Transcriptomic and metabolomic reveals silicon enhances adaptation of rice under dry cultivation by improving flavonoid biosynthesis, osmoregulation, and photosynthesis.

Dry cultivation is a new rice crop mode used to alleviate water shortage and develop water-saving agriculture. There is obvious genetic difference compared with drought-tolerant rice. Silicon (Si) plays an important role in plant adaptation to adverse environmental conditions and can significantly improve the drought tolerance and yield of rice. However, the regulatory mechanism via which Si provides plant tolerance or adaptation under dry cultivation is not well understood. The present study investigated the changes in plant growth, photosynthetic gas exchange, and oxidative stress of the rice cultivar "Suijing 18" under dry cultivation. Si improved photosynthetic performance and antioxidant enzyme activity and subsequently reduced lipid peroxidation of rice seedlings, promoted LAI and promoted leaf growth under dry cultivation. Further, transcriptomics combined with quasi-targeted metabolomics detected 1416 and 520 differentially expressed genes (DEGs), 38 and 41 differentially accumulated metabolites (DAMs) in the rice leaves and roots, respectively. Among them, 13 DEGs were involved in flavonoid biosynthesis, promoting the accumulation of flavonoids, anthocyanins, and flavonols in the roots and leaves of rice under dry cultivation. Meanwhile, 14 DEGs were involved in photosynthesis, promoting photosystem I and photosystem II responses, increasing the abundance of metabolites in leaves. On the other hand, 24 DAMs were identified involved in osmoregulatory processes, significantly increasing amino acids and carbohydrates and their derivatives in roots. These results provide new insight into the role of Si in alleviating to adverse environmental, Si enhanced the accumulation of flavonoids and osmoregulatory metabolites, thereby alleviating drought effect on the roots. On the other hand, improving dehydration resistance of leaves, guaranteeing normal photosynthesis and downward transport of organic matter. In conclusion, Si promoted the coordinated action between the above-ground and below-ground plant parts, improved the root/shoot ratio (R/S) of rice and increased the sugar content and enhancing rice adaptability under dry cultivation conditions. The establishment of the system for increasing the yield of rice under dry cultivation provides theoretical and technical support thereby promoting the rapid development of rice in Northeast China, and ensuring national food security.

Tetramethoxystilbene, a selective CYP1B1 inhibitor, suppresses adipogenesis of C3H10T1/2 pluripotent stem cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the inhibitory effects of tetramethoxystilbene, a selective CYP1B1 inhibitor, on adipogenic differentiation of C3H10T1/2 multi-potent mesenchymal cells.</p><p><b>METHODS</b>In vitro cultured C3H10T1/2 cells at full confluence were induced by adipogenic agents (10 µg/ml insulin, 2 µmol/L dexamethasone and 0.5 mmol/L 3-isobutyl-1-methylxanthine) and exposed simultaneously to TMS at the final concentrations of 1.0, 2.0 or 4.0 µg/ml. Oil Red-O staining was used to observe the cell differentiation. The expression of peroxisome proliferator-activated receptor gamma (PPARγ) and its target genes cluster of differentiation 36 (CD36) and fatty acid binding protein 4 (FABP4) were quantified by real-time RT-PCR and Western blotting.</p><p><b>RESULTS</b>Oil Red-O staining and TG contents revealed that TMS suppressed induced differentiation of C3H10T1/2 cells. TMS exposure of the cells dose-dependently decreased both mRNA and protein expressions of PPARγ, a key nuclear transcription factor during adipogenesis, and also lowered the mRNA expressions of PPARγ target genes CD36 and FABP4.</p><p><b>CONCLUSION</b>TMS can suppress adipogenic differentiation of C3H10T1/2 cells by inhibiting PPARγ</p>

