Enhancement of salt tolerance of alfalfa: Physiological and molecular responses of transgenic alfalfa plants expressing Syntrichia caninervis-derived ScABI3.

Alfalfa (Medicago sativa L.), a perennial forage plant, is a rich source of nutrients such as vitamins, minerals, and proteins. Salt stress, however, impedes its growth. The plant-specific transcription factor abscisic acid insensitive 3 (ABI3) has a critical contribution to the control of abscisic acid (ABA) signaling pathway and abiotic stress response. The gene ScABI3 from Syntrichia caninervis, a moss species tolerant to desiccation, could be considered a potential candidate gene to modify alfalfa's nutritional and growth aspects. However, it remains unclear how ScABI3 affects the salt stress response of transgenic alfalfa. Therefore, we elucidated the role and molecular mechanism of ScABI3 from S. caninervis as an ABA signaling factor in transgenic alfalfa. Our findings demonstrate that ScABI3 overexpression in transgenic alfalfa improves salt tolerance by promoting relative water content, antioxidant enzyme activity, and photosynthetic parameters. Furthermore, the key genes of plant hormone signaling and the classical salt tolerance pathway were activated in ScABI3 transgenic lines under salt stress. Based on these results, ScABI3 could be considered a potentially critical candidate gene to alleviate salt stress in alfalfa. The present study provides valuable insights for developing transgenic crop breeding strategies for saline-alkaline soils.

Transcriptomics-based investigation of manganese dioxide nanoparticle toxicity in rats' choroid plexus.

Manganese dioxide nanoparticles (MnO2-NPs) have a wide range of applications in biomedicine. Given this widespread usage, it is worth noting that MnO2-NPs are definitely toxic, especially to the brain. However, the damage caused by MnO2-NPs to the choroid plexus (CP) and to the brain after crossing CP epithelial cells has not been elucidated. Therefore, this study aims to investigate these effects and elucidate potential underlying mechanisms through transcriptomics analysis. To achieve this objective, eighteen SD rats were randomly divided into three groups: the control group (control), low-dose exposure group (low-dose) and high-dose exposure group (high-dose). Animals in the two treated groups were administered with two concentrations of MnO2-NPs (200 mg kg-1 BW and 400 mg kg-1 BW) using a noninvasive intratracheal injection method once a week for three months. Finally, the neural behavior of all the animals was tested using a hot plate tester, open-field test and Y-type electric maze. The morphological characteristics of the CP and hippocampus were observed by H&E stain, and the transcriptome of CP tissues was analysed by transcriptome sequencing. The representative differentially expressed genes were quantified by qRT-PCR. We found that treatment with MnO2-NPs could induce learning capacity and memory faculty decline and destroy the structure of hippocampal and CP cells in rats. High doses of MnO2-NPs had a more obvious destructive capacity. For transcriptomic analysis, we found that there were significant differences in the numbers and types of differential genes in CP between the low- and high-dose groups compared to the control. Through GO terms and KEGG analysis, high-dose MnO2-NPs significantly affected the expression of transporters, ion channel proteins, and ribosomal proteins. There were 17 common differentially expressed genes. Most of them were transporter and binding genes on the cell membrane, and some of them had kinase activity. Three genes, Brinp, Synpr and Crmp1, were selected for qRT-PCR to confirm their expression differences among the three groups. In conclusion, high-dose MnO2-NPs exposure induced abnormal neurobehaviour, impaired memory function, destroyed the structure of the CP and changed its transcriptome in rats. The most significant DEGs in the CP were within the transport system.

Selection of the reference genes for quantitative gene expression by RT-qPCR in the desert plant Stipagrostis pennata.

