Griseusins F and G, spiro-naphthoquinones from a tin mine tailings-derived alkalophilic Nocardiopsis species.

Griseusins F (1) and G (2), two 2a-hydro-8a-(2-oxopropyl)-substituted spiro-naphthoquinones with a previously undescribed C23 polyketide skeleton, were isolated from a Yunnan tin mine tailings-derived alkalophilic actinomycete, Nocardiopsis sp. YIM DT266. Their complete structure assignments with the absolute stereochemistry were elucidated by spectroscopic data, X-ray crystal diffraction, calculation of optical rotation, and CD spectroscopic analysis. Compounds 1 and 2 exhibited strong cytotoxicity (IC50 0.37-0.82 µM) and antibacterial activity (MIC 0.80-1.65 µg/mL) against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) in vitro.

[Alternation of thioredoxin system in postconditioning with hydrogen sulfide against hepatic ischemia-reperfusion injury in rats].

OBJECTIVE: To explore the relationship between the protection of hydrogen sulfide (H(2)S) against hepatic ischemia-reperfusion injury and thioredoxin system in rats. METHODS: Eighteen adult rats were divided randomly into 3 groups, i.e. sham, ischemia-reperfusion (IR) and sodium hydrogen sulfide (NaHS). The rats in the IR and NaHS groups were subjected to ischemia for 60 min and followed by reperfusion for 6 hours. In the NaHS group, there was an intraperitoneal dosing of NaHS (28 µmol/kg) at 5 min pre-reperfusion. Blood samples were collected for the measurements of alanine transaminase (ALT) and aspartate transaminase (AST). Liver tissue samples were collected for measurements of Trx and TrxR activity by enzyme-linked immunosorbent assay (ELISA), Western blot detection of Trx system proteins and thioredoxin interacting protein (TXNIP) expression. Hematoxylin-eosin staining was used to observe the hepatic histopathological changes. RESULTS: Compared with the sham group, increased activities of ALT and AST were found in the IR group, accompanied by aggravated pathological injury. In addition, NaHS administrated at pre-reperfusion could alleviate hepatic injury. Compared with the sham group, the IR group had decreased Trx activity and Trx1 protein expression and increased TXNIP protein expression (P < 0.05) while the NaHS group had increased Trx activity and Trx1 protein expression and decreased TXNIP protein expression (P < 0.05). It indicated that the postconditioning with H(2)S could reduce the inhibition of Trx system and boost tissue antioxidant capacity. CONCLUSION: Hydrogen sulfide postconditioning can enhance the cellular Trx system and play a protective role in hepatic ischemia-reperfusion injury.

Influence of Adding Chinese Yam (Dioscorea opposita Thunb.) Flour on Dough Rheology, Gluten Structure, Baking Performance, and Antioxidant Properties of Bread.

Impacts of wheat flour substituted with various levels of Chinese yam (Dioscorea opposita Thunb.) flour (from 0% to 25%) on the dough rheological characteristics, gluten structure, baking performance, and antioxidant properties of bread were investigated. The water absorption increased significantly (p < 0.05), while development time and stability decreased remarkably (p < 0.05) as the proportion of yam flour increased. SEM results indicated that the addition of yam flour destroyed the gluten network structure in the dough. Fourier Transform Infrared Spectroscopy (FTIR) spectra showed that addition of yam flour decreased the content of α-helix and ß-sheet in gluten. With the increase in the proportion of yam flour, the specific volume and overall acceptability decreased (p < 0.05) whereas the total phenolics content (TPC), polysaccharides content, total flavonoids content (TFC), allantoin content, The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capability, fractal dimension, and hardness increased (p < 0.05). Overall, breads made of wheat flour replacement with no more than 15% Guihuai number 2 yam flour were of a high quality and had more antioxidant properties. These showed that Guihuai number 2 had broad application prospects in baked products.

[Effects of light quality on carbon-nitrogen metabolism, growth, and quality of Chinese chives]. / å ‰è´¨å¯¹éŸ­èœç¢³æ°®ä»£è°¢ã€ç”Ÿé•¿å’Œå“è´¨çš„å½±å“.

