Two ground-state bright solitons in fractional-order spin-orbit-coupled Bose-Einstein condensates

We study two types of bright solitons in zero and non-zero detuning spin-orbit-coupled (SOC) Bose-Einstein condensates in fractional effect by variational and imaginary-time evolution method. The results show that the variation of SOC with fractional kinetic energy operator affects the existence and form of solitons. In particular, we found that SOC strengthγ=1.0could be a transition point. In other words, forγ<1.0andγ⩾1.0, the soliton states and pseudo-spin polarization in non-zero detuning show opposite changes. In addition, moving bright solitons with zero and non-zero detuning are studied.

Single-cell transcriptomic dissection of the cellular and molecular events underlying the triclosan-induced liver fibrosis in mice

BACKGROUND

Triclosan [5-chloro-2-(2,4-dichlorophenoxy) phenol, TCS], a common antimicrobial additive in many personal care and health care products, is frequently detected in human blood and urine. Therefore, it has been considered an emerging and potentially toxic pollutant in recent years. Long-term exposure to TCS has been suggested to exert endocrine disruption effects, and promote liver fibrogenesis and tumorigenesis. This study was aimed at clarifying the underlying cellular and molecular mechanisms of hepatotoxicity effect of TCS at the initiation stage.

METHODS

C57BL/6 mice were exposed to different dosages of TCS for 2 weeks and the organ toxicity was evaluated by various measurements including complete blood count, histological analysis and TCS quantification. Single cell RNA sequencing (scRNA-seq) was then carried out on TCS- or mock-treated mouse livers to delineate the TCS-induced hepatotoxicity. The acquired single-cell transcriptomic data were analyzed from different aspects including differential gene expression, transcription factor (TF) regulatory network, pseudotime trajectory, and cellular communication, to systematically dissect the molecular and cellular events after TCS exposure. To verify the TCS-induced liver fibrosis, the expression levels of key fibrogenic proteins were examined by Western blotting, immunofluorescence, Masson's trichrome and Sirius red staining. In addition, normal hepatocyte cell MIHA and hepatic stellate cell LX-2 were used as in vitro cell models to experimentally validate the effects of TCS by immunological, proteomic and metabolomic technologies.

RESULTS

We established a relatively short term TCS exposure murine model and found the TCS mainly accumulated in the liver. The scRNA-seq performed on the livers of the TCS-treated and control group profiled the gene expressions of > 76,000 cells belonging to 13 major cell types. Among these types, hepatocytes and hepatic stellate cells (HSCs) were significantly increased in TCS-treated group. We found that TCS promoted fibrosis-associated proliferation of hepatocytes, in which Gata2 and Mef2c are the key driving TFs. Our data also suggested that TCS induced the proliferation and activation of HSCs, which was experimentally verified in both liver tissue and cell model. In addition, other changes including the dysfunction and capillarization of endothelial cells, an increase of fibrotic characteristics in B plasma cells, and M2 phenotype-skewing of macrophage cells, were also deduced from the scRNA-seq analysis, and these changes are likely to contribute to the progression of liver fibrosis. Lastly, the key differential ligand-receptor pairs involved in cellular communications were identified and we confirmed the role of GAS6_AXL interaction-mediated cellular communication in promoting liver fibrosis.

CONCLUSIONS

TCS modulates the cellular activities and fates of several specific cell types (including hepatocytes, HSCs, endothelial cells, B cells, Kupffer cells and liver capsular macrophages) in the liver, and regulates the ligand-receptor interactions between these cells, thereby promoting the proliferation and activation of HSCs, leading to liver fibrosis. Overall, we provide the first comprehensive single-cell atlas of mouse livers in response to TCS and delineate the key cellular and molecular processes involved in TCS-induced hepatotoxicity and fibrosis.

