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International audience; The coordinated distribution of inorganic phosphate (Pi) between roots and shoots is an important process that plants use to maintain Pi homeostasis. SHORT-ROOT (SHR) is well characterized for its function in root radial patterning. Here we demonstrate a role of SHR in controlling Pi allocation from root to shoot by regulating PHOSPHATE1 in the root differentiation zone. We recovered a weak mutant allele of SHR in Arabidopsis that accumulates much less Pi in the shoot and shows a constitutive Pi starvation response under Pi-sufficient conditions. In addition, Pi starvation suppresses SHR protein accumulation and releases its inhibition on the HD-ZIP III transcription factor PHB. PHB accumulates and directly binds the promoter of PHOSPHATE2 to upregulate its transcription, resulting in PHOSPHATE1 degradation in the xylem-pole pericycle cells. Our findings reveal a previously unrecognized mechanism of how plants regulate Pi translocation from roots to shoots.Plants confronted with nutrient deficiency allocate more resources to roots to maximize nutrient acquisition and growth. This study uncovers how plants repress phosphate uploading to curtail the long-distance transportation of phosphate to shoots.

CRISPR–Cas9 methods have been applied to generate random insertions and deletions, large deletions, targeted insertions or replacements of short sequences, and precise base changes in plants1–7. However, versatile methods for targeted insertion or replacement of long sequences and genes, which are needed for functional genomics studies and trait improvement in crops, are few and largely depend on the use of selection markers8–11. Building on methods developed in mammalian cells12, we used chemically modified donor DNA and CRISPR–Cas9 to insert sequences of up to 2,049 base pairs (bp), including enhancers and promoters, into the rice genome at an efficiency of 25%. We also report a method for gene replacement that relies on homology-directed repair, chemically modified donor DNA and the presence of tandem repeats at target sites, achieving replacement with up to 130-bp sequences at 6.1% efficiency. Rice genes are replaced using chemically modified donor DNA and CRISPR targeting.

The maintenance of cellular phosphate (Pi) homeostasis is of great importance in living organisms. The SPX domain-containing protein 1 (SPX1) proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status. The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants, however, remains to be identified, as Pi itself does not bind to the SPX domain. Here, we report the identification of the inositol pyrophosphate InsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis. Polyacrylamide gel electrophoresis profiling of InsPs revealed that InsP8 level positively correlates with cellular Pi concentration. We demonstrated that the homologs of diphosphoinositol pentakisphosphate kinase (PPIP5K), VIH1 and VIH2, function redundantly to synthesize InsP8, and that the vih1 vih2 double mutant overaccumulates Pi. SPX1 directly interacts with PHR1, the central regulator of Pi starvation responses, to inhibit its function under Pi-replete conditions. However, this interaction is compromised in the vih1 vih2 double mutant, resulting in the constitutive induction of Pi starvation-induced genes, indicating that plant cells cannot sense cellular Pi status without InsP8. Furthermore, we showed that InsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1. Collectively, our study suggests that InsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.

Aiming at the problems of complex time-consuming and heavy data processing workload in the field test of commercial vehicle handling stability, a vehicle handling stability test solution based on virtual instrument technology is proposed. This solution is based on the existing test equipment and conditions, using LABVIEW virtual instrument, integrated application of GPS, AHRS and steering force angle tester to form a set of road test system solutions that can realize vehicle handling and stability. The system can meet the requirements of the national standard Controllability and Stability Test Procedure for Automobile (GB / T 6323-2014) to realize the vehicle handling stability test, and the system test is verified by the real vehicle test data, which provides a more efficient and convenient test method for the study of vehicle handling stability test.

