Transcription factor ZmEREB97 regulates nitrate uptake in maize (Zea mays) roots.

Maize (Zea mays L.) has very strong requirements for nitrogen. However, the molecular mechanisms underlying the regulations of nitrogen uptake and translocation in this species are not fully understood. Here, we report that an APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor ZmEREB97 functions as an important regulator in the N-signaling network in maize. Predominantly expressed and accumulated in main root and lateral root primordia, ZmEREB97 rapidly responded to nitrate treatment. By overlapping the analyses of differentially expressed genes and conducting a DAP-seq assay, we identified 1446 potential target genes of ZmEREB97. Among these, 764 genes were co-regulated in two lines of zmereb97 mutants. Loss of function of ZmEREB97 substantially weakened plant growth under both hydroponic and soil conditions. Physiological characterization of zmereb97 mutant plants demonstrated that reduced biomass and grain yield were both associated with reduced nitrate influx, decreased nitrate content and less N accumulation. We further demonstrated that ZmEREB97 directly targets and regulates the expression of six ZmNRT genes by binding to the GCC box-related sequences in gene promoters. Collectively, these data suggest that ZmEREB97 is a major positive regulator of the nitrate response and that it plays an important role in optimizing nitrate uptake, offering a target for improvement of nitrogen use efficiency in crops.

Nitrogen-dependent binding of the transcription factor PBF1 contributes to the balance of protein and carbohydrate storage in maize endosperm.

Fluctuations in nitrogen (N) availability influence protein and starch levels in maize (Zea mays) seeds, yet the underlying mechanism is not well understood. Here, we report that N limitation impacted the expression of many key genes in N and carbon (C) metabolism in the developing endosperm of maize. Notably, the promoter regions of those genes were enriched for P-box sequences, the binding motif of the transcription factor prolamin-box binding factor 1 (PBF1). Loss of PBF1 altered accumulation of starch and proteins in endosperm. Under different N conditions, PBF1 protein levels remained stable but PBF1 bound different sets of target genes, especially genes related to the biosynthesis and accumulation of N and C storage products. Upon N-starvation, the absence of PBF1 from the promoters of some zein genes coincided with their reduced expression, suggesting that PBF1 promotes zein accumulation in the endosperm. In addition, PBF1 repressed the expression of sugary1 (Su1) and starch branching enzyme 2b (Sbe2b) under normal N supply, suggesting that, under N-deficiency, PBF1 redirects the flow of C skeletons for zein toward the formation of C compounds. Overall, our study demonstrates that PBF1 modulates C and N metabolism during endosperm development in an N-dependent manner.

Analysis of deep inspiration breath-hold technique to improve dosimetric and clinical advantages in postoperative intensity-modulated radiation therapy for thymomas.

Background: Radiation therapy is one of the essential treatment modalities for invasive thymomas. Clinically, respiratory motion poses a challenge for the radiotherapy of thoracic tumors. One method to address this issue is to train patients to hold their breath at the end of deep inspiration. The purpose of this retrospective cohort study was to investigate the dosimetric and clinical advantages of the deep inspiration breath-hold (DIBH) technique in postoperative intensity-modulated radiation therapy (IMRT) for thymomas. Methods: Thymoma patients undergoing postoperative IMRT were included. Each patient underwent two computed tomography (CT) scans, one under free breath (FB) and the other under DIBH. Dosimetric parameters of organs at risk (OARs) were evaluated in three series plans. Dose analysis and volume comparisons were conducted during FB-3 mm (FB with 3 mm internal target volume margin), FB-10 mm (FB with 10 mm internal target volume margin), and DIBH and compared using a paired sample Student's t-test. Normal tissue complication probabilities (NTCP) for lungs and heart were calculated and compared. Results: The total lung volume significantly increased by 31% (4,216±198 vs. 2,884±166 mL) and the heart volume reduced by 12% (552±25 vs. 636±35 mL) between DIBH acquisitions compared to FB. A significant improvement was observed in all the dosimetric parameters (Dmean, V20, V5) of the lung on DIBH compared to FB-3 mm (54%±2.85% vs. 47%±2.90%, P<0.001; 15%±1.37% vs. 12%±1.32%, P=0.004; and 10.28±0.58 vs. 8.76±0.57 Gy, P<0.001, respectively), as well as in the Dmax and D2% of the esophagus and spine. The lung volume increment was related to a reduction in the mean dose of lungs, with a correlation coefficient of r=0.27, P=0.03. The NTCP values for pneumonitis significantly reduced with DIBH compared to the FB state (0.6% vs. 1.1%, P<0.001). Conclusions: The radiation dose to the OARs can be significantly reduced by using the DIBH technique in postoperative IMRT for thymomas. The increased volume of lungs using DIBH acquisitions can significantly reduce the incidence of pneumonitis.

