Conserved features and diversity attributes of chimeric RNAs across accessions in four plants.

As a non-collinear expression form of genetic information, chimeric RNAs increase the complexity of transcriptome in diverse organisms. Although chimeric RNAs have been identified in plants, few common features have been revealed. Here, we systemically explored the landscape of chimeric RNAs across multi-accession and multi-tissue using pan-genome and transcriptome data of four plants: rice, maize, soybean, and Arabidopsis. Among the four species, conserved characteristics of breakpoints and parental genes were discovered. In each species, chimeric RNAs displayed a high level of diversity among accessions, and the clustering of accessions using chimeric events was generally concordant with clustering based on genomic variants, implying a general relationship between genetic variations and chimeric RNAs. Through mass spectrometry, we confirmed a fusion protein OsNDC1-OsGID1L2 and observed its subcellular localization, which differed from the original proteins. Phenotypic cues in transgenic rice suggest the potential functions of OsNDC1-OsGID1L2. Moreover, an intriguing chimeric event Os01g0216500-Os01g0216900, generated by a large deletion in basmati rice, also exists in another accession without the deletion, demonstrating its convergence in evolution. Our results illuminate the characteristics and hint at the evolutionary implications of plant chimeric RNAs, which serve as a supplement to genetic variations, thus expanding our understanding of genetic diversity.

NtMYB12 requires for competition between flavonol and (pro)anthocyanin biosynthesis in Narcissus tazetta tepals.

The color of flowers is one of the main characteristics adopted for plants to attract pollinators to ensure the reproductive success of the plant, they are also important in their ornamental appeal in Narcissus plant. In this study, we identified a NtMYB12 locus encoding an R2R3-MYB transcription factor. Comparative transcriptome analysis of loss- and gain- of NtMYB12 tissue relative to wild-type narcissus showed NtMYB12 was mainly involved in flavonol and phenylpropanoid metabolic pathways. Biochemical evidences of dual-luciferase activity and chromatin immunoprecipitation assay supported that MYB12 directly bound to promoters of NtFLS, NtLAR, and NtDFR that were cloned by genome walking assay, and activated NtFLS and NtLAR expression but repressed NtDFR expression. More interestingly, NtMYB12 can interact with NtbHLH1 and NtWD40-1 proteins via R3 domain that were selected by transcriptome-based WGCNA and confirmed by yeast two hybrid, bimolecular fluorescence complementation and coimmunoprecipitation assay. Interaction of NtMYB12 with NtbHLH1 and NtWD40-1 forming MYB-bHLH-WD40 triplex specially activated NtDFR and NtANS expression and promoted (pro)anthocyanin accumulation, while NtMYB12 alone activated NtFLS and NtLAR expression and accumulated flavonols, but repressed NtDFR expression. These results indicated that NtMYB12 alone or NtMYB12-bHLH1-WD40-1 triplex requires for competition of metabolism fluxes between flavonol and (pro)anthocyanin biosynthesis. NtMYB12 dually functions on flavonol and proanthocyanin biogenesis via physically binding to NtFLS and NtLAR promoter activating their expression and on (pro)anthocyanin biosynthesis via NtMYB12-NtWD40-NtbHLH (MBW) triplex activating NtDFR and NtANS expression. Requirement of NtMYB12 alone or MBW complex for the competition between flavonol and anthocyanin biosynthesis results in narcissus colorized petal traits.

NtMYB1 and NtNCED1/2 control abscisic acid biosynthesis and tepal senescence in Chinese narcissus (Narcissus tazetta).

Chinese narcissus (Narcissus tazetta var. chinensis cv. 'Jinzhanyintai') is one of the 10 most famous traditional flowers of China, having a beautiful and highly ornamental flower with a rich fragrance. However, the flower longevity affects its commercial appeal. While petal senescence in Narcissus is ethylene-independent and abscisic acid-dependent, the regulatory mechanism has yet to be determined. In this study, we identified a R2R3-MYB gene (NtMYB1) from Narcissus tazetta and generated oeNtMYB1 and Ntmyb1 RNA interference mutants in Narcissus as well as an oeNtMYB1 construct in Arabidopsis. Overexpressing NtMYB1 in Narcissus or Arabidopsis led to premature leaf yellowing, an elevated level of total carotenoid, a reduced level of chlorophyll b, and a decrease in photosystem II fluorescence (Fv/Fm). A dual-luciferase assay and chromatin immunoprecipitation-quantitative PCR revealed that NtMYB1 directly binds to the promoter of NtNCED1 or NtNCED2 and activates NtNCED1/2 gene expression both in vitro and in vivo. Moreover, overexpressing NtMYB1 accelerated abscisic acid biosynthesis, up-regulated the content of zeatin and abscisic acid, and down-regulated the level of ß-carotene and gibberellin A1, leading to petal senescence and leaf yellowing in Narcissus. This study revealed a regulatory process that is fundamentally different between non-photosynthetic organs and leaves.