We examined the effect of white + red (WR), white + blue (WB), white + green (WG), white + purple (WP) on the carbon-nitrogen metabolism, growth and quality of Chinese chives, with ‘Pingjiu 2’ as the material and white light (W) as the control. The results showed that photosynthetic rate (Pn) in WR treatment was significantly higher than that in the control (CK) and that there was no difference among WB, WG, WP and CK. The activity of RuBPCase in all the four treatments was higher than that in CK. Compared with other treatments, WR showed the highest total sugar content, then WP, with WB and WG showing the lowest. Compared with CK, sucrose phosphate synthase (SPS) activity in WR was higher, and lower in the other three treatments, especially the lowest in WB. WB showed the highest activity of sucrose synthetase (SS) and amylase (AMS), WR displayed the lowest as well as the similar or lower in WG or WP compared with CK. These results implied that the increases of the proportion of red and purple light could improve carbon assimilation and transformation and thus accelerate sugar accumulation of Chinese chives. The content of total nitrogen, protein nitrogen, the activities of NR, GS and GOGAT of WB were the highest among all the treatments. The GDH activity of WB was the lowest and notably lower compared with CK. WR showed the lower contents of total nitrogen, protein nitrogen, the activities of NR and GS, and higher activities of GOGAT and GDH than those in CK, while the GDH activity of WR was the highest. WG showed lower total nitrogen, no-protein nitrogen content, and GDH activity, but higher protein nitrogen, NR and GOGAT activities than those in CK. Compared with the control, WP showed the similar results as WG, besides the higher GS activity, with most of these parameters in WP being better than in WG. These results indicated that blue, purple and green light could promote nitrogen metabolism, while red light might inhibit protein synthesis in Chinese chives. The growth of Chinese chives was much better under red and purple light, but worse under blue light, which led to thinner leaves and lower growth mass. Chinese chives of WP with the lowest crude fiber content showed the optimal comprehensive quality. Therefore, purple light exhibited the best effect on the growth of Chinese chives.

Interactive effects of drought stresses and elevated CO2 concentration on photochemistry efficiency of cucumber seedlings.

To reveal and quantify the interactive effects of drought stresses and elevated CO2 concentration [CO2] on photochemistry efficiency of cucumber seedlings, the portable chlorophyll meter was used to measure the chlorophyll content, and the Imaging-PAM was used to image the chlorophyll fluorescence parameters and rapid light response curves (RLC) of leaves in two adjacent greenhouses. The results showed that chlorophyll content of leaves was reduced significantly with drought stress aggravated. Minimal fluorescence (Fo) was increased while maximal quantum yield of PSII (Fv/Fm) decreased significantly by severe drought stress. The significant decrease of effective quantum yield of PSII (Y(II)) accompanied by the significant increase of quantum yield of regulated energy dissipation (Y(NPQ)) was observed under severe drought stress condition, but there was no change of quantum yield of nonregulated energy dissipation (Y(NO)). We detected that the coefficient of photochemical quenching (qP) decreased, and non-photochemical quenching (NPQ) increased significantly under severe drought stress. Furthermore, we found that maximum apparent electron transport rate (ETR(max)) and saturating photosynthetically active radiation (PPFD(sat)) decreased significantly with drought stress aggravated. However, elevated [CO2] significantly increased Fv/Fm, qP and PPFD(sat), and decreased NPQ under all water conditions, although there were no significant effects on chlorophyll content, Fo, Y(II), Y(NPQ), Y(NO) and ETR(max). Therefore, it is concluded that CO2-fertilized greenhouses or elevated atmospheric [CO2] in the future could be favorable for cucumber growth and development, and beneficial to alleviate the negative effects of drought stresses to a certain extent.

[Effects of light quality ratio on photosynthetic characteristics and quality of purple lettuce]. / ä¸åŒå ‰è´¨é æ¯”å¯¹ç´«å¶ç”Ÿèœå ‰åˆç‰¹æ€§å’Œå“è´¨çš„å½±å“.