Serum cytokine profiling reveals different immune response patterns during general and severe Mycoplasma pneumoniae pneumonia.

Mycoplasma pneumoniae (MP) is an important human pathogen that mainly affects children causing general and severe Mycoplasma pneumoniae pneumonia (G/SMPP). In the present study, a comprehensive immune response data (33 cytokines) was obtained in school-age children (3-9 years old) during MPP, aiming to analyze the immune response patterns during MPP. At acute phase, changes of cytokines were both detected in GMPP (24/33) and SMPP (23/33) groups compared to the healthy group (p < 0.05), with 20 identical cytokines. Between MPP groups, the levels of 13 cytokines (IL-2, IL-10, IL-11, IL-12, IL-20, IL-28A, IL-32, IL-35, IFN-α2, IFN-γ, IFN-ß, BAFF, and TSLP) were higher and three cytokines (LIGHT, OPN and CHI3L1) were lower in the SMPP group than in the GMPP group (p < 0.05). Function analysis reveals that macrophage function (sCD163, CHI3L1) are not activated in both MPP groups; difference in regulatory patterns of T cells (IL26, IL27, OPN, LIGHT) and defective activation of B cells (BAFF) were detected in the SMPP group compared to the GMPP group. Besides, the level of osteocalcin; sIL-6Rß and MMP-2 are both decreased in MPP groups at acute and convalescent phases compared to the healthy group, among which the levels of sIL-6Rß and MMP-2 showed negative correlations (p < 0.1) to the application of bronchial lavage in SMPP group, indicating their roles in the development of MPP. At the convalescent phase, more cytokines recovered in GMPP (18) than SMPP (11), revealing better controlled immune response during GMPP. These results reveal different immune response patterns during GMPP and SMPP. In addition, the differentiated cytokines may serve as potential indicators of SMPP; early intervention on immune response regulations may be helpful in reducing the severity of SMPP.

Immobilization-assisted abdominal deep inspiration breath-hold in post-mastectomy radiotherapy of left-sided breast cancer with internal mammary chain coverage.

BACKGROUND: Whether to prophylactically irradiate the ipsilateral internal mammary chain (IMC) in post-mastectomy radiotherapy (PMRT) remains controversial because of equivocal clinical benefits against the added toxicities. Our previous study revealed that the cardiac dose was decreased during left-sided breast radiotherapy with abdominal deep inspiration breath-hold (aDIBH) as compared with free-breathing (FB) and thoracic deep inspiration breath-hold (tDIBH). Here we present the dosimetric advantage of aDIBH for patients undergoing PMRT with IMC coverage. METHODS: We prospectively analyzed 19 patients with left-sided breast cancer who underwent PMRT. Patients underwent computed tomography (CT) simulation under both free-breathing (FB) and aDIBH. The heart, left anterior descending coronary artery (LAD), lungs, and the contralateral breast was defined as organs at risk (OARs). Three-dimensional conformal radiation therapy (3D-CRT), inverse planning intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT) were used to calculate the doses received by both the planning target volume (PTV) and OARs, which were compared using the Wilcoxon signed-rank test. RESULTS: Compared with FB, the Dmean of the heart and LAD were respectively reduced by 3.5 Gy (P<0.003) and 8.9 Gy (P<0.001) in 3D-CRT, 2.6 Gy (P<0.001), and 7.8 Gy (P=0.001) in IMRT, 1.5 Gy (P<0.001) and 4.5 Gy (P=0.001) in VMAT plans under aDIBH. Among all these plans, the Dmean of the heart was lowest in aDIBH IMRT and 1.3 Gy lower than in aDIBH VMAT (P=0.002). aDIBH IMRT also resulted in a significantly reduced dose to the ipsilateral lung than plans under FB (P<0.05). Dmean and V5 to the contralateral lung and breast were higher in VMAT plans (P<0.05). CONCLUSIONS: Using an immobilization-assisted aDIBH technique, radiation doses to the heart can be kept at reasonably low levels even if IMC is included in the clinical target volume (CTV). Among 3D-CRT, IMRT, and VMAT plans, IMRT plus aDIBH results in the best heart-sparing effect. We recommend that the aDIBH technique be routinely applied in suitable patients if the IMC is irradiated.

