Comparative transcriptome analysis reveals transcriptional regulation of anthocyanin biosynthesis in purple radish (Raphanus sativus L.).

Radish exhibits significant variation in color, particularly in sprouts, leaves, petals, fleshy roots, and other tissues, displaying a range of hues such as green, white, red, purple, and black. Although extensive research has been conducted on the color variation of radish, the underlying mechanism behind the variation in radish flower color remains unclear. To date, there is a lack of comprehensive research investigating the variation mechanism of radish sprouts, leaves, fleshy roots, and flower organs. This study aims to address this gap by utilizing transcriptome sequencing to acquire transcriptome data for white and purple radish flowers. Additionally, the published transcriptome data of sprouts, leaves, and fleshy roots were incorporated to conduct a systematic analysis of the regulatory mechanisms underlying anthocyanin biosynthesis in these four radish tissues. The comparative transcriptome analysis revealed differential expression of the anthocyanin biosynthetic pathway genes DFR, UGT78D2, TT12 and CPC in the four radish tissues. Additionally, the WGCNA results identified RsDFR.9c and RsUGT78D2.2c as hub genes responsible for regulating anthocyanin biosynthesis. By integrating the findings from the comparative transcriptome analysis, WGCNA, and anthocyanin biosynthetic pathway-related gene expression patterns, it is hypothesized that genes RsDFR.9c and RsUGT78D2.2c may serve as pivotal regulators of anthocyanins in the four radish tissues. Furthermore, the tissue-specific expression of the four copies of RsPAP1 is deemed crucial in governing anthocyanin synthesis and accumulation. Our results provide new insights into the molecular mechanism of anthocyanin biosynthesis and accumulation in different tissues of radish.

Molecular evolution analysis of MYB5 in Brassicaceae with specific focus on seed coat color of Brassica napus.

BACKGROUND: MYB transcription factors are splay a vital role in plant biology, with previous research highlighting the significant impact of the R2R3-MYB-like transcription factor MYB5 on seed mucilage biosynthesis, trichome branching, and seed coat development. However, there is a dearth of studies investigating its role in the regulation of proanthocyanidin (PA) biosynthesis. RESULTS: In this study, a total of 51 MYB5 homologous genes were identified across 31 species belonging to the Brassicaceae family, with particular emphasis on Brassica napus for subsequent investigation. Through phylogenetic analysis, these genes were categorized into four distinct subclasses. Protein sequence similarity and identity analysis demonstrated a high degree of conservation of MYB5 among species within the Brassicaceae family. Additionally, the examination of selection pressure revealed that MYB5 predominantly underwent purifying selection during its evolutionary history, as indicated by the Ka/Ks values of all MYB5 homologous gene pairs being less than one. Notably, we observed a higher rate of non-synonymous mutations in orthologous genes compared to paralogous genes, and the Ka/Ks value displayed a stronger correlation with Ka. In B. napus, an examination of expression patterns in five tissues revealed that MYB5 exhibited particularly high expression in the black seed coat. The findings from the WGCNA demonstrated a robust correlation between MYB5 and BAN(ANR) associated with PA biosynthesis in the black seed coat, providing further evidence of their close association and co-expression. Furthermore, the results obtained from of the analysis of protein interaction networks offer supplementary support for the proposition that MYB5 possesses the capability to interact with transcriptional regulatory proteins, specifically TT8 and TT2, alongside catalytic enzymes implicated in the synthesis of PAs, thereby making a contribution to the biosynthesis of PAs. These findings imply a plausible and significant correlation between the nuique expression pattern of MYB5 and the pigmentation of rapeseed coats. Nevertheless, additional research endeavors are imperative to authenticate and substantiate these findings. CONCLUSIONS: This study offers valuable insights into the genetic evolution of Brassicaceae plants, thereby serving as a significant reference for the genetic enhancement of Brassicaceae seed coat color.

Genome-wide identification and expression analysis of the anthocyanin-related genes during seed coat development in six Brassica species.