The remodeling of root architecture is a major developmental response of plants to phosphate (Pi) deficiency and is thought to enhance a plant's ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps10 (hypersensitive to Pi starvation 10), which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi deficiency. hps10 is a previously identified allele (als3-3) of the ALUMINUM SENSITIVE3 (ALS3) gene, which is involved in plant tolerance to aluminum toxicity. Our results show that ALS3 and its interacting protein AtSTAR1 form an ABC transporter complex in the tonoplast. This protein complex mediates a highly electrogenic transport in Xenopus oocytes. Under Pi deficiency, als3 accumulates higher levels of Fe3+ in its roots than the wild type does. In Arabidopsis, LPR1 (LOW PHOSPHATE ROOT1) and LPR2 encode ferroxidases, which when mutated, reduce Fe3+ accumulation in roots and cause root growth to be insensitive to Pi deficiency. Here, we provide compelling evidence showing that ALS3 cooperates with LPR1/2 to regulate Pi deficiency-induced remodeling of root architecture by modulating Fe homeostasis in roots.

The maintenance of cellular phosphate (Pi) homeostasis is of great importance in living organisms. The SPX domain-containing protein 1 (SPX1) proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status. The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants, however, remains to be identified, as Pi itself does not bind to the SPX domain. Here, we report the identification of the inositol pyrophosphate InsP

The inhibition of primary root (PR) growth is a major developmental response of Arabidopsis (Arabidopsis thaliana) to phosphate (Pi) deficiency. Previous studies have independently uncovered key roles of the LOW PHOSPHATE RESPONSE1 (LPR1) ferroxidase, the tonoplast-localized ALUMINUM SENSITIVE3 (ALS3)/SENSITIVE TO ALUMINUM RHIZOTOXICITY1 (STAR1) transporter complex, and the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1; a transcription factor)-ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (ALMT1; a malate transporter) regulatory module in mediating this response by controlling iron (Fe) homeostasis in roots, but how these three components interact to regulate PR growth under Pi deficiency remains unknown. Here, we dissected genetic relationships among these three key components and found that (1) STOP1, ALMT1, and LPR1 act downstream of ALS3/STAR1 in controlling PR growth under Pi deficiency; (2) ALS3/STAR1 inhibits the STOP1-ALMT1 pathway by repressing STOP1 protein accumulation in the nucleus; and (3) STOP1-ALMT1 and LPR1 control PR growth under Pi deficiency in an interdependent manner involving the promotion of malate-dependent Fe accumulation in roots. Furthermore, this malate-mediated Fe accumulation depends on external Pi availability. We also performed a detailed analysis of the dynamic changes in the tissue-specific Fe accumulation patterns in the root tips of plants exposed to Pi deficiency. The results indicate that the degree of inhibition of PR growth induced by Pi deficiency is not linked to the level of Fe accumulated in the root apical meristem or the elongation zone. Our work provides insights into the molecular mechanism that regulates the root developmental response to Pi deficiency.

CRISPR-Cas9 methods have been applied to generate random insertions and deletions, large deletions, targeted insertions or replacements of short sequences, and precise base changes in plants

Background: Although genome-wide association studies (GWAS) and subsequent meta-analyses have confirmed associations between the PTPN2 (protein tyrosine phosphatase, nonreceptor type 2) gene and Crohn's disease (CD), the potential causal variants remain unidentified. We aimed to dissect potential causal CD-associated PTPN2 variants, assess their functional significance, and relate PTPN2 protein expression with inflammation in CD. Methods: A 3-stage study was carried out. In stage 1, we genotyped tagging single nucleotide polymorphisms (tag-SNPs) in the PTPN2 gene in a sample of patients with CD (

Background: Genome-wide association studies (GWAS) in Crohn's disease (CD) have identified associations with single-nucleotide polymorphism (SNP) rs11175593 at chromosome 12q12. The MUC19 and LRRK2 genes reside close to the GWAS signal, but it is as yet unclear which of the 2 genes represent the CD susceptibility genes. Methods: We studied associations between nonsynonymous coding variants in the MUC19 (5) and LRRK2 (3) genes in a case-control sample comprising CD cases aged