To explore the effects of different light quality ratios on the growth and development of purple lettuce, we used LED intelligent light control console as light source to study the effects of adding different proportions of red and blue light (1:1, 2:1, 4:1 and 1:2) to the white light on photosynthetic characteristics and commercial quality of purple lettuce (Lactuca sativa L. cv 'Zhongshu Purple Lettuce'). The results showed that when the ratio of red to blue light was 4:1, the chlorophyll content, RuBP carboxylase activity, electron transport efficiency of photosynthesis, net photosynthetic rate and growth were all significantly higher than that in control and other treatments, whereas the nitrate content was the lowest. When the ratio of red to blue light was 1:2, the contents of soluble protein, vitamin C, secondary metabolites such as anthocyanins, flavonoids, total phenolic compounds, and the contents of antioxidant capacity were significantly higher than those in the control and other treatments. We concluded that adding appropriate ratios of red to blue light to the white light could increase photosynthesis and improve commercial quality of purple lettuce.

[Effect of water-nitrogen coupling on photosynthesis and ultrastructure of cucumber leaves under CO2 enrichment]. / CO2åŠ å¯Œä¸‹æ°´æ°®è€¦åˆå¯¹é»„ç“œå¶ç‰‡å ‰åˆä½œç”¨å’Œè¶ å¾®ç»“æž„çš„å½±å“.

Using split plot and then-split plot design, effects of water-nitrogen coupling on photosynthesis and ultrastructure of cucumber (Cucumis sativus) (Jinyou No.35) under CO2 enrichment were investigated. The main plot had two CO2 concentrations: ambient CO2 concentration (400 µmol·mol-1, A) and doubled CO2 concentration (800±20 µmol·mol-1, E). The split plot had two treatments: no drought stress (95% of field capacity, W) and drought stress (75% of field capacity, D). The then-split plot contained low nitrogen treatment (450 kg·hm-2, N1) and high nitrogen treatment (900 kg·hm-2, N2). The results showed that under the condition of drought and high nitrogen, increasing CO2 enhanced the cucumber plant height, and no matter what kinds of water treatment, CO2 enrichment increased the leaf area significantly under high nitrogen. Under the condition of normal irrigation, the photosynthetic rate, stomatal conductance and transpiration rate of high nitrogen treatment were higher than low nitrogen treatment, while it was under the drought condition. Elevated CO2 enhanced the water use efficiency of cucumber leaf which increased with increasing nitrogen application rate. Under drought stress, cucumber adaxial surface porosity density was increased, and the CO2 enrichment and high nitrogen significantly reduced the stomatal density. Increasing nitrogen application improved the number of chloroplast, and reduced that of starch grains. Drought stress decreased the number of chloroplast, but tended to promote the number of starch grains. Drought stress increased the chloroplast length and width, and the size of the starch grains, while high nitrogen reduced the length and width of the chloroplast and starch grains. CO2 enrichment and high nitrogen increased grana thickness and layers (except ADN2), and the slice layer of EDN2 was significantly higher than that of ADN2. In conclusion, CO2 enrichment and suitable water and nitrogen could promote the development of chloroplast thylakoid membrane system, significantly increase the thickness of grana and the number of grana lamella, and effectively improve the chloroplast structure of cucumber, which would benefit the photosynthesis of cucumber plants and ability to utilize CO2 and water and nitrogen.

[Effects of weikangning contained serum on growth of gastric cancer cell, expression of vascular endothelial growth factor and its receptors including KDR and fit-1].

