Fine-tuning rice heading date through multiplex editing of the regulatory regions of key genes by CRISPR-Cas9.

Heading date (or flowering time) is a key agronomic trait that affects seasonal and regional adaption of rice cultivars. An unoptimized heading date can either not achieve a high yield or has a high risk of encountering abiotic stresses. There is a strong demand on the mild to moderate adjusting the heading date in breeding practice. Genome editing is a promising method which allows more precise and faster changing the heading date of rice. However, direct knock out of major genes involved in regulating heading date will not always achieve a new germplasm with expected heading date. It is still challenging to quantitatively adjust the heading date of elite cultivars with best adaption for broader region. In this study, we used a CRISPR-Cas9 based genome editing strategy called high-efficiency multiplex promoter-targeting (HMP) to generate novel alleles at cis-regulatory regions of three major heading date genes: Hd1, Ghd7 and DTH8. We achieved a series of germplasm with quantitative variations of heading date by editing promoter regions and adjusting the expression levels of these genes. We performed field trials to screen for the best adapted lines for different regions. We successfully expanded an elite cultivar Ningjing8 (NJ8) to a higher latitude region by selecting a line with a mild early heading phenotype that escaped from cold stress and achieved high yield potential. Our study demonstrates that HMP is a powerful tool for quantitatively regulating rice heading date and expanding elite cultivars to broader regions.

The superior allele LEA12OR in wild rice enhances salt tolerance and yield.

Soil salinity has negative impacts on food security and sustainable agriculture. Ion homeostasis, osmotic adjustment and reactive oxygen species scavenging are the main approaches utilized by rice to resist salt stress. Breeding rice cultivars with high salt tolerance (ST) and yield is a significant challenge due to the lack of elite alleles conferring ST. Here, we report that the elite allele LEA12OR, which encodes a late embryogenesis abundant (LEA) protein from the wild rice Oryza rufipogon Griff., improves osmotic adjustment and increases yield under salt stress. Mechanistically, LEA12OR, as the early regulator of the LEA12OR-OsSAPK10-OsbZIP86-OsNCED3 functional module, maintains the kinase stability of OsSAPK10 under salt stress, thereby conferring ST by promoting abscisic acid biosynthesis and accumulation in rice. The superior allele LEA12OR provides a new avenue for improving ST and yield via the application of LEA12OR in current rice through molecular breeding and genome editing.

Optimization of the Preparation Process of Glucuronomannan Oligosaccharides and Their Effects on the Gut Microbiota in MPTP-Induced PD Model Mice.

Parkinson's disease (PD) is a prevalent neurodegenerative disorder, and accumulating evidence suggests a link between dysbiosis of the gut microbiota and the onset and progression of PD. In our previous investigations, we discovered that intraperitoneal administration of glucuronomannan oligosaccharides (GMn) derived from Saccharina japonica exhibited neuroprotective effects in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. However, the complicated preparation process, difficulties in isolation, and remarkably low yield have constrained further exploration of GMn. In this study, we optimized the degradation conditions in the preparation process of GMn through orthogonal experiments. Subsequently, an MPTP-induced PD model was established, followed by oral administration of GMn. Through a stepwise optimization, we successfully increased the yield of GMn, separated from crude fucoidan, from 1~2/10,000 to 4~8/1000 and indicated the effects on the amelioration of MPTP-induced motor deficits, preservation of dopamine neurons, and elevation in striatal neurotransmitter levels. Importantly, GMn mitigated gut microbiota dysbiosis induced by MPTP in mice. In particular, GM2 significantly reduced the levels of Akkermansia, Verrucomicrobiota, and Lactobacillus, while promoting the abundance of Roseburia and Prevotella compared to the model group. These findings suggest that GM2 can potentially suppress PD by modulating the gut microbiota, providing a foundation for the development of a novel and effective anti-PD marine drug.

Alternative splicing of OsGS1;1 affects nitrogen-use efficiency, grain development, and amylose content in rice.