Deciphering Nonbioavailable Substructures Improves the Bioavailability of Antidepressants by Serotonin Transporter

Inadequate bioavailability is one of the most critical reasons for the failure of oral drug development. However, the way that substructures affect bioavailability remains largely unknown. Serotonin transporter (SERT) inhibitors are first-line drugs for major depression disorder, and improving their bioavailability may be able to decrease side-effects by reducing daily dose. Thus, it is an excellent model to probe the relationship between substructures and bioavailability. Here, we proposed the concept of "nonbioavailable substructures", referring to substructures that are unfavorable to bioavailability. A machine learning model was developed to identify nonbioavailable substructures based on their molecular properties and shows the accuracy of 83.5%. A more potent SERT inhibitor DH4 was discovered with a bioavailability of 83.28% in rats by replacing the nonbioavailable substructure of approved drug vilazodone. DH4 exhibits promising anti-depression efficacy in animal experiments. The concept of nonbioavailable substructures may open up a new venue for the improvement of drug bioavailability.

Evolution of volatile profile and aroma potential of 'Gold Finger' table grapes during berry ripening

BACKGROUND

'Gold Finger' is a grape cultivar with a finger-like shape and a milk flavor. The process by which its aroma profile evolves during ripening is unclear. Thus, changes in the free and bound volatile compounds present in 'Gold Finger' grapes during ripening were investigated using headspace sampling-solid-phase microextraction-gas chromatography-mass spectroscopy (HS-SPME-GC-MS).

RESULTS

A total of 83 volatile aroma components were identified in the grapes, with aldehydes, esters, acids, and alcohols being the main components. The total aroma compound content exhibited significant differences between the bound and free forms. The total content of bound volatile compounds did not change significantly during fruit development, although the free aroma compound content was significantly higher than the bound content. The total content of free aldehydes, free alcohols, bound norisoprenoids, and ketones gradually increased for up to 70 days after flowering (DAF), while the total free ester, terpene, and acid content decreased. The characteristic aroma compounds of 'Gold Finger' grapes were identified as hexanal, (E)-2-hexenal, and ethyl hexanoate.

CONCLUSIONS

These results give a foundation for the further development of 'Gold Finger' grapes and provide a theoretical basis for the selection and breeding of novel aromatic grape varieties. © 2021 Society of Chemical Industry.

[Endovascular repair of ruptured abdominal aortic aneurysms assisted by double balloon occlusion technique combined with intra-aneurysm fibrin binder injection technique]

Objective: To investigate the long-term efficacy and safety of alternating double balloon occlusion combined with intra-aneurysm injection of human fibrin binder in the endovascular repair of ruptured abdominal aortic aneurysm (rAAA). Methods: The clinical data of 28 patients with rAAA admitted to Department of Vascular Surgery, the Fourth Affiliated Hospital of Guangxi Medical University from January 2015 to December 2019 were retrospectively analyzed. There were 23 males and 5 females, aged (62±5) years (range: 46 to 88 years).The maximum diameter of the tumors was (65.2±10.5) mm (range: 47.3 to 100.5 mm), all of which were subrenal rAAA. The intraoperative EVAR for abdominal aortic aneurysm was successfully performed under the emergency green channel procedure, and this surgery was assisted used the double balloon occlusion technique in aorta of inferior renal and superior renalcombined with intraoperative human fibrin binder injection technique. Observation indexes included: patients with preoperative preparation, operation time, hospitalization days, surgical treatment success rate and the incidence of postoperative complications, and aortic stent form during the follow-up period, the incidence of leakage, branch stents patency rate and infection rates. Results: The preoperative preparation time of 28 patients was (45.5±8.5) minutes (range:20 to 100 minutes). The operation time was (100.0±15.5) minutes (range:85 to 210 minutes), the ICU stay time was (7±2) days(range:1 to 17 days). The length of hospitalization was (13.5±2.5) days(range:5 to 43 days). The success rate of surgical treatment was 92.9% (26/28). Two patients died, 1 case died of postoperative multifocal lacunar cerebral infarction and massive gastrointestinal hemorrhage, and another elderly patient (84 years old) died of massive abdominal fluid due to preoperative abdominal aortic aneurysm rupture, postoperative complicated with significant abdominal compartment syndrome, and secondary multiple organ failure. Balloon occlusion of the upper renal aorta took (13±2)minutes (range:12 to 30 minutes). The intraoperative injection of fibrin adhesive was (14±2) ml(range:6 to 28 ml) in 22 cases. The incidence of major postoperative complications was 57.1% (16/28). Among the 26 patients who survived the surgery, 69.2% (18/26) completed the 3-year follow-up, and the follow-up time was (30±3) months(range:13 to 36 months). During the follow-up, the aortic stent was in good shape without obvious displacement. The incidence of leakage within 6 months after the operation was 10.7% (3/28), and there was no internal leakage in the patients who were followed up for 36 months after the operation. The patency rate of renal artery and iliac artery branch stents was 16/18. The incidence of stent infection was 7.7% (2/26), 1 case occurred at 1 month and another case at 6 months, respectively. All patients recovered after prolonged intensive anti-infection therapy. Conclusions: Under the standard emergency treatment process, the double balloon alternating occlusion technique combined with the intra-aneurysm injection of human fibrin adhesive technique can assist the successful completion of the endovascular repair of rAAA, effectively improve the success rate of treatment for patients, and reduce the incidence of postoperative leakage and serious complications. The mid-term and long-term results of EVAR for rAAA are good, safe and reliable.

