Identification of candidate genes associated with double flowers via integrating BSA-seq and RNA-seq in Brassica napus.

As a Brassica crop, Brassica napus typically has single flowers that contain four petals. The double-flower phenotype of rapeseed has been a desirable trait in China because of its potential commercial value in ornamental tourism. However, few double-flowered germplasms have been documented in B. napus, and knowledge of the underlying genes is limited. Here, B. napus D376 was characterized as a double-flowered strain that presented an average of 10.92 ± 1.40 petals and other normal floral organs. F1, F2 and BC1 populations were constructed by crossing D376 with a single-flowered line reciprocally. Genetic analysis revealed that the double-flower trait was a recessive trait controlled by multiple genes. To identify the key genes controlling the double-flower trait, bulk segregant analysis sequencing (BSA-seq) and RNA-seq analyses were conducted on F2 individual bulks with opposite extreme phenotypes. Through BSA-seq, one candidate interval was mapped at the region of chromosome C05: 14.56-16.17 Mb. GO and KEGG enrichment analyses revealed that the DEGs were significantly enriched in carbohydrate metabolic processes, notably starch and sucrose metabolism. Interestingly, five and thirty-six DEGs associated with floral development were significantly up- and down-regulated, respectively, in the double-flowered plants. A combined analysis of BSA-seq and RNA-seq data revealed that five genes were candidates associated with the double flower trait, and BnaC05.ERS2 was the most promising gene. These findings provide novel insights into the breeding of double-flowered varieties and lay a theoretical foundation for unveiling the molecular mechanisms of floral development in B. napus.

Genetic and multi-omics analyses reveal BnaA07.PAP2In-184-317 as the key gene conferring anthocyanin-based color in Brassica napus flowers.

The molecular mechanisms underlying anthocyanin-based flower coloration remain unknown in Brassica napus. To identify the key genes and metabolites associated with apricot and pink flower colors, metabolome, BSA-seq, and RNA-seq analyses were conducted on apricot-, pink-, yellow-, and white-flowered F2B. napus. Yellow carotenoids and red anthocyanins were abundant in apricot petals, while colorless carotenoids and red anthocyanins accumulated in pink petals. Most carotenoid genes were not differentially regulated between apricot and yellow or between pink and white petals. Three regulator genes, BnaMYBL2, BnaA07.PAP2, and BnaTT8, and structural genes in anthocyanin biosynthesis were dramatically enhanced in apricot and pink petals in comparison with yellow and white petals. Map-based cloning revealed that BnaA07.PAP2 is responsible for anthocyanin-based flower color and encodes a nucleus-localized protein predominantly expressed in apricot and pink flowers. Two insertions in the promoter region are responsible for the transcriptional activation of BnaA07.PAP2 in flowers. Introducing the BnaA07.PAP2In-184-317 allele broadly activated the expression of anthocyanin-related genes and promoted anthocyanin accumulation in flowers, yielding color change from yellow to apricot. These findings illustrate the genetic basis of anthocyanin-based flower coloration and provide a valuable genetic resource for breeding varieties with novel flower colors in B. napus.

Combined BSA-Seq Based Mapping and RNA-Seq Profiling Reveal Candidate Genes Associated with Plant Architecture in Brassica napus.

Plant architecture involves important agronomic traits affecting crop yield, resistance to lodging, and fitness for mechanical harvesting in Brassica napus. Breeding high-yield varieties with plant architecture suitable for mechanical harvesting is the main goal of rapeseed breeders. Here, we report an accession of B. napus (4942C-5), which has a dwarf and compact plant architecture in contrast to cultivated varieties. A BC8 population was constructed by crossing a normal plant architecture line, 8008, with the recurrent parent 4942C-5. To investigate the molecular mechanisms underlying plant architecture, we performed phytohormone profiling, bulk segregant analysis sequencing (BSA-Seq), and RNA sequencing (RNA-Seq) in BC8 plants with contrasting plant architecture. Genetic analysis indicated the plant architecture traits of 4942C-5 were recessive traits controlled by multiple genes. The content of auxin (IAA), gibberellin (GA), and abscisic acid (ABA) differed significantly between plants with contrasting plant architecture in the BC8 population. Based on BSA-Seq analysis, we identified five candidate intervals on chromosome A01, namely those of 0 to 6.33 Mb, 6.45 to 6.48 Mb, 6.51 to 6.53 Mb, 6.77 to 6.79 Mb, and 7 to 7.01 Mb regions. The RNA-Seq analysis revealed a total of 4378 differentially expressed genes (DEGs), of which 2801 were up-regulated and 1577 were down-regulated. There, further analysis showed that genes involved in plant hormone biosynthesis and signal transduction, cell structure, and the phenylpropanoid pathway might play a pivotal role in the morphogenesis of plant architecture. Association analysis of BSA-Seq and RNA-Seq suggested that seven DEGs involved in plant hormone signal transduction and a WUSCHEL-related homeobox (WOX) gene (BnaA01g01910D) might be candidate genes responsible for the dwarf and compact phenotype in 4942C-5. These findings provide a foundation for elucidating the mechanisms underlying rapeseed plant architecture and should contribute to breed new varieties suitable for mechanization.

Ectopic Expression of Gs5PTase8, a Soybean Inositol Polyphosphate 5-Phosphatase, Enhances Salt Tolerance in Plants.