Excessive nitrogen fertilizer application is harmful to the environment and reduces the quality of cereal crops. Maintaining crop yields under low nitrogen (LN) conditions and improving quality are important goals for cereal crop breeding. Although the effects of nitrogen assimilation on crop nitrogen-use efficiency (NUE) have been intensively studied, natural variations of the key assimilation genes underlying grain development and quality are largely unclear. Here, we identified an NUE-associated gene, OsGS1;1, encoding glutamine synthase, through genome-wide association analysis, followed by validation experiments and functional analysis. Fifteen single-nucleotide polymorphisms in the OsGS1;1 region led to alternative splicing that generated two functional transcripts: OsGS1;1a and OsGS1;1b. The elite haplotype of OsGS1;1 showed high OsGS1;1b activity, which improved NUE, affected grain development, and reduced amylose content. The results show that OsGS1;1, which is induced under LN conditions, affects grain formation by regulating sugar metabolism and may provide a new avenue for the breeding of high-yield and high-quality rice (Oryza sativa).

The expression of autophagy markers in IVIG-resistant Kawasaki disease and the establishment of prediction model.

BACKGROUND: The aim of this study was to find early predictors of Intravenous Immunoglobulin (IVIG)-Resistant Kawasaki Disease. METHODS: Patients diagnosed with Kawasaki disease were enrolled in this study. Univariate analysis and multiple logistic regression were used to analyze the clinical characteristics and laboratory findings of patients in both groups before IVIG treatment. Independent predictors of Intravenous Immunoglobulin-Resistant Kawasaki Disease were analyzed, and a prediction model for children with Intravenous Immunoglobulin-Resistant Kawasaki Disease was constructed. RESULTS: A total of 108 children (67 males and 41 females) with IVIG-sensitive Kawasaki disease and 31 children (20 males and 11 females) with IVIG-resistant Kawasaki disease participated in this study. Compared with the IVIG-sensitive group, the duration of hospitalization, ALT, AST, GLB, r-GT, IgG, PCT, and ESR was elevated in the IVIG-resistant KD group, and ATG16L1, LC3II, BECN1, RBC, HGB, ALB, A/G, and CK were significantly lower (P < 0.05). mRNA expression of ESR, BECN1, and LC3II were independent risk factors for IVIG-resistant Kawasaki disease. A logistic regression model and scoring system were established, and the cut-off values of independent risk factors were derived from ROC curves: ESR ≥ 79.5 mm/h, BECN1 ≤ 0.645, LC3II ≤ 0.481. A new scoring system was established according to the respective regression coefficients as follows: ESR ≥ 79.5 mm/h (1 point), BECN1 ≤ 0.645 (1 point). LC3II ≤ 0.481 (2 points), 0-1 as low risk for IVIG non-response, and ≥ 2 as high risk. Applied to this group of study subjects, the sensitivity was 87.10%, specificity 83.33%, Youden index 0.70, AUC 0.9. CONCLUSIONS: Autophagy markers ATG16L1, BECN1, and LC3II are down-regulated in the expression of IVIG -resistant KD. ESR, BECN1, and LC3II mRNAs are independent risk factors for IVIG-resistant KD and may be involved in the development of IVIG-resistant KD. This study established a new model that can be used to predict IVIG-resistant KD, and future validation in a larger population is needed.

OsTUB1 confers salt insensitivity by interacting with Kinesin13A to stabilize microtubules and ion transporters in rice.

Salt stress is one of the major environmental factors limiting plant growth and development. Although microtubule (MT) organization is known to be involved in response to salt stress, few tubulin genes have been identified that confer salt insensitivity in plants. In this study, we identified a MT encoding gene, OsTUB1, that increased the survival rate of rice plants under salt stress by stabilizing MT organization and ion transporters. We found that OsTUB1 interacted with Kinesin13A protein, which was essential for OsTUB1-regulated MT organization under salt stress. Further molecular evidence revealed that a OsTUB1-Kinesin13A complex protected rice from salt stress by sustaining membrane-localized Na+ transporter OsHKT1;5, a key regulator of ionic homeostasis. Our results shed light on the function of tubulin and kinesin in regulating MT organization and stabilizing Na+ transporters and Na+ flux at the plasma membrane in rice. The identification of the OsTUB1-Kinesin13A complex provides novel genes for salt insensitivity rice breeding in areas with high soil salinity.

Underwater Acoustic Target Recognition Based on Attention Residual Network.

