GRAS transcription factor PINNATE-LIKE PENTAFOLIATA2 controls compound leaf morphogenesis in Medicago truncatula.

The milestone of compound leaf development is the generation of separate leaflet primordia during the early stages, which involves two linked but distinct morphogenetic events: leaflet initiation and boundary establishment for leaflet separation. Although some progress in understanding the regulatory pathways for each event have been made, it is unclear how they are intrinsically coordinated. Here, we identify the PINNATE-LIKE PENTAFOLIATA2 (PINNA2) gene encoding a newly identified GRAS transcription factor in Medicago truncatula. PINNA2 transcripts are preferentially detected at organ boundaries. Its loss-of-function mutations convert trifoliate leaves into a pinnate pentafoliate pattern. PINNA2 directly binds to the promoter region of the LEAFY orthologue SINGLE LEAFLET1 (SGL1), which encodes a key positive regulator of leaflet initiation, and downregulates its expression. Further analysis revealed that PINNA2 synergizes with two other repressors of SGL1 expression, the BEL1-like homeodomain protein PINNA1 and the C2H2 zinc finger protein PALMATE-LIKE PENTAFOLIATA1 (PALM1), to precisely define the spatiotemporal expression of SGL1 in compound leaf primordia, thereby maintaining a proper pattern of leaflet initiation. Moreover, we showed that the enriched expression of PINNA2 at the leaflet-to-leaflet boundaries is positively regulated by the boundary-specific gene MtNAM, which is essential for leaflet boundary formation. Together, these results unveil a pivotal role of the boundary-expressed transcription factor PINNA2 in regulating leaflet initiation, providing molecular insights into the coordination of intricate developmental processes underlying compound leaf pattern formation.

CRISPRlnc: a machine learning method for lncRNA-specific single-guide RNA design of CRISPR/Cas9 system.

CRISPR/Cas9 is a promising RNA-guided genome editing technology, which consists of a Cas9 nuclease and a single-guide RNA (sgRNA). So far, a number of sgRNA prediction softwares have been developed. However, they were usually designed for protein-coding genes without considering that long non-coding RNA (lncRNA) genes may have different characteristics. In this study, we first evaluated the performances of a series of known sgRNA-designing tools in the context of both coding and non-coding datasets. Meanwhile, we analyzed the underpinnings of their varied performances on the sgRNA's specificity for lncRNA including nucleic acid sequence, genome location and editing mechanism preference. Furthermore, we introduce a support vector machine-based machine learning algorithm named CRISPRlnc, which aims to model both CRISPR knock-out (CRISPRko) and CRISPR inhibition (CRISPRi) mechanisms to predict the on-target activity of targets. CRISPRlnc combined the paired-sgRNA design and off-target analysis to achieve one-stop design of CRISPR/Cas9 sgRNAs for non-coding genes. Performance comparison on multiple datasets showed that CRISPRlnc was far superior to existing methods for both CRISPRko and CRISPRi mechanisms during the lncRNA-specific sgRNA design. To maximize the availability of CRISPRlnc, we developed a web server (http://predict.crisprlnc.cc) and made it available for download on GitHub.

A comparative full-length transcriptomic resource provides insight into the perennial monocarpic mass flowering.

