An inner-filter-effect based ratiometric fluorescent sensor for the detection of uranyl ions in real samples.

In this work, a ratiometric fluorescence system was designed for the detection of trace UO22+ in water based on the inner filter effect (IFE) between gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs). IFE-induced fluorescence quenching was achieved due to the enhanced complementary overlap between the absorption spectra of AuNPs and the emission spectrum of AuNCs after the addition of UO22+. Blue carbon dots (B-CDs) were added to serve as reference fluorophores to expand the color tonality and make human eye recognition easier. The ratiometric fluorescent sensor demonstrated a unique fluorescence color change from red to blue when different doses of UO22+ were added, with a detection limit of 8.4 nM. Furthermore, the ratiometric fluorescent sensor was effectively used for UO22+ determination in real-world water samples, with acceptable recoveries.

Arabidopsis galacturonosyltransferase (GAUT) 13 and GAUT14 have redundant functions in pollen tube growth.

Cell wall biosynthesis is indispensable for pollen tube growth. Despite its importance to sexual reproduction, the molecular mechanisms of pollen tube wall biosynthesis remain poorly understood. Here, we report functional characterization of two putative Arabidopsis galacturonosyltransferase genes, GAUT13 and GAUT14, which are essential for pollen tube growth. GAUT13 and GAUT14 encode the proteins that share a high amino acid sequence identity and are located in the Golgi apparatus. The T-DNA insertion mutants, gaut13 and gaut14, did not exhibit any observable defects, but the gaut13 gaut14 double mutants were defective in pollen tube growth; 35.2-37.3% pollen tubes in the heterozygous double mutants were swollen and defective in elongation. The outer layer of the cell wall did not appear distinctly fibrillar in the double mutant pollen tubes. Furthermore, distribution of homogalacturonan labeled with JIM5 and JIM7 in the double mutant pollen tube wall was significantly altered compared to wild-type. Our results suggest that GAUT13 and GAUT14 function redundantly in pollen tube growth, possibly through participation in pectin biosynthesis of the pollen tube wall.

[Effects of wounding on jasmonic acid distribution in vicia faba leaves].

Higher plants have to cope with environmental stimulus such as wounding. Jasmonic acid (JA) is an essential long-distance signaling compound. There is rare information about JA cellular and subcellular localization by now. In this work, using the immuno-fluorescence and immuno-gold electron microscopy, distributions of JA were determined in different cells of Vicia faba leaf. It showed that JA existed in the epidermal cells, mesophyll cells and guard cells, mainly localized in the cytosol and chloroplast of mesophyll cells, cell wall of epidermal cells, and cytosol, cell wall, chloroplast and nucleus of guard cells. Wounding increased JA accumulation in the apoplast and guard cells. Our results suggest that JA plays an important role as a signal in the defense response and involves in regulation of the stomatal movement in response to wounding stress.

[Effects of radix salviae miltiorrhiae, radix aconiti lateralis preparata and rhizoma anemarrhena on nitric oxide systems of endotoxemia mice].

OBJECTIVE: To investigate the effects of Radix Salviae Miltiorrhiae, Radix Aconiti Lateralis Preparata and Rhizoma Anemarrhena on nitric oxide (NO) system of heart, liver, intestine, lung, kidney and serum in mice with endotoxemia, and to explore the potential molecular mechanism of the three kinds of traditional Chinese drugs. METHODS: Model mice of endotoxemia were established by intraperitoneally injected with E. coli. endotoxin at the dose of 6 mg/kg. The levels of NO, nitric oxide synthase ( NOS) and superoxide dismutase ( SOD) in heart, liver, intestine, lung, kidney and serum of mice were measured at the points after injection for 4 hours, 8 hours and 24 hours, respectively. RESULTS: (1) Radix Salviae Miltiorrhiae could significantly increase the contents of constitutive nitric oxide synthase (cNOS) and SOD in the above tissues and serum, while decrease the content of inducible nitric oxide synthase (iNOS). (2) As compared with the model group, Radix Aconiti Lateralis could significantly decrease the contents of iNOS and NO, increase content of SOD in heart, lung and kidney tissues. (3) N.-Nitro-L-arginine (L-NNA) significantly decreased the content of iNOS, NO and SOD in all above tissues and serum, and also decreased the content of cNOS in lung and kidney tissues and serum. (4) Rhizoma Anemarrhenae could significantly increase the concentrations of iNOS and NO and decrease content of SOD in liver, lung and kidney tissues than those in the model group. CONCLUSION: Radix Salviae Miltiorrhiae and Radix Aconiti Lateralis have a protective effect on the endotoxemia mice by suppressing the content of iNOS to reduce the production of NO induced by iNOS. At the same time, Radix Salviae Miltiorrhiae can improve the mice symptoms by increasing the beneficial NO through the increasing production of cNOS. Rhizoma Anemarrhenae can aggravate the injury of endotoxemia mice by increasing the production of NO due to producing large numbers of iNOS. L-NNA, non-selective inhibitor of NOS, aggravates damage of tissues and increases mortality, though it can reduce the increase of iNOS and NO induced by lipopolysaccharide.

Opposite patterns in the annual distribution and time-course of endogenous abscisic acid and indole-3-acetic acid in relation to the periodicity of cambial activity in Eucommia ulmoides Oliv.

The seasonal change of free abscisic acid (ABA) and indole-3-acetic acid (IAA) and their relationship with the cambial activity in Eucommia ulmoides trees were investigated by ABA and IAA immunolocalization using primary polyclonal and rhodamine-red fluorescing secondary antibodies, ABA and IAA quantification using high performance liquid chromatography (HPLC), and systematic monitoring of vascular cell layers production. ABA and IAA clearly displayed opposite annual distribution patterns. In the active period (AP), both immunolocalization and HPLC detected an abrupt decrease of ABA, reaching its lowest level in the summer. During dormancy, ABA started increasing in the first quiescence (Q1) (autumn), peaked in the rest (winter), and gradually decreased from the onset of the second quiescence (Q2) (the end of winter). IAA showed a reverse pattern to that of ABA: it sharply increased in AP, but noticeably decreased from the commencement of Q1. Longitudinally, the ABA distribution increased apico-basally, contrasting with IAA. Laterally, most of the ABA was located in mature vascular tissues, whereas the IAA essentially occurred in the cambial region. The concomitant IAA-ABA distribution and seasonal changes in vascular tissues greatly correlated with xylem and phloem cell production, and late wood differentiation and maturation. Interestingly, the application of exogenous ABA to quiescent E. ulmoides branches, in a water-culture system, inhibited external IAA action on cambial activity reactivation. These results suggest that, in E. ulmoides, ABA and IAA might probably interact in the cambial region. The annual cambial activity could be influenced by an IAA:ABA ratio; and ABA might play a key role in vascular cambium dormancy in higher plants. The relationship between hormonal changes and the (particular) annual life cycle of E. ulmoides is also discussed.

[New targets of anticancer drugs and their pathways].

This article reviews recent advances in apoptosis on the pathway inducing cancer cell to death, including Bcl-2 family pathway, NF-kappa B pathway, P13K/Akt pathway, Rb gene and p53 gene, especially the targets of anticancer drug in these pathways. It could be useful for the anticancer drug design and estimate. Furthermore, those cancer/testis antigen gene products are potential targets for antigen-specific immunotherapy of carcinoma.