OBJECTIVE: To observe the effect of drug-containing serum of Chinese traditional herbal decoction Weikangning (WKN) on growth of gastric cancer cell, expression of vascular endothelial growth factor (VEGF) and its receptors including KDR and Flt-1. METHODS: A total of 120 male Wistar rats were given high, medium and low-dose WKN. After the drug-containing serum was prepared, the gastric cancer cells MGC-803 of different dose groups were cultured with the drug-containing serum, respectively. The gastric cell growth was observed by using light microscope and flow cytometer,the expression of VEGF and its receptor Flt-1 was detected with SABC immunohistochemistry method and the mRNA expression levels of VEGF and its receptors including KDR and Flt-1 of different groups were detected with reverse transcription-polymerase chain reaction (RT-PCR), respectively. RESULTS: The gastric cancer cell growth and cell cycle of the three medicated groups were significantly improved as compared with those of the control group (P <0. 01) ,the proportion of cells in G0 - G1 phase was increased,while the cells in S phase were decreased. It was shown that the apoptotic rates were increased in the medicated groups in a dose-dependent manner. The gray scales ( microm(2) ) of VEGF and Flt-1 in high, medium and low dose groups was 182. 44 +/-0. 54,178. 65 +/-0. 56,174. 80 +/-0. 81 and 168. 51 +/- 0. 81,162. 01 +/-0. 52,148. 20 +/-0. 69, respectively vs 147.82 +/-0. 15(P <0.01) and 144.31 +/-0.71 (P <0.01) in the control group. The mRNA expression of VEGF and its receptors significantly decreased in gastric cancer cells after cultured with WKN contained serum (P < 0. 01 ). CONCLUSION: WKN has inhibitory effects on gastric cancer cell growth and mRNA expression of VEGF as well as its receptors KDR and Flt-1.

[Effect of weikangning decoction on expression of cyclin E, CDK2, and p27].

OBJECTIVE: To observe the effect of containing drugs serum of weikanguing decoction (WKN) on expression of Cyclin E, CDK2 (Cyclin dependant kinase 2, CDK2) and p27 in gastric cancer cell line MGC-803. METHODS: Total of 120 male Wistar rats were divided into control group, high dose group, medium dose group and low dose group fed with natural saline, 20,10, and 5 g/kg of WKN, respectively. The experimental animals were finally killed for the preparation of drug-containing serum. The gastric cancer cell MGC-803 was cultured with the drug-containing serum drawn from the rats in different groups. The expression of Cyclin E, CDK2 and p27 was detected with immunohistochemistry method-SABC. The expression of mRNA of Cyclin E, CDK2 and p27 were detected with RT-PCR. RESULTS: In high, medium and low dose groups, the gray scales of cyclin E, CDK2 and the OPDTI values of p27 increased significantly, but the gray scales of p27 and the OPDTI values of cyclin E, CDK2 decreased remarkble, compared with that in control group. CONCLUSION: The decoction of WKN can decrease the expression of Cyclin E, CDK2, increases the expression of p27. This effect may be involved in mechanism of gastric cancer cell growth inhibition induced by WKN.

[Anti-proliferation effect of serum containning WEI KANG NING on gastric cancer MGC-803 cells and its mechanism].

OBJECTIVE: To investigate the anti-proliferation effect of WEI KANG NING on gastric cancer. METHODS: MGC-803 cells were cultured in different concentrations of serum containning WEI KANG NING. The inhibitory ratio of the cells was measured by MTT assay. Apoptosis was observed by Hoechst 33258 fluorescence staining. RESULTS: Each concentration of serum containning WEI KANG NING could inhibit cells proliferation. Among them, both high and medium concentration could inhibit longer. Moreover, high concentration could induce cells apoptosis. CONCLUSION: WEI KANG NING serum has anti-proliferation effect on MGC-803 cells and the effect may be related to cell apoptosis induced by WEI KANG NING.

[Effects of Naohuandan Recipe on learning and memory abilities of SAM-P/8 mice and its role in anti-oxidation and anti-apoptosis].

