Salisediminibacterium halotolerans gen. nov., sp. nov., a halophilic bacterium from soda lake sediment.

An orange-pigmented, Gram-reaction-positive, non-spore-forming, halophilic, alkali-tolerant rod, designated strain halo-2(T), was isolated from sediment of Xiarinaoer soda lake, in China's Inner Mongolia Autonomous Region. Strain halo-2(T) grew in a complex medium with 3-30 % (w/v) NaCl and at pH 5-10. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the major respiratory isoprenoid quinone was MK-7. The predominant cellular fatty acids were anteiso-C(15 : 0) (43.6 %), anteiso-C(17 : 0) (14.8 %) and iso-C(15 : 0) (6.8 %) and the polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content of the novel strain was 48.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain halo-2(T) was most closely related to Bacillus agaradhaerens DSM 8721(T) (93.9 % sequence similarity). However, strain halo-2(T) could be clearly differentiated from its closest phylogenetic relatives on the basis of several phenotypic, genotypic and chemotaxonomic characteristics. Strain halo-2(T) therefore represents a novel species in a new genus for which the name Salisediminibacterium halotolerans gen. nov., sp. nov. is proposed. The type strain of the type species is halo-2(T) (= CGMCC 1.7654(T) = NBRC 104935(T)).

Engineering Lignin Nanomicroparticles for the Antiphotolysis and Controlled Release of the Plant Growth Regulator Abscisic Acid.

Lignin is the most abundant aromatic biopolymer in nature and is a major byproduct from the paper industry. The unlocking of lignin's potential for high-value applications has gained increasing attention in recent years. In this study, alkali lignin (AL), with a rigid conjugated structure and amphiphilic property, was used as a sustainable and eco-friendly encapsulation material for the protection and controlled release of photosensitive abscisic acid (ABA), an important and widely used plant growth regulator. Cetyltrimethylammonium bromide (CTAB) was used to induce the formation of AL-CTAB nanomicroparticles by self-assembly. The size and morphology of AL-CTAB particles were modified by changing the AL concentration and the dispersion agent. AL (0.3 M) dissolved in tetrahydrofuran could form a uniform size (300 nm) of particles with a regular spherical structure. Subsequently, ABA was loaded on the prepared nanomicroparticles to synthesize the capsule formulation of ABA@AL-CTAB. The controlled-release behavior and the antiphotolysis performance as well as the thermal stability of ABA@AL-CTAB were proved to be superior. Lasting inhibition of Arabidopsis and rice seed germination by ABA@AL-CTAB under light irradiations implied protection of ABA from photolysis. In addition, ABA@AL-CTAB could effectively regulate plant stomata, thereby increasing plant drought resistance. Overall, lignin is suitable for the preparation of agrochemical formulations with excellent controlled release and antiphotolysis performances.

Development of a sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for the antimalaria active ingredient artemisinin in the Chinese herb Artemisia annua L.

Artemisinin is an endoperoxide sesquiterpene lactone isolated from the Chinese medicinal plant Artemisia annua L. It has been widely used in South-East Asia and Africa as an effective drug against sensitive and multidrug-resistant Plasmodium falciparum malaria. A monoclonal antibody (mAb), designated as 3H2, was generated with artesunate-bovine serum albumin conjugate as the immunogen. mAb 3H2 was used to develop a highly sensitive and specific indirect competitive enzyme-linked immunosorbent assay (icELISA) for artemisinin. The concentration of analyte producing 50% of inhibition (IC(50)) and the working range of the icELISA were 1.3 and 0.2-5.8 ng/mL, respectively. The mAb 3H2 recognized the artemisinin analogs artesunate, dihydroartemisinin, and artemether with cross-reactivity of 650%, 57%, and 3%, respectively, but negligibly recognized deoxyartemisinin and the artemisinin precursors arteannuin B and artemisinic acid. The average recoveries of artemisinin fortified in A. annua samples at concentrations from 156 to 5,000 microg/g determined by icELISA ranged from 91% to 98%. The icELISA was applied for the determination of artemisinin in different wild A. annua samples and the results were confirmed by high-performance liquid chromatography (HPLC) analysis. The correlation coefficient (R(2)) between the two assays was larger than 0.99, demonstrating a good agreement between the icELISA and HPLC results. This ELISA is suitable for quality assurance of A. annua L. materials.