Underwater acoustic target recognition is very complex due to the lack of labeled data sets, the complexity of the marine environment, and the interference of background noise. In order to enhance it, we propose an attention-based residual network recognition method (AResnet). The method can be used to identify ship-radiated noise in different environments. Firstly, a residual network is used to extract the deep abstract features of three-dimensional fusion features, and then a channel attention module is used to enhance different channels. Finally, the features are classified by the joint supervision of cross-entropy and central loss functions. At the same time, for the recognition of ship-radiated noise in other environments, we use the pre-training network AResnet to extract the deep acoustic features and apply the network structure to underwater acoustic target recognition after fine-tuning. The two sets of ship radiation noise datasets are verified, the DeepShip dataset is trained and verified, and the average recognition accuracy is 99%. Then, the trained AResnet structure is fine-tuned and applied to the ShipsEar dataset. The average recognition accuracy is 98%, which is better than the comparison method.

Enhanced OsNLP4-OsNiR cascade confers nitrogen use efficiency by promoting tiller number in rice.

Increased use of nitrogen fertilizers has deleterious impact on the environment. Increase in yield potential at low nitrogen supply is regarded as a cereal breeding goal for future agricultural sustainability. Although natural variations of nitrogen transporters have been investigated, key genes associated with assimilation remain largely unexplored for nitrogen use efficiency (NUE) enhancement. Here, we identified a NIN-like protein NLP4 associated with NUE through a GWAS in rice. We found that OsNLP4 transactivated OsNiR encoding nitrite reductase that was critical in nitrogen assimilation in rice. We further constructed quadrupling NREs (Nitrate-responsive cis-elements) in the promoter of OsNiR (p4xNRE:OsNiR) and enhanced nitrogen assimilation significantly. We demonstrated that OsNLP4-OsNiR increased tiller number and yield through enhancing nitrogen assimilation and NUE. Our discovery highlights the genetic modulation of OsNLP4-OsNiR signalling cascade as a strategy for high NUE and yield breeding in rice.

Titanium oxide-coated titanium-loaded metal organic framework (MOF-Ti) nanoparticles show improved electrorheological performance.

Uniform small-sized MOF-Ti nanoparticles were prepared by a one-step hydrothermal method, and then a 5-10 nm TiO2 shell was coated onto them by using the sol-gel method, and MOF-Ti/TiO2 with a specific surface area of 50.2 m2 g-1 was successfully prepared. The nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption isotherms (BET), and X-ray photoelectron spectroscopy (XPS). The above-analyses have elaborated the experimental study of their morphology, elements, and energy of organic functional groups. At the same time, through the use of a high-voltage rotary rheometer to test their rheological properties, the analysis of shear stress, ER efficiency, shear viscosity, etc. was performed and their dielectric constant and dielectric loss were studied by using a broadband dielectric spectrometer. Finally, we found that MOF-Ti/TiO2 is a new core-shell nanocomposite particle with a small particle size and good electrorheological properties.

Bioinformatic Exploration of the Targets of Xylem Sap miRNAs in Maize under Cadmium Stress.

Cadmium (Cd) has the potential to be chronically toxic to humans through contaminated crop products. MicroRNAs (miRNAs) can move systemically in plants. To investigate the roles of long-distance moving xylem miRNAs in regulating maize response to Cd stress, three xylem sap small RNA (sRNA) libraries were constructed for high-throughput sequencing to identify potential mobile miRNAs in Cd-stressed maize seedlings and their putative targets in maize transcriptomes. In total, about 199 miRNAs (20⁻22 nucleotides) were identified in xylem sap from maize seedlings, including 97 newly discovered miRNAs and 102 known miRNAs. Among them, 10 miRNAs showed differential expression in xylem sap after 1 h of Cd treatment. Two miRNAs target prediction tools, psRNAtarget (reporting the inhibition pattern of cleavage) and DPMIND (discovering Plant MiRNA-Target Interaction with degradome evidence), were used in combination to identify, via bioinformatics, the targets of 199 significantly expressed miRNAs in maize xylem sap. The integrative results of these two bioinformatic tools suggested that 27 xylem sap miRNAs inhibit 34 genes through cleavage with degradome evidence. Moreover, nearly 300 other genes were also the potential miRNAs cleavable targets without available degradome data support, and the majority of them were enriched in abiotic stress response, cell signaling, transcription regulation, as well as metal handling. These approaches and results not only enhanced our understanding of the Cd-responsive long-distance transported miRNAs from the view of xylem sap, but also provided novel insights for predicting the molecular genetic mechanisms mediated by miRNAs.

