Comparative transcriptomic profiles of Paulownia catalpifolia under different degrees of chilling stress during the seedling stage.

BACKGROUND: Paulownia, an ecologically and economically valuable plant species native to China, is notable for its excellent timber quality and strong adaptability. Among them, Paulownia catalpifolia displays the ability to survive in cold climate, a trait associated with northern China. Yet, the molecular information for its cold-tolerance has not been explored. This study was to investigate the changes in physiological indices and transcript levels of P. catalpifolia following cold exposure, which could provide evidence for revealing whether there were differences in the genetic basis of inducing physiological perturbations between moderate low temperature (MLT) and extreme low temperature (ELT). RESULTS: The detection of physiological indices under diverse degrees of chilling stress showed similar patterns of alteration. Enhanced accumulation of osmoregulatory substances, such as soluble sugar and soluble protein, were more conducive under ELT compared to MLT in P. catalpifolia. Moreover, we observed leaf wilting symptoms distinctly after exposure to ELT for 48 h, while this effect was not obvious after MLT exposure for 48 h. Comparative transcriptomic analysis between MLT and ELT demonstrated 13,688 differentially expressed genes (DEGs), most of them appeared after 12 h and 48 h of treatment. GO and KEGG analyses elucidated prominent enrichment in aromatic-L-amino-acid decarboxylase activity term and carbohydrate metabolism pathways. Therefore, it was speculated that the DEGs involved in the above processes might be related to the difference in the contents of soluble protein and soluble sugar between MLT and ELT. Time series clustering analyses further highlighted several key genes engaged in the 'Glycosyltransferases', 'Galactose metabolism' and 'Starch and sucrose metabolism' pathways as well as the 'tyrosine decarboxylase activity' term. For instance, cellulose synthase-like A (CLSA2/9), raffinose synthase (RafS2), ß-amylase (BAM1) and tyrosine/DOPA decarboxylase (TYDC1/2/5) genes, diverging in their expression trends between MLT and ELT, might significantly affect the soluble sugar and soluble protein abundance within P. catalpifolia. CONCLUSION: Between MLT and ELT treatments, partial overlaps in response pathways of P. catalpifolia were identified, while several genes regulating the accumulation of osmotic adjustment substances had disparate expression patterns. These findings could provide a novel physiological and molecular perspective for P. catalpifolia to adapt to complex low temperature habitats.

Drought Stress Induced Different Response Mechanisms in Three Dendrobium Species under Different Photosynthetic Pathways.

Many Dendrobium species, which hold a high status and value in traditional Chinese medicine, grow on barks and rocks in the wild, often encountering harsh environments and facing droughts. However, the molecular mechanisms underlying the shift in the photosynthetic pathway induced by drought remain unclear. To address this issue, three Dendrobium species with different photosynthetic pathways were selected for sequencing and transcriptome data analysis after drought treatment. The findings included 134.43 GB of sequencing data, with numerous Differentially Expressed Genes (DEGs) exhibiting different response mechanisms under drought stress. Gene Ontology (GO)-KEGG-based enrichment analysis of DEGs revealed that metabolic pathways contributed to drought tolerance and alterations in photosynthetic pathways. Phosphoenolpyruvate Carboxylase (PEPC) was subjected to phylogenetic tree construction, sequence alignment, and domain analysis. Under drought stress, variations were observed in the PEPC gene structure and expression among different Dendrobium species; the upregulation of Dc_gene2609 expression may be caused by dof-miR-384, which resulted in the shift from C3 photosynthesis to CAM, thereby improving drought tolerance in Dendrobium. This study revealed the expression patterns and roles of PEPC genes in enhancing plant drought tolerance and will provide an important basis for in-depth research on Dendrobium's adaptation mechanisms in arid environments.

Detection of Circulating Tumor Cells by Fluorescent Immunohistochemistry in Patients with Esophageal Squamous Cell Carcinoma: Potential Clinical Applications.