Effect of 1-butyl-3-methylimidazolium tetrafluoroborate on the wheat (Triticum aestivum L.) seedlings.

Although many studies describe ionic liquids (ILs) as potentially greener solvents, few studies address their relationship with the environment. Recent researches suggest that some ILs have toxicity. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was reported to have the lowest toxicity among ILs. In this work, we studied the toxicity of this IL on wheat seedlings. It was shown that wheat germination was reduced to 38.0% in the presence of 4.4 mmol/L [C4mim][BF4] compared with 100% germination for the control. Similarly, the root and shoot length of wheat seedlings decreased with increasing concentrations of [C4mim][BF4]. The activity of amylase increased in shoots and roots, but it decreased significantly in germinating seeds when the [C4mim][BF4] concentration exceeded 1.8 mmol/L. Peroxidase (POD) activity and soluble protein content in shoots treated with [C4mim][BF4] changed similarly, but chlorophyll content tended to decrease with increasing concentration of [C4mim][BF4], except for at 1.8 mmol/L. Thus, [C4mim][BF4] at the concentration of 0.9 mmol/L or more was toxic to wheat seedlings. Some remedial measures are suggested to deal with IL pollution in the environment.

[Effects of mepiquat chloride on inorganic elements contents in seeds of transgenic insect-resistant cotton determined by ICP-MS].

To evaluate the effects of a worldwide used plant growth regulator mepiquat chloride on the nutrition value and safety of seeds of transgenic Bt cotton, inorganic element components and contents in seeds of Bt cotton (Gossypium hirsutum cv. Guoxin 6) under field condition were determined using ICP-MS. In Bt cotton seeds, 54 kinds of inorganic elements were identified by ICP-MS, and 5 kinds of major elements, K, P, Mg, Ca and Na, were in range from 138.3 to 13,835.1 microg x g(-1). The contents of 14 kinds of microelements were determined as in descending order of Si, B, Mn, Sr, Zn, Ni, Cu, Mo, Fe, Co, Se, V, I and Sn, in the range from 14.2 ng x g(-1) to 81.7 microg x g(-1). Five kinds of heavy metals were detected with the contents from 0.14 to 55.3 ng x g(-1), and their order from high to low is Pb, Cd, Cr, As and Hg. Other 30 kinds of elements were also detected in Bt cotton seeds by ICP-MS, including Rb, Be, La, Ce, Pr, Nd, Sm, Gd, Ge, Rh, Ag, Sb, W, U and Y. Foliar application of mepiquat chloride significantly reduced the contents of Ca, Fe, Si, Mn, Co, Ni, Cu and I, and remarkably decreased heavy metals Pb, Cd and Cr in the cotton seeds, by 68%, 67% and 54% respectively. While mepiquat chloride did not change the contents of most major and micro elements, it heightened 8 kinds, but lowered 7 kinds of the other 30 trace elements. This research indicated that mepiquat chloride application strengthened the security regarding the cotton seed as the material of cooking oil.

[Application of ICP-AES to detection of inorganic elements in roots bleeding sap from maize and soybean plants].

The constituents of the roots bleeding sap are an important index characteristic of roots activity and roots-shoots relationship. To compare the differences between the constituents of roots bleeding sap from maize and soybean plants, roots bleeding saps were collected from maize (Zea mays L. cultivar 3138) and soybean [Glycine max (L.) Merr. cultivar Ludou 11] plants at different growth and development stages under field condition, and the inorganic elements were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results indicated that both the constituents of inorganic elements and flow intensities were various between roots bleeding saps from maize and soybean plants at different growth and development stages. The flux of inorganic elements in roots bleeding sap showed different trends with progress in plants growth and development. In the roots bleeding sap from maize, the predominant inorganic elements were K, Ca, Mg, P, Na, Si, Zn, Mn and Fe, with flux ranging from 1 to 1 851.5 microg x h(-1) x plant(-1). The flux of B, Cu and Mo was relatively lower and less than 1 microg x h(-1) x plant(-1), while none of the elements of Co, Cd, Ba, Pb, Sr and As could be detected, and was estimated to be lower than 0.01 microg x h(-1) x plant(-1) based on the detection limit. The flow of most inorganic elements showed decreasing trends with plant development progressing from booting to grain filling stage. In the roots bleeding sap from soybean, Ca, Mg, K, P, Na, Zn, Mn, Fe and Cu were found as predominant inorganic constituents, ranging from 1 to 1 158 microg x h(-1) x plant(-1). The flow of both B and Mo was found lower than 1 microg x h(-1) x plant(-1), and none of Si, Co, Cd, Ba, Pb, Sr and As could be found. With the growth and development, different inorganic elements showed various changing pattern.

