Role of Plant-Growth-Promoting Rhizobacteria in Plant Machinery for Soil Heavy Metal Detoxification.

Heavy metals migrate easily and are difficult to degrade in the soil environment, which causes serious harm to the ecological environment and human health. Thus, soil heavy metal pollution has become one of the main environmental issues of global concern. Plant-growth-promoting rhizobacteria (PGPR) is a kind of microorganism that grows around the rhizosphere and can promote plant growth and increase crop yield. PGPR can change the bioavailability of heavy metals in the rhizosphere microenvironment, increase heavy metal uptake by phytoremediation plants, and enhance the phytoremediation efficiency of heavy-metal-contaminated soils. In recent years, the number of studies on the phytoremediation efficiency of heavy-metal-contaminated soil enhanced by PGPR has increased rapidly. This paper systematically reviews the mechanisms of PGPR that promote plant growth (including nitrogen fixation, phosphorus solubilization, potassium solubilization, iron solubilization, and plant hormone secretion) and the mechanisms of PGPR that enhance plant-heavy metal interactions (including chelation, the induction of systemic resistance, and the improvement of bioavailability). Future research on PGPR should address the challenges in heavy metal removal by PGPR-assisted phytoremediation.

Efficient Screening of Pharmaceutical Cocrystals by Microspacing In-Air Sublimation.

Cocrystal screening and single-crystal growth remain the primary obstacles in the development of pharmaceutical cocrystals. Here, we present a new approach for cocrystal screening, microspacing in-air sublimation (MAS), to obtain new cocrystals and grow high-quality single crystals of cocrystals within tens of minutes. The method possesses the advantages of strong designable ability of devices, user-friendly control, and compatibility with materials, especially for the thermolabile molecules. A novel drug-drug cocrystal of favipiravir (FPV) with salicylamide (SAA) was first discovered by this method, which shows improved physiochemical properties. Furthermore, this method proved effective in cultivating single crystals of FPV-isonicotinamide (FPV-INIA), FPV-urea, FPV-nicotinamide (FPV-NIA), and FPV-tromethamine (FPV-Tro) cocrystals, and the structures of these cocrystals were determined for the first time. By adjusting the growth temperature and growth distance precisely, we also achieved single crystals of 10 different paracetamol (PCA) cocrystals and piracetam (PIR) cocrystals, which underscores the versatility and efficiency of this method in pharmaceutical cocrystal screening.

Genome-wide association mapping for yield-related traits in soybean (Glycine max) under well-watered and drought-stressed conditions.

Soybean (Glycine max) productivity is significantly reduced by drought stress. Breeders are aiming to improve soybean grain yields both under well-watered (WW) and drought-stressed (DS) conditions, however, little is known about the genetic architecture of yield-related traits. Here, a panel of 188 soybean germplasm was used in a genome wide association study (GWAS) to identify single nucleotide polymorphism (SNP) markers linked to yield-related traits including pod number per plant (PN), biomass per plant (BM) and seed weight per plant (SW). The SLAF-seq genotyping was conducted on the population and three phenotype traits were examined in WW and DS conditions in four environments. Based on best linear unbiased prediction (BLUP) data and individual environmental analyses, 39 SNPs were significantly associated with three soybean traits under two conditions, which were tagged to 26 genomic regions by linkage disequilibrium (LD) analysis. Of these, six QTLs qPN-WW19.1, qPN-DS8.8, qBM-WW1, qBM-DS17.4, qSW-WW4 and qSW-DS8 were identified controlling PN, BM and SW of soybean. There were larger proportions of favorable haplotypes for locus qPN-WW19.1 and qSW-WW4 rather than qBM-WW1, qBM-DS17.4, qPN-DS8.8 and qSW-DS8 in both landraces and improved cultivars. In addition, several putative candidate genes such as Glyma.19G211300, Glyma.17G057100 and Glyma.04G124800, encoding E3 ubiquitin-protein ligase BAH1, WRKY transcription factor 11 and protein zinc induced facilitator-like 1, respectively, were predicted. We propose that the further exploration of these locus will facilitate accelerating breeding for high-yield soybean cultivars.

Different Dissolution Molecular Pathways of Azilsartan Crystals with Different Forms Revealed by In Situ Atomic Force Microscopy.

Here, using in situ atomic force microscopy (AFM), the dissolution behaviors and dissolution molecular pathways of two azilsartan crystals, the isopropanol solvate (AZ-IPA), and form I (AZ-I), in pure water and 6-30% poly(ethylene glycol) (PEG) aqueous solutions are revealed. The dissolution behaviors of step retreat and etch pit formation are observed on the (100) faces of the two crystals, with a single step corresponding to one molecular monolayer in crystal structures. Etching rates of pits increase with PEG concentration. Furthermore, our results show that AZ-IPA dissolves by the direct detachment of molecules from the step front to solution. Such a mechanism remains even when the PEG concentration changes. However, AZ-I dissolves primarily by the surface diffusion mechanism involving molecular detachment from the step front at first and then diffusion over the terraces before desorption into solution. PEG promotes the dissolution of AZ-I crystals by favoring the molecular detachment from the step front.

In Situ Formation of CoP/Co3 O4 Heterojunction for Efficient Overall Water Splitting.