BACKGROUND Circulating tumor cells (CTCs) are tumor cells that leave the primary tumor site and enter the bloodstream, where they can spread to other organs; they are very important in the diagnosis, treatment, and prognosis of malignant tumors. However, few studies have investigated CTCs in esophageal squamous cell carcinoma (ESCC). The aim of this study was to investigate the CTCs in blood of ESCC patients and its potential relevance to clinicopathological features and prognosis. MATERIAL AND METHODS CTCs were acquired by a negative enrichment method that used magnetic activated cell sorting (MACSTM). Fluorescent immunohistochemistry (IHC) was used to identify the CTCs. Then, the positive CTC patients with ESCC were analyzed, after which the relationship between CTCs and clinicopathologic features was evaluated. RESULTS In the present study, 62 out of 140 (44.3%) patients with ESCC were positive for CTCs. The positive rate of CTCs was significantly related with stage of ESCC patients (P=0.013). However, there was no relationship between CTC status and age, sex, smoking tumor history, tumor location, differentiation of tumor, lymphatic invasion, or lymph venous invasion (P>0.05). Kaplan-Meier analysis showed that patients positive for CTCs had significantly shorter survival time than patients negative for CTCs. Multivariate analysis demonstrated that stage and CTC status were significant prognostic factors for patients with ESCC. CONCLUSIONS CTCs positivity is an independent prognostic biomarker that indicates a worse prognosis for patients with ESCC.

Photovoltaic performance of bithiazole-bridged dyes-sensitized solar cells employing semiconducting quantum dot CuInS2 as barrier layer material.

In this work, the quantum dot CuInS2 layer was deposited on TiO2 film using successive ionic layer absorption and reaction (SILAR) method, and then two bithiazole-bridged dyes (BTF and BTB) were sensitized on the CuInS2/TiO2 films to form dye/CuInS2/TiO2 photoanodes for DSSCs. It was found that the quantum dots CuInS2 as an energy barrier layer not only could effectively improve open-circuit voltage (Voc) of solar cell, but also increase short-circuit photocurrent (Jsc) compared to the large decrease in Jsc of ZnO as energy barrier layer. The electrochemical impedance spectroscopy (EIS) measurement showed that the CuInS2 formed a barrier layer to suppress the recombination from injection electron to the electrolyte and improve open-circuit voltage. Finally, the open-circuit voltage increased about 22 and 27mV for BTF and BTB-/CuInS2/TiO2-based cells, the overall conversion efficiencies also reached to 7.20% and 6.74%, respectively.

New bithiazole-based sensitizers for efficient and stable dye-sensitized solar cells.

A series of new push-pull organic dyes (BT-I-VI), incorporating electron-withdrawing bithiazole with a thiophene, furan, benzene, or cyano moiety, as π spacer have been synthesized, characterized, and used as the sensitizers for dye-sensitized solar cells (DSSCs). In comparison with the model compound T1, these dyes containing a thiophene moiety between triphenylamine and bithiazole display enhanced spectral responses in the red portion of the solar spectrum. Electrochemical measurement data indicate that the HOMO and LUMO energy levels can be tuned by introducing different π spacers between the bithiazole moiety and cyanoacrylic acid acceptor. The incorporation of bithiazole substituted with two hexyl groups is highly beneficial to prevent close π-π aggregation, thus favorably suppressing charge recombination and intermolecular interaction. The overall conversion efficiencies of DSSCs based on bithiazole dyes are in the range of 3.58 to 7.51 %, in which BT-I-based DSSCs showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 81.1 %, a short-circuit photocurrent density (J(sc)) of 15.69 mA cm(-2), an open-circuit photovoltage (V(oc)) of 778 mV, and a fill factor (ff) of 0.61, which correspond to an overall conversion efficiency of 7.51 % under standard global AM 1.5 solar light conditions. Most importantly, long-term stability of the BT-I-III-based DSSCs with ionic-liquid electrolytes under 1000 h of light soaking was demonstrated and BT-II with a furan moiety exhibited better photovoltaic performance of up to 5.75 % power conversion efficiency.

[Research on optimization system on tissue culture and rapid propagation of Pueraria mirifica].

OBJECTIVE: To study the tissue culture and rapid-proliferation techniques of Pueraria mirifica. METHOD: The tender branch were used as explants and cultivated in different media. The optimum media for inducing buds, proliferation and rooting were selected by adjusting the kinds and doses of plant hormones and special compounds. RESULT: The medium of MS + IBA 0.05 mg L(-1) + BA 0.5 mg L(-1) was suitable for buds inducing and could be used in the first generation cultivation; MS + IBA 0. 02 mg L(-1) + BA 0.2 mg L(-1) and MS +BA 0.1 mg L(-1) were employed by turns in subculture, 25 days propagation coefficient was 3.0; and the medium of 1/2MS + IBA 0.1 mg L(-1) + IAA 0.2 mg L(-1) + C (special compound) 10 mg L(-1) was used for roots inducing, the rooting rate was 76.9%. Rooting plantlets were transplanted in spring and summer; the surviving rate was 81.0%. CONCLUSION: This technique system could be employed for rapid propagation of P. mirifica.