Variation of drought resistance of rice genotypes released in different years in China.

BACKGROUND: Drought is the most serious limiting factor of rice production worldwide and is becoming more intensive with climate change in recent years. Screening and breeding drought-tolerant rice genotypes are essential to maintain yield gain and ensure food security under adverse environments. However, thus far, little attention has been given to the temporal changes of drought resistance concomitant with the year of release in rice genetic breeding. RESULTS: Sixteen rice genotypes bred or widely cultivated from 1934 to 2007 were grown in paddy fields (control) and upland fields (drought stress) to explore the variation of drought resistance in rice genotypes with the year of release. Grain yield and daily grain yield significantly increased with the year of release. The genetic improvements in the grain yield partially resulted from the significant increase in panicle, spikelets per panicle and filling percentage. In addition, various growth-related characteristics like biomass, harvest index, relative growth rate, grain density and growth duration increased with an increase of genetic refinement of the genotypes through the years, and they contributed to improvement of final rice yields. However, grain yield, yield components and these growth-related traits sharply declined under drought stress. Furthermore, the drought resistance coefficients of KYield , KDaily grain yield , KPanicle number , KSpikelets per panicle , KBiomass , KPlant height , KRelative growth rate and KFilling percentage were prominently improved by genetic breeding. CONCLUSIONS: Drought resistance of rice genotypes has been significantly enhanced by genetic processes during the last 73 years in China, but they are still sensitive to drought conditions. Currently, there is still room for further improvement in drought resistance which is an important target in future breeding programs. © 2019 Society of Chemical Industry.

The preparation and electrorheological behavior of bowl-like titanium oxide nanoparticles.

Bowl-like titanium oxide nanoparticles were successfully prepared by a simple solvothermal method using absolute ethanol and isopropanol as the cosolvent. Ostwald ripening coupled with the inner-stress-induce effect were assumed to play an important role in the formation of this unique bowl-like morphology. The morphological evolution from solid nanosphere to bowl-like nanoparticle was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Besides, the structural characteristics of the as-synthesized TiO2 nanoparticles were confirmed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and thermogravimetric analysis (TGA). Moreover, a rotational rheometer was operated to examine the electrorheological (ER) effect. Excellent ER properties were achieved when the TiO2 particles were dispersed in silicone oil under an external electric field.

Synthesis of anatase TiO2 with exposed (100) facets and enhanced electrorheological activity.

Herein, a simple hydrothermal method is employed to synthesize anatase TiO2 with dominant (100) facets, as a precursor, using titanate nanofibers derived from alkali treatment. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) are carried out to confirm the surface morphology and phase structure of the TiO2 product. The formation mechanism of TiO2 enclosed by (100) and (101) facets is deduced to be the selective adsorption of OH- on the (100) facets of anatase TiO2. Electroheological (ER) experiments indicate that the tetragonal-facet-rod anatase TiO2 with exposed (100) facets exhibits an excellent ER performance with a high ER efficiency of up to 52.5, which results from the anisotropy of its special morphology. In addition, the effect of shape on its dielectric property is investigated via broadband dielectric spectroscopy.

Salt Response Analysis in Two Rice Cultivars at Seedling Stage.

In order to explore the salt-stress responses of two rice varieties, the physiological responses and biochemical responses were investigated using proteomics and classical biochemical methods. The results showed that the seedling growth was inhibited under salt condition in two rice varieties, the seedling growth in the tolerant variety was better than the sensitive variety. The sensitive variety(L7) appeared obvious salt-injury under 3-day salt stress, the tolerant variety (T07339) keep normal growth under 7-day salt stress except that the shoot length was decreased. Through the growth-parameters analysis, most of them in L7 were restrained by salinity and most in T07339 were unaffected. In T07339, the fresh root weight, the content of chlorophyll and the fresh shoot weight were even increased after 7 days of salt stress. A comparison of two-dimensional gel electrophoresis (2-DGE) protein profiles revealed 8 differently expressed proteins. Four proteins were expressed in different pattern between sensitive and tolerant varieties. These results provide novel insights into the investigations of the salt-response proteins that involved in improved salt tolerance.