Supersensitive and reusable perovskite nanocomposite fiber paper for time-resolved single-droplet detection

Traditional test paper cannot be reusable and needs much sample solution. In this study, a reusable perovskite nanocomposite fiber paper consisting of CsPbBr₃ quantum dots in-situ growing in the solid polymer fibers with high concentration is fabricated via microwave and electrospinning methods. RhoB is used as the sample solution because it is a hazardous matter but often occurs in printing and dyeing wastewater or appears in food as additives, and traditional detection system generally requires much sample solution (>1 ml) to concentrate for higher concentrations due to the low detection sensitivity. Just need a droplet of sample solution (<25 μl) can this perovskite fiber paper achieve 0.01 ppm of supersensitive detection, which is superior to a majority of reported detection limit. Different from traditional detection based on luminescence intensity, this detection is a new kind of time-resolved method, so that it gets rid of complex and time-consuming calibration (>1 h) usually in traditional detection, and this time-resolved detection can be achieved within ~3 min. Moreover, this perovskite fiber paper is endowed with recyclable property without losing advantages of supersensitive detection (~0.01 ppm), rapid measuring speed (<3 min), and tiny dosage (<25 μl), which is another advantage than conventional detection systems.

Computational Fragment-Based Design Facilitates Discovery of Potent and Selective Monoamine Oxidase-B (MAO-B) Inhibitor

Parkinson's disease (PD) is one of the most common age-related neurodegenerative diseases. Inhibition of monoamine oxidase-B (MAO-B), which is mainly found in the glial cells of the brain, may lead to an elevated level of dopamine (DA) in patients. MAO-B inhibitors have been used extensively for patients with PD. However, the discovery of the selective MAO-B inhibitor is still a challenge. In this study, a computational strategy was designed for the rapid discovery of selective MAO-B inhibitors. A series of (S)-2-(benzylamino)propanamide derivatives were designed. In vitro biological evaluations revealed that (S)-1-(4-((3-fluorobenzyl)oxy)benzyl)azetidine-2-carboxamide (C3) was more potent and selective than safinamide, a promising drug for regulating MAO-B. Further studies revealed that the selectivity mechanism of C3 was due to the steric clash caused by the residue difference of Phe208 (MAO-A) and Ile199 (MAO-B). Animal studies showed that compound C3 could inhibit cerebral MAO-B activity and alleviate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neuronal loss.