The desert pioneer plant Stipagrostis pennata plays an important role in sand fixation, wind prevention, and desert ecosystem recovery. An absence of reference genes greatly limits investigations into the regulatory mechanism by which S. pennata adapts to adverse desert environments at the molecular and genetic levels. In this study, eight candidate reference genes were identified from rhizosheath development transcriptome data from S. pennata, and their expression stability in the rhizosheaths at different development stages, in a variety of plant tissues, and under drought stress was evaluated using four procedures, including geNorm, NormFinder, BestKeeper, and RefFinder. The results showed that GAPDH and elF were the most stable reference genes under drought stress and in rhizosheath development, and ARP6 and ALDH were relatively stable in all plant tissues. In addition, elF was the most suitable reference gene for all treatments. Analysis of the consistency between the reverse transcription-quantitative PCR (RT-qPCR) and RNA sequencing data showed that the identified elF and GAPDH reference genes were stable during rhizosheath development. These results provide reliable reference genes for assuring the accuracy of RT-qPCR and offer a foundation for further investigations into the genetic responses of S. pennata to abiotic stress.

Components and Functional Diversification of Florigen Activation Complexes in Cotton.

In shoot apex cells of rice, a hexameric florigen activation complex (FAC), comprising flowering locus T (FT), 14-3-3 and the basic leucine zipper transcription factor FD, activates downstream target genes and regulates several developmental transitions, including flowering. The allotetraploid cotton (Gossypium hirsutum L.) contains only one FT locus in both of the A- and D-subgenomes. However, there is limited information regarding cotton FACs. Here, we identified a 14-3-3 protein that interacts strongly with GhFT in the cytoplasm and the nuclei, and five FD homoeologous gene pairs were characterized. In vivo, all five GhFD proteins interacted with Gh14-3-3 and GhFT in the nucleus. GhFT, 14-3-3 and all the GhFDs interacted in the nucleus as well, suggesting that they formed a ternary complex. Virus-induced silencing of GhFD1, -2 and -4 in cotton delayed flowering and inhibited the expression of floral meristem identity genes. Silencing GhFD3 strongly decreased lateral root formation, suggesting a function in lateral root development. GhFD overexpression in Arabidopsis and transcriptional activation assays suggested that FACs containing GhFD1 and GhFD2 function mainly in promoting flowering with partial functional redundancy. Moreover, GhFD3 was specifically expressed in lateral root meristems and dominantly activated the transcription of auxin response factor genes, such as ARF19. Thus, the diverse functions of FACs may depend on the recruited GhFD. Creating targeted genetic mutations in the florigen system using Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) genome editing may fine-tune flowering and improve plant architecture.

Roles of the 14-3-3 gene family in cotton flowering.

BACKGROUND: In plants, 14-3-3 proteins, also called GENERAL REGULATORY FACTORs (GRFs), encoded by a large multigene family, are involved in protein-protein interactions and play crucial roles in various physiological processes. No genome-wide analysis of the GRF gene family has been performed in cotton, and their functions in flowering are largely unknown. RESULTS: In this study, 17, 17, 31, and 17 GRF genes were identified in Gossypium herbaceum, G. arboreum, G. hirsutum, and G. raimondii, respectively, by genome-wide analyses and were designated as GheGRFs, GaGRFs, GhGRFs, and GrGRFs, respectively. A phylogenetic analysis revealed that these proteins were divided into ε and non-ε groups. Gene structural, motif composition, synteny, and duplicated gene analyses of the identified GRF genes provided insights into the evolution of this family in cotton. GhGRF genes exhibited diverse expression patterns in different tissues. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that the GhGRFs interacted with the cotton FLOWERING LOCUS T homologue GhFT in the cytoplasm and nucleus, while they interacted with the basic leucine zipper transcription factor GhFD only in the nucleus. Virus-induced gene silencing in G. hirsutum and transgenic studies in Arabidopsis demonstrated that GhGRF3/6/9/15 repressed flowering and that GhGRF14 promoted flowering. CONCLUSIONS: Here, 82 GRF genes were identified in cotton, and their gene and protein features, classification, evolution, and expression patterns were comprehensively and systematically investigated. The GhGRF3/6/9/15 interacted with GhFT and GhFD to form florigen activation complexs that inhibited flowering. However, GhGRF14 interacted with GhFT and GhFD to form florigen activation complex that promoted flowering. The results provide a foundation for further studies on the regulatory mechanisms of flowering.