Perennial monocarpic mass flowering represents as a key developmental innovation in flowering time diversity in several biological and economical essential families, such as the woody bamboos and the shrubby Strobilanthes. However, molecular and genetic mechanisms underlying this important biodiversity remain poorly investigated. Here, we generated a full-length transcriptome resource incorporated into the BlueOmics database (http://blueomics.iflora.cn) for two Strobilanthes species, which feature contrasting flowering time behaviors. Using about 112 and 104 Gb Iso-seq reads together with ~185 and ~75 Gb strand-specific RNA seq data, we annotated 80 971 and 79 985 non-redundant full-length transcripts for the perennial polycarpic Strobilanthes tetrasperma and the perennial monocarpic Strobilanthes biocullata, respectively. In S. tetrasperma, we identified 8794 transcripts showing spatiotemporal expression in nine tissues. In leaves and shoot apical meristems at two developmental stages, 977 and 1121 transcripts were differentially accumulated in S. tetrasperma and S. biocullata, respectively. Interestingly, among the 33 transcription factors showing differential expression in S. tetrasperma but without differential expression in S. biocullata, three were involved potentially in the photoperiod and circadian-clock pathway of flowering time regulation (FAR1 RELATED SEQUENCE 12, FRS12; NUCLEAR FACTOR Y A1, NFYA1; PSEUDO-RESPONSE REGULATOR 5, PRR5), hence provides an important clue in deciphering the flowering diversity mechanisms. Our data serve as a key resource for further dissection of molecular and genetic mechanisms underpinning key biological innovations, here, the perennial monocarpic mass flowering.

Salicylic acid inhibits rice endocytic protein trafficking mediated by OsPIN3t and clathrin to affect root growth.

Salicylic acid (SA) plays important roles in different aspects of plant development, including root growth, where auxin is also a major player by means of its asymmetric distribution. However, the mechanism underlying the effect of SA on the development of rice roots remains poorly understood. Here, we show that SA inhibits rice root growth by interfering with auxin transport associated with the OsPIN3t- and clathrin-mediated gene regulatory network (GRN). SA inhibits root growth as well as Brefeldin A-sensitive trafficking through a non-canonical SA signaling mechanism. Transcriptome analysis of rice seedlings treated with SA revealed that the OsPIN3t auxin transporter is at the center of a GRN involving the coat protein clathrin. The root growth and endocytic trafficking in both the pin3t and clathrin heavy chain mutants were SA insensitivity. SA inhibitory effect on the endocytosis of OsPIN3t was dependent on clathrin; however, the root growth and endocytic trafficking mediated by tyrphostin A23 (TyrA23) were independent of the pin3t mutant under SA treatment. These data reveal that SA affects rice root growth through the convergence of transcriptional and non-SA signaling mechanisms involving OsPIN3t-mediated auxin transport and clathrin-mediated trafficking as key components.

Ultra-sensitive temperature and pressure sensor based on PDMS-based FPI and Vernier effect.

An ultra-sensitive sensor, based on two Fabry-Perot interferometers (FPIs), has been realized for temperature and pressure sensing. A polydimethylsiloxane (PDMS)-based FPI1 was used as a sensing cavity, and a closed capillary-based FPI2 was used as a reference cavity for its insensitivity to both temperature and pressure. The two FPIs were connected in series to obtain a cascaded FPIs sensor, showing a clear spectral envelope. The temperature and pressure sensitivities of the proposed sensor reach up to 16.51 nm/°C and 100.18 nm/MPa, which are 25.4 and 21.6 times, respectively, larger than these of the PDMS-based FPI1, showing a great Vernier effect.

The MIO1-MtKIX8 module regulates the organ size in Medicago truncatula.

Plant organ size is an important agronomic trait tightly related to crop yield. However, the molecular mechanisms underlying organ size regulation remain largely unexplored in legumes. We previously characterized a key regulator F-box protein MINI ORGAN1 (MIO1)/SMALL LEAF AND BUSHY1 (SLB1), which controls plant organ size in the model legume Medicago truncatula. In order to further dissect the molecular mechanism, MIO1 was used as the bait to screen its interacting proteins from a yeast library. Subsequently, a KIX protein, designated MtKIX8, was identified from the candidate list. The interaction between MIO1 and MtKIX8 was confirmed further by Y2H, BiFC, split-luciferase complementation and pull-down assays. Phylogenetic analyses indicated that MtKIX8 is highly homologous to Arabidopsis KIX8, which negatively regulates organ size. Moreover, loss-of-function of MtKIX8 led to enlarged leaves and seeds, while ectopic expression of MtKIX8 in Arabidopsis resulted in decreased cotyledon area and seed weight. Quantitative reverse-transcription PCR and in situ hybridization showed that MtKIX8 is expressed in most developing organs. We also found that MtKIX8 serves as a crucial molecular adaptor, facilitating interactions with BIG SEEDS1 (BS1) and MtTOPLESS (MtTPL) proteins in M. truncatula. Overall, our results suggest that the MIO1-MtKIX8 module plays a significant and conserved role in the regulation of plant organ size. This module could be a good target for molecular breeding in legume crops and forages.