Streamlined MRM method transfer between instruments assisted with HRMS matching and retention-time prediction

Multiple reaction monitoring (MRM) mode using liquid-chromatography tandem mass spectrometry (e.g., LC-QqQ-MS/MS) has been extensively employed in the small molecule analysis with trace levels in complex samples owing to its high sensitivity. However, most of the reported MRM methods are developed using authentic standards, which are often costly yet not readily available. To address this question, a practical platform for the MRM method transfer between different LC-QqQ-MS/MS instruments, assisted by the high-resolution mass spectrometry (LC-HRMS) and retention time (RT) prediction, has been developed in this study. The reported platform can take advantage of both the high sensitivity of LC-MRM method and ion transition pairs from the previous publications. LC-HRMS can provide the accurate mass measurement of the compounds, though high-quality MS/MS fragments are usually difficult to obtain for chemicals at trace levels. Retention time matching and peaks matching between both instrumental platforms rule out isobaric candidates. With an additional retention time prediction filter from quantitative structure retention relationship (QSRR) model based on random forest feature selection (Pearson r² = 0.63), identification of small molecules is achieved at a high confidence level without using authentic standards. The developed platform has been validated with robustness by examining spiked environmental chemicals in sludge water samples, biological urine, and cell extracts.

Cluster bagging promotes melatonin biosynthesis in the berry skins of Vitis vinifera cv. Cabernet Sauvignon and Carignan during development and ripening

Melatonin, a tryptophan derivative, is an important functional component in grape berries. We investigated the effect of cluster bagging on melatonin biosynthesis in the berries of two wine grape cultivars, Cabernet Sauvignon and Carignan, during fruit development and ripening. Cluster bagging delayed fruit coloring and ripening, and bag-treated berries of both grape cultivars synthesized more melatonin and most of the precursor compounds including L-tryptophan, N-acetylserotonin, tryptamine, and serotonin compared to those exposed to light (control) conditions. Interestingly, 5-methoxytryptamine was only detected in the berries of Carignan and not of Cabernet Sauvignon, both in the cluster bagging and control groups. In addition, melatonin and most of its precursors, decreased after veraison. VvSNAT1 and VvT5H expression levels were positively correlated with melatonin content. Our findings suggested that melatonin synthesis pathways differ among grape cultivars, and that VvSNAT1 and VvT5H may show key regulatory roles in the melatonin synthesis of grape berries.

[Application of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa]

Objective: To discuss the feasibility, effect and safety of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa. Methods: The clinical data of 40 patients with pernicious placenta previa complicated with placenta accreta from January 2015 to August 2017 in Liuzhou workers hospital were analyzed retrospectively. The study group included 20 cases, which were operated in the way of cesarean section combined lower abdominal aorta balloon occlusion technique by ultrasound guiding, while the control group also included 20 cases, which were operated in the way of the conventional cesarean section without balloon occlusion technique. The bleeding amount, blood transfusion volume, operative total time, hysterectomy and complications of the two groups were compared. Results: The bleeding amount and blood transfusion volume in study group were(850±100)ml and (400±50)ml, which were lower than that of the control group[(2 500±230)ml and (1 500±100)ml], the difference was statistically significant(t=35.624, 16.523, all P<0.05). In addition, the hysterectomy rate in study group was 5%, which was lower than that in the control group(30%), the difference was statistically significant(χ²=8.672, P<0.05). And the total time of operation was (2.0±0.5)h in the study group, which was shorter than that in the control group[(3.5±0.4)h]. The difference was statistically significant(t=11.362, P<0.05). No postoperative complications took place in the study group.The blood pressure, heart rate and blood oxygen fluctuated significantly, and the postoperative renal function was significantly reduced in the control group. Conclusions: The lower abdominal aorta balloon occlusion technique by ultrasound guiding during a caesarean section in patients with pernicious placenta previa can effectively control the bleeding during operation, and preserve reproductive function to the utmost degree.Therefore, the technique is safe, feasible, convenient and cheaper, and worthy of being widely applied in clinic.

The pretreatment thrombocytosis may predict prognosis of patients with colorectal cancer: a systematic review and meta-analysis

AIM

Recently, several studies have reported that thrombocytosis may be associated with the poor prognosis of colorectal cancer (CRC). Nevertheless, their conclusions were still controversial. Results & methodology: We searched PubMed, Embase, Cochrane Library and Web of Science up to April 2016. A total of 30 studies including 9129 patients were included in this meta-analysis. Thrombocytosis had a close relationship with the poor overall survival of CRC compared with normal platelet counts, with the pooled hazard ratios being 1.89 (95% CI: 1.45-2.47; p < 0.00001) and 1.83 (95% CI: 1.33-2.53; p = 0.0002), with univariate and multivariate analyses, respectively.