Anti-inflammatory effect, plasma effective components and therapeutic targets of Huanglian Jiedu Decoction on ulcerative colitis mice / 中国中药杂志

This paper was to investigate the effect of Huanglian Jiedu Decoction(HLJD) on ulcerative colitis(UC) in mice, and determine the effective components in plasma, and virtually screen its therapeutic target, and predict its mechanism. Sixty Balb/c mice were randomly divided into blank group, model group, mesalazine treatment group(0.3 g·kg~(-1)), and HLJD treatment groups(24.66, 12.33, 6.17 g·kg~(-1)). Excepted for the blank group, all the mice in HLJD and mesalazine treatment groups were gavage administration. All mice freely drank 2.5% DSS solution for seven days to induce UC. The disease activity index(DAI) was detected each day. At the end of the experiment, HE staining was used to observe the pathological changes in colon. The content of IL-1β, IL-6 and TNF-α in colon were determined by ELISA. The effective components in plasma were determined by UPLC-Q-TOF-MS. The reverse docking in PharmMapper was used to screen the component targets. The disease targets of UC were collected by searching TTD, OMIM and GeneCards databases. The intersection of the component targets and disease targets was selected as the therapeutic targets. Then the therapeutic targets were imported into the STRING for GO and KEGG enrichment analysis. Discovery Studio was used to simulate the docking between the components and the targets. RESULTS:: showed that the DAI in the model group increased significantly(P<0.05), and the number of inflammatory cells and infiltration degree increased significantly compared with the blank group. The DAI in HLJD treatment group was significantly reduced(P<0.05), and the number and infiltration degree of inflammatory cells were reduced compared with the model group. The ELISA results showed that the levels of IL-1β, IL-6 and TNF-α were increased significantly in the model group(P<0.01) compared with the blank group, and significantly down regulated in the HLJD treatment group(P<0.05) compared with the model group. After UPLC-Q-TOF-MS analyse, ten components were identified. The network pharmacology analysis showed that the action targets were significantly enriched in 129 of biological processes, such as response to organic substance, chemical and oxygen-containing compound, etc., as well as 16 of signal pathways, such as IL-17, TNF and hepatitis B signal pathways, were enriched too. The results of molecular docking showed that limonin, palmatine and berberine could bind to CASP3 and MMP9 by hydrogen bond. In conclusion, HLJD could alleviate the colonic mucosal inflammatory infiltration and mucosal damage in UC mice. The mechanism may be related to the anti-inflammatory effect on UC mice by reducing the levels of IL-1β, IL-6 and TNF-α in colon through limonin, palmatine and berberine regulating IL-17 signal pathway and TNF signal pathway via CASP3 and MMP9 meditated.

Thermal tolerance of dried shoots of the moss Bryum argenteum.

We conducted laboratory experiments to determine the lethal temperatures of the shoots of dried Bryum argenteum and to determine how this restoration species responds to extreme environments. We specifically assessed changes in gene expression levels in the shoots of dried B. argenteum plants that were subjected to sudden heat shock (control (20 ± 2°C), 80°C, 100°C, 110°C or 120°C) followed by exposure to heat for an additional 10, 20, 30 or 60 min. After they were exposed to heat, the samples were placed in wet sand medium, and their survival and regeneration abilities were evaluated daily for 56 days. The results showed that lethal temperatures significantly reduced the shoot regeneration potential, delayed both shoot and protonemal emergence times and reduced the protonemal emergence area. In addition, the expression of nine genes (HSF3, HSP70, ERF, LEA, ELIP, LHCA, LHCB, Tr288 and DHN) was induced by temperature stress, as assessed after 30 min of exposure. Additionally, a new thermal tolerance level for dried B. argenteum - 120°C for 20 min - was determined, which was the highest temperature recorded for this moss; this tolerance exceeded the previous record of 110°C for 10 min. These findings help elucidate the survival mechanism of this species under heat shock stress and facilitate the recovery and restoration of destroyed ecosystems.

Synchrotron Radiation-Based Three-Dimensional Visualization of Angioarchitectural Remodeling in Hippocampus of Epileptic Rats.