Reduction in rectal doses of pelvic radiotherapy with excessive rectal gas extraction: a single-institution case report.

During radiotherapy for pelvic tumors, there might be insufficient radiation doses delivered that result from concerns of immediately adjacent critical organs, most notebly the rectum. Several measures have been proposed to reduce the rectal doses, such as use of a radioprotective spacer to shift the rectum away from the lesion or an endorectal balloon to reduce the internal target volume (ITV). The removal of rectal gas is supposed to achieve the similar effect by reducing the rectal volume and ITV. This is because the distance of the rectum to lesions can be increased with decreasing rectal volumes, which also makes it easy for physicists to avoid the rectum during field design. Besides, a reduced ITV can be obtained due to stability in rectal volume, as with use of an endorectal balloon. The procedure is most suitable for patients receiving stereotactic body radiotherapy (SBRT) and high dose rate brachytherapy (HDR-BR) because of limited treatment sessions. In this study, we showed that the rectal dose decreased significantly with rectal gas extraction, as manifested by dose parameters of D2 cm3 and D0.1 cm3 (the doses delivered to the most exposed 2 cm, 3 and 0.1 cm3 of the rectum, respectively). This technique is especially benefitable for candidates with excessive rectal gas fillings.

Identification of loci and candidate gene GmSPX-RING1 responsible for phosphorus efficiency in soybean via genome-wide association analysis.

BACKGROUND: Phosphorus (P) is an essential element in maintaining high biomass and yield in crops. Soybean [Glycine max (L.) Merr.] requires a large amount of P during growth and development. Improvement of P efficiency and identification of P efficiency genes are important strategies for increasing soybean yield. RESULTS: Genome-wide association analysis (GWAS) with NJAU 355 K SoySNP array was performed to identify single nucleotide polymorphisms (SNPs) significantly associated with three shoot P efficiency-related traits of a natural population of 211 cultivated soybeans and relative values of these traits under normal P (+P) condition and P deficiency (-P) condition. A total of 155 SNPs were identified significantly associated with P efficiency-related traits. SNPs that were significantly associated with shoot dry weight formed a SNP cluster on chromosome 11, while SNPs that were significantly associated with shoot P concentration formed a SNP cluster on chromosome 10. Thirteen haplotypes were identified based on 12 SNPs, and Hap9 was considered as the optimal haplotype. Four SNPs (AX-93636685, AX-93636692, AX-93932863, and AX-93932874) located on chromosome 10 were identified to be significantly associated with shoot P concentration under +P condition in two hydroponic experiments. Among these four SNPs, two of them (AX-93636685 and AX-93932874) were also significantly associated with the relative values of shoot P concentration under two P conditions. One SNP AX-93932874 was detected within 5'-untranslated region of Glyma.10 g018800, which contained SPX and RING domains and was named as GmSPX-RING1. Furthermore, the function research of GmSPX-RING1 was carried out in soybean hairy root transformation. Compared with their respective controls, P concentration in GmSPX-RING1 overexpressing transgenic hairy roots was significantly reduced by 32.75% under +P condition; In contrast, P concentration in RNA interference of GmSPX-RING1 transgenic hairy roots was increased by 38.90 and 14.51% under +P and -P conditions, respectively. CONCLUSIONS: This study shows that the candidate gene GmSPX-RING1 affects soybean phosphorus efficiency by negatively regulating soybean phosphorus concentration in soybean hairy roots. The SNPs and candidate genes identified should be potential for improvement of P efficiency in future soybean breeding programs.

High-resolution profile of transcriptomes reveals a role of alternative splicing for modulating response to nitrogen in maize.