DISCUSSION & CONCLUSION

This meta-analysis indicated that thrombocytosis may be a cost-effective and noninvasive indicator for poor prognosis of patients with CRC, especially for overall survival.

Lewis Acid Catalyzed Friedel-Crafts Alkylation of Alkenes with Trifluoropyruvates

A Friedel-Crafts alkylation reaction of styrenes with trifluoropyruvates has been developed, which delivered allylic alcohols in excellent yields (up to 98%) using the Ni(ClO4)2·6H2O/bipyridine complex as a catalyst. The asymmetric reaction was catalyzed by the chiral Cu(OTf)2/bisoxazoline complex to afford the corresponding chiral allylic alcohols bearing trifluoromethylated quaternary stereogenic centers in moderate enantioselectivities (up to 75% ee).

Palladium-catalyzed dearomative arylalkynylation of indoles

A palladium-catalyzed indole dearomative bisfunctionalization via a domino arylation/alkynylation sequence to achieve tetracyclic indolines bearing vicinal tertiary and quaternary stereocenters.

The ameliorative effects of exogenous melatonin on grape cuttings under water-deficient stress: antioxidant metabolites, leaf anatomy, and chloroplast morphology

Grapes are an important economic crop and are widely cultivated around the world. Most grapes are grown in arid or semi-arid regions, and droughts take a heavy toll in grape and wine production areas. Developing effective drought-resistant cultivation measures is a priority for viticulture. Melatonin, an indoleamine, mediates many physiological processes in plants. Herein, we examined whether exogenously applied melatonin could improve the resistance of wine grape seedlings grown from cuttings to polyethylene glycol-induced water-deficient stress. The application of 10% polyethylene glycol (PEG) markedly inhibited the growth of cuttings, caused oxidative stress and damage from H2 O2 and O2∙-, and reduced the potential efficiency of Photosystem II and the amount of chlorophyll. Application of melatonin partially alleviated the oxidative injury to cuttings, slowed the decline in the potential efficiency of Photosystem II, and limited the effects on leaf thickness, spongy tissue, and stoma size after application of PEG. Melatonin treatment also helped preserve the internal lamellar system of chloroplasts and alleviated the ultrastructural damage induced by drought stress. This ameliorating effect may be ascribed to the enhanced activity of antioxidant enzymes, increased levels of nonenzymatic antioxidants, and increased amount of osmoprotectants (free proline). We conclude that the application of melatonin to wine grapes is effective in reducing drought stress.

A pathogenesis related protein, VpPR-10.1, from Vitis pseudoreticulata: an insight of its mode of antifungal activity

Previously, VpPR-10.1 was isolated and characterized from a cDNA library of a fungus-resistant accession of Chinese wild grape (Vitis pseudoreticulata). We found that expression of VpPR-10.1 is affected by the fungal pathogen Erysiphe necator. To investigate the biochemical basis of the nuclease activity of VpPR-10.1 and its role in antifungal resistance, we generated recombinant VpPR-10.1 as well as site-directed mutations targeting three conserved amino acid residues among plant PR-10 s: Lys55, Glu149, and Tyr151. We showed that wild-type recombinant VpPR-10.1 exhibits both RNase and DNase activities. Mutant VpPR10.1-Y151H essentially retained all these activities. In contrast, VpPR10.1-K55N, where Lys55 in the P-loop region is mutated to Asn, and VpPR10.1-E149G, where Glu149 is mutated to Gly, lost their nuclease activity, indicating that both residues play a critical role in catalyzing RNA and DNA degradation. Furthermore, VpPR10.1 and VpPR10.1-Y151H inhibited the growth of the cultured fungal pathogen Alternaria alternate. Through transient expression in grapevine, we also demonstrated that VpPR10.1-K55N and VpPR10.1-E149G compromised resistance to E. necator. Finally, we further found that VpPR-10.1 can lead to programmed cell death and DNA degradation when incubated with tobacco BY-2 suspension cells. We show here that Lys55 and Glu149, but not Tyr151, are required for the RNase, DNase and antifungal activities of VpPR-10.1. The strong correlation between the level of VpPR-10.1 nuclease activity and its antifungal property indicates that the former is the biochemical basis for the latter. Taken together, our experiments revealed that VpPR-10.1 is critical in mediating fungal resistance in grape, potentially playing a dual role by degrading pathogen RNA and inducing programmed death of host cells.