OBJECTIVE: To investigate the effects of Naohuandan Recipe on learning and memory abilities of SAM-P/8 mice and its role in anti-oxidation and anti-apoptosis. METHODS: Forty SAM-P/8 mice were randomly divided into four groups, which were untreated (normal saline-treated) group, Yinkeluo Tablets (extracts of gingko leaf)-treated group, low-dose Naohuandan Recipe-treated group and high-dose Naohuandan Recipe-treated group. Mice in these groups were given corresponding drugs orally for 105 days. Then the performances of learning and memory of mice were tested by a step-down passive avoidance task and a Y-maze test. The serum levels of superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were detected. The expression level of bcl-xl mRNA in cerebral cortex and hippocampus of mice was detected by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The performances of learning and memory in the Yinkeluo Tablets-treated group, low- and high-dose Naohuandan Recipe-treated groups were significantly improved as compared with those in the untreated group (P<0.05 or P<0.01), and such performance was the best in the high-dose Naohuandan Recipe-treated group among these four groups (P<0.01). The serum levels of SOD and GSH-Px and the expression of bcl-xl mRNA in cerebral cortex and hippocampus of mice in the Yinkeluo Tablets-treated group, low- and high-dose Naohuandan Recipe-treated groups were also significantly higher than those in the untreated group (P<0.05 or P<0.01), while the serum level of MDA in the untreated group was higher than that in the other three groups (P<0.01). CONCLUSION: Naohuandan Recipe can improve learning and memory abilities of SAM-P/8 mice, and this effect may be related to its anti-oxidation efficacy and enhancement of expression level of bcl-xl mRNA.

[Influence of over expression of CsRCA on photosynthesis of cucumber seedlings under high temperature stress.] / CsRCAè¶ è¡¨è¾¾å¯¹é«˜æ¸©èƒè¿«ä¸‹é»„ç“œå¹¼è‹—å ‰åˆä½œç”¨çš„å½±å“.

In the present work, transgenic cucumber seedlings over expressing CsRCA and wild-type cucumber seedlings '08-1'at three-leaf stage exposed to high temperature (40 ℃, PFD 600 µmol· m-2 · s-1) were used to study the regulatory mechanism of photosynthesis by CsRCA. The results showed that the mRNA abundance of rbcL and rbcS as well as the activities of ribulose bisphosphate carboxylic enzyme (Rubisco) and Rubisco activase (RCA) were significantly higher in CsRCA over-expressing cucumber seedlings than in wild type (WT). Following 2-h exposure to high temperature, a notable decrease was observed in photosynthetic rate (Pn), photochemical perfor-mance index based on the absorption of light energy (PIABS), activities of Rubisco and RCA as well as the relative expression of rbcL, rbcS and CsRCA in both wild-type cucumber seedlings and transgenic cucumber seedlings. It was found that high temperature stress led to higher Wk, a parameter of chlorophyll (Chl) a fluorescence OJIP curve. Furthermore, high temperature greatly reduced the efficiency of electron transfer along the electron transport chain beyond QA(ψ0) and the quantum yield for electron transport (φE0), indicating that PSII oxygen complexes (OEC) and electron transport chain downstream QA were inhibited by high temperature. However, the inhibition could be alleviated by over expressing CsRCA in cucumber seedlings. Taken together, our data suggested that over expressing CsRCA improves photosynthesis in cucumber seedlings under high temperature stress by enhancing activities of the Rubisco and RCA, and maintaining the number of active reaction centers.

[Effects of calcium and ABA on photosynthesis and related enzymes activities in cucumber seedlings under drought stress]. / é’™ä¸Žè„±è½é ¸å¯¹å¹²æ—±èƒè¿«ä¸‹é»„ç“œå¹¼è‹—å ‰åˆåŠç›¸å ³é ¶æ´»æ€§çš„å½±å“.

To investigate the effect of calcium and ABA on photosynthesis and the activities of antioxidant enzymes in cucumber seedlings under drought stress, the cucumber was used as the expe-riment materials, normal nutrient solution culture was considered as the control, and PEG-6000 application in the nutrient solution simulated the drought stress. There were five different treatments which were spraying water, ABA, CaCl2+ABA, LaCl3(calcium channel inhibitor)+ABA and EGTA (calcium ion chelating agent)+ABA under drought stress. The results showed that drought stress inhibited the growth of cucumber seedlings, and reduced the activities of antioxidant enzymes, nitrate reductase, net photosynthetic rate and fluorescence parameters of the cucumber seedlings leaves. The application of ABA reduced the inhibition of activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), photosynthesis (Pn, gs) and the fluorescence parameters (Fv'/Fm', qP and ETR), and decreased the damage of drought stress on plant. Spraying CaCl2+ABAsignificantly promoted the positive effect of ABA, while EGTA+ABA and LaCl3 +ABA didn't show the promoting effect.