Yellow seed is one favorite trait for the breeding of Brassica oilseed crops, but the performance of seed coat color is very complicated due to the involvement of various pigments. The change of seed coat color of Brassica crops is related to the specific synthesis and accumulation of anthocyanin, and the expression level of structural genes in anthocyanin synthesis pathway is specifically regulated by transcription factors. Despite some previous reports on the regulations of seed coat color from linkage marker development, gene fine-mapping and multi-omics association analysis, the trait of Brassica crops is affected by the evolutionary events such as genome triploidization, the regulatory mechanism is still largely unknown. In this study, we identified genes related to anthocyanin synthesis in six Brassica crops in U-triangle at the genome-wide level and performed collinearity analysis. A total of 1119 anthocyanin-related genes were identified, the collinear relationship of anthocyanin-related genes on subgenomic chromosomes was the best in B. napus (AACC) and the worst in B. carinata (BBCC). The comparisons of gene expressions for anthocyanin metabolic pathways in seed coats during seed development revealed differences in its metabolism among these species. Interestingly, the R2R3-MYB transcription factors MYB5 and TT2 were differentially expressed at all eight stages of seed coat development, indicating that they might be the key genes that caused the variation of the seed coat color. The expression curve and trend analyses of the seed coat development period showed that the main reason for the unexpressed copies of MYB5 and TT2 was likely gene silencing caused by gene structural variation. These results were valuable for the genetic improvement of Brassica seed coat color, and also provided new insights into gene multicopy evolution in Brassica polyploids.

Identification and characterization of the gene BraANS.A03 associated with purple leaf color in pak choi (Brassica rapa L. ssp. chinensis).

MAIN CONCLUSION: BraANS.A3 was the key gene controlling purple leaf color in pak choi, and two short fragments of promoter region in green pak choi might be interfering its normal expression. Pak choi (B. rapa L. ssp. chinensis) is an influential and important vegetable with green, yellow, or purple leaves that is cultivated worldwide. The purple leaves are rich in anthocyanins, but the underlying genetics and evolution have yet to be extensively studied. Free-hand sections of the purple leaves indicated that anthocyanins mainly accumulate throughout the adaxial and abaxial epidermal leaf cells. Segregation analyses of an F2 population of a B. rapa ssp. chinensis L. purple leaf mutant ZBC indicated that the purple trait is controlled by an incompletely dominant nuclear gene. Bulked segregant analysis (BSA) showed that the key genes controlling the trait were between 24.25 and 38.10 Mb on chromosome A03 of B. rapa. From the annotated genes, only BraA03g050560.3C, homologous to Arabidopsis AtANS, was related to the anthocyanin synthesis pathway. Genome annotation results and transcriptional sequencing analyses revealed that the BraANS.A3 gene was involved in the purple leaf trait. qRT-PCR analyses showed that BraANS.A3 was highly upregulated in ZBC but hardly expressed in the leaves of an inbred homozygous line of B. campestris ssp. chinensis L. green leaf mutant WTC, indicating that BraANS.A3 played a key role catalyzing anthocyanin synthesis in ZBC. Full-length sequence alignment of BraANS.A3 in WTC and ZBC showed that it was highly conserved in the gene region, with significant variation in the promoter region. In particular, the insertion of two short fragments of the promoter region in WTC may interfere with its normal expression. The promoter regions of ANS in six Brassica species all had multiple cis-elements involved in responses to abscisic acid, light, and stress, suggesting that ANS may be involved in multiple metabolic pathways or biological processes. Protein-protein interactions predicted that BraANS.A3 interacts with virtually all catalytic proteins in the anthocyanin synthesis pathway and has a strong relationship with Transparent Testa 8 (TT8). These results suggest that BraANS.A3 promotes anthocyanin accumulation in purple pak choi and provide new insights into the functional analysis of anthocyanin-related genes in Chinese cabbage and transcriptional regulatory networks.