The functions of microRNAs in plants.

MicroRNAs (miRNAs) are a class of small regulatory RNAs, which repress gene expression at the posttranscriptional levels through binding to target mRNAs for directly cleaving mRNAs or inhibiting protein translation. Mature miRNAs are produced from miRNA genes by multiple biological processes, in which several important enzymes are involved in. To date, several hundreds of miRNAs have been identified in plants using a various computational and/or experimental approaches. These miRNAs regulate plant tissue differentiation, development and growth, control auxin signal transduction, involve in plant response to a variety of abiotic and biotic environmental stresses.

Ensifer shofinae sp. nov., a novel rhizobial species isolated from root nodules of soybean (Glycine max).

Two bacterial strains isolated from root nodules of soybean were characterized phylogenetically as members of a distinct group in the genus Ensifer based on 16S rRNA gene comparisons. They were also verified as a separated group by the concatenated sequence analyses of recA, atpD and glnII (with similarities ≤93.9% to the type strains for defined species), and by the average nucleotide identities (ANI) between the whole genome sequence of the representative strain CCBAU 251167T and those of the closely related strains in Ensifer glycinis and Ensifer fredii (90.5% and 90.3%, respectively). Phylogeny of symbiotic genes (nodC and nifH) grouped these two strains together with some soybean-nodulating strains of E. fredii, E. glycinis and Ensifer sojae. Nodulation tests indicated that the representative strain CCBAU 251167T could form root nodules with capability of nitrogen fixing on its host plant and Glycine soja, Cajanus cajan, Vigna unguiculata, Phaseolus vulgaris and Astragalus membranaceus, and it formed ineffective nodules on Leucaena leucocephala. Strain CCBAU 251167T contained fatty acids 18:1 ω9c, 18:0 iso and 20:0, differing from other related strains. Utilization of l-threonine and d-serine as carbon source, growth at pH 6.0 and intolerance of 1% (w/v) NaCl distinguished strain CCBAU 251167T from other type strains of the related species. The genome size of CCBAU 251167T was 6.2Mbp, comprising 7,581 predicted genes with DNA G+C content of 59.9mol% and 970 unique genes. Therefore, a novel species, Ensifer shofinae sp. nov., is proposed, with CCBAU 251167T (=ACCC 19939T=LMG 29645T) as type strain.

Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for the herbicide chlorimuron-ethyl.

Hybridomas secreting a monoclonal antibody (mAb) against the herbicide chlorimuron-ethyl (CE) were produced by fusing the mouse myeloma cell line (SP2/0) with splenocytes from a mouse immunized against the conjugate of the sulfonamide moiety of CE and bovine serum albumin (BSA). The mAb, designated 1F5C5A10, had very weak affinity with metsulfuron, ethametsulfuron, pyrazosulfuron, bensulfuron, and chlorsulfuron. Two mAb-based indirect competitive enzyme-linked immunosorbent assays (icELISA) were developed. A conventional icELISA (icELISA-I) showed a concentration of half-maximum inhibition (IC(50)) of 11.6 ng/mL with a dynamic range of 1.6-84 ng/mL. A simplified icELISA (icELISA-II) had an IC(50) of 28.7 ng/mL and a dynamic range of 2.2-372 ng/mL. The two assays were tested on spiked water and soil samples. CE (1-500 ng/mL) fortified in water samples could be analyzed directly without any sample preparation by both immunoassays with an average recovery between 74 and 114%. icELISA-II, but not icELISA-I, was able to accurately analyze the herbicide residues in the crude soil extracts with recoveries between 99 and 129% without obvious matrix effects due to its lesser amount of sample used. In contrast to icELISA-I, icELISA-II is more convenient, whereas it consumes more reagents of coating antigen and goat anti-mouse IgG-peroxidase.

[Effect of HKL-4 on active oxygen metabolism and photochemical efficiency in licorice leaf].

