quinone (PQQ), a novel class of indole-2-carboxylate derivatives was designed, synthesized and assayed for antiproliferative activity in cancer cells in vitro. The biological results showed that some derivatives exhibited significant antiproliferative activity against HepG2, A549 and MCF7 cells. Notably, the novel compounds, methyl 6-amino-4-cyclohexylmethoxy-1H-indole-2-carboxylate (6e) and methyl 4-isopropoxy-6-methoxy-1H-indole-2-carboxylate (9l) exhibited more potent antiproliferative activity than the reference drugs PQQ and etoposide in vitro, with IC50 values ranging from 3.78 ± 0.58 to 24.08 ± 1.76 µM. Further biological assay showed that both compounds 6e and 9l increased ROS generation dose-dependently, and induced PARP cleavage in A549 cells. Consequently, 6e and 9l appeared as promising anticancer lead compounds for further optimization.

Synthesis and antiviral activity of a novel class of (5-oxazolyl)phenyl amines.

A series of novel (5-oxazolyl)phenyl amine derivatives were synthesized and their antiviral activities against the hepatitis C virus (HCV) and the coxsackie virus B3 (CVB3) and B6 (CVB6) were evaluated in vitro. Bioassays showed that the synthesized compounds 17a1, 17a4, 17a6, 17b1, 17d1, 17e2 and 17g3 exhibited potent antiviral activity against HCV (IC50 = 0.28-0.92 µM) and most synthesized compounds exhibited low cytotoxicity in Huh7.5 cells, compared to telaprevir. The compounds 17a1, 17a4, 17a5, 17a6, 17b1, 17b2, 17g1 and 17g3 showed strong activity against the CVB3 and/or CVB6 at low concentrations (IC50 < 2.0 µM). The (5-oxazolyl)phenyl amines 17a1, 17a4, 17a8, 17b1, 17d1, 17e2, 17f3 and 17g3 were identified as the most active on the biological assays, and will be studied further.