RNA-Seq analysis reveals the important co-expressed genes associated with polyphyllin biosynthesis during the developmental stages of Paris polyphylla.

BACKGROUND: Plants synthesize metabolites to adapt to a continuously changing environment. Metabolite biosynthesis often occurs in response to the tissue-specific combinatorial developmental cues that are transcriptionally regulated. Polyphyllins are the major bioactive components in Paris species that demonstrate hemostatic, anti-inflammatory and antitumor effects and have considerable market demands. However, the mechanisms underlying polyphyllin biosynthesis and regulation during plant development have not been fully elucidated. RESULTS: Tissue samples of P. polyphylla var. yunnanensis during the four dominant developmental stages were collected and investigated using high-performance liquid chromatography and RNA sequencing. Polyphyllin concentrations in the different tissues were found to be highly dynamic across developmental stages. Specifically, decreasing trends in polyphyllin concentration were observed in the aerial vegetative tissues, whereas an increasing trend was observed in the rhizomes. Consistent with the aforementioned polyphyllin concentration trends, different patterns of spatiotemporal gene expression in the vegetative tissues were found to be closely related with polyphyllin biosynthesis. Additionally, molecular dissection of the pathway components revealed 137 candidate genes involved in the upstream pathway of polyphyllin backbone biosynthesis. Furthermore, gene co-expression network analysis revealed 74 transcription factor genes and one transporter gene associated with polyphyllin biosynthesis and allocation. CONCLUSIONS: Our findings outline the framework for understanding the biosynthesis and accumulation of polyphyllins during plant development and contribute to future research in elucidating the molecular mechanism underlying polyphyllin regulation and accumulation in P. polyphylla.

GCEN: An Easy-to-Use Toolkit for Gene Co-Expression Network Analysis and lncRNAs Annotation.

Gene co-expression network analysis has been widely used in gene function annotation, especially for long noncoding RNAs (lncRNAs). However, there is a lack of effective cross-platform analysis tools. For biologists to easily build a gene co-expression network and to predict gene function, we developed GCEN, a cross-platform command-line toolkit developed with C++. It is an efficient and easy-to-use solution that will allow everyone to perform gene co-expression network analysis without the requirement of sophisticated programming skills, especially in cases of RNA-Seq research and lncRNAs function annotation. Because of its modular design, GCEN can be easily integrated into other pipelines.

Femtosecond laser processing for a high sensitivity fiber MZI microcavity.

An ultra-compact fiber inline Mach-Zehnder interferometer sensor based on femtosecond laser micromachining technology is demonstrated. It is found that the microstructure has an ultra-high refractive index sensitivity of 16660 nm/RIU when a femtosecond pulsed laser is used to remove the upper cladding and part of the core of a standard single-mode fiber. However, its temperature sensitivity is not much different from that of most pure quartz fibers and can be as high as 7.934 nm/°C when the microcavity is coated with a low-refractive-index ultraviolet adhesive, which was originally used for bonding glass. With this coating, however, it demonstrates excellent robustness.

MtGSTF7, a TT19-like GST gene, is essential for accumulation of anthocyanins, but not proanthocyanins in Medicago truncatula.

