Effect of phosphorus deficiency on aluminium-induced citrate exudation in soybean (Glycine max)

Aluminium (Al) toxicity or phosphorus (P) deficiency can induce exudation of organic acids from the roots of some plants, which is believed to be a tolerance mechanism against Al toxicity or P deficiency. In the present study, the effect of P deficiency on Al-induced citrate exudation was investigated in three soybean varieties differing in low-P tolerance. P starvation alone failed to induce secretion of organic acids from all three soybean varieties. However, P deficiency altered Al-induced citrate exudation over time, showing a complex interaction. Short × term P starvation (4 days) produced up to 50% increase in Al-induced citrate secretion, while longer-term (10 days) starvation reduced Al-induced citrate secretion to trace amounts. However, after a further 1 day in complete nutrient solution for recovery, Al-induced citrate exudation from the recovered roots was approximately 6 times higher than that from the continuously P-starved plants, but still approximately 3.6 times lower than that from the P-sufficient control. With increasing P or Al supply, Al-induced citrate exudation increased, while Al accumulation in soybean roots decreased in parallel with the decrease of P supply. The photosynthetic rate, stomatal conductance and transpiration were decreased by P deficiency, whereas the intracellular CO₂ concentration was increased. These findings indicate that P nutrition has a significant effect on Al-induced citrate exudation and Al accumulation in soybean root apices.     

Negative Affect Mediates Effects of Psychological Stress on Disordered Eating in Young Chinese Women

Background

The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women.

Methodology

A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10), Beck Depression Inventory Revised (BDI-II), Beck Anxiety Inventory (BAI), and Eating Attitude Test (EAT-26) were administered to all participants.

Principal Findings

The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (–0.012, 95%CI: –.038∼0.006, p = 0.357), however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022∼0.044, p<0.001) and 0.015 (95%CI: 0.005∼0.023, p<0.01), respectively.

Conclusions

Perceived stress and negative affects of depression and anxiety were demonstrated to be strongly associated with disordered eating. Negative affect mediated the relationship between perceived stress and disordered eating. The findings suggest that effective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population.     

SDS‐PAGE‐free protocol for comprehensive identification of cytochrome P450 enzymes and uridine diphosphoglucuronosyl transferases in human liver microsomes

Comprehensive identification of cytochrome P450 enzymes (CYPs) and uridine diphosphoglucuronosyl transferases (UGTs) in human liver microsomes (HLMs) was performed with an SDS‐PAGE‐free protocol. HLMs were solubilized with 5% v/v ionic liquid, 1‐butyl‐3‐methyl imidazolium tetrafluoroborate, followed by tryptic digestion, and 2D‐SCX‐RPLC‐ESI‐MS/MS (LTQ XL) analysis in triplicate. In total, 27 CYPs and 12 UGTs were confidently identified with average sequence coverage as 30.99 and 25.07%, average peptide number as 14 and 13, and average unique peptide number as 7 and 4, respectively. The highly similar isoforms of CYP3A, CYP2C, and CYP4F subfamilies could be unambiguously differentiated from each other, despite the fact that the sequence similarity of CYP2C9 and CYP2C19 is 91%. In addition, protein spectral count was used to approximately evaluate the relative abundance of identified CYPs and UGTs, and the results agreed with previous immunochemistry reports.     

Molecular Detection and Complete Genome Sequences of Tomato chlorosis virus Isolates from Infectious Outbreaks in China

Tomato chlorosis virus (ToCV) is a whitefly‐transmitted, phloem‐limited, bipartite Crinivirus. In 2012, severe interveinal symptoms characteristic of ToCV infections were observed in greenhouse tomato plants in the Shandong province of China. High levels of infestation by whiteflies (Bemisia tabaci), which transmit ToCV, were also observed on tomato plants in all the greenhouses investigated. The presence of ToCV was confirmed by specific RT‐PCR either in the sampled plants or in the whiteflies collected from the ventral surface of the leaves of diseased plants. The complete genomic nucleotide sequences (RNA1 and RNA2) of the Shandong isolate of ToCV (ToCV‐SDSG) were determined and analysed. ToCV‐SDSG RNA1 consisted of 8594 nucleotides encompassing four open reading frames (ORFs). ToCV‐SDSG RNA2 consisted of 8242 nucleotides encompassing nine ORFs. Phylogenetic analysis suggests that the Chinese ToCV‐SDSG isolate is most similar to the ToCV‐Florida isolate.     