Inositol polyphosphate 5-phosphatases (5PTases) function in inositol signaling by regulating the catabolism of phosphoinositol derivatives. Previous reports showed that 5PTases play a critical role in plant development and stress responses. In this study, we identified a novel 5PTase gene, Gs5PTase8, from the salt-tolerance locus of chromosome 3 in wild soybean (Glycine soja). Gs5PTase8 is highly up-regulated under salt treatment. It is localized in the nucleus and plasma membrane with a strong signal in the apoplast. Ectopic expression of Gs5PTase8 significantly increased salt tolerance in transgenic BY-2 cells, soybean hairy roots and Arabidopsis, suggesting Gs5PTase8 could increase salt tolerance in plants. The overexpression of Gs5PTase8 significantly enhanced the activities of catalase and ascorbate peroxidase under salt stress. The seeds of Gs5PTase8-transgenic Arabidopsis germinated earlier than the wild type under abscisic acid treatment, indicating Gs5PTase8 would alter ABA sensitivity. Besides, transcriptional analyses showed that the stress-responsive genes, AtRD22, AtRD29A and AtRD29B, were induced with a higher level in the Gs5PTase8-transgenic Arabidopsis plants than in the wild type under salt stress. These results reveal that Gs5PTase8 play a positive role in salt tolerance and might be a candidate gene for improving soybean adaptation to salt stress.

Comparison of clinical and radiological outcomes between modified Gallie graft fusion-wiring technique and posterior cervical screw constructs for Type II odontoid fractures.

The aim of this study was to compare clinical and radiological outcomes between modified Gallie graft fusion-wiring technique and posterior cervical screw constructs for Type II odontoid fractures, and hope to provide references in decision making and surgical planning for both spinal surgeons and surgically treated patients.This is a retrospective study. By retrieving the medical records from January 2005 to July 2015 in our hospital, 53 Type II odontoid fracture patients were reviewed. According to the instrumentation type, patients were divided into 2 groups: Wiring group and Screw group. Three categorized factors were analyzed statistically: patient characteristics: age, body mass index, preoperative neurological status, duration, complicated injuries; surgical variables: surgery time, blood loss, vertebral artery injury, spinal cord or nerve root injury, major systemic complications, wound infection, pain at the bone donor area, instrumentation failure, revision rate; and radiographic parameters: preoperative and final follow-up data of C0-2 curvature, C2-7 curvature, C2-C7 sagittal vertical axis, C7 slope, fracture classification, separation, and displacement of odontoid fracture, fusion rate. An additional comparison of surgical outcomes was done, including patient satisfaction, visual analog scale score for neck pain, neck stiffness, medical expense.There was no statistically significant difference between the 2 groups in patient characteristics of age, sex, body mass index, preoperative neurological status, duration, and complicated injuries. No statistically significant difference was noted in surgical variables of blood loss, vertebral artery injury, spinal cord or nerve root injury, major systemic complications, wound infection, bone harvested zone pain, instrumentation failure, revision rate. The surgery time was shorter in Wiring group than that in Screw group, with a statistically significant difference. We noted no significant difference between the 2 groups when comparing radiographic parameters of preoperative and final follow-up data of C0-2 curvature, C2-C7 sagittal vertical axis, fracture classification, the separation and displacement of odontoid fracture, and fusion rate. Although we noted no significant difference in preoperative C2-7 curvature and C7 slope, the final follow-up data showed that C2-7 curvature and C7 slope were smaller in Wiring group than that in Screw group. We noted no significant difference in visual analog scale score, neck stiffness, and neurological status at final follow-up. The medical expense was less in Wiring group; the patient satisfaction was lower in the Wiring group than that in the Screw group.The modified Gallie graft fusion-wiring technique provided solid fusion and stabilization for patients with Type II odontoid fractures, Gallie graft fusion-wiring resulted in less surgery time, less medical expense, but lower patient satisfaction when compared with the posterior cervical screw constructs.

Surgical site infection following open reduction and internal fixation of a closed ankle fractures: A retrospective multicenter cohort study.

BACKGROUND: Identification of risk factors for surgical site infection (SSI) after surgical ankle fractures was important, but related evidence was inadequate. This study was conducted to investigate the incidence and risk factors for SSI after open reduction and internal fixation (ORIF) of a closed ankle fractures. METHODS: Patients who underwent ORIF for a closed ankle fractures at 3 centers between July 2015 and January 2017 were included. Electronic medical recordings (EMR) and Picture Archiving and Communication Systems (PACS) were inquired for information on patients' clinical and radiographic characteristics. The potential factors include 4 aspects: demographics, injury-related, surgery-related and biochemical indictors. Factors related with SSI were analyzed by univariate and further by multivariate logistic regression model. RESULTS: During the hospitalization, 3.7% (46/1247) of patients developed SSI, with 1.12% (14/1247) for deep and 2.57% (32/1247) for superficial SSI. Approximately half of SSIs were caused by Methicillin-resistant Staphylococcus aureus (MRSA). After adjustment for confounding factors, higher body mass index (BMI), surgeon level (residents or treating surgeon), surgical duration>130mins, delayed surgery, preoperative TP < 60 g/L were significant risk factor or predictors for SSI occurrence. CONCLUSIONS: After comprehensive evaluation of patients medical conditions, immediate operation by a surgeon with more expertise could effectively reduce SSI occurrence.