Anthocyanins and proanthocyanins (PAs) are two end products of the flavonoid biosynthesis pathway. They are believed to be synthesized in the endoplasmic reticulum and then sequestered into the vacuole. In Arabidopsis thaliana, TRANSPARENT TESTA 19 (TT19) is necessary for both anthocyanin and PA accumulation. Here, we found that MtGSTF7, a homolog of AtTT19, is essential for anthocyanin accumulation but not required for PA accumulation in Medicago truncatula. MtGSTF7 was induced by the anthocyanin regulator LEGUME ANTHOCYANIN PRODUCTION 1 (LAP1), and its tissue expression pattern correlated with anthocyanin deposition in M. truncatula. Tnt1-insertional mutants of MtGSTF7 lost anthocyanin accumulation in vegetative organs, and introducing a genomic fragment of MtGSTF7 could complement the mutant phenotypes. Additionally, the accumulation of anthocyanins induced by LAP1 was significantly reduced in mtgstf7 mutants. Yeast-one-hybridization and dual-luciferase reporter assays revealed that LAP1 could bind to the MtGSTF7 promoter to activate its expression. Ectopic expression of MtGSTF7 in tt19 mutants could rescue their anthocyanin deficiency, but not their PA defect. Furthermore, PA accumulation was not affected in the mtgstf7 mutants. Taken together, our results show that the mechanism of anthocyanin and PA accumulation in M. truncatula is different from that in A. thaliana, and provide a new target gene for engineering anthocyanins in plants.

Compartmentalized biosynthesis of mycophenolic acid.

Mycophenolic acid (MPA) from filamentous fungi is the first natural product antibiotic to be isolated and crystallized, and a first-line immunosuppressive drug for organ transplantations and autoimmune diseases. However, some key biosynthetic mechanisms of such an old and important molecule have remained unclear. Here, we elucidate the MPA biosynthetic pathway that features both compartmentalized enzymatic steps and unique cooperation between biosynthetic and ß-oxidation catabolism machineries based on targeted gene inactivation, feeding experiments in heterologous expression hosts, enzyme functional characterization and kinetic analysis, and microscopic observation of protein subcellular localization. Besides identification of the oxygenase MpaB' as the long-sought key enzyme responsible for the oxidative cleavage of the farnesyl side chain, we reveal the intriguing pattern of compartmentalization for the MPA biosynthetic enzymes, including the cytosolic polyketide synthase MpaC' and O-methyltransferase MpaG', the Golgi apparatus-associated prenyltransferase MpaA', the endoplasmic reticulum-bound oxygenase MpaB' and P450-hydrolase fusion enzyme MpaDE', and the peroxisomal acyl-coenzyme A (CoA) hydrolase MpaH'. The whole pathway is elegantly comediated by these compartmentalized enzymes, together with the peroxisomal ß-oxidation machinery. Beyond characterizing the remaining outstanding steps of the MPA biosynthetic steps, our study highlights the importance of considering subcellular contexts and the broader cellular metabolism in natural product biosynthesis.

Multidimensional Gene Regulatory Landscape of Motor Organ Pulvinus in the Model Legume Medicago truncatula.

Nyctinastic leaf movement of Fabaceae is driven by the tiny motor organ pulvinus located at the base of the leaf or leaflet. Despite the increased understanding of the essential role of ELONGATED PETIOLULE1 (ELP1)/PETIOLE LIKE PULVINUS (PLP) orthologs in determining pulvinus identity in legumes, key regulatory components and molecular mechanisms underlying this movement remain largely unclear. Here, we used WT pulvinus and the equivalent tissue in the elp1 mutant to carry out transcriptome and proteome experiments. The omics data indicated that there are multiple cell biological processes altered at the gene expression and protein abundance level during the pulvinus development. In addition, comparative analysis of different leaf tissues provided clues to illuminate the possible common primordium between pulvinus and petiole, as well as the function of ELP1. Furthermore, the auxin pathway, cell wall composition and chloroplast distribution were altered in elp1 mutants, verifying their important roles in pulvinus development. This study provides a comprehensive insight into the motor organ of the model legume Medicago truncatula and further supplies a rich dataset to facilitate the identification of novel players involved in nyctinastic movement.

Extended mining of the oil biosynthesis pathway in biofuel plant Jatropha curcas by combined analysis of transcriptome and gene interactome data.