[Association between platelet-activating factor acetylhydrolase gene polymorphisms and gastrointestinal bleeding in children with Henoch-Schönlein purpura].

OBJECTIVE: To study the association between the single nucleotide polymorphisms (SNPs) of the ninth exon Val279Phe of platelet-activating factor acetylhydrolase (PAF-AH) gene and gastrointestinal bleeding in children with Henoch-Schönlein purpura (HSP). METHODS: A total 516 children with HSP were enrolled, among whom 182 had gastrointestinal bleeding and 334 had no gastrointestinal bleeding. PCR was used to investigate the distribution of genotypes and alleles in the SNPs of Val97Phe. The plasma PAF-AH activity was measured, as well as the levels of platelet-activating factor (PAF), granular membrane protein-140 (GMP-140), ß-thromboglobulin (ß-TG), and platelet factor 4 (PF4). RESULTS: The Val279Phe genotype and allele frequencies were in Hardy-Weinberg equilibrium, and the homozygous genotype TT and heterozygotes accounted for 0.97% and 6.05% respectively. The gastrointestinal bleeding group had a significantly higher allele frequency than the control group (5.22% vs 3.33%; P<0.01). The HSP patients with GG genotype in the gastrointestinal bleeding group had significantly higher levels of plasma PAF and GMP-140 than those in the non-gastrointestinal bleeding group (P<0.05), while the non-gastrointestinal bleeding group had a significantly higher PAF-AH activity than the gastrointestinal bleeding group (P<0.05). There were no significant differences in ß-TG and PF4 between the two groups (P>0.05). CONCLUSIONS: Val279Phe gene polymorphisms in PAF-AH are associated with PAF-AH activity and PAF and GMP-140 levels and may be a risk factor for HSP with gastrointestinal bleeding.

[Detection rate of Helicobacter pylori and its clinical significance in children with Meckel's diverticulum].

OBJECTIVE: To determine the detection rate of Helicobacter pylori (Hp) in children with Meckel's diverticulum (MD) and its clinical significance among children with MD. METHODS: Eighty-one children with MD were divided into two groups according to the presence (n=45) or absence (n=36) of digestive hemorrhage. The detection rates of Hp in MD tissues and stomach tissues were determined by immunohistochemistry. The detection rates of Hp were compared between the two groups and between the MD tissues with different clinical features in the hemorrhage group. RESULTS: The detection rate of Hp in MD tissues for the hemorrhage group was 76% (34/45), which was significantly higher than that for the non-hemorrhage group (47%, 17/36) (P<0.05). The detection rate of Hp in stomach tissues for the hemorrhage group (87%, 39/45) was insignificantly higher than that for the non-hemorrhage group (67%, 24/36) (P>0.05). Among patients in the bleeding group, the detection rate of Hp in MD tissues showed no relationship with age, sex, preoperative hemorrhage frequency, amount of hemorrhage, length of MD, basal diameter of MD, and pathological type (P>0.05), but was related to location of MD, presence or absence of ulcer, and depth of ulcer (P<0.05). For the hemorrhage group, a significant positive correlation was found between the detection rates of Hp in MD tissues and stomach tissues (P<0.05), as shown by the Spearman correlation analysis. CONCLUSIONS: The detection rate of Hp in MD tissues is increased in children with MD complicated by digestive hemorrhage. Hp infection may play some role in the hemorrhage process among children with MD.

Intestinal mucosal permeability of children with cefaclor-associated serum sickness-like reactions.