Characterizing the three-dimensional (3D) morphological alterations of microvessels under both normal and seizure conditions is crucial for a better understanding of epilepsy. However, conventional imaging techniques cannot detect microvessels on micron/sub-micron scales without angiography. In this study, synchrotron radiation (SR)-based X-ray in-line phase-contrast imaging (ILPCI) and quantitative 3D characterization were used to acquire high-resolution, high-contrast images of rat brain tissue under both normal and seizure conditions. The number of blood microvessels was markedly increased on days 1 and 14, but decreased on day 60 after seizures. The surface area, diameter distribution, mean tortuosity, and number of bifurcations and network segments also showed similar trends. These pathological changes were confirmed by histological tests. Thus, SR-based ILPCI provides systematic and detailed views of cerebrovascular anatomy at the micron level without using contrast-enhancing agents. This holds considerable promise for better diagnosis and understanding of the pathogenesis and development of epilepsy.

The progresses and perspectives of the control and eradication of persistent bacteria / 医学研究生学报

Persistent bacteria is a microbial subpopulation which can survive from lethal concentration of antimicrobial agents. Unlike the resistant bacteria which usually acquire the resistance from heritable gene mutations, persisters are genetically identical to regular cells in genome but show a distinct antibiotic tolerant phenotype through a state of dormancy. Once the antimicrobial therapy is removed,the persisters can regrow to a new population and cause the recurrent infectious diseases. The increased threats due to the in-fections and drug tolerance caused by persistent bacteria promote the interests of preventing bacterial persistence. This review discusses the harmfulness of persistent infections, the mechanisms of bacterial persistence and summarizes the different control and eradication strategies,aiming to provide ideas and references for further research.

Differential expression of IQGAP1/2 in Hepatocellular carcinoma and its relationship with clinical outcomes.

PURPOSE: To investigate IQGAP1 and IQGAP2 expression in hepatocellular carcinoma (HCC) and itsassociation with HCC clinicopathological characteristics and survival outcomes. METHODS: IQGAP1 and IQGAP2 mRNA and protein were measured in HCC tissues, para-tumor tissues and normal tissues by RT-PCR and Western blotting. We further examined 150 HCC samples with adjacent para-tumor tissues and 11 normal specimens by immunohistochemistry to evaluate the correlation of IQGAP1 and IQGAP2 with clinicopathological features and prognosis. RESULTS: IQGAP1 mRNA and protein were up-regulated while IQGAP2 mRNA and protein were down-regulated in human HCC tissues compared with para-tumor and normal liver tissues (p<0.05). IQGAP1 expression was higher in primary HCC (122/150, 81.3%) than matched adjacent tissues (30/150, 20%, p<0.001), whereas IQGAP2 was lower (31/150, 20.7% as compared to 112/150, 74.7%, P<0.001). Positive IQGAP1 expression correlated with larger tumor size (p=0.002), advanced TNM stage (p=0.002) and tumor differentiation (III and IV, p=0.034). Negative IQGAP2 expression was significantly associated with larger tumor size (p=0.009), multicentric tumor occurrence (p=0.01), advanced TNM stage (0.009) and tumor differentiation (III and IV, p=0.020). Survival analysis revealed that patients with either IQGAP1+ or IQGAP2- tumors had significantly reduced disease-free survival (p<0.001 and 0.006 respectively) and overall survival (p<0.001 for both). Multivariate analysis showed that IQGAP1/2 switch was an independent prognosis factor for disease-free survival (HR=2.824) and overall survival (HR=2.189). CONCLUSION: Positive IQGAP1 and negative IQGAP2 expression were closely correlated with tumor progression and could be used as adjunctive biomarkers to improve prognostication for HCC patients.

Arbuscular mycorrhizal fungi: potential biocontrol agents against the damaging root hemiparasite Pedicularis kansuensis?