BACKGROUND: Jatropha curcas L. is an important non-edible oilseed crop with a promising future in biodiesel production. However, little is known about the molecular biology of oil biosynthesis in this plant when compared with other established oilseed crops, resulting in the absence of agronomically improved varieties of Jatropha. To extensively discover the potentially novel genes and pathways associated with the oil biosynthesis in J. curcas, new strategy other than homology alignment is on the demand. RESULTS: In this study, we proposed a multi-step computational framework that integrates transcriptome and gene interactome data to predict functional pathways in non-model organisms in an extended process, and applied it to study oil biosynthesis pathway in J. curcas. Using homologous mapping against Arabidopsis and transcriptome profile analysis, we first constructed protein-protein interaction (PPI) and co-expression networks in J. curcas. Then, using the homologs of Arabidopsis oil-biosynthesis-related genes as seeds, we respectively applied two algorithm models, random walk with restart (RWR) in PPI network and negative binomial distribution (NBD) in co-expression network, to further extend oil-biosynthesis-related pathways and genes in J. curcas. At last, using k-nearest neighbors (KNN) algorithm, the predicted genes were further classified into different sub-pathways according to their possible functional roles. CONCLUSIONS: Our method exhibited a highly efficient way of mining the extended oil biosynthesis pathway of J. curcas. Overall, 27 novel oil-biosynthesis-related gene candidates were predicted and further assigned to 5 sub-pathways. These findings can help better understanding of the oil biosynthesis pathway of J. curcas, as well as paving the way for the following J. curcas breeding application.

Data integration and evolutionary analysis of long non-coding RNAs in 25 flowering plants.

BACKGROUND: Long non-coding RNAs (lncRNAs) play vital roles in many important biological processes in plants. Currently, a large fraction of plant lncRNA studies center at lncRNA identification and functional analysis. Only a few plant lncRNA studies focus on understanding their evolutionary history, which is crucial for an in-depth understanding of lncRNAs. Therefore, the integration of large volumes of plant lncRNA data is required to deeply investigate the evolution of lncRNAs. RESULTS: We present a large-scale evolutionary analysis of lncRNAs in 25 flowering plants. In total, we identified 199,796 high-confidence lncRNAs through data integration analysis, and grouped them into 5497 lncRNA orthologous families. Then, we divided the lncRNAs into groups based on the degree of sequence conservation, and quantified the various characteristics of 756 conserved Arabidopsis thaliana lncRNAs. We found that compared with non-conserved lncRNAs, conserved lncRNAs might have more exons, longer sequence length, higher expression levels, and lower tissue specificities. Functional annotation based on the A. thaliana coding-lncRNA gene co-expression network suggested potential functions of conserved lncRNAs including autophagy, locomotion, and cell cycle. Enrichment analysis revealed that the functions of conserved lncRNAs were closely related to the growth and development of the tissues in which they were specifically expressed. CONCLUSIONS: Comprehensive integration of large-scale lncRNA data and construction of a phylogenetic tree with orthologous lncRNA families from 25 flowering plants was used to provide an oversight of the evolutionary history of plant lncRNAs including origin, conservation, and orthologous relationships. Further analysis revealed a differential characteristic profile for conserved lncRNAs in A. thaliana when compared with non-conserved lncRNAs. We also examined tissue specific expression and the potential functional roles of conserved lncRNAs. The results presented here will further our understanding of plant lncRNA evolution, and provide the basis for further in-depth studies of their functions.

INDITTO2 transposon conveys auxin-mediated DRO1 transcription for rice drought avoidance.