Comparison of helical blade versus lag screw in intertrochanteric fractures of the elderly treated with proximal femoral nail: A meta-analysis of randomized-controlled trials.

OBJECTIVES: In this review, we aimed to compare the radiological and functional outcomes between the helical blade and lag screw in treating intertrochanteric fractures among the elderly and to provide suggestions for clinical treatment. MATERIALS AND METHODS: Between January 1st, 1990 and January 12th, 2022, the literature search in document databases identified eligible randomized-controlled trials (RCT) studies directly comparing the helical blade and lag screws for treating hip fractures. The mechanical failure rates, the excellent and good rate of fracture reduction, Harris Hip Score (HHS), and postoperative hip pain of two intramedullary devices (helical blades versus lag screws) in patients with intertrochanteric fractures were analyzed using the RevMan software and Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The random-effects models were used for statistical analysis. RESULTS: A total of 11 articles containing 1,146 patients for helical blade and lag screw comparison were included. Compared to the lag screws, the mechanical failure rate (odds ratio [OR]=0.71, 95% confidence interval [CI]: 0.40-1.27, p=0.25), the excellent and good rate of fracture reduction (OR=1.33, 95% CI: 0.61-2.90, p=0.48), HHS (mean differences 1.83, 95% CI: -0.29-1.83, p=0.09), and postoperative hip pain (OR=0.41, 95% CI: 0.14-1.21, p=0.11) were similar with the helical blades. There was no significant difference between the two implants in terms of the treatment outcomes. CONCLUSION: Both helical blades and lag screws are good choices for treating intertrochanteric fracture among elderly.

Phosphorus Substitution Preference in Ye'elimite: Experiments and Density Functional Theory Simulations.

Density functional theory (DFT) simulation has been recently introduced to understand the doping behavior of impurities in clinker phases. P-doped ye'elimite, a typical doping clinker phase, tends to form when phosphogypsum is used to manufacture calcium sulfoaluminate cement (CSA) clinkers. However, the substitution mechanism of P has not been uncovered yet. In this study, the influence of different doping amounts of P on the crystalline and electronic structure of ye'elimite was investigated using backscattered scanning electron microscopy-energy X-ray dispersive spectroscopy, X-ray diffraction tests, Rietveld quantitative phase analysis, and DFT simulations. Furthermore, the substitution preference of P in ye'elimite was revealed. Our results showed that increasing the doping amount of P increased the impurity contents in CSA clinkers, transforming the ye'elimite crystal system from the orthorhombic to the cubic system and decreasing the interplanar spacing of ye'elimite. Based on the calculation results of the defect formation energies, additional energies were required for P atoms to substitute Ca/Al atoms compared with those required for P atoms to substitute S atoms in both orthorhombic and cubic systems of ye'elimite. Combined calculation results of the bond length-bond order and partial density of states showed that the doped P atoms preferably substituted S atoms; the second possible substituted atoms were Al atoms, while there was only a slight possibility for substitution of Ca atoms. The substitution of P atoms for S atoms can be verified based on the elemental distribution in P-doped ye'elimite and the increasing residual CaSO4 contents. The transition of the crystal system and a decrease in the interplanar spacing for ye'elimite can also prove that the substitution of P atoms for Al atoms occurred substantially.

Transcriptome-Based WGCNA Analysis Reveals Regulated Metabolite Fluxes between Floral Color and Scent in Narcissus tazetta Flower.

A link between the scent and color of Narcissus tazetta flowers can be anticipated due to their biochemical origin, as well as their similar biological role. Despite the obvious aesthetic and ecological significance of these colorful and fragrant components of the flowers and the molecular profiles of their pigments, fragrant formation has addressed in some cases. However, the regulatory mechanism of the correlation of fragrant components and color patterns is less clear. We simultaneously used one way to address how floral color and fragrant formation in different tissues are generated during the development of an individual plant by transcriptome-based weighted gene co-expression network analysis (WGCNA). A spatiotemporal pattern variation of flavonols/carotenoids/chlorophyll pigmentation and benzenoid/phenylpropanoid/ monoterpene fragrant components between the tepal and corona in the flower tissues of Narcissus tazetta, was exhibited. Several candidate transcription factors: MYB12, MYB1, AP2-ERF, bZIP, NAC, MYB, C2C2, C2H2 and GRAS are shown to be associated with metabolite flux, the phenylpropanoid pathway to the production of flavonols/anthocyanin, as well as related to one branch of the phenylpropanoid pathway to the benzenoid/phenylpropanoid component in the tepal and the metabolite flux between the monoterpene and carotenoids biosynthesis pathway in coronas. It indicates that potential competition exists between floral pigment and floral fragrance during Narcissus tazetta individual plant development and evolutionary development.