Ultraviolet-B Radiation (UV-B) Relieves Chilling-Light-Induced PSI Photoinhibition And Accelerates The Recovery Of CO2 Assimilation In Cucumber (Cucumis sativus L.) Leaves.

Ultraviolet-B radiation (UV-B) is generally considered to negatively impact the photosynthetic apparatus and plant growth. UV-B damages PSII but does not directly influence PSI. However, PSI and PSII successively drive photosynthetic electron transfer, therefore, the interaction between these systems is unavoidable. So we speculated that UV-B could indirectly affect PSI under chilling-light conditions. To test this hypothesis, the cucumber leaves were illuminated by UV-B prior or during the chilling-light treatment, and the leaves were then transferred to 25 °C and low-light conditions for recovery. The results showed that UV-B decreased the electron transfer to PSI by inactivating the oxygen-evolving complex (OEC), thereby protecting PSI from chilling-light-induced photoinhibition. This effect advantages the recoveries of PSI and CO2 assimilation after chilling-light stress, therefore should minimize the yield loss caused by chilling-light stress. Because sunlight consists of both UV-B and visible light, we suggest that UV-B-induced OEC inactivation is critical for chilling-light-induced PSI photoinhibition in field. Moreover, additional UV-B irradiation is an effective strategy to relieve PSI photoinhibition and yield loss in protected cultivation during winter. This study also demonstrates that minimizing the photoinhibition of PSI rather than that of PSII is essential for the chilling-light tolerance of the plant photosynthetic apparatus.

Effect of Weikangning on gastric cancer cell growth and expression of vascular endothelial growth factor and its receptors KDR and Flt-1.

AIM: To observe the effect of Chinese traditional herbal decoction Weikang-ning (WKN) on cell growth and expression of VEGF and its receptors KDR and Flt-1 in gastric cancer cell line MGC-803. METHODS: A total of 120 male Wistar rats were divided into control group, high dose, medium dose and low dose groups fed with natural saline, 20, 10, and 5 g/kg of WKN, respectively. The experimental animals were finally killed for the preparation of drug-containing serum. The gastric cancer cell MGC-803 was cultured with the drug-containing serum drawn from the rats in different groups. We observed the growth condition of the cancer cells with light microscope and flow cytometer. The expression of mRNA of VEGF and its receptors KDR and Flt-1 was detected with RT-PCR. RESULTS: The proportion of cells in G(0)-G(1) phase was (65.40+/-0.41)%, (56.92+/-0.62)%, (55.89+/-0.69)% in high, medium and low dose groups respectively vs (41.35+/-0.55)% in control group (P<0.01), while the cells in G(2)-S and S phases were (11.62+/-0.62)% and (22.99+/-0.69)%, (17.08+/-0.80)% and (26.00+/-0.71)%, (19.37+/-0.57)% and (24.74+/-0.64)% in high, medium and low dose groups, respectively, vs (23.65+/-0.56)% and (35.00+/-0.60)% in control group (P<0.01). The expression of mRNA of VEGF and its receptors was significantly decreased, the area of electrophoresis bands (AREA), the absorptivity of mean optical density (A) and the product of AREA and A were significantly lower in WKN-administered groups than that in control group (P<0.01). CONCLUSION: The decoction of WKN suppresses the growth of gastric cancer cell MGC-803 and decreases the expression of mRNA of both VEGF and its receptors KDR and Flt-1.

Clinical observation and mechanism study on treatment of senile dementia with Naohuandan.

