Cross Talk among Phytohormone Signal and Carbohydrate Metabolism Involving Regenerable Calli Induction under Osmotic Treatment

Nonregenerable calli (NRC) derived from immature seeds of japonica rice were inoculated on MS medium containing 10 μM 2,4-D (MSD10). They turned to highly regenerable calli (HRC) when sorbitol was supplemented into the medium. Meanwhile, high levels of endogenous IAA and ABA were accumulated in HRC. Exogenous IAA precursor and ABA in MSD10 have the same effect to enhance regeneration ability. However, there are only partial effects if IAA precursor or ABA was supplemented, respectively. The regeneration ability is prominently decreased from 75% to 25% while an auxin transport inhibitor, 2,3,5-triiodobenzoic acid, was included in the medium. It suggested that endogenous auxin signal and ABA may involve in the induction of HRC. Furthermore, it showed higher contents of glucose, sucrose, and starch and higher expression levels of wall-bound invertase 1, sucrose transporter 1 (OsSUT1), and OsSUT2 genes in HRC than in NRC. The expression levels of PIN-formed 1 and LEA1 were also consistent with the trend of carbohydrate metabolisms. We thus concluded a flowchart for HRC induction by osmotic stress. According to the hypothesis, osmotic stress may regulate endogenous levels of auxin interacting with ABA, then affect carbohydrate metabolism to trigger callus initiation and further shoot regeneration in rice

An ammonium iron(II) pyrophosphate, (NH4)2[Fe3(P2O7)2(H2O)2], with a layered structure

Diammonium diaquabis(phosphato)triferrate(II), (NH4)2[Fe3(P2O7)2(H2O)2], was synthesized under solvo­thermal conditions at 463 K. The crystal structure, isotypic to its Mn and Ni analogues, is built from iron pyrophosphate layers parallel to (100), which are linked by ammonium ions sitting in the inter­layer space via O—H⋯O and N—H⋯O hydrogen bonds. There are two crystallographic Fe sites in the crystal structure, one at a special position (2a, ), the other at a general position (4e, 1). The former Fe atom on the inversion centre is coordinated by six O atoms, forming an FeO6 octa­hedron, while the latter is coordinated by five phosphate O atoms and one water mol­ecule, forming an FeO5(H2O) octa­hedron. Each FeO6 octa­hedron shares trans edges with two FeO5(H2O) octa­hedra, forming a linear trimeric unit. These trimers share the lateral edges of FeO5(H2O) with other trimers, forming a zigzag chain running along [010]. The zigzag chains are further linked by P2O7 groups into a layered structure parallel to (100)

Daphne Genkwa Sieb. et Zucc. Water-Soluble Extracts Act on Enterovirus 71 by Inhibiting Viral Entry

Dried flowers of Daphne genkwa Sieb. et Zucc. (Thymelaeaceae) are a Chinese herbal medicine used as an abortifacient with purgative, diuretic and anti-inflammatory activities. However, the activity of this medicine against enteroviral infections has not been investigated. The water-extract of dried buds of D. genkwa Sieb. et Zucc. (DGFW) was examined against various strains of enterovirus 71 (EV71) by neutralization assay, and its initial mode of action was characterized by time-of-addition assay followed by attachment and penetration assays. Pretreatment of DGFW with virus abolished viral replication, indicating that DGFW inhibits EV71 by targeting the virus. GFW exerts its anti-EV71 effects by inhibiting viral entry without producing cytotoxic side effects and thus provides a potential agent for antiviral chemotherapeutics

Andrographis paniculata

Andrographolide is the most abundant terpenoid of A. paniculata which is used in the treatment of diabetes. In this study, we investigated the effects of A. paniculata extract (APE) and andrographolide on the expression of drug-metabolizing enzymes in rat liver and determined whether modulation of these enzymes changed the pharmacokinetics of tolbutamide. Rats were intragastrically dosed with 2 g/kg/day APE or 50 mg/kg/day andrographolide for 5 days before a dose of 20 mg/kg tolbutamide was given. APE and andrographolide reduced the AUC0–12 h of tolbutamide by 37% and 18%, respectively, compared with that in controls. The protein and mRNA levels and enzyme activities of CYP2C6/11, CYP1A1/2, and CYP3A1/2 were increased by APE and andrographolide. To evaluate whether APE or andrographolide affected the hypoglycemic action of tolbutamide, high-fat diet-induced obese mice were used and treated in the same manner as the rats. APE and andrographolide increased CYP2C6/11 expression and decreased plasma tolbutamide levels. In a glucose tolerance test, however, the hypoglycemic effect of tolbutamide was not changed by APE or andrographolide. These results suggest that APE and andrographolide accelerate the metabolism rate of tolbutamide through increased expression and activity of drug-metabolizing enzymes. APE and andrographolide, however, do not impair the hypoglycemic effect of tolbutamide