Genome-wide identification of R2R3-MYB gene family and association with anthocyanin biosynthesis in Brassica species.

Brassica species include important oil crops and vegetables in the world. The R2R3-MYB gene participates in a variety of plant functions, including the activation or inhibition of anthocyanin biosynthesis. Although previous studies have reported its phylogenetic relationships, gene structures, and expression patterns in Arabidopsis, the number and sequence variation of this gene family in Brassica crops and its involvement in the natural quantitative variation in anthocyanin biosynthesis regulation are still largely unknown. In this study, by using whole genome sequences and comprehensive genome-wide comparative analysis among the six cultivated Brassica species, 2120 R2R3-MYB genes were identified in six Brassica species, in total These R2R3-MYB genes were phylogenetically clustered into 12 groups. The R2R3-MYB family between A and C subgenomes showed better collinearity than between B and C and between A and B. From comparing transcriptional changes of five Brassica species with the purple and green leaves for the detection of the R2R3-MYB genes associated with anthocyanin biosynthesis, 7 R2R3-MYB genes were co-differentially expressed. The promoter and structure analysis of these genes showed that some variations between non-coding region, but they were highly conserved at the protein level and spatial structure. Co-expression analysis of anthocyanin-related genes and R2R3-MYBs indicated that MYB90 was strongly co-expressed with TT8, and they were co-expressed with structural genes F3H, LDOX, ANS and UF3GT at the same time. These results further clarified the roles of the R2R3-MYBs for leaf coloration in Brasica species, which provided new insights into the functions of the R2R3-MYB gene family in Brasica species.

Anti-Symmetric Electromagnetic Interactions' Response in Electron Circular Dichroism and Chiral Origin of Periodic, Complementary Twisted Angle in Twisted Bilayer Graphene.

Many novel physical properties of twisted bilayer graphene have been discovered and studied successively, but the physical mechanism of the chiral modulation of BLG by a twisted angle lacks theoretical research. In this work, the density functional theory, the wavefunction analysis of the excited state, and the quantum theory of atoms in molecules are used to calculate and analyze the anti-symmetric chiral characteristics of zigzag-edge twisted bilayer graphene quantum dots based on periodic complementary twisted angles. The analysis of the partial density of states shows that Moiré superlattices can effectively adjust the contribution of the atomic basis function of the fragment to the transition dipole moment. The topological analysis of electron density indicates that the Moiré superlattices structure can enhance the localization of the system, increasing the electron density of the Moiré central ring, reducing the electron surge capacity in general and inducing the reversed helical properties of the top and underlying graphene, which can be used as the origin of the chiral discrimination; it also reveals the mole in the superlattice chiral physical mechanism. On this basis, we will also study the nonlinear optical properties of twisted bilayer graphene based on a twisted angle.

Synthesis and herbicidal activity of optically active α-(substituted phenoxyacetoxy) (substituted phenyl) methylphosphonates.

α-(Substituted phenoxyacetoxy) alkylphosphonates containing one chiral carbon atom have been demonstrated to be PDHc inhibitor with good herbicidal activity and some of them could be used as potential herbicide. In order to determine any difference in herbicidal activities between (R) and (S) isomers, the synthetic method of optically active substituted phenylalkylphosphonates IB were explored. A highly practical, enantioselective hydrophosphonylation was developed to prepare optically active O,O-dimethyl α-hydroxyalkylphosphonates 3 as key intermediate by asymmetric addition reaction of dimethylphosphite 1 and several kinds of aldehydes 2 using tridentate Schiff base Al(III) complexes as catalysts. A series of novel O,O-dimethyl α-(substituted phenoxyacetoxy)(substituted phenyl)methylphosphonates IB including (R) and (S) enantiomers were further synthesized with excellent enantioselectivity (95-99% ee) by the condensation of optically active α-hydroxyl (substituted phenyl)methylphosphonates 3 and substituted phenoxyacetyl chlorides 4. The herbicidal activities of title compound IB including their racemates, (R) and (S) enantiomers were evaluated in greenhouse for post-emergence application. All compounds IB showed significant inhibitory activity against dicotyledonous plants. A difference in herbicidal effect among racemate, (R) and (S) enantiomers were observed. Especially IB7 and IB10 showed obvious chiral selectivity in inhibitory activity against chickweed. (S)-IB7 with ED50 of 22.8gai/ha was found to be most effective enantiomer against chickweed and its inhibitory activity was 8.17 times higher than (R)-IB7. (S)-IB7 as potential herbicide would be effective at lower rates than (R)-IB7 or (rac)-IB7.