Isolation and characterization of two VpYABBY genes from wild Chinese Vitis pseudoreticulata

The establishment of abaxial-adaxial polarity is an important feature of the development of lateral organs in plants. Members of the YABBY gene family may be specific to seed-plant-specific transcriptional regulators that play critical roles in promoting abaxial cell fate in the model eudicot, Arabidopsis thaliana. However, recent study has shown that the roles of YABBY genes are not conserved in the development of angiosperms. The establishment of abaxial-adaxial polarity has not been studied in perennial fruit crops. Grapes are an important fruit crop in many regions of the world. Investigating YABBY genes in grapevines should help us to discover more about the key genetic and molecular pathways in grapevine development. To understand the characterization of YABBY genes in grapevines, two YABBY genes, VpYABBY1 (GenBank accession No. KC139089) and VpYABBY2 (GenBank accession No. KC139090), were isolated from the wild Chinese species Vitis pseudoreticulata. Both of these encode YABBY proteins. Sequence characterization and phylogenetic analyses show that VpYABBY1 is group classified into the FIL subfamily while VpYABBY2 is a member of the YAB2 subfamily of Arabidopsis thaliana. Subcellular localization analysis indicates that VpYABBY1 and VpYABBY2 proteins are localized in the nucleus. Tissue specific expressional analysis reveals that VpYABBY1 is expressed strongly in young leaves of grape but only weakly in the mature leaves. Meanwhile, VpYABBY2 is expressed in grape stems, flowers, tendrils, and leaves. Transgenic Arabidopsis plants ectopically expressing VpYABBY1 caused the partial abaxialization of the adaxial epidermises of leaves, behaving similarly to those over-expressing FIL or YAB3 with abaxialized lateral organs. By contrast, ectopic expression of VpYABBY2 in Arabidopsis did not cause any alteration in the adaxial-abaxial polarity. Sequence characterization and phylogenetic analysis revealed that VpYABBY1 and VpYABBY2 are group-classified into two different subfamilies. They have diverged functionally in the control of lateral organ development. VpYABBY1 may have a function in leaf development, while VpYABBY2 may play a specific role in carpel development and grape berry morphogenesis. It is further possible that during the evolution of different species, YABBY family members have preserved different expression regulatory systems and functions.

Hydrolysates of lignocellulosic materials for biohydrogen production

Lignocellulosic materials are commonly used in bio-H₂ production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-H₂ production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to H₂ by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-H₂ production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized. [BMB Reports 2013; 46(5): 244-251]

Cloning and expression of thermo-alkali-stable laccase of Bacillus licheniformis in Pichia pastoris and its characterization

A thermo-alkali-stable laccase gene from Bacillus licheniformis was cloned and expressed in Pichia pastoris. The recombinant laccase was secreted into the culture medium with a maximum activity of 227.9 U/L. The purified laccase is a monomeric glycoprotein, and its molecular weight was estimated to be 65 kDa on SDS-PAGE after deglycosylation. Optimal enzyme activity was observed at pH 6.2 and 70°C with syringaldazine as substrate. The recombinant laccase was highly stable in the pH range 7-9 after 10 days at 30°C. The enzyme displayed remarkable thermostability at 50-70°C, with a half-life of inactivation at 70°C of 6.9 h. It also exhibited high tolerance to NaCl and organic solvents like the native spore laccase. The purified laccase could rapidly decolorize reactive blue 19, reactive black 5 and indigo carmine in the presence of acetosyringone. More than 93% of the tested dyes were decolorized in 4 h at pH 9.0.