BACKGROUND: The fluctuation of nitrogen (N) contents profoundly affects the root growth and architecture in maize by altering the expression of thousands of genes. The differentially expressed genes (DEGs) in response to N have been extensively reported. However, information about the effects of N variation on the alternative splicing in genes is limited. RESULTS: To reveal the effects of N on the transcriptome comprehensively, we studied the N-starved roots of B73 in response to nitrate treatment, using a combination of short-read sequencing (RNA-seq) and long-read sequencing (PacBio-sequencing) techniques. Samples were collected before and 30 min after nitrate supply. RNA-seq analysis revealed that the DEGs in response to N treatment were mainly associated with N metabolism and signal transduction. In addition, we developed a workflow that utilizes the RNA-seq data to improve the quality of long reads, increasing the number of high-quality long reads to about 2.5 times. Using this workflow, we identified thousands of novel isoforms; most of them encoded the known functional domains and were supported by the RNA-seq data. Moreover, we found more than 1000 genes that experienced AS events specifically in the N-treated samples, most of them were not differentially expressed after nitrate supply-these genes mainly related to immunity, molecular modification, and transportation. Notably, we found a transcription factor ZmNLP6, a homolog of AtNLP7-a well-known regulator for N-response and root growth-generates several isoforms varied in capacities of activating downstream targets specifically after nitrate supply. We found that one of its isoforms has an increased ability to activate downstream genes. Overlaying DEGs and DAP-seq results revealed that many putative targets of ZmNLP6 are involved in regulating N metabolism, suggesting the involvement of ZmNLP6 in the N-response. CONCLUSIONS: Our study shows that many genes, including the transcription factor ZmNLP6, are involved in modulating early N-responses in maize through the mechanism of AS rather than altering the transcriptional abundance. Thus, AS plays an important role in maize to adapt N fluctuation.

Cross-Species Root Transcriptional Network Analysis Highlights Conserved Modules in Response to Nitrate between Maize and Sorghum.

Plants have evolved complex mechanisms to respond to the fluctuation of available nitrogen (N) in soil, but the genetic mechanisms underlying the N response in crops are not well-documented. In this study, we generated a time series of NO3--mediated transcriptional profiles in roots of maize and sorghum, respectively. Using weighted gene co-expression network analysis, we identified modules of co-expressed genes that related to NO3- treatments. A cross-species comparison revealed 22 conserved modules, of which four were related to hormone signaling, suggesting that hormones participate in the early nitrate response. Three other modules are composed of genes that are mainly upregulated by NO3- and involved in nitrogen and carbohydrate metabolism, including NRT, NIR, NIA, FNR, and G6PD2. Two G2-like transcription factors (ZmNIGT1 and SbNIGT1), induced by NO3- stimulation, were identified as hub transcription factors (TFs) in the modules. Transient assays demonstrated that ZmNIGT1 and SbNIGT1 are transcriptional repressors. We identified the target genes of ZmNIGT1 by DNA affinity-purification sequencing (DAP-Seq) and found that they were significantly enriched in catalytic activity, including carbon, nitrogen, and other nutrient metabolism. A set of ZmNIGT1 targets encode transcription factors (ERF, ARF, and AGL) that are involved in hormone signaling and root development. We propose that ZmNIGT1 and SbNIGT1 are negative regulators of nitrate responses that play an important role in optimizing nutrition metabolism and root morphogenesis. Together with conserved N responsive modules, our study indicated that, to encounter N variation in soil, maize and sorghum have evolved an NO3--regulatory network containing a set of conserved modules and transcription factors.

The NIN-like protein 5 (ZmNLP5) transcription factor is involved in modulating the nitrogen response in maize.

Maize exhibits marked growth and yield response to supplemental nitrogen (N). Here, we report the functional characterization of a maize NIN-like protein ZmNLP5 as a central hub in a molecular network associated with N metabolism. Predominantly expressed and accumulated in roots and vascular tissues, ZmNLP5 was shown to rapidly respond to nitrate treatment. Under limited N supply, compared with that of wild-type (WT) seedlings, the zmnlp5 mutant seedlings accumulated less nitrate and nitrite in the root tissues and ammonium in the shoot tissues. The zmnlp5 mutant plants accumulated less nitrogen than the WT plants in the ear leaves and seed kernels. Furthermore, the mutants carrying the transgenic ZmNLP5 cDNA fragment significantly increased the nitrate content in the root tissues compared with that of the zmnlp5 mutants. In the zmnlp5 mutant plants, loss of the ZmNLP5 function led to changes in expression for a significant number of genes involved in N signalling and metabolism. We further show that ZmNLP5 directly regulates the expression of nitrite reductase 1.1 (ZmNIR1.1) by binding to the nitrate-responsive cis-element at the 5' UTR of the gene. Interestingly, a natural loss-of-function allele of ZmNLP5 in Mo17 conferred less N accumulation in the ear leaves and seed kernels resembling that of the zmnlp5 mutant plants. Our findings show that ZmNLP5 is involved in mediating the plant response to N in maize.