Transposable elements exist widely throughout plant genomes and play important roles in plant evolution. Auxin is an important regulator that is traditionally associated with root development and drought stress adaptation. The DEEPER ROOTING 1 (DRO1) gene is a key component of rice drought avoidance. Here, we identified a transposon that acts as an autonomous auxin-responsive promoter and its presence at specific genome positions conveys physiological adaptations related to drought avoidance. Rice varieties with a high and auxin-mediated transcription of DRO1 in the root tip show deeper and longer root phenotypes and are thus better adapted to drought. The INDITTO2 transposon contains an auxin response element and displays auxin-responsive promoter activity; it is thus able to convey auxin regulation of transcription to genes in its proximity. In the rice Acuce, which displays DRO1-mediated drought adaptation, the INDITTO2 transposon was found to be inserted at the promoter region of the DRO1 locus. Transgenesis-based insertion of the INDITTO2 transposon into the DRO1 promoter of the non-adapted rice variety Nipponbare was sufficient to promote its drought avoidance. Our data identify an example of how transposons can act as promoters and convey hormonal regulation to nearby loci, improving plant fitness in response to different abiotic stresses.

CRISPRlnc: a manually curated database of validated sgRNAs for lncRNAs.

The CRISPR/Cas9 system, as a revolutionary genome editing tool for all areas of molecular biology, provides new opportunities for research on lncRNA's function. However, designing a CRISPR/Cas9 single guide RNA (sgRNA) for lncRNA is not easy with an unwarrantable effectiveness. Thus, it is worthy of collecting validated sgRNAs, to assist in efficiently choosing sgRNA with an expected activity. CRISPRlnc (http://www.crisprlnc.org or http://crisprlnc.xtbg.ac.cn) is a manually curated database of validated CRISPR/Cas9 sgRNAs for lncRNAs from all species. After manually reviewing more than 200 published literature, the current version of CRISPRlnc contains 305 lncRNAs and 2102 validated sgRNAs across eight species, including mammalian, insect and plant. We handled the ID, position in the genome, sequence and functional description of these lncRNAs, as well as the sequence, protoacceptor-motif (PAM), CRISPR type and validity of their paired sgRNAs. In CRISPRlnc, we provided the tools for browsing, searching and downloading data, as well as online BLAST service and genome browse server. As the first database against the validated sgRNAs of lncRNAs, CRISPRlnc will provide a new and powerful platform to promote CRISPR/Cas9 applications for future functional studies of lncRNAs.

Behavioral, Histopathologic, and Molecular Biological Responses of Nanoparticle- and Solution-Based Formulations of Vincristine in Mice.

Clinical use of the chemotherapeutic agent vincristine (VCR) is limited by chemotherapy-induced peripheral neuropathy (CiPN). A new formulation of VCR encapsulated by nanoparticles has been proposed and developed to alleviate CiPN. We hypothesized in nonclinical animals that the nanoparticle drug would be less neurotoxic due to different absorption and distribution properties to the peripheral nerve from the unencapsulated free drug. Here, we assessed whether VCR encapsulation in nanoparticles alleviates CiPN using behavioral gait analysis (CatWalk), histopathologic and molecular biological (RT-qPCR) approaches. Adult male C57BL/6 mice were assigned to 3 groups (empty nanoparticle, nano-VCR, solution-based VCR, each n = 8). After 15 days of dosing, animals were euthanized for tissue collection. It was shown that intraperitoneal administration of nano-VCR (0.15 mg/kg, every other day) and the empty nanoparticle resulted in no changes in gait parameters; whereas, injection of solution-based VCR resulted in decreased run speed and increased step cycle and stance (P < 0.05). There were no differences in incidence and severity of degeneration in the sciatic nerves between the nano-VCR-dosed and solution-based VCR-dosed animals. Likewise, decreased levels of a nervous tissue-enriched microRNA-183 in circulating blood did not show a significant difference between the nano- and solution-based VCR groups (P > 0.05). Empty nanoparticle administration did not cause any behavioral, microRNA, or structural changes. In conclusion, this study suggests that the nano-VCR formulation may alleviate behavioral changes in CiPN, but it does not improve the structural changes of CiPN in peripheral nerve. Nanoparticle properties may need to be optimized to improve biological observations.

