Flowering, the floral transition from vegetative growth to reproductive growth, is induced by diverse endogenous and exogenous cues, such as photoperiod, temperature, hormones and age. Precise flowering time is critical to plant growth and evolution of species. The numerous renewal molecular and genetic results have revealed five flowering time pathways, including classical photoperiod pathway, vernalization pathway, autonomous pathway, gibberellins (GA) pathway and newly identified age pathway. These pathways take on relatively independent role, and involve extensive crosstalks and feedback loops. This review describes the complicated regulatory network of this floral transition to understand the molecular mechanism of flowering and provide references for further research in more plants.
Arabidopsis ; physiology ; Flowers ; physiology ; Gene Expression Regulation, Plant ; Gene Regulatory Networks

Objective To investigate the bacteriostatic effect of starch-based alkyl poly glycoside(APG).Methods The nutrient broth dilution method was used to investigate the inhibiting effect of C8-10,C12 and pilot product C12 APG to the E.coli and Staphylococcus aureus.Results Determination of antibacterial fluid absorption was performed after 24 h-reaction.The MIC of C12,pilot product C12 and C8-10 were 0.03125,0.25 and 0.0156 g/ml for the E.coli;and were 0.062 5,0.25 and 0.062 5 g/ml for Staphylococcus aureus.Based on bacterial culture counts,at the APG concentration of MIC or higher than the MIC,the inhibitory rate of bacteria was more than 99%,the bacteriostatic effect was accorded with the absorbance.Conclusion Starch-based APG may have some antibacterial effects.

OBJECTIVE：To observe effect of L-NAME on apoptosis in the gerbil hippocampus after recirculation following ischemia.METHOD：Bilateral occlusion of common carotid arteries and TUNEL stain methods in gerbitil hippocampal tissue slice were used.RESULTS：L-NAME inhibited apoptosis in the CA1 subfield.CONCLUSION:Endogenous NO mediated apoptosis is inhibited by the L-NAME.

Objective To explore the effects of neuronal apoptosis in the hippocampal CA 1 region by the selective nitric oxide synthase(NOS) inhibitor, 7 nitroindazole (7 NI).Methods 72 postnatal 7 day old Wistar rats were randomly divided into 3 groups.(1)Sham operation group:12 rats were cut in their neck centre without ligature in common carotid artery;(2)Obersevertion group(7 NI group):the abdominal cavity of 30 rats were injected intraperitoneally into 7 NI (25 mg/kg) after anoxic ischemic damaged models were made;(3)The control group(the normal saline):30 rats were injected intraperitoneally into the normal saline the same volume after HIBD.The sham operative group was later than the operative one.The rats in the observation group and the control one by killed later,they were cut heads and brains in 48h.and were detected by HE and TUNEL stainning,the numbers of cerebral apoptosis were detected under the lightmicroscope.Results Typal apoptotic cells in the hippocampal CA 1 region in the control group were detected by HE stainning. They showed cell pyknosis,cytoplasm deep stain,nucleus concentration,fragment,karyoplasm unclear,apoptosis corpuscle was formed;in 7 NI group the above apoptosis decresed significantly;There was significant difference between Group 2 and Group 3(TUNEL positive apoptotic cells in Group 2)( P

The purpose of the present work is to observe cGMP positive cells after cerebral ischemia-reperfusion in the gerbil hip-pocampus. Immunofluorescent methods were used in gerbil hippocampal tissue slices. The results showed that after cerebral is-chemia cGMP synthesis in the CAi-a subfields was increased, cGMP positive cells were distributed mainly in CA1 subfield. Mostof cGMP positive cells were astrocytes. The number of small round cGMP positive cells were increased after recirculation follow-ing ischemia in the dentate gyrus. These results indicate that after cerebral ischemia cGMP synthesis was increased in the CA1-asubfield, It is possible that astrocytes play an important role in the regulation of metabolism in the early stage after ischemia-reperfusion.

Glycosyltransferases (GTs) catalyze the transfer of a sugar residue of an activated sugar donor to an acceptor molecule. Many families 1 GTs utilize an uridine diphosphate (UDP) activated sugar as donor in the glycosylation reaction, and most of these belong to a group of GTs referred to as the UGTs. The relationship between the degree of amino acid sequence identity and substrate specificity of the plant UGTs is highly complicated, and the prediction of substrate specificity based on phylogenetic analyses need to be improved by more biochemical characterization. This review summarizes the three dimensional structures of plant UGTs published in the Protein Data Bank (PDB), including the detailed substrate interactions with the sugar and receptor binding pockets and mutational analyses of some critical amino acids. It will be helpful for biochemical characterization the substrate specificity of the individual UGT, and lay the foundation for the enzymatic and genetic manipulation of plant UGTs in the future.
Amino Acid Sequence ; Glycosylation ; Glycosyltransferases ; chemistry ; Phylogeny ; Plant Proteins ; chemistry ; Plants ; enzymology ; Protein Structure, Tertiary ; Substrate Specificity ; Uridine Diphosphate ; chemistry