Although the serum sickness-like reaction (SSLR) in children after the administration of cefaclor has long been recognized, the exact mechanism of cefaclor-associated SSLR remains unclear. This study aims to investigate the association between intestinal mucosal permeability and cefaclor-associated SSLR in children. A total of 82 pediatric patients with upper respiratory tract infection following the cefaclor therapy was divided into cefaclor-associated SSLR positive group and negative group based on the presence or absence of SSLR after taking cefaclor, and 30 healthy volunteers served as control group. Urinary lactulose/mannitol (L/M) ratios and serum diamine oxidase (DAO) levels were determined in all cases on days 7, 9, 11, 13, and 15 after oral administration of cefaclor. The children in the control group were given the same measurements after enrollment in this study. From days 7 to 13, the urinary L/M ratio of children with cefaclor SSLR gradually increased and reached to the highest level of 0.38 ± 0.14 on day 13. Compared with the cefaclor-associated SSLR negative group and control group, urinary L/M ratios increased significantly in the cefaclor SSLR positive group on days 7, 9, 11, 13, and 15 after taking cefaclor, and serum levels of DAO following the treatment of cefaclor increased significantly in children with cefaclor SSLR on days 9, 11, 13, and 15. No significant difference in urinary L/M ratios and serum levels of DAO between SSLR negative group and control group through the entire experiment was observed. In conclusion, administration of cefaclor may induce SSLR in children by increasing the intestinal mucosal permeability and/or affecting the integrity of the intestinal mucosa. Determinations of urinary L/M ratios and serum DAO levels may be helpful for observing or predicting the occurrence of SSLR after administration of cefaclor, which will encourage physicians to proceed with extreme caution when prescribing cefaclor for pediatric patients.

Detection of quantitative trait loci (QTLs) for resistances to small brown planthopper and rice stripe virus in rice using recombinant inbred lines.

Small brown planthopper (SBPH) and rice stripe virus (RSV) disease transmitted by SBPH cause serious damage to rice (Oryza sativa L.) in China. In the present study, we screened 312 rice accessions for resistance to SBPH. The indica variety, N22, is highly resistant to SBPH. One hundred and eighty two recombinant inbred lines (RILs) derived from a cross of N22 and the highly susceptible variety, USSR5, were used for quantitative trait locus (QTL) analysis of resistances to SBPH and RSV. In a modified seedbox screening test, three QTLs for SBPH resistance, qSBPH2, qSBPH3 and qSBPH7.1, were mapped on chromosomes 2, 3 and 7, a total explaining 35.1% of the phenotypic variance. qSBPH7.2 and qSBPH11.2, conferring antibiosis against SBPH, were detected on chromosomes 7 and 11 and accounted for 20.7% of the total phenotypic variance. In addition, qSBPH5 and qSBPH7.3, expressing antixenosis to SBPH, were detected on chromosomes 5 and 7, explaining 23.9% of the phenotypic variance. qSBPH7.1, qSBPH7.2 and qSBPH7.3, located in the same region between RM234 and RM429 on chromosome 7, using three different phenotyping methods indicate that the locus or region plays a major role in conferring resistance to SBPH in N22. Moreover, three QTLs, qSTV4, qSTV11.1 and qSTV11.2, for RSV resistance were detected on chromosomes 4 and 11. qSTV11.1 and qSTV11.2 are located in the same region between RM287 and RM209 on chromosome 11. Molecular markers spanning these QTLs should be useful in the development of varieties with resistance to SBPH and RSV.

The clinical experience of double-orifice tricuspid valve.

BACKGROUND AND AIM OF THE STUDY: Double-orifice tricuspid valve (DOTV) is an extremely rare congenital anomaly. By analysing the feature of its diagnosis and surgical treatment, we want to summarise the clinical experience of treating DOTV. MATERIALS AND METHODS: Review two cases of DOTV treated by us between August 2009 and December 2011. One case was diagnosed as partial atrioventricular septum defect, and the other was tetralogy of Fallot. The defects were both identified during the operation for other congenital cardiac malformations and both accessory orifices were normal. But one of them was sutured because of its possible effect in future. RESULTS: Cardiac colour Doppler echocardiogram was made at three to five days after operation and all results were normal. No operative complication or late deaths occurred. The time of follow-up were one month, three months, six months, one year and two years after operation, and all examinations were normal. CONCLUSIONS: The accessory orifice of DOTV patients has its own independent chordae tendinea and mastoid muscle. So the gap of tricuspid valve should be excluded and the classification should be amended according to it. It should be surgically treated, when there is of dysfunction with it or potential harmful effect in sequent treatment.