Spatial expansion of root hemiparasitic Pedicularis kansuensis in Bayanbulak Grassland of Xinjiang Uygur Autonomous Region (China) has caused great loss of herbage yield and has threatened the local livestock industry. Current management practices using manual eradication and chemical control have been proved problematic. Arbuscular mycorrhizal (AM) fungi have been suggested to be potential biocontrol agents against a number of plant pests, but experimental evidence is lacking against weedy P. kansuensis. In this study, we tested the hypothesis that inoculation with AM fungi will cause growth depression in P. kansuensis and reduce its damage to host plants. Based on the confirmation of AM status and host community of the hemiparasite in the field, a pot cultivation experiment was conducted to test the influence of an AM fungus (Glomus mosseae) on growth of P. kansuensis and the parasitized host (Elymus nutans). AM colonization was observed in roots of P. kansuensis, but the levels were much lower than those of its adjacent host species. A negative correlation between AM levels and the numbers of haustoria was detected for the field samples of the hemiparasite. Strong suppression of haustorium formation, a significant reduction in plant dry weight (DW), as well as marked reduction in the survival rate of P. kansuensis after inoculation with AM fungi was observed. In contrast, inoculation with G. mosseae increased root DW and whole plant DW of parasitized host plants. Our findings demonstrated significantly repressive effects of AM fungi on growth performance of P. kansuensis with and without the presence of a host. The potential of AM fungi as biocontrol agents against the damaging hemiparasite was confirmed.

Distinct resting-state brain activities in heroin-dependent individuals.

Previous functional imaging studies on heroin addicts have focused on abnormal brain functions based on specific tasks, while few fMRI studies concentrated on the resting-state abnormalities of heroin-dependent individuals. In the current study, we applied the pattern classification technique, which employs the feature extraction method of non-negative matrix factorization (NMF) and a support vector machine (SVM) classifier. Its main purpose was to characterize the discrepancy in activation patterns between heroin-dependent individuals and healthy subjects during the resting state. The results displayed a high accuracy in the activation pattern differences of the two groups, which included the orbitofrontal cortex (OFC), cingulate gyrus, frontal and para-limbic regions such as the anterior cingulate cortex (ACC), hippocampal/parahippocampal region, amygdala, caudate, putamen, as well as the posterior insula and thalamus. These findings indicate that significant biomarkers exist among the network of circuits that are involved in drug abuse. The implications from our study may help explain the behavioral and neuropsychological deficits in heroin-dependent individuals and shed light on the mechanisms underlying heroin addiction.

Association of HLA-DR4, PAD4, and STAT4 expression in the peripheral blood with disease activity in patients with rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of the expressions of human leukocyte antigen (HLA)-DR4, peptidyl arginine deiminase type4(PAD4), and signal transducer and activator of transcription 4 (STAT4) in the peripheral blood with the disease activity in patients with rheumatoid arthritis (RA).</p><p><b>METHODS</b>Twenty-four RA patients in active stage (DAS28 score>or=2.6) and 14 RA patients in remission stage (DAS28 score<2.6) were enrolled in this study, with 12 healthy volunteers as the control. The QuantiGene Plex method was used to measure the expression level of HLA-DR4, PAD4, and STAT4 mRNA, and the relationship between the expressions of these genes and the DAS28 score, levels of anti-cyclic citrullinated peptide antibody (anti-CCP antibody) and rheumatoid factor (RF) was analyzed.</p><p><b>RESULTS</b>The expressions of HLA-DR4, PAD4, and STAT4 were significantly higher in RA patients than in the healthy controls (P<0.05). The level of HLA-DR4 mRNA in the two RA groups showed no significant difference, but was significantly higher than that in the healthy controls. HLA-DR4 expression was not found to correlated to DAS28 score, anti-CCP antibody level or RF in the RA patients. The expressions of PAD4 and STAT4 were significantly different between the two RA groups (P<0.05). In the RA patients, PAD4 mRNA expression was positively correlated to DAS28 and anti-CCP antibody level (P<0.05), and STAT4 expression showed positive correlations to DAS28 and RF levels (P<0.05).</p><p><b>CONCLUSION</b>HLA-DR4, PAD4 and STAT4 are overexpressed in RA patients and may be involved in the pathogenesis of RA. The expressions of PAD4 and STAT4, but not HLA-DR4, are closely related to the disease activity of RA. Detection of peripheral blood PAD4 and STAT4 expressions can be helpful for evaluating the disease activity of RA.</p>