OBJECTIVE: To study the effects of HKL-4 on physiological changes during growth of leaves. METHOD: Using licorice (Glycyrrhiza uralensis) as material, the effects of HKL-4 on active oxygen metabolism and photochemical efficiency in licorice leaf were determined under field condition. RESULT AND CONCLUSION: The contents of chlorophyll, activity of SOD and CAT increased, while the MDA contents in leaves decreased. The senescence was delayed, so that the photochemical efficiency (Fv/Fm) was increasing comparing to the control.

Improved biological effects of uniconazole using porous hollow silica nanoparticles as carriers.

BACKGROUND: The aim of this work is to prepare a controlled-release formulation of uniconazole using porous hollow silica nanoparticles (PHSNs) as carrier, and to investigate the biological effects on rice growth. RESULTS: PHSNs with a shell thickness of ~15 nm and a particle size of 80-100 nm were synthesised through a sol-gel route using nanosized calcium carbonate particles as templates. Simple immersing (SI) and supercritical fluid drug loading (SFDL) technologies were employed to load uniconazole into PHSNs with loading efficiencies of ~22 and ~26% respectively. The prepared uniconazole-loaded PHSNs (UCZ-PHSNs) by SI and SFDL both demonstrated sustained release properties, and the latter showed better controlled release ability with a slower release rate. Compared with free uniconazole, UCZ-PHSNs exhibited a weaker growth retardation effect in the early stage but more significant retardation ability in later stages for agar-cultured rice seedlings. For the rice that grew in clay, UCZ-PHSNs demonstrated a weaker plant height retardation effect than free uniconazole at the early jointing stage by foliar spraying, but exhibited a stronger retardation capacity than free uniconazole by being applied into soil before seedling transplantation. CONCLUSION: The results indicated that the prepared UCZ-PHSNs possessed good controlled-release properties and had improved retardation effects on rice growth. It is recommended that UCZ-PHSNs be applied into soil before seedling transplantation rather than administered by foliar spraying at the early jointing stage.

Comparison between conventional indirect competitive enzyme-linked immunosorbent assay (icELISA) and simplified icELISA for small molecules.

A simplified indirect competitive enzyme-linked immunosorbent assay (icELISA) for small molecules was established by modifying the procedure of conventional icELISA. The key change was that the analyte, antibody, and enzyme-labeled second antibody in the simplified icELISA were added in one step, whereas in conventional icELISA these reagents were added in two separate steps. Three small chemicals, namely zeatin riboside, glycyrrhetinic acid, and chlorimuron-ethyl, were used to verify the new assay format and compare the results obtained from conventional icELISA and simplified icELISA. The results indicated that, under optimized conditions, the new assay offered several advantages over the conventional icELISA, which are simpler, less time consuming and higher sensitive although it requires more amount of reagents. The assay sensitivity (IC50) was improved for 1.2-1.4-fold. Four licorice roots samples were analyzed by conventional icELISA and simplified icELISA, as well as liquid chromatography (LC). There was no significant difference among the content obtained from the three methods for each sample. The correlation between data obtained from conventional icELISA and simplified icELISA analyses was 0.9888. The results suggest that the simplified icELISA be useful for high throughput screening of small molecules.

Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for the analysis of glycyrrhizic acid.

Glycyrrhizic acid (GL) is a major active compound of licorice. The specific monoclonal antibody (MAb) (designated as 8F8A8H42H7) against GL was produced with the immunogen GL-BSA conjugate. The dissociation constant (Kd) value of the MAb was approximately 9.96x10(-10) M. The cross reactivity of the MAb with glycyrrhetic acid was approximately 2.6%. The conventional indirect competitive enzyme-linked immunosorbent assay (icELISA) and simplified icELISA adapted with a modified procedure were established using the MAb. The IC50 value and the detect range by the conventional icELISA were 1.1 ng mL-1 and 0.2-5.1 ng mL-1, respectively. The IC50 value and the detect range by the simplified icELISA were 5.3 ng mL-1 and 1.2-23.8 ng mL-1, respectively. The two icELISA formats were used to analyze GL contents in the roots of wild licorice and different parts of cultivated licorice (Glycyrrhiza uralensis Fisch). The results obtained with the two icELISAs agreed well with those of the HPLC analysis. The correlation coefficient was more than 0.98 between HPLC and the two icELISAs. The two icELISAs were shown to be appropriate, simple, and effective for the quality control of raw licorice root materials.