RNA-Seq analysis reveals transcript diversity and active genes after common cutworm (Spodoptera litura Fabricius) attack in resistant and susceptible wild soybean lines.

BACKGROUND: Common cutworm (CCW) is highly responsible for destabilizing soybean productivity. Wild soybean is a resource used by breeders to discover elite defensive genes. RESULTS: The transcriptomes of two wild accessions (W11 and W99) with different resistance to CCW were analyzed at early- and late-induction time points. After induction, the susceptible accession W11 differentially expressed 1268 and 508 genes at the early and late time points, respectively. Compared with W11, the resistant accession W99 differentially expressed 1270 genes at the early time point and many more genes (2308) at the late time point. In total, 3836 non-redundant genes were identified in both lines. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the differentially expressed genes (DEGs) in W99 at the late time point were mostly associated with specific processes and pathways. Among the non-redundant genes, 146 genes were commonly up-regulated in the treatment condition compared with the control condition at the early- and late-induction time points in both accessions used in this experiment. Approximately 40% of the common DEGs were related to secondary metabolism, disease resistance, and signal transduction based on their putative function. Excluding the common DEGs, W99 expressed more unique DEGs than W11. Further analysis of the 3836 DEGs revealed that the induction of CCW not only up-regulated defense-related genes, including 37 jasmonic acid (JA)-related genes, 171 plant-pathogen-related genes, and 17 genes encoding protease inhibitors, but also down-regulated growth-related genes, including 35 photosynthesis-related genes, 48 nutrition metabolism genes, and 28 auxin metabolism genes. Therefore, representative defense-related and growth-related genes were chosen for binding site prediction via co-expression of transcription factors (TFs) and spatial expression pattern analyses. In total, 53 binding sites of 28 TFs were identified based on 3 defense-related genes and 3 growth-related genes. Phosphate transporter PT1, which is a representative growth-related gene, was transformed into soybean, and the transgenic soybean plants were susceptible to CCW. CONCLUSIONS: In summary, we described transcriptome reprograming after herbivore induction in wild soybean, identified the susceptibility of growth-related genes, and provided new resources for the breeding of herbivore-resistant cultivated soybeans.

A cation diffusion facilitator, GmCDF1, negatively regulates salt tolerance in soybean.

Salt stress is one of the major abiotic factors that affect the metabolism, growth and development of plants, and soybean [Glycine max (L.) Merr.] germination is sensitive to salt stress. Thus, to ensure the successful establishment and productivity of soybeans in saline soil, the genetic mechanisms of salt tolerance at the soybean germination stage need to be explored. In this study, a population of 184 recombinant inbred lines (RILs) was utilized to map quantitative trait loci (QTLs) related to salt tolerance. A major QTL related to salt tolerance at the soybean germination stage named qST-8 was closely linked with the marker Sat_162 and detected on chromosome 8. Interestingly, a genome-wide association study (GWAS) identified several single nucleotide polymorphisms (SNPs) significantly associated with salt tolerance in the same genetic region on chromosome 8. Resequencing, bioinformatics and gene expression analyses were implemented to identify the candidate gene Glyma.08g102000, which belongs to the cation diffusion facilitator (CDF) family and was named GmCDF1. Overexpression and RNA interference of GmCDF1 in soybean hairy roots resulted in increased sensitivity and tolerance to salt stress, respectively. This report provides the first demonstration that GmCDF1 negatively regulates salt tolerance by maintaining K+-Na+ homeostasis in soybean. In addition, GmCDF1 affected the expression of two ion homeostasis-associated genes, salt overly sensitive 1 (GmSOS1) and Na+/H+ exchanger 1 (GmNHX1), in transgenic hairy roots. Moreover, a haplotype analysis detected ten haplotypes of GmCDF1 in 31 soybean genotypes. A candidate-gene association analysis showed that two SNPs in GmCDF1 were significantly associated with salt tolerance and that Hap1 was more sensitive to salt stress than Hap2. The results demonstrated that the expression level of GmCDF1 was negatively correlated with salt tolerance in the 31 soybean accessions (r = -0.56, P < 0.01). Taken together, these results not only indicate that GmCDF1 plays a negative role in soybean salt tolerance but also help elucidate the molecular mechanisms of salt tolerance and accelerate the breeding of salt-tolerant soybean.