Effects of variable-temperature heat reservoirs on performance of irreversible Carnot refrigerator with heat recovery.

The outlet temperature of the heat recovery reservoir is an important parameter in the design of refrigeration with heat recovery systems. In this paper the second law of thermodynamics has been applied to an irreversible Carnot refrigerator with heat recovery (CRHR) coupled to variable-temperature heat reservoirs. The refrigerating rate, input power, refrigeration coefficient, heat recovery coefficient, comprehensive coefficient of performance and exergy efficiency are chosen as the objective functions. The design rule chosen for this study is that the heat transfer area should be constrained. The mathematical expressions for assessing performance parameters with respect to area ratio, were derived for this study. These expressions are transcendental equations. The numerical solution method was employed to calculate the approximate solutions of the optimum performance parameters in a numerical example. The results indicate that the increase in the outlet temperature of heat recovery reservoir could lead to a rise in the maximum value of refrigerating rate and minimum value of input power; also it will lead to the decline in the maximum value of refrigeration coefficient, heat recovery coefficient, comprehensive coefficient and the exergy efficiency. When the ratio of heat recovery heat exchanger area to the summation of high temperature heat exchanger area and the heat recovery heat exchanger area is 1.0, the performance coefficients would attain their limit values and all of the condensing heat could be recycled. Our findings are helpful to the design and optimization to inform preparation of standard relating to the development of refrigerator with heat recovery.

Anatomical and biomechanical analysis of sacral pedicle and lateral mass.

OBJECTIVE: To study the anatomical and biomechanical features of sacral pedicle and lateral mass so as to provide reference for clinical screw fixation technology of sacral pedicle and lateral mass. METHODS: A total of 60 adult patients'spiral CT images of the sacrum and coccyx were selected randomly. The entry points of sacral pedicle and lateral mass screws were determined, and the screw trajectory was measured using the three dimensional reconstruction method. Meanwhile, the gross anatomy was scrutinized in 15 adult cadaver specimens to determine the sacral pedicle and lateral mass screw entry points. The length, width and angle of sacral pedicle and lateral mass screw trajectory were measured. Eight of 15 cadaver specimens were selected to test the maximal extraction force of sacral pedicle and lateral mass screws. The clinical data of 15 cases treated by pedicle and lateral mass screw technology were collected and analyzed. RESULTS: The diameter and length of S(1)-S(5) sacral pedicle and lateral mass screw trajectory were regular, with about 20 degree inclination angle. The S(1) pedicle screw entry point was located at the intersection point of the basal lateral part of articular process and median line of transverse process, and no significant difference was found for the maximal extraction force between pedicle and lateral mass screws (P larger than 0.05). The entry points of S(2)-S(5) pedicle screws were located at the intersection point of the line connecting adjacent posterior sacral foramina and median line of the transverse process. The lateral mass screw entry point of S(2)-S(5) was on the median side of intersection point between median line of the transverse process and lateral sacral crest. The maximal extraction force of pedicle screws was significantly greater than that of lateral mass screws (P less than 0.05). CONCLUSION: Both the sacral pedicle and the lateral mass screw fixation techniques can offer effective fixation and reconstruction for fracture of the sacrum and coccyx, but pedicle screw fixation may be more convenient, safe and reliable than lateral mass screw fixation.