GsSnRK1 interplays with transcription factor GsERF7 from wild soybean to regulate soybean stress resistance.

Although the function and regulation of SnRK1 have been studied in various plants, its molecular mechanisms in response to abiotic stresses are still elusive. In this work, we identified an AP2/ERF domain-containing protein (designated GsERF7) interacting with GsSnRK1 from a wild soybean cDNA library. GsERF7 gene expressed dominantly in wild soybean roots and was responsive to ethylene, salt, and alkaline. GsERF7 bound GCC cis-acting element and could be phosphorylated on S36 by GsSnRK1. GsERF7 phosphorylation facilitated its translocation from cytoplasm to nucleus and enhanced its transactivation activity. When coexpressed in the hairy roots of soybean seedlings, GsSnRK1(wt) and GsERF7(wt) promoted plants to generate higher tolerance to salt and alkaline stresses than their mutated species, suggesting that GsSnRK1 may function as a biochemical and genetic upstream kinase of GsERF7 to regulate plant adaptation to environmental stresses. Furthermore, the altered expression patterns of representative abiotic stress-responsive and hormone-synthetic genes were determined in transgenic soybean hairy roots after stress treatments. These results will aid our understanding of molecular mechanism of how SnRK1 kinase plays a cardinal role in regulating plant stress resistances through activating the biological functions of downstream factors.

[Determination of total Bromine in urine by inductively coupled plasma mass spectrometry (ICP-MS)].

OBJECTIVE: To establish a method to determine total bromine in urine. METHOD: Diluted urine samples were directly introduced into ICP-MS then quantized by standard curve. RESULT: Total bromine in urine was linear within 1.0~50 mg/L with r > 0.999, When spiked at a concentration of 0.020 mg/L, 0.050 mg/L, 0.150 mg/L, the recovery was 95%~98%, intra-assay precision was 1.4% 3.2%, inter-assay precision was 3.4% to 5.0%. Urine could store in -20 °C refrigerator 3 months without any bromine loss. CONCLUSION: Using ICP-MS to determine the urinary total bromine, the method is fast, accurate, wide linear range of features, could meet with the requirement of Part 5 of occupational health standards guide: Method determination of chemical substances in biological materials (GBZ/T 210.5-2008), a strong competitive advantage in a wide range of survey, suitable for promotion.

Screening of cry-type promoters with strong activity and application in Cry protein encapsulation in a sigK mutant.

To optimize the expression of cry genes in a Bacillus thuringiensis sigK mutant failing in crystal releasing, the transcriptional activity of the cry promoters cry1A, cry3A, cry4A, and cry8E was compared using lacZ gene fusions. A beta-galactosidase assay indicated that the cry8E promoter showed the highest transcriptional activity. A novel Escherichia coli-B. thuringiensis shuttle vector pHT315-8E21b was constructed for cry gene expression using the cry8E promoter and the multiple cloning sites from vector pET21b, based on vector pHT315. SDS-PAGE analysis showed that the expression of the cry1Ac gene directed by the cry8E promoter was increased by approximately 2.4-fold over the expression directed by the cry3A promoter. The cry1Ba gene was expressed in the sigK mutant with the constructed vector pHT315-8E21b. Normal bipyramidal crystals encapsulated in mother cell were observed by transmission electron microscopy (TEM). The encapsulated Cry1Ba protein expressed in the sigK mutant showed activity against Ostrinia furnacalis and Plutella xylostella similar to that of the released Cry1Ba protein expressed in the acrystalliferous strain HD73 and can be protected from inactivation by UV light. All these results suggest that the cry8E promoter can be an efficient transcriptional element for cry gene expression in sigK mutants and can be utilized for the construction of a genetically engineered strain.

[Effect of Shenmai injection on expression of hypoxia-inducible factor-1alpha in hypoxic-ischemic brain damage: experiment with rats].