Abdominal DIBH reduces the cardiac dose even further: a prospective analysis.

BACKGROUND: Deep inspiration breath hold (DIBH) can be performed using different breathing maneuvers, such as DIBH with a thoracic breathing maneuver (T-DIBH) and DIBH with an abdominal breathing maneuver (A-DIBH). Dosimetric benefits of A-DIBH were investigated in the treatment of left-sided breast cancer radiotherapy (RT) with both 3-Dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques. METHODS: Twenty-two patients with left-sided breast cancer were enrolled in this study. 3D-CRT and IMRT plans were generated for each patient with three different CT scans of free breathing (FB), T-DIBH and A-DIBH. There were total of six treatment plans generated for each patient: FB_3D-CRT; TDIBH_3D-CRT; ADIBH_3D-CRT; FB-IMRT; TDIBH-IMRT; ADIBH-IMRT. Doses to the heart, left anterior descending coronary artery (LADCA), and ipsilateral lung were evaluated and compared using the Wilcoxon signed-rank test. RESULTS: The mean doses to the heart, LADCA and ipsilateral lung in 3D-CRT plans generated from 3D-CRT with FB, T-DIBH and A-DIBH were (2.89 ± 1.30), (1.67 ± 0.90) and (1.34 ± 0.43) Gy (all P < 0.05), respectively, with FB; (29.08 ± 16.72), (13.94 ± 14.74) and (10.22 ± 10.30) Gy (all P < 0.05), respectively, with T-DIBH; and (7.77 ± 2.71), (7.32 ± 1.42) and (6.90 ± 1.60) Gy (all P < 0.05), respectively, with A-DIBH. The mean doses to the heart, LADCA and ipsilateral lung in IMRT plans were generated from IMRT with FB, T-DIBH and A-DIBH were (1.96 ± 2.25), (1.37 ± 0.44) and (1.18 ± 0.26) Gy (all P < 0.05), respectively, with FB; (16.10 ± 7.45), (8.6 ± 6.60) and (7.35 ± 5.42) Gy (all P < 0.05), respectively, with T-DIBH; and (5.90 ± 2.24), (5.65 ± 1.58) and (5.62 ± 1.05) Gy (all P > 0.05), respectively, with A-DIBH. CONCLUSIONS: This study indicates that both 3D-CRT and IMRT plans with A-DIBH achieved lower cardiac and LADCA doses than plans with FB and T-DIBH; 3D-CRT plans with A-DIBH achieved lower ipsilateral lung doses than plans with FB and T-DIBH; and IMRT plans with A-DIBH had better outcomes than 3D-CRT plans with A-DIBH with respect to the mean dose to the heart, LADCA and ipsilateral lung. IMRT plans with A-DIBH should be incorporated into the daily routine for left-sided breast RT.

Identification of novel loci for salt stress at the seed germination stage in soybean.

Salt tolerance in soybean [Glycine max (L.) Merr.] at the seed germination stage is a critical determinant of stable stand establishment in saline soil. This study examined one population of 184 recombinant inbred lines (RILs, F7:11) derived from a cross between Kefeng1 and Nannong1138-2 and one natural population consisting of 196 soybean landraces. A total of 11 quantitative trait loci (QTLs) and 22 simple sequence repeat (SSR) loci associated with three salt tolerance indices were detected by linkage and association mapping. The SSR marker Sat_162 was found to be closely linked to the co-localized QTLs at a site 792,811 bp from the gene Glyma08g12400.1, which was verified in response to salt stress at the germination stage. Five SSR markers, Satt201, BE475343, CSSR306, Satt664 and Satt567, were co-associated with two of the salt tolerance indices, and two SSR markers, Satt156 and Satt636, were co-associated with all three salt tolerance indices. Furthermore, elite alleles and their carrier materials were identified by analyzing alleles at the loci associated with these salt tolerance indices. These results may be beneficial for the future breeding of soybean salt tolerance at the germination stage using marker-assisted selection and molecular pyramiding breeding.

Genome-wide characterization of the ankyrin repeats gene family under salt stress in soybean.