Electrochemical water splitting is an environmentally friendly and effective energy storage method. However, it is still a huge challenge to prepare non-noble metal based electrocatalysts that possess high activity and long-term durability to realize efficient water splitting. Here, we present a novel method of low-temperature phosphating for preparing CoP/Co3 O4 heterojunction nanowires catalyst on titanium mesh (TM) substrate that can be used for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting. CoP/Co3 O4 @TM heterojunction showed an excellent catalytic performance and long-term durability in 1.0 M KOH electrolyte. The overpotential of CoP/Co3 O4 @TM heterojunction was only 257 mV at 20 mA cm-2 during the OER process, and it could work stably more than 40 h at 1.52 V versus reversible hydrogen electrode (vs. RHE). During the HER process, the overpotential of CoP/Co3 O4 @TM heterojunction was only 98 mV at -10 mA cm-2 . More importantly, when used as anodic and cathodic electrocatalyst, they achieved 10 mA cm-2 at 1.59 V. The Faradaic efficiencies of OER and HER were 98.4 % and 99.4 %, respectively, outperforming Ru/Ir-based noble metal electrocatalysts and other non-noble metal electrocatalysts for overall water splitting.

Thermochromism Perovskite (COOH(CH2)3NH3)2PbI4 Crystals: Single-Crystal to Single-Crystal Phase Transition and Excitation-Wavelength-Dependent Emission.

As a potential multifunctional phase transition material, the organic-inorganic hybrid perovskite has attracted extensive attention in recent years. Here, we report the single-crystal to single-crystal phase transition and excitation-wavelength-dependent emission (EDE) of layered perovskite (COOH(CH2)3NH3)2PbI4. Single-crystal X-ray diffraction indicated that the crystal structure changes from layered Ruddlesden-Popper (RP) at 302 K to "X" network composed of face-sharing and corner-sharing [PbX6]4- octahedra at 425 K. The material exhibits thermochromic change from orange to yellow at higher temperature. Considering the thermochromism of the material, we apply it for anticounterfeiting and information encryption. The material exhibits EDE properties with a fluorescence color changing from green to red upon 420 and 546 nm excitation, respectively. Time-dependent density functional theory indicated that this phenomenon is mainly related to the laser-induced crystal structural transfer. Our research shows that the (COOH(CH2)3NH3)2PbI4 crystal has a potential application for multifunctional devices.

Screening diverse soybean genotypes for drought tolerance by membership function value based on multiple traits and drought-tolerant coefficient of yield.

BACKGROUND: Drought is a major limiting factor seriously influencing worldwide soybean production and its impact on yield, morphological and physiological traits depend on the timing it occurs and the intensity of water shortage. Only limited research has however been conducted on identifying the drought-tolerant genotypes at different growth stages (vegetative growth phase, reproductive growth phase and the whole growth phase) as well as evaluate the effectiveness and reliability of multiple phenotypic and yield-related characteristics in soybean. RESULTS: Two pot experiments and a 2-year field experiment were conducted to evaluate soybean drought tolerance at different growth stages. The membership function value of drought tolerance (MFVD) was used to identify drought-resistant cultivars during vegetative growth phase and reproductive growth stage; the relative drought index (RDI) of yield was used to assess drought-resistant cultivars during the whole growing period. In this study, regression models built based on MFVD indicated that the variation of drought tolerant coefficient (DC) of R/S, TRL, LAI and RSR could explain 73.70% of the total variation at vegetative growth phase. However, higher heritability only found in LAI and RSR, indicating the two traits could serve as reliable criteria for drought evaluation. Similarly, the DC of SPP, YPP, PH, PB, MSNN and STB could explain 94.30% of the total variation in MFVD according to stepwise multiple linear regression analyses at reproductive growth phase. Thus, these six traits were identified as indicators for screening drought resistance genotypes in soybean. In addition, correlation analysis revealed that the MFVD was significantly positively correlated with the DCRB, DCR/S, DCRSA, DCRSR and DCRBR at vegetative growth phase and DCYPP, DCSPP, DCRB, and DCPB at reproductive growth phase. This indicated that these traits were closely related to the drought resistance of plants. CONCLUSIONS: LD24, JD36 and TF31 of vegetative growth phase, and TD37 and LD26 of reproductive growth phase were identified with drought tolerant and highly drought tolerant, respectively. Moreover, 30 accessions with drought tolerance were screened in the field trial and could be applied for the drought resistance of other genotypes by cross-breeding.

Association between abortion and breast cancer: an updated systematic review and meta-analysis based on prospective studies.

OBJECTIVE: Although positive association between abortion and breast cancer was frequently reported from case-control studies, results from prospective studies were still unclear. This study aimed to evaluate this association based on prospective studies. METHODS: PubMed, ISI Web of Knowledge and Embase were systematically searched for prospective studies on the association between abortion and breast cancer up to April 2014, supplemented by manual searches on the references. Two reviewers independently conducted the literature search, study selection, data extraction, and quality assessment of included studies. Random effects models were used to estimate the combined relative risks (RRs) and corresponding 95 % confidence intervals (95 % CIs). RESULTS: Fifteen prospective studies [14 focused on induced abortion (IA), and 12 focused on spontaneous abortion (SA)] were included in the final analysis. The combined RRs (95 % CIs) of breast cancer risk were 1.00 (0.94-1.05) [1.00 (0.92-1.08) for cumulative-incidence data and 1.00 (0.94-1.05) for incidence-rate data] for IA, and 1.02 (0.95-1.09) [1.06 (0.96-1.16) for cumulative-incidence data and 1.01 (0.92-1.09) for incidence-rate data] for SA, respectively. Non-significant associations of breast cancer with IA and SA were also found among nulliparous women, women with abortion before or after the first full-term pregnancy, women with one or ≥ 2 abortions, and women with first abortion after 30 years old. CONCLUSION: The current prospective evidences are not sufficient to support the positive association between abortion (including IA and SA) and breast cancer risk.