Objective To evaluate therapeutic effects of simvastatin on serum expressions of cytokines and synovial tissue aspartic protease-3 (Caspase-3) in collagen induced arthritis (CIA) in rats, and the mechanism thereof. Methods The rat model of CIA was established by injecting bovine Ⅱ collagen. Sixteen model rats were randomly divided into two groups:CIA model group (sterile water 5 mL·kg-1·d-1 by gavage) and simvastatin group (2.0 mg·kg-1·d-1 by gavage). Seven normal rats were included in control group (sterile water 5 mL·kg-1·d-1 by gavage). The arthritis index (AI) and hind paw vol-umes were recorded once a week. The serum levels of cytokine, tumor necrosis factor (TNF)-αand interleukin (IL)-6 were measured by ELISA 42 days after the initial immunization. The expression of Caspase-3 in ankle synovial tissue was detect-ed by immunohistochemical method, and pathological results of HE staining in rat ankle were compared between three groups. Results Values of AI were decreased on the 24-d of the initial immunization in simvastatin group and CIA model group, which was significantly decreased on the 35-d of the initial immunization in simvastatin group than that of CIA model group (P＜0.05). The values of hind paw volumes were decreased on the 14-d of the initial immunization in simvastatin group and CIA model group, which was still significantly higher than those of control group (P＜0.05). The values of hind paw volumes were decreased on the 35-d and 42-d of the initial immunization in simvastatin group than those of CIA model group (P＜0.05). The serum levels of TNF-αand IL-6 on the 42-d of the initial immunization were significantly lower in simvastatin group than those of CIA model group, but which were significantly higher than those of control group ( P＜0.05). There were more synovial hyperplasia in simvastatin group than those of CIA model group. Only a small amount of inflamma-tory cell infiltration was found in simvastatin group. The expression of Caspase-3 was significantly higher in simvastatin group than that of CIA model group. Conclusion Simvastatin can significantly inhibit the serum levels of TNF-αand IL-6 in CIA model rats, and can up-regulate the expression of Caspase-3 in ankle of model rats.

AIM: To investigate the effect of Ginkgo biloba extrac (GBE) on cerebral ischemia during early stage of subarachnoid hemorrhage (SAH). METHODS: Noncraniotomy models of SAH in Wistar rats were used and animals were divided into sham-operated group, SAH group and SAH+GBE group. Dynamic change of regional cerebral blood flow (rCBF) was detected. Brain endothelin-1(ET-1) and calcium contents were also determined at different time point during 24 hours after the operation. Pathological change of neurons of hippocampus CA1 region was observed. RESULTS: In SAH group, rCBF decreased immediately and persistently after induction of SAH. Values of brain ET-1 content and calcium content at 1 hour, 6 hours and 24 hours were significantly higher than those in sham-operated group. Neurons of hippocampus CA1 region were damaged severely 3 days after onset of SAH. Above abnormal changes in SAH+GBE group were much slighter than those in SAH group. CONCLUSION: GBE may relieve cerebral ischemic damage after SAH.

AIM: To investigate the changes of somatosensory evoked potential(SEP), nitric oxide (NO) levels both in serum and in brain tissue after subarachnoid hemorrhage(SAH) and the influence of Ginkgo biloba extract(GBE) on them. METHODS: Wistar rats were divided into sham-operated group, pure SAH group and GBE-treated group. Dynamic changes of regional cerebral blood flow( rCBF),SEP, and NO levels both in serum and in brain tissue were detected within 24 hours after operation. RESULTS: In pure SAH group, rCBF decreased immediately after operation, with no tendency to recover within 24 hours. Latency of SEP delayed progressively from 1 hour to 24 hours after SAH.NO levels in serum and in brain tissue decreased and increased respectively from 1 hour to 24 hours after SAH. GBE effectively antagonized the changes of above parameters. CONCLUSION: SEP is useful in the judgement of cerebral ischemic damage after SAH. Decrease of serum NO and increase of brain NO are important factors leading to cerebral vasospasm and neural damage respectively after SAH. GBE relieves cerebral ischemic damage by reversing the pathological alterations of NO.

AIM: To investigate the pathological feature of neuron in the process of lymphostatic cerebro dema.METHODS: The model of lyphostatic cerebro edema was established by occluding and removing both the shallow and deep cervical lymph nodes in rats. The tissues of their brains were studied at different times after the operation, under light-microscope (HE stain and TUNEL stain) and electron-microscope.RESULTS: Cerebroedema appeared 2 days after the blockage of cervical lymphatic. Apoptosis and necrosis of neuron were observed in cerebral cortical of parietal lobus and hippocampal CA1 sector mainly. The alterations above were most noticeable at fifths day after the blockage. CONCLUSION: The blockage of the drainage of the cerebral lymphatic can lead to lymphastatic cerebroedema. Neuronal apoptosis and necrosis was the main pathological feature in the brain.