Therapeutic effect of infliximab on moderate and severe active rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the clinical efficacy of infliximab in the treatment of moderate and severe active rheumatoid arthritis (RA).</p><p><b>METHODS</b>This randomized double-blind II/III clinical trial involved 30 patients with moderate and severe active RA, who were randomly allocated into 3 groups (groups A, B, and C) at the ratio of 3:1:1. At weeks 0, 2, 6, and 14, the patients in groups A and C received infliximab or placebo, and those in group B had placebo at week 14 with a stable background dose of methotrexate. The indicators for efficacy evaluation included the proportions of ACR20/50/70 of the responders and DAS28. The sharp scores of the hand joints were recorded before and after the treatment.</p><p><b>RESULTS</b>Twenty-nine patients completed the clinical trial (18 in group A, 5 in group B, and 6 in group C). At week 14, the proportions of ACR20/50/70 in the 3 groups reached 83.33%, 60%, and 33.33%, respectively (P<0.05), as compared to 100%, 100%, and 33.33% at week 18 (P<0.05). The other indicators for clinical efficacy evaluation also suggested similar clinical improvement of the patients (P=0.000). The proportions of the patients with DAS28<3.2 and DAS28<2.6 were significantly different. Compared to the baseline, the Sharp scores in group A showed no significant changes at week 18 (P>0.930), while those in group C exhibited significant radiographic progression (P<0.044).</p><p><b>CONCLUSION</b>Infliximab produces good short-term therapeutic effect against moderate and severe active RA and may help arrest the radiographic progression of the diseases, which can be more obvious in patients with moderate severity.</p>

Partial correlation investigation on the default mode network involved in acupuncture: an fMRI study.

Certain clinical reports and researches have shown that acupuncture effects can sustain a period during the post-stimulation state, and modulate the default mode network (DMN). In this study, partial correlation approach was utilized to investigate whether or not electro-acupuncture stimulation (EAS) at the three acupoints (GB37 (Guangming), BL60 (Kunlun) and KI8 (Jiaoxin)) and one sham point on the left leg modulated the DMN and how to change the intrinsic connectivity of the DMN. The results indicated that DMN could be modulated after EAS, and there existed different modulation patterns of the four points. Meanwhile, we found that the posterior cingulate cortex and precuneus (PCC/pC) strongly interacted with other nodes during the pre- and post-stimulation states. The correlation was interrupted between the PCC/pC and anterior cingulate cortex (ACC). The orbital prefrontal cortex (OFC) negatively interacted with the left medial temporal cortex (lMTC) at the acupoints. We suggested that the distinct modulation patterns to the DMN attributed to the different effects evoked by the three acupoints and one sham point.

Anti-tumor and bystander effects of cationic liposome-mediated CD/5-FC suicide gene system combined with interferon-gamma in vivo / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the antitumor and distant bystander effects of cationic liposome-mediated cytosine deaminase (CD)/5-fluorocytosine (5-FC) suicide gene system combined with interferon-gamma (IFN-gamma) in vivo.</p><p><b>METHODS</b>Murine hepatoma 22 (H22) cells transfected by CD gene were inoculated subcutaneous in Kunming mice in the left axillary region, and the H22 cells without CD gene transfection were inoculated in the right axillary region. The mice were randomly divided into 4 groups and treated with normal saline , 5-FC, IFN-gamma, and 5-FC+ IFN-gamma on a daily basis. The tumor inhibition and distant bystander effects were observed in the mice.</p><p><b>RESULTS</b>Exposure of CD gene-transfected tumor to 5-Fc resulted in obvious tumor growth inhibition with an inhibition rate of 78.38%, which was significantly increased to 93.21% (P<0.01) with 5-Fc +IFN-gamma treatment. A notable distant bystander effect in the CD/5-FC suicide gene system was observed in vivo, with a tumor inhibition rate of was 54.42%; when combined with IFN-gamma, the inhibition rate increased significantly to 87.57% (P<0.05).</p><p><b>CONCLUSION</b>When combined with IFN-gamma, CD/5-FC suicide system has stronger anti-tumor and distant bystander effects. CD/5-FC suicide gene system combined with IFN-gamma may provide a potential therapy for malignant tumors.</p>