Ankyrin repeats (ANK) gene family are common in diverse organisms and play important roles in cell growth, development and response to environmental stresses. Recently, genome-wide identification and evolutionary analyses of the ANK gene family have been carried out in Arabidopsis, rice and maize. However, little is known about the ANK genes in the whole soybean genome. In this study, we described the identification and structural characterization of 162ANK genes in soybean (GmANK). Then, comprehensive bioinformatics analyses of GmANK genes family were performed including gene locus, phylogenetic, domain composition analysis, chromosomal localization and expression profiling. Domain composition analyses showed that GmANK proteins formed eleven subfamilies in soybean. In sicilo expression analysis of these GmANK genes demonstrated that GmANK genes show a diverse/various expression pattern, suggesting that functional diversification of GmANK genes family. Based on digital gene expression profile (DGEP) data between cultivated soybean and wild type under salt treatment, some GmANKs related to salt/drought response were investigated. Moreover, the expression pattern and subcellular localization of GmANK6 were performed. The results will provide important clues to explore ANK genes expression and function in future studies in soybean.

Association analysis for detecting significant single nucleotide polymorphisms for phosphorus-deficiency tolerance at the seedling stage in soybean [Glycine max (L) Merr].

Tolerance to low-phosphorus soil is a desirable trait in soybean cultivars. Previous quantitative trait locus (QTL) studies for phosphorus-deficiency tolerance were mainly derived from bi-parental segregating populations and few reports from natural population. The objective of this study was to detect QTLs that regulate phosphorus-deficiency tolerance in soybean using association mapping approach. Phosphorus-deficiency tolerance was evaluated according to five traits (plant shoot height, shoot dry weight, phosphorus concentration, phosphorus acquisition efficiency and use efficiency) comprising a conditional phenotype at the seedling stage. Association mapping of the conditional phenotype detected 19 SNPs including 13 SNPs that were significantly associated with the five traits across two years. A novel cluster of SNPs, including three SNPs that consistently showed significant effects over two years, that associated with more than one trait was detected on chromosome 3. All favorable alleles, which were determined based on the mean of conditional phenotypic values of each trait over the two years, could be pyramided into one cultivar through parental cross combination. The best three cross combinations were predicted with the aim of simultaneously improving phosphorus acquisition efficiency and use efficiency. These results will provide a thorough understanding of the genetic basis of phosphorus deficiency tolerance in soybean.

[Study on hemolytic mechanism of polyphyllin II].

To study the hemolytic effect of polyphyllin II (PP II) mediated by anion channel protein and glucose transporter 1 (GLUT1), in order to initially reveal its hemolytic mechanism in vitro. In the experiment, the spectrophotometric method was adopted to detect the hemolysis of PP II in vitro and the effect of anion channel-related solution and blocker, glucose channel-related inhibitor and multi-target drugs dehydroepiandrosterone (DHEA) and diazepam on the hemolysis of PP II. The scanning electron microscope and transmission electron microscope were used to observe the effect of PP II on erythrocyte (RBC) morphology. The results showed that PP II -processed blood cells were severely deformed into spherocytes, acanthocyturia and vesicae. According to the results of the PP II hemolysis experiment in vitro, the anion hypertonic solution LiCl, NaHCO3, Na2SO4 and PBS significantly inhibited the hemolysis induced by PP II (P < 0.05), while blockers NPPB and DIDS remarkably promoted it (P < 0.01). Hyperosmotic sodium chloride, fructose and glucose at specific concentrations notably antagonized the hemolysis induced by PP II (P < 0.05). The glucose channel inhibitor Cytochalasin B and verapamil remarkably antagonized the hemolysis induced by PP II (P < 0.01). The hemolysis induced by PP II could also be antagonized by 1 gmol x L(1) diazepam and 100 µmol x L(-1) DHEA pretreated for 1 min (P < 0.01). In conclusion, the hemolytic mechanism of PP II in vitro may be related to the increase in intracellular osmotic pressure and rupture of erythrocytes by changing the anion channel transport activity, with GLUT1 as the major competitive interaction site.

[Epidemiological survey of childhood asthma in 2010 in urban Baotou, China].