OBJECTIVE: To observe the therapeutic effect and mechanism of Naohuandan (NHD) in treating senile dementia (SD). METHODS: Clinical study: Fifty-eight patients with SD, whose diagnosis conforms to the Diagnostic Standard of DSM-IV issued by American Association of Psychiatry, were enrolled and randomly assigned into two groups. The 30 patients in the treated group were treated with NHD, 4 capsules each time, 3 times daily. The 28 patients in the control group were treated with Piracetam, 1.6 g each time, 3 times daily. The therapeutic course for both groups was 3 months. The therapeutic efficacy was estimated and compared by comprehensive scores of memory and cognition, scores of Mini-mental State Examination (MMSE) and Activities of Daily Living (ADL). Experimental study: Rats were divided into the control group, the model group and the high-dosage and low-dosage NHD treated groups. The protective effect of NHD on the per-oxidative damage of hippocampal neurons in beta-amyloid protein induced SD model was observed and the related criteria were determined. RESULTS: Clinical study showed that both NHD and Piracetam could improve the clinical symptoms of patients, the two medicines showing insignificant difference in total effective rate. But NHD was better in elevating MMSE score and lowering ADL score in patients than Piracetam (P < 0.05 and P < 0.01). Experimental study showed that (1) 24 and 72 hrs after modeling, the activity of SOD and GSH were lower and the level of MDA higher in the model group than those in the control group (P < 0.05 or P < 0.01). Compared with the model group at the corresponding time points, in the high-dosage NHD group, SOD and GSH were higher, MDA was lower (P < 0.05 or P < 0.01); but in the low-dosage NHD group, SOD at the 72nd hr was higher (P < 0.05) and MDA at 24th and 72nd hrs was lower (P < 0.01). And most of the criteria in the high-dosage NHD group was improved better than that in the low-dosage NHD group. (2) The survival rates of neurons in various groups were not different significantly (P > 0.05) 24 hrs after modeling, but that in the high-dosage NHD group was significantly higher than that in the model group (P < 0.01) and in the low-dosage NHD group 72 hrs after modeling (P < 0.05). CONCLUSION: NHD is an effective Chinese herbal preparation for treatment of SD, and its mechanism is related with its inhibition on peroxidative injury and protection on neurons.

[Effects of NO3- stress on photosynthetic characteristics and nitrogen metabolism of strawber- ry seedlings].

In order to explore the effects of NO3- stress on photosynthetic characteristics and nitrogen metabolism, strawberry seedlings were grown in sand culture condition under different concentrations of NO3- (64, 112 and 160 mmol · L(-1)) with the control of 16 mmol NO3- · L(-1). The results indicated that at the 8th day after treatment, with the increased NO3- concentration, the strawberry leaf net photosynthetic rate (Pn), stomatal conductance (g(s)), PS II actual photochemical efficiency (ΦPS II), PS II maximum photochemical efficiency (Fv/Fm), and photochemical quenching coefficient (q(P)) significantly decreased, and decreased by 67.7%, 68.4%, 35.7%, 23.2% and 26.9%, respectively, when NO3- concentration reached 160 mmol · L(-1) compared with the control. The non-photochemical quenching coefficient (q(N)) increased by 4.4%, 10.9% and 75.8% respectively in the treatments of 64, 112 and 160 mmol NO3- · L(-1) compared with the control. The intercellular CO2 concentration (Ci) decreased under low NO3- concentration stress and then increased under high NO3- concentration stress, while the stomatal limitation (Ls) was vice versa. With the increased NO3- concentration, the nitrate nitrogen, ammonia nitrogen, total nitrogen and Kjeldahl nitrogen contents in the strawberry leaves and roots increased, but the protein nitrogen content decreased. The activities of nitrate reductase (NR) , glutamine sybthetase (GS), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) increased at low NO3- concentration and then decreased at high NO3 concentration. Consequently, the net photosynthetic rate of strawberry seedling leaves decreased, the PS II electron transfer was blocked, the nitrogen accumulated with the increasing NO3- concentration, and the nitrogen metabolism enzyme activity decreased at high NO3- concentrations. When the NO3- concentration reached 64 mmol · L(-1) or higher in the nutrient solution, the growth of strawberry seedlings were inhibited significantly.

Water Status Related Root-to-Shoot Communication Regulates the Chilling Tolerance of Shoot in Cucumber (Cucumis sativus L.) Plants.