Evaluation of residue-residue contact prediction methods: From retrospective to prospective

Sequence-based residue contact prediction plays a crucial role in protein structure reconstruction. In recent years, the combination of evolutionary coupling analysis (ECA) and deep learning (DL) techniques has made tremendous progress for residue contact prediction, thus a comprehensive assessment of current methods based on a large-scale benchmark data set is very needed. In this study, we evaluate 18 contact predictors on 610 non-redundant proteins and 32 CASP13 targets according to a wide range of perspectives. The results show that different methods have different application scenarios: (1) DL methods based on multi-categories of inputs and large training sets are the best choices for low-contact-density proteins such as the intrinsically disordered ones and proteins with shallow multi-sequence alignments (MSAs). (2) With at least 5L (L is sequence length) effective sequences in the MSA, all the methods show the best performance, and methods that rely only on MSA as input can reach comparable achievements as methods that adopt multi-source inputs. (3) For top L/5 and L/2 predictions, DL methods can predict more hydrophobic interactions while ECA methods predict more salt bridges and disulfide bonds. (4) ECA methods can detect more secondary structure interactions, while DL methods can accurately excavate more contact patterns and prune isolated false positives. In general, multi-input DL methods with large training sets dominate current approaches with the best overall performance. Despite the great success of current DL methods must be stated the fact that there is still much room left for further improvement: (1) With shallow MSAs, the performance will be greatly affected. (2) Current methods show lower precisions for inter-domain compared with intra-domain contact predictions, as well as very high imbalances in precisions between intra-domains. (3) Strong prediction similarities between DL methods indicating more feature types and diversified models need to be developed. (4) The runtime of most methods can be further optimized.     

A global alfalfa diversity panel reveals genomic selection signatures in Chinese varieties and genomic associations with root development

Alfalfa (Medicago sativa L.) is an important forage crop worldwide. However, little is known about the effects of breeding status and different geographical populations on alfalfa improvement. Here, we sequenced 220 alfalfa core germplasms and determined that Chinese alfalfa cultivars form an independent group, as evidenced by comparisons of F_ST values between different subgroups, suggesting that geographical origin plays an important role in group differentiation. By tracing the influence of geographical regions on the genetic diversity of alfalfa varieties in China, we identified 350 common candidate genetic regions and 548 genes under selection. We also defined 165 loci associated with 24 important traits from genome-wide association studies. Of those, 17 genomic regions closely associated with a given phenotype were under selection, with the underlying haplotypes showing significant differences between subgroups of distinct geographical origins. Based on results from expression analysis and association mapping, we propose that 6-phosphogluconolactonase (MsPGL) and a gene encoding a protein with NHL domains (MsNHL) are critical candidate genes for root growth. In conclusion, our results provide valuable information for alfalfa improvement via molecular breeding.     

Fetal nucleated erythrocyte recovery: fluorescence activated cell sorting-based positive selection using anti-gamma globin versus magnetic activated cell sorting using anti-CD45 depletion and anti-gamma globin positive selection

BACKGROUND: Fluorescence activated cell sorting (FACS)-based anti-gamma (gamma) positive selection and magnetic activated cell sorting (MACS)-based anti-CD45 depletion followed by anti-gamma positive staining have been two of the most frequently used methods to isolate fetal cells from maternal blood. To date, there has been no direct comparison of fetal cell recovery by these two methods. This study was designed to address this issue. METHODS: Fluorescence in situ hybridization (FISH) was performed on nucleated anti-gamma positive cells using X and Y probes. Twenty-four maternal blood samples were obtained immediately after elective termination of pregnancy to ensure a detectable number of fetal cells. RESULTS: The yield and purity of fetal nucleated erythrocytes (FNRBCs) was statistically higher in FACS sorted samples (P < 0.01). The specificity of staining for FNRBCs was statistically higher in MACS sorted samples (P < 0.01). CONCLUSIONS: The data from this study demonstrate that both techniques have benefits and limitations. FACS has the advantage of having higher yield, higher purity, higher FISH efficiency and ease in microscope analysis, and MACS has the advantage of having higher specificity and less cell loss during FISH.     

肌醇磷脂激酶(PI4-K)单克隆抗体的制备及其对细胞生长的抑制

制备了抗肌醇磷脂激酶 ( PI4- K)单克隆抗体 ( A6D)并测定了抗原 -抗体反应基本特性及功能 .结果表明 ,单克隆抗体与固相及溶液中肌醇磷脂激酶的亲和常数分别为 7.5× 1 0 6和 6× 1 0 8( mol/L) -1.单抗 1 .9× 1 0 -7mol/L可以抑制从细胞提取液的 PI4- K酶活力 50 % .用 FITC标记单抗在蛋白微球引导下进入细胞内 ,主要富集在细胞质膜区 ,并对 He La细胞和小鼠小脑细胞生长有明显抑制作用 .     

Cranial Suture Regeneration Mitigates Skull and Neurocognitive Defects in Craniosynostosis

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大蒜体细胞胚发生过程中内源激素含量及相关基因表达的变化特征

该研究以大蒜品种'二水早'为材料,采用高效液相色谱串联质谱法(LC-MS/MS),检测了大蒜体细胞胚发生过程中花序轴(EX)、愈伤组织(CA)、早期胚性愈伤组织(PC)、后期胚性愈伤组织(LC)和球形胚(GE)阶段的5种生长素及其类似物、4种细胞分裂素(CTK)和脱落酸(ABA)含量,结合激素合成和信号转导相关基因表达...