When plants are subjected to a deficiency in inorganic phosphate (Pi), they exhibit an array of responses to cope with this nutritional stress. In this work, we have characterized two Arabidopsis mutants, hps3-1 and hps3-2 (hypersensitive to Pi starvation 3), that have altered expression of Pi starvation-induced (PSI) genes and enhanced production of acid phosphatase (APase) when grown under either Pi sufficiency or deficiency conditions. hps3-1 and hps3-2, however, accumulate less anthocyanin than the wild type when grown on a Pi-deficient medium. Molecular cloning indicated that the phenotypes of hps3 mutants were caused by mutations within the ETO1 (ETHYLENE OVERPRODUCTION 1) gene. In Arabidopsis, ETO1 encodes a negative regulator of ethylene biosynthesis, and mutation of ETO1 causes Arabidopsis seedlings to overproduce ethylene. The ethylene biosynthesis inhibitor aminoethoxyvinyl glycine or the ethylene perception inhibitor Ag(+) suppressed all the mutant phenotypes of hps3. Taken together, these results provide further genetic evidence that ethylene is an important regulator of multiple plant responses to Pi starvation. Furthermore, we found that a change in ethylene level has differential effects on the expression of PSI genes, maintenance of Pi homeostasis, production of APase and accumulation of anthocyanin. We also demonstrated that ethylene signaling mainly regulates the activity of root surface-associated APases rather than total APase activity.

Background: Genome-wide association studies (GWAS) and replication studies have shown conflicting associations between the NELL1, NCF4, and FAM92B genes and susceptibility for Crohn's disease (CD). We sought to examine whether these genes were associated with CD in Canadian children and young adults. Methods: A case-control study was carried out at three pediatric gastroenterology clinics across Canada. Patients, ≤20 years at diagnosis, along with controls representative of the general population were selected. Study subjects were genotyped for 22 single nucleotide polymorphisms (SNPs) across the target genes. Allelic and haplotype associations were examined. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated. Results: In all, 566 CD cases and 602 controls were investigated. The mean (±SD) age of the patients was 12.3 (±3.3) years. Most patients were male (57.8%), of Caucasian ancestry (98.2%), and had ileocolonic disease location (48.8%). Barring nominal associations with one FAM92B SNP, none of the other 21 SNPs analyzed were associated with CD either at the allelic or haplotype level. Separate analysis for ileal CD (L1 plus L3) also did not reveal significant associations with any of the SNPs. Similarly, a pooled analysis using data from two recent studies did not demonstrate associations between the NCF4 (OR = 1.10, 95% CI = 0.91–1.32, P = 0.32) and FAM92B (OR = 1.05, 95% CI = 0.95–1.17, P = 0.36) GWAS lead SNPs and ileal CD. Conclusions: GWAS-reported associations in the NELL1, NCF4, and FAM92B genes could not be replicated in Canadian children and young adults. Further investigation in other populations will be required to confirm the presence/absence of associations, if any. (Inflamm Bowel Dis 2012;)

A recent pediatric-focused genome-wide association study has implicated three novel susceptibility loci for Crohn' disease (CD).We aimed to investigate whether the three recently reported and other previously reported genes/loci were also associated with CD in Canadian children. A case-control design was implemented at three pediatric gastroenterology clinics in Canada. Children19 years of age with a confirmed diagnosis of CD were recruited along with controls. Single nucleotide polymorphisms (SNPs) in 19 reported genes/loci were genotyped. Associations between individual SNPs and CD were examined. A total of 563 cases and 553 controls were studied. The mean (+/-SD) age of the cases was 12.3 (+/-3.2) years. Most cases were male (56.0%), had ileo-colonic disease (L3 +/- L4, 48.8%) and inflammatory behavior (B1 +/- p, 87.9%) at diagnosis. Allelic association analysis (two-tailed) showed that 8 of the 19 targeted SNPs were significantly associated with overall susceptibility for CD. Associations with one additional SNP was borderline non-significant. Significantly associated SNPs included SNPs rs1250550 (p = 0.026) and rs8049439 (p = 0.04), recently reported to be specifically associated with pediatric-onset CD.Based on the results, we confirmed associations between two of the three novel pediatric-CD loci and other regions reported for associations with either pediatric and/or adult-onset CD.