Interplay between periodicity and nonlinearity of indirect excitons in coupled quantum wells

Inspired by a recent experiment of localization-delocalization transition (LDT) of indirect excitons in lateral electrostatic lattices (Remeika et al 2009 Phys. Rev. Lett. 102 186803), we theoretically investigate the interplay between periodic potential and nonlinear interactions of indirect excitons in coupled quantum wells. It is shown that the model involving both attractive two-body and repulsive three-body interactions can lead to a natural account for the LDT of excitons across the lattice when reducing lattice amplitude or increasing particle density. In addition, the observations that the smooth component of the photoluminescent energy increases with increasing exciton density and that the exciton interaction energy is close to the lattice amplitude at the transition are also qualitatively explained. Our model provides an alternative way of understanding the underlying physics of the exciton dynamics in lattice potential wells.

Co-expression of VpROMT gene from Chinese wild Vitis pseudoreticulata with VpSTS in tobacco plants and its effects on the accumulation of pterostilbene

Plant secondary metabolites, such as stilbenes, have fungicidal potential and have been found in several plant species. Stilbenes in grapevine, such as resveratrol and pterostilbene, have recently attracted much attention, they are not only helping the plant to fight against pathogen attack, but they are also being widely used as ingredients of fungicide, anti-inflammatory drugs, antioxidant, and anti-infective agents. However, resveratrol O-methyltransferase gene, related with the synthesis of pterostilbene from resveratrol, has not been characterized effectively from Chinese wild Vitis pseudoreticulata. In this study, a candidate of resveratrol O-methyltransferase gene designated as VpROMT was isolated from a powdery mildew-resistant Chinese wild V. pseudoreticulata 'Baihe-35-1', and characterization studies were performed. Expression studies showed that VpROMT was predominantly expressed in developing roots yet not found in the leaves, stems, nor tendrils when the plants are not challenged. Results of qRT-PCR showed that VpROMT was rapidly induced by Erysiphe necator in V. pseudoreticulata and by methyl-jasmonate, UV-irradiation in suspension culture cells of Vitis romanetii. The expression level varies in different tissues of grapevine, which MeJA and UV-C treatment significantly upregulated the expression of VpROMT gene while UV-B treatment failed to. Co-expression of VpROMT and grapevine stilbene synthase (VpSTS) gene leads to the accumulation of pterostilbene in leaves of tobacco (Nicotiana tabacum) indicating that VpROMT was able to catalyze the biosynthesis of pterostilbene from resveratrol in over-expression transgenic tobacco plants.

[Genetic transformation of autotetraploid Isatis indigotica fort. induced by Ri T-DNA and plant regeneration]

OBJECTIVE

To establish an effective system for genetic transformation of autotetraploid Isatis indigotica by Agrobacterium rhizogenes.

METHOD

Agrobacterium rhizogenes strains R1601, ATCC15834 and A4 were employed to induce hairy roots from autotetraploid Isatis indigotica, and the obtained hairy roots were developed into regenerated plants on solid MS media with different Kinds of plant growth regulators.

RESULT

Root induction differed obviously. By three Agrobacterium strains. Hairy roots grew rapidly on solid MS medium without plant growth regulators and showed the typical hairy root phenotype: profuse branching, high density of root hairs and plagiotropism. And the transformation of Ri T-DNA was confirmed by opine analysis. The biomass of hairy roots increased nearly 35 times regulator-free MS after suspended in plant growth two weeks. On solid MS medium with BA, adventitious buds were differentiated directly from hairy roots without callus formation. All of the adventitious buds were rooted on root induction medium and developed into regenerated plants. Opine analysis indicated the integration of Ri T-DNA in the transformed plants.

CONCLUSION

Agrobacterium rhizogene can induce hairy roots from autotetraploid Isatis indigotica, and the obtained hairy roots can develop into regenerated plants.