OBJECTIVE: To investigate the prevalence rate of childhood asthma in 2010 in urban Baotou, China, as well as the characteristics of attacks and the status of diagnosis and treatment of childhood asthma. METHODS: More than 10 000 children (0-14 years) were selected from 3 secondary schools, 3 primary schools, 6 kindergartens, and 4 community vaccination sites in urban Baotou by cluster random sampling between September 2009 and August 2010. A standardized preliminary questionnaire was used for screening out suspected cases, which were then confirmed or excluded by a clinician; the confirmed cases underwent further questionnaire survey. Double entry and validation was adopted for all data using Epi-Info software, and analysis was performed using SPSS 13.0. RESULTS: A total of 11 323 children were surveyed. Asthma was diagnosed in 127 cases (including 121 children with typical asthma and 6 children with cough variant asthma), with a prevalence rate of 1.12%. The prevalence rate of asthma in male children was significantly higher than that in female children (1.51% vs 0.72%; P<0.01). The prevalence rate of asthma in 2010 was significantly increased compared with that in 1990 (0.55%) and 2000 (0.88%) (P<0.05). Systemic glucocorticoid use decreased significantly from 60.2% in 2000 to 25.9% in 2010 (P<0.01); inhaled corticosteroid use increased significantly from 13.6% in 2000 to 85.8% in 2010 (P<0.01); antibiotic use decreased from 98.1% in 2000 to 66.9% in 2010 (P<0.01). The multivariate logistic regression analysis showed that family history of allergy, allergic rhinitis, chronic cough, and recurrent respiratory tract infection were independent risk factors for childhood asthma. CONCLUSIONS: The prevalence rate of childhood asthma in urban Baotou shows an increasing trend. Inhaled corticosteroids have been widely used.

Functional properties and expression quantitative trait loci for phosphate transporter GmPT1 in soybean.

Phosphate (Pi) remobilization within a plant is critical for plant survival under Pi-limiting conditions. In this paper, a soybean Pi transporter gene, GmPT1, was characterized. A marked induction of GmPT1 transcript was observed in young leaves, mature leaves and lateral roots during long-term Pi starvation. Transgenic tobacco plants containing the GmPT1 gene were obtained using an Agrobacterium-mediated transformation system. Compared with wild-type plants, transgenic plants showed significant increases in phosphorus-use efficiency (PUE), photosystem II (PSII) function, total dry weight and seed weight under Pi-deficient conditions. GmPT1 expression levels and PUE were determined in a soybean recombinant inbred line population during a pot experiment that was conducted to measure chlorophyll fluorescence parameters, photosynthetic rate (PN ) and seed yield. Correlation analysis revealed that GmPT1 expression levels had significantly positive correlations with seed yield, PUE, PN and the quantum yield of PSII primary photochemistry (ΦPSII ). Expression quantitative trait loci (eQTL) mapping for GmPT1 revealed two eQTLs, one of which coincided with both the physical location of GmPT1 and a QTL associated with seed yield. These results suggest that GmPT1 plays a role in Pi remobilization, and it may be possible to improve soybean seed yields under Pi-limiting conditions by modulating GmPT1 expression levels.

Clinical Significance of the Dynamic Changes in Serum Eotaxin, Interleukin 13 and Total IgE in Children with Bronchial Asthma.

OBJECTIVE: To determine the serum levels of eotaxin, IL-13 and total IgE (TIgE) in asthmatic children during the acute and clinical remission periods, as well as the changes in pulmonary function to determine their roles, relationships and clinical significance during asthma exacerbation. METHODS: A total of 30 asthmatic children and 22 healthy children were enrolled in the study. The serum eotaxin and IL-13 levels were detected using an enzyme-linked immunosorbent assay and the TIgE level was detected using a fluorescent enzyme-linked immunosorbent assay. The asthmatic children were subjected to pulmonary function tests. FINDINGS: The serum eotaxin, IL-13 and TIgE levels of the asthmatic children during the acute period significantly differed from those during clinical remission. The serum eotaxin, IL-13 and TIgE levels of the asthmatic children during both periods significantly differed from those of healthy children (P<0.001). The serum eotaxin levels during the acute and clinical remission periods were positively correlated with serum IL-13 and with TIgE, and serum IL-13 was correlated with serum TIgE. The pulmonary function indices of asthmatic children during the acute period significantly differed from those during clinical remission (P<0.001). The serum eotaxin and IL-13 levels in the asthmatic children were positively correlated with the forced expiratory volume in 1 second (FEV1) and the peak expiratory flow (PEF) during the acute and clinical remission periods (P<0.05). However, the serum TIgE levels in asthmatic children were not significantly correlated with the FEV1 and PEF during both periods (P>0.05). CONCLUSION: Serum TIgE, IL-13 and eotaxin influence each other during exacerbation of bronchial asthma and influence the corresponding pathophysiologic changes. Serum IL-13 and eotaxin could be used as markers for evaluating the severity of bronchial asthma.