A recent pediatric-focused genome-wide association study has reported novel associations of the 20q13 and 21q22 loci with inflammatory bowel disease (IBD). We aimed to investigate these associations with Crohn's disease (CD) in Canadian children.A combined case-control and case-parent design was implemented at three pediatric gastroenterology clinics in Canada. Children less than 20 years of age with a confirmed diagnosis of CD were recruited along with controls. For a subset of the patients, biological parents were also recruited. Three single-nucleotide polymorphisms (SNPs) at the 20q13 locus and 1 SNP at the 21q22 locus were genotyped. Associations between individual SNPs and haplotypes were examined.A total of 410 cases, 415 controls, and 302 parents were studied. The mean (+/-s.d.) age for the cases was 12.3 (+/-3.2) years. Most cases were men (56.1%) who had ileocolonic disease (L3+/-L4, 52.2%) and inflammatory behavior (B1+/-B4, 87.0%) at diagnosis. Single SNP analysis showed that all 3 SNPs at the 20q13 locus were significantly associated with CD (rs2297441, P=2.24x10(-4); rs2315008, P=4.77x10(-4); rs4809330, P=6.08x10(-3)). Haplotype analysis suggested that the association signal at 20q13 resided on a common haplotype comprising the minor allele of rs2297441 (P=2.8x10(-5)). SNP rs2836878 at the 21q22 locus showed a trend for association with CD that was statistically not significant (P=0.06).Our results support an association between the 20q13 locus and CD in Canadian children. Positional cloning studies are required to further dissect the potential causative genes in the region.

Supporting Figures S1â S22. This file contains all supporting figures. (DOCX 11257 kb)

Supporting Tables S1â S4. This file contains all supporting tables. (DOCX 75 kb)

Background Previously, several long non-coding RNAs (lncRNAs) were characterized as regulators in phosphate (Pi) starvation responses. However, systematic studies of novel lncRNAs involved in the Pi starvation signaling pathways have not been reported. Results Here, we used a genome-wide sequencing and bioinformatics approach to identify both poly(A) + and poly(A)– lncRNAs that responded to Pi starvation in Arabidopsis thaliana. We sequenced shoot and root transcriptomes of the Arabidopsis seedlings grown under Pi-sufficient and Pi-deficient conditions, and predicted 1212 novel lncRNAs, of which 78 were poly(A)– lncRNAs. By employing strand-specific RNA libraries, we discovered many novel antisense lncRNAs for the first time. We further defined 309 lncRNAs that were differentially expressed between P+ and P– conditions in either shoots or roots. Through Gene Ontology enrichment of the associated protein-coding genes (co-expressed or close on the genome), we found that many lncRNAs were adjacent or co-expressed with the genes involved in several Pi starvation related processes, including cell wall organization and photosynthesis. In total, we identified 104 potential lncRNA targets of PHR1, a key regulator for transcriptional response to Pi starvation. Moreover, we identified 16 candidate lncRNAs as potential targets of miR399, another key regulator of plant Pi homeostasis. Conclusions Altogether, our data provide a rich resource of candidate lncRNAs involved in the Pi starvation regulatory network. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2929-2) contains supplementary material, which is available to authorized users.

Given the coupled tractor-trailer interacting with each other, road train is a complex system. The study on lateral stability of tractor trailer system is related to several fields such as multi-rigid dynamics, rigid-flexible coupling mechanics, aerodynamics. The research about the tractor-trailer lateral stability involves multi-discipline, multi-dimension, complex system, nonlinear vehicle kinematics and electronic controllability. Overview is made of the current development, method and test means about the tractor-trailer lateral stability study at home and abroad. The effects of parameters use and structure on the tractor-trailer lateral stability study are discussed. At the same time, the lateral acceleration response to step input of steering angle is also analyzed. Digital simulation algorithm of the tractor-trailer dynamics is presented, as well as typical simulation models.

Power train parameter is an important factor of vehicle power performance and fuel economy, and mathematical modeling of engine and vehicle performance is the foundation of computer simulation. In this paper, least-square fitting is used to develop engine full load performance characteristic model, engine multi-performance characteristic model is given to camber fitting method. And computer simulation platform of vehicle power performance and fuel economy is given with Matlab. The intercomparable results of digital simulation and road test show that the mathematical models, the algorithm and simulation platform given in this paper are correct. The simulation results are effective and reliable. It offers a reference method for analysis and evaluation of vehicle performance.