OBJECTIVE: To investigate the effects of Shenmai injection containing active principles of Ginseng and ophiopogon root on the expression of hypoxia-inducible factor 1-alpha (HIF-1alpha) in brain after hypoxic-ischemic brain damage (HIBD). METHODS: 108 neonatal SD rats were randomly divided into 2 equal groups: (1) Shenmai group (Group SM), undergoing ligation of the right common carotid artery to establish HIBD models, breathing immediately a mixed gas with 8% oxygen and 92% nitrogen for 2 hours to cause HI insult, and then injected intraperitoneally with Shenmai injection 10 mg/kg once a day for 7 days, and (2) normal saline (NS) group (Group NS) undergoing ligation of the right common carotid artery to establish HIBD models, breathing immediately a mixed gas with 8% oxygen and 92% nitrogen for 2 h, and then injected intraperitoneally with NS 10 mg/kg once a day for 7 days. Another 54 neonatal rats underwent sham operation but did not undergo hypoxia as control group (Group C), 2, 12, and 24 hours, and 3, 7, and 14 days after HI insult 9 rats from each group were killed with their right hippocampal tissues taken out. Flow cytometry was used to examine the apoptotic rate of the hippocampal neurons. RT-PCR was used to detect the mRNA expression of HIF-1alpha. RESULTS: (1) The apoptosis rate of the right hippocampal tissues began increase 2 h after Hi insult, peaked 24 h after HI, then gradually decreased, and almost returned to the original levels 14 d after HI. There was no significant differences in apoptosis rates 14d after HI among the 3 groups (all P > 0.05). The neuron apoptosis rates 12 h, 24 h, 3 d, and 7 d after HI of Group SM were all significantly lower than those of Group NS (e.g 24 h: (11.95 +/- 1.13)% vs (16.80 +/- 1.44)%, all P < 0.05). (2) The HIF-1alpha mRNA expression level in right brain began to increase 2 h after HI, peaked 24 h after HI, then gradually decreases, and returned to the original level 14 d after Hi in both Group SM and Group NS; The HIF-1alpha mRNA expression in right brain 12 h, 24 h, 3 d, and 7 d after HI of Group SM were all significantly higher than those of Group NS (e.g 24 h: (44.32 +/- 4.03)% vs (35.63 +/- 3.73)%, all P < 0.05). CONCLUSION: The HIF-1alpha mRNA expression in brain tissue is up-regulated after HI insult. Shenmai injection helps increase the mRNA expression of HIF-1alpha in brain and reduces the apoptosis of hippocampus neurons after HI insult.

[Effects of Shenfu injection on hypoxic-ischemic brain damage: experiment with neonatal rats].

OBJECTIVE: To investigate the effect of Shenfu (ginseng and aconite root) injection on hypoxic-ischemic brain damage (HIBD). METHODS: Sixty 7-day-old Sprague-Dawley rats undergoing ligation of left common carotid artery and then put into a container with 8% O2 and 92% N(2) for 2 h so as to establish HIBD models, were randomly divided into 3 groups: Shenfu injection pretreatment group (since 4 days before the experiment Shenfu injection 10 ml/kg was injected intraperitoneally once a day for 4 days), Shenfu injection treatment group [Shenfu injection 10 ml/kg was injected intraperitoneally immediately after hypoxic-ischemia (HI) insult once a day for 7 days], and control group (normal saline 10 ml/mg was injected intraperitoneally immediately after HI insult once a day for 7 days). Twenty neonatal rats underwent sham operation as control group. The 4 groups were further divided into subgroups of 6 rats according to the time points: 2 hours before and 2 hours, 12 hours, 24 hours, 3 days, 7 days, 14 days, and 28 days after HI insult. 3, 7, 14, and 28 days after the HI insult the body weight was observed and the survival rate was observed 28 d after the HI insult. At different time points the rats of different subgroups were killed and their brains were taken out. Flow cytometry was used to calculate the neuron apoptosis rate in the hippocampal CA1 region. RESULTS: The body weight increase levels 3, 7, 14 and 28 days after HI insult of the control group were all significantly less than those of the sham operation group (e.g 7 days: 8.8 g +/- 2.1 g vs 14.0 g +/- 2.9 g, all P < 0.01) and the body weight increase levels 3, 7, 14, and 28 days after HI insult of the control group were all significantly less than those of the Shenfu injection pretreatment group (e.g 7 d: 11.7 g +/- 3.3 g) and Shenfu injection treatment group (e.g 7 d: 10.9 g +/- 2.7 g, P < 0.01 or P < 0.05). The survival rate 28 d after HI insult of the control group was 60%, significantly less than those of other groups (all P < 0.05), and there was no significant difference in the survival rate among the other groups (all P > 0.05). Compared with the sham operation group the neuron apoptosis rates of the hippocampal CA1 region of the Shenfu injection treatment group and Shenfu injection pretreatment group began to increase 2 hours after HI insult, peaked 24 hours after, then gradually decreased, and recovered to normal 14 days after. The neuron apoptosis rates 2, 12, 24, 72 hours, and 7 days after HI insult of the Shenfu injection pretreatment group were all significantly lower than those of the control group (e.g 24 hours: 16.0% +/- 4.2% vs 11.9% +/- 2.3% vs 18.1%, P < 0.01 or P < 0.05), and the neuron apoptosis rates 72 hours and 7 days after HI insult of the Shenfu injection treatment group were significantly lower than those of the control group. CONCLUSION: Shenfu injection can enhance the physical development and elevate the survival rate of neonatal rats with HI insult, and significantly prevents apoptosis of the hippocampus neurons from HI insult.