Although root-to-shoot communication has been intensively investigated in plants under drought, few studies have examined root-to-shoot communication under chilling. Here we explored whether root-to-shoot communication contributes to the chilling-light tolerance of cucumber shoots and clarified the key signal involves in this communication. After leaf discs chilling-light treatment, the photoinhibitions of Photosystem I (PSI) and Photosystem II (PSII) were similar in leaf discs of two cucumber varieties (JY-3 and JC-4). When the whole plants, including roots, were chilled under light, the photosynthetic performances in JC-4 leaves decreased more seriously than that in JY-3 leaves. However, when the water status of leaves was maintained by warming roots or floating the attached leaves on water, the PSII activity and amount of PSI in the leaves of the two varieties were similar after chilling-light treatment. In addition, the differences of PSII activities and amount of PSI between the two varieties under whole plant chilling-light treatment were independent of ABA pretreatment. Above results indicate that (1) the better water status in leaves under chilling contributes to the higher chilling tolerance of JY-3; (2) the water status, rather than an ABA signal, dominates root-to-shoot communication under chilling and the chilling tolerance of cucumber shoot.

[Responses of non-structural carbohydrate metabolism of cucumber seedlings to drought stress and doubled CO2 concentration].

The effects of doubled CO2 concentration on non-structural carbohydrate metabolism of cucumber (Cucumis sativus L. cv. 'Jinyou No.1') seedlings under drought stress were investigated. Split plot design was deployed, with two levels of CO2 concentrations (ambient CO2 concentration, 380 µmol . mol-1, and doubled CO2 concentration, 760±20 µmol . mol-1) in the main plots, and three levels of water treatments (control, moderate drought stress, and severe drought stress) simulated by PEG 6000 in the split-plots. The results showed that non-structural carbohydrates of cucumber leaves, including glucose, fructose, sucrose, and stachyose, increased with the doubling of CO2 concentration, which resulted in the decreased osmotic potential, improving the drought stress in cucumber seedlings. During the drought stress, sucrose synthase, soluble acid invertase and al- kaline invertase started with an increase, and followed with a decline in the leaves. In the root system, however, soluble acid invertase and alkaline invertase increased gradually throughout the whole process, whereas sucrose phosphate synthase firstly increased and then decreased. The treatment of doubled CO2 enhanced the activity of sucrose synthase, but decreased the activity of sucrose phosphate synthase. The synergistic action of the two enzymes and invertase accelerated the decomposition of sucrose and inhibited the synthesis of sucrose, leading to the accumulation of hexose, which lowered the cellular osmotic potential and enhanced the water uptake capacity. In conclusion, doubled CO2 concentration could alleviate the adverse effects of drought stress and improve the drought tolerance of cucumber seedlings. Such mitigating effect on cucumber was more significant under severe drought stress.

[Variation patterns of soil wall temperature and heat flux in sunken solar greenhouse].

From December 2011 to March 2012, a consecutive test was conducted on the temperature and heat flux of different thickness of the soil backwall of sunken solar greenhouse in Shouguang of Shandong Province, East China, aimed to analyze the variation patterns of soil wall temperature and heat flux of the sunken solar greenhouse and to confirm the suitable wall thickness. In winter, the temperature and heat flux of the wall inner surface and outer surface varied over a wide range, which was in accordance with the variation trend of indoor and outdoor air temperature. Overall, the wall temperature decreased from the inner to the outer surface, and the layers of the inner wall with higher variation range of temperature and heat flux were more than those of the outer wall. The variation range of temperature and heat flux decreased gradually from the shallow layers to deep layers of the wall. In successive cloudy days, the temperature of each layer of inner wall decreased to different degrees, and the layers releasing heat to the indoor deepened constantly, whereas the heat in the layers of outer wall was mainly released to the outdoor. According to the variation patterns of temperature and heat flux in the wall, the wall from inside to outside could be divided into heat storage layer, transitional layer, and cold resistant layer, and their thickness was 0.8-1.0 m, 2.2-2.6 m, and 0.4-0.6 m, respectively, under the condition of the outer surface being covered. Without considering the transitional layer, the suitable thickness of the soil wall in Shouguang solar greenhouse would be 1.4-1.6 m.