滲透壓促進水稻未成熟胚誘導之癒合組織植株再生

The callus regeneration ability of fifteen rice cultivars including 7 indica and 8 japonica type varieties under osmotic stress treatment were compared. The callus growth and cellular water status were further determined. The responses are different among rice cultivars as follows. Group l, shoots regenerated high frequency without any osmotic treatment. The frequency approximates to 75%. Group 2, shoot regeneration frequency, closed to 50-75%, was the highest by middle concentration of osmotic treatment. Group 3, shoot regeneration frequency, closed to 60-80%, was highest by highly osmotic treatment and only japonica type cultivars are included. Group 4, shoot regeneration is lower either with or without osmotic treatment. Further studies showed that the callus growth, water content, water potential and osmotic potential are decreased in shoot regenerable callus induced by osmotic stress. These results suggest that the growth and differentiation of rice callus can be regulated by cellular water status itself. 本研究比較15個水稻品種(包括7個印度型與8個日本型品種)未成熟胚在滲透壓處理下誘導之癒合組織之植株再生率，並進一步測定滲透壓逆境下合組生長及細胞內水分狀態，以瞭解滲透壓處理對水稻癒合組織再生植株之影響。依其再生率差異，可將其區分為四大群；第一群不需經滲透壓處理即有高植怽再生率，其再生率約為75%左右；第二群僅需中度滲透壓處理即可獲得高株再生率，再生率介於50-75%之問，滲透壓處理濃度過高，再生率反而下降，第三群則需高濃度滲透壓處理才可獲得高值株再生率，其再生率介於60-80% 之間，且皆為日本型水稻品種；第四群不論有無滲透壓處理，植株再生率均低於25%。進一步的分析發現，在高滲透壓處理誘導之高植株再玍率合組織中，其鮮重、水分含量、水勢能、及滲透勢能均顯著下降，上述結果顯示影響水稻合組織生長與植株之再生可能與滲透壓藉由調節細胞內水分狀態有密切相關

Induction of Nrf2-dependent Antioxidation and Protection Against Carbon Tetrachloride-induced Liver Damage by Andrographis Herba (穿心蓮chuān xīn lián) Ethanolic Extract

Andrographis paniculata is a traditional Chinese herb and displays diverse biological activities including antioxidation, anti-tumorigenesis, anti-virus, and anti-atherogenesis. In this study, we investigated the up-regulation of ethanolic extract of A. paniculata (APE) on the antioxidant defense in rat livers and whether this enhancement protected against carbon tetrachloride (CCl4)-induced liver damage. Male Sprague-Dawley rats were orally administered (i.g.) 0, 0.75, or 2 g/kg/d APE for 5 d. At d 6, rats were sacrificed and liver tissues were removed. Some animals (n=8) were intraperitoneally injected CCl4 (1 mL/kg, 50% in olive oil) and blood was drawn 24 h after CCl4 treatment. The results showed that APE increased hepatic glutathione (GSH) content and superoxide dismutase, GSH peroxidase, and GSH S-transferase activities in a dose-dependent manner (p<0.05). Results of immunoblotting and RT-PCR revealed that rats treated with APE had higher glutamate cysteine ligase catalytic and modifier subunits, heme oxygenase 1, superoxide dismutase 1, and GSH S-transferase Ya and Yb protein and mRNA expression than those of control rats. Moreover, APE increased Nrf2 nuclear translocation and Nrf2 binding to DNA in rat liver. In the presence of CCl4, APE decreased hepatic thiobarbituric acid-reactive substances production and plasma aspartate aminotransferase and alanine aminotransferase activities. These results suggest that APE protection against CCl4 insult is attributed, at least in part, to its up-regulation of antioxidant defense in rat liver