Effects of preconditioning of wufu jingfang on ischemia/reperfusion injury induced apoptosis in rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the protective effect of Wufu Jingfang (WJ, containing Aconitum carmichaeli Debx, Radix Aconiti Lateralis Preparatae, Rhizoma Pinelliae, and snakegourd fruit) on myocardial ischemia-reperfusion injury (I/R) of rats, thus exploring the feasibility of recipes containing eighteen incompatible pairs for specific pathological conditions.</p><p><b>METHODS</b>Fifty male Wistar rats were randomly divided into five groups, i.e., the sham-operative control group (the SH group), the I/R group, the low dose WJ I/R group (the I/R +JFL group), the middle dose WJ I/R group (the I/R +JFM group), the high dose WJ I/R group (the I/R +JFH group), 10 in each group. Rats in the latter three groups were administered with WJ at 0.75 mL/100 g, 1.50 mL/100 g, and 3.00 mL/100 g body weight for 14 consecutive days by gastrogavage. All groups except the SH group received ligation of left anterior descending branch of coronary artery for 30-min ischemia followed by 120-min reperfusion. The micro-structural changes of myocardial mitochondria were observed by transmission electron microscope. The ischemic cardiomyocyte apoptosis was detected in each group using one-step terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mRNA expressions of B-cell leukemia/lymphoma 2 (Bcl-2) and Bcl-2 associated x protein (Bax) were detected by RT-PCR. The activities of lactic dehydrogenase (LDH) and creatine kinase (CK) were detected using ELISA. The myocardial infarct size was detected.</p><p><b>RESULTS</b>Compared with the I/R group, WJ pretreatment significantly suppressed the release of LDH and CK (Besides, the release of LDH and CK reduced along with increased dose.), reduced the myocardial infarct size, and lowered myocardial apoptosis index (P < 0.05). WJ pretreatment also modulated Bcl-2/Bax ratio by up-regulating Bcl-2 expression level while decreasing Bax expression level.</p><p><b>CONCLUSIONS</b>WJ pretreatment might protect the heart from I/R injury via decreasing myocardial cell apoptosis. The results suggested that eighteen incompatible pairs is not absolute, but relative. Chinese medical preparation containing opposite Chinese herbs could be used in specific pathological states such as ischemic cardiomyopathy.</p>

Brain-derived neurotrophic factor mRNA expressions in rat brain induced by short-term in vivo exposure to deltamethrin / 中华预防医学杂志

<p><b>OBJECTIVE</b>To elucidate the mechanism of damage on central nervous system (CNS) caused by deltamethrin (DM).</p><p><b>METHODS</b>The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) in the cerebral cortex and hippocampus of the rats exposed to DM were measured by retro-transcription-polymerase chain reaction (RT-PCR), dot blot, flow cytometry analysis and immunohistochemistry.</p><p><b>RESULTS</b>After exposure to DM at high-dose (DM1, 25.0 mg x kg(-1) x d(-1), i.p.) once and low-dose (DM2, 12.5 mg x kg(-1) x d(-1), i.p.) for 5 days, the level of BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats increased significantly. The levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus measured by of RT-PCR in the rats with DM1 and DM2 were higher than those in the controls by 48% and 56%, and 59% and 54%, respectively. And, those measured by dot blot in the rats with MD1 and MD2 were 186% and 161%, and 148% and 158% of those in the controls, respectively, basically similar to those measured by RT-PCR. Flow cytometric analysis showed that the levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus in the rats with DM1 and DM2 were higher than those in the controls by 53% and 89%, and 45% and 46%, respectively. Immunohistochemical analysis showed that protein expression in the cerebral cortex of the rats with DM1 and DM2 were 129% and 147% of those in the controls, same as the flow cytometric analysis, but those were significantly higher in the hippocampus mainly in the CA1 and DG areas of the rats with MD1 and the CA3 and DG areas of the rats with DM2.</p><p><b>CONCLUSIONS</b>DM could induce BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats, which could play an important role in repairing of nerve damage.</p>

Effects of deltamethrin on cell survival rate and intracellular free Ca2+ concentration in primary cultured astrocytes of rat / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat.</p><p><b>METHODS</b>The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM.</p><p><b>RESULTS</b>The survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min.</p><p><b>CONCLUSION</b>The cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.</p>

Effects of pyrethroids on the activity of gamma-aminobutyric acid transferase in rat brain / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of pyrethroids on the activity of gamma-aminobutyric acid transferase (GABAT) in rat brain.</p><p><b>METHOD</b>The coupled enzyme ultraviolet spectrophotography was applied to observe the effects of deltamethrin (DM) and permethrin (PM) on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum in vitro and in vivo.</p><p><b>RESULTS</b>In vitro, DM and PM had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum at the final concentration of 10(-9) - 10(-4) mol/L. When 37.5 mg/kg DM and 600 mg/kg PM were orally administrated to the rats at one time, the activities of GABAT in rat cerebral cortex, hippocampus and cerebellum in the DM group [(2.96 +/- 0.43), (2.13 +/-0.44), (5.12 +/- 1.36) nmol x mg pro(-1) x min(-1), respectively] were lower than those in the control group [(3.43 +/- 0.41), (2.68 +/- 0.47), (6.74 +/- 1.64) nmol x mg pro(-1) x min(-1)] (P < 0.05), and the activities of GABAT in rat cerebral cortex and hippocampus in the PM group [(4.57 +/- 0.30), (4.18 +/- 0.63) nmol.mg pro(-1) x min(-1), respectively] were higher than those in the control group (P < 0.05). When 12.5 mg/kg DM and 200 mg/kg PM were orally administrated to the rats once a day for consecutive five days, the two pesticides had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum (P > 0.05).</p><p><b>CONCLUSIONS</b>In vitro, DM and PM had no significant effects on the activity of GABAT in rat brain; in vivo, DM and PM may have different effects on the activity of GABAT in rat brain, which deserve further study.</p>