Transcriptional activation by WRKY23 and derepression by removal of bHLH041 coordinately establish callus pluripotency in Arabidopsis regeneration.

Induction of the pluripotent cell mass termed callus from detached organs or tissues is an initial step in typical in vitro plant regeneration, during which auxin-induced ectopic activation of root stem cell factors is required for subsequent de novo shoot regeneration. While Arabidopsis (Arabidopsis thaliana) AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 and their downstream transcription factors LATERAL ORGAN BOUNDARIES DOMAIN (LBD) are known to play key roles in directing callus formation, the molecules responsible for activation of root stem cell factors and thus establishment of callus pluripotency are unclear. Here, we identified Arabidopsis WRKY23 and BASIC HELIX-LOOP-HELIX 041 (bHLH041) as a transcriptional activator and repressor, respectively, of root stem cell factors during establishment of auxin-induced callus pluripotency. We show that auxin-induced WRKY23 downstream of ARF7 and ARF19 directly activates the transcription of PLETHORA 3 (PLT3) and PLT7 and thus that of the downstream genes PLT1, PLT2, and WUSCHEL-RELATED HOMEOBOX 5 (WOX5), while LBD-induced removal of bHLH041 derepresses the transcription of PLT1, PLT2, and WOX5. We provide evidence that transcriptional activation by WRKY23 and loss of bHLH041-imposed repression act synergistically in conferring shoot-regenerating capability on callus cells. Our findings thus disclose a transcriptional mechanism underlying auxin-induced cellular reprogramming, which, together with previous studies, outlines the molecular framework of auxin-induced pluripotent callus formation for in vitro plant regeneration programs.

Two C-terminal isoforms of Aplysia tachykinin-related peptide receptors exhibit phosphorylation-dependent and independent desensitization mechanisms.

Diversity, a hallmark of G protein-coupled receptor (GPCR) signaling, partly stems from alternative splicing of a single gene generating more than one isoform for a receptor. Additionally, receptor responses to ligands can be attenuated by desensitization upon prolonged or repeated ligand exposure. Both phenomena have been demonstrated and exemplified by the deuterostome tachykinin (TK) signaling system, although the role of phosphorylation in desensitization remains a subject of debate. Here, we describe the signaling system for tachykinin-related peptides (TKRPs) in a protostome, mollusk Aplysia. We cloned the Aplysia TKRP precursor, which encodes three TKRPs (apTKRP-1, apTKRP-2a, and apTKRP-2b) containing the FXGXR-amide motif. In situ hybridization and immunohistochemistry showed predominant expression of TKRP mRNA and peptide in the cerebral ganglia. TKRPs and their post-translational modifications were observed in extracts of CNS ganglia using mass spectrometry. We identified two Aplysia TKRP receptors (TKRPRs), named apTKRPR-A and apTKRPR-B. These receptors are two isoforms generated through alternative splicing of the same gene and differ only in their intracellular C-termini. Structure-activity relationship analysis of apTKRP-2b revealed that both C-terminal amidation and conserved residues of the ligand are critical for receptor activation. C-terminal truncates and mutants of apTKRPRs suggested that there is a C-terminal phosphorylation-independent desensitization for both receptors. Moreover, apTKRPR-B also exhibits phosphorylation-dependent desensitization through the phosphorylation of C-terminal Ser/Thr residues. This comprehensive characterization of the Aplysia TKRP signaling system underscores the evolutionary conservation of the TKRP and TK signaling systems, while highlighting the intricacies of receptor regulation through alternative splicing and differential desensitization mechanisms.

The calcium signaling module CaM-IQM destabilizes IAA-ARF interaction to regulate callus and lateral root formation.

Induction of a pluripotent cell mass, called callus, from detached organs is an initial step in in vitro plant regeneration, during which phytohormone auxin-induced ectopic activation of a root developmental program has been shown to be required for subsequent de novo regeneration of shoots and roots. However, whether other signals are involved in governing callus formation, and thus plant regeneration capability, remains largely unclear. Here, we report that the Arabidopsis calcium (Ca2+) signaling module CALMODULIN IQ-MOTIF CONTAINING PROTEIN (CaM-IQM) interacts with auxin signaling to regulate callus and lateral root formation. We show that disruption of IQMs or CaMs retards auxin-induced callus and lateral root formation by dampening auxin responsiveness, and that CaM-IQM complexes physically interact with the auxin signaling repressors INDOLE-3-ACETIC ACID INDUCIBLE (IAA) proteins in a Ca2+-dependent manner. We further provide evidence that the physical interaction of CaM6 with IAA19 destabilizes the repressive interaction of IAA19 with AUXIN RESPONSE FACTOR 7 (ARF7), and thus regulates auxin-induced callus formation. These findings not only define a critical role of CaM-IQM-mediated Ca2+ signaling in callus and lateral root formation, but also provide insight into the interplay of Ca2+ signaling and auxin actions during plant regeneration and development.