Regulatory roles of long noncoding RNAs implicated in cancer hallmarks.

Cancer cells acquire numerous biological properties (designated "cancer hallmarks"), such as cell survival and energy metabolism, that facilitate tumor growth and metastatic dissemination during development. To date, eight hallmarks of cancer have been identified that provide a logical framework for understanding the remarkable diversity of neoplastic diseases, as proposed by Douglas Hanahan and Robert A. Weinberg. Long noncoding RNAs (lncRNAs), a category of transcripts widely demonstrated to exert significant regulatory effects on biological processes, have attracted considerable research attention due to their association with the occurrence and development of cancer. The mechanisms by which lncRNAs exert their functions require elucidation to optimize their potential utility as alternative biomarkers and therapeutic targets during tumor occurrence and progression. In this review, we have discussed recent research progress on lncRNAs involved in various cancer hallmarks and their related mechanisms of action, with a view to providing an updated picture of their immense therapeutic potential in the fight against cancer.

No Evidence of Neurogenesis in Adult Rat Sympathetic Ganglia Following Guanethidine-Induced Neuronal Loss.

The potential for neurogenesis in the cranial (superior) cervical ganglia (SCG) of the sympathetic nervous system was evaluated. Eleven consecutive daily doses of guanethidine (100 mg/kg/d) were administered intraperitoneally to rats in order to destroy postganglionic sympathetic neurons in SCG. Following the last dose, animals were allowed to recover 1, 3, or 6 months. Right and left SCG from guanethidine-treated and age-matched, vehicle-treated control rats were harvested for histopathologic, morphometric, and stereologic evaluations. Both morphometric and stereologic evaluations confirmed neuron loss following guanethidine treatment. Morphometric analysis revealed a 50% to 60% lower number of tyrosine hydroxylase (TH)-positive neurons per unit area of SCG at both 3 and 6 months of recovery, compared to ganglia of age-matched controls, with no evidence of restoration of neuron density between 3 and 6 months. Reductions in TH-positive neurons following guanethidine treatment were corroborated by unbiased stereology of total hematoxylin and eosin-stained neuron numbers in SCG. Stereologic analyses revealed that total neuron counts were lower by 37% at 3 months of recovery when compared to age-matched vehicle controls, again with no obvious restoration between 3 and 6 months. Thus, no evidence was found that postganglionic neurons of the sympathetic nervous system in the adult rat have a neurogenic capacity.

Genome-wide identification, phylogeny, and expression analysis of the SBP-box gene family in Euphorbiaceae.

BACKGROUND: Euphorbiaceae is one of the largest families of flowering plants. Due to its exceptional growth form diversity and near-cosmopolitan distribution, it has attracted much interest since ancient times. SBP-box (SBP) genes encode plant-specific transcription factors that play critical roles in numerous biological processes, especially flower development. We performed genome-wide identification and characterization of SBP genes from four economically important Euphorbiaceae species. RESULTS: In total, 77 SBP genes were identified in four Euphorbiaceae genomes. The SBP proteins were divided into three length ranges and 10 groups. Group-6 was absent in Arabidopsis thaliana but conserved in Euphorbiaceae. Segmental duplication played the most important role in the expansion processes of Euphorbiaceae SBP genes, and all the duplicated genes were subjected to purify selection. In addition, about two-thirds of the Euphorbiaceae SBP genes are potential targets of miR156, and some miR-regulated SBP genes exhibited high intensity expression and differential expression in different tissues. The expression profiles related to different stress treatments demonstrated broad involvement of Euphorbiaceae SBP genes in response to various abiotic factors and hormonal treatments. CONCLUSIONS: In this study, 77 SBP genes were identified in four Euphorbiaceae species, and their phylogenetic relationships, protein physicochemical characteristics, duplication, tissue and stress response expression, and potential roles in Euphorbiaceae development were studied. This study lays a foundation for further studies of Euphorbiaceae SBP genes, providing valuable information for future functional exploration of Euphorbiaceae SBP genes.