Extracorporeal membrane oxygenation in long-term COVID-19 with severe neutropenia and thrombocytopenia after allogeneic hematopoietic stem cell transplantation: a case report.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) was associated with potentially life-threatening complications. Among patients supported by extracorporeal membrane oxygenation (ECMO), those who underwent HSCT had a worse prognosis than those who did not. Advances in HSCT and critical care management have improved the prognosis of ECMO-supported HSCT patients. CASE: The patient in the remission stage of lymphoma after 22 months of allogeneic hematopoietic stem cell transplantation, suffered from ARDS, severe neutropenia, thrombocytopenia, and long-term COVID-19. We evaluated the benefits and risks of ECMO for the patient, including the possibility of being free from ECMO, the status of malignancy, the interval from HSCT to ARDS, the function of the graft, the amount of organ failure, and the comorbidities. ECMO was ultimately used to save his life. CONCLUSIONS: We did not advocate for the general use of ECMO in HSCT patients and we believed that highly selected patients, with well-controlled tumors, few comorbidities, and fewer risk factors for death, tended to benefit from ECMO with well ICU management.

Gas-Phase Regeneration of Metal-Poisoned V2O5-WO3/TiO2 NH3-SCR Catalysts via a Masking and Reconstruction Strategy.

Renewing metal-poisoned NH3-SCR catalysts holds great potential for mitigating environmental pollution and utilizing hazardous wastes simultaneously. Ionic compounds containing heavy metals often exhibit limited solubility due to their high polarizability, making traditional washing techniques ineffective in removing heavy metal poisons. This study presents a gas-based method for regenerating heavy-metal-poisoned V2O5-WO3/TiO2 catalysts employed in NH3-SCR techniques. The regeneration is achieved by employing a masking and reconstruction strategy, which involves the in situ formation of NO2 to mediate the production of SO3. This enables the effective bonding of Pb and triggers the reconstruction of active VOx sites. In situ spectroscopy confirms that the sulfation of PbO restores acidity, while the occupied effect resulting from the sulfation of TiO2 promotes the formation of more polymeric VOx species. Consequently, the regenerated catalyst exhibits enhanced activity and superior resistance to metal poisons compared with the fresh catalyst. The innovative method offers a promising solution for extending the lifespan of poisoned catalysts, reducing waste generation, and enhancing the efficiency of NH3-SCR systems.

Deep eutectic solvent self-assembled reverse nanomicelles for transdermal delivery of sparingly soluble drugs.

BACKGROUND: Transdermal delivery of sparingly soluble drugs is challenging due to their low solubility and poor permeability. Deep eutectic solvent (DES)/or ionic liquid (IL)-mediated nanocarriers are attracting increasing attention. However, most of them require the addition of auxiliary materials (such as surfactants or organic solvents) to maintain the stability of formulations, which may cause skin irritation and potential toxicity. RESULTS: We fabricated an amphiphilic DES using natural oxymatrine and lauric acid and constructed a novel self-assembled reverse nanomicelle system (DES-RM) based on the features of this DES. Synthesized DESs showed the broad liquid window and significantly solubilized a series of sparingly soluble drugs, and quantitative structure-activity relationship (QSAR) models with good prediction ability were further built. The experimental and molecular dynamics simulation elucidated that the self-assembly of DES-RM was adjusted by noncovalent intermolecular forces. Choosing triamcinolone acetonide (TA) as a model drug, the skin penetration studies revealed that DES-RM significantly enhanced TA penetration and retention in comparison with their corresponding DES and oil. Furthermore, in vivo animal experiments demonstrated that TA@DES-RM exhibited good anti-psoriasis therapeutic efficacy as well as biocompatibility. CONCLUSIONS: The present study offers innovative insights into the optimal design of micellar nanodelivery system based on DES combining experiments and computational simulations and provides a promising strategy for developing efficient transdermal delivery systems for sparingly soluble drugs.

AI protein structure prediction-based modeling and mutagenesis of a protostome receptor and peptide ligands reveal key residues for their interaction.

The protostome leucokinin (LK) signaling system, including LK peptides and their G protein-coupled receptors, has been characterized in several species. Despite the progress, molecular mechanisms governing LK peptide-receptor interactions remain to be elucidated. Previously, we identified a precursor protein for Aplysia leucokinin-like peptides (ALKs) that contains the greatest number of amidated peptides among LK precursors in all species identified so far. Here, we identified the first ALK receptor from Aplysia, ALKR. We used cell-based IP1 activation assays to demonstrate that two ALK peptides with the most copies, ALK1 and ALK2, activated ALKR with high potencies. Other endogenous ALK-derived peptides bearing the FXXWX-amide motif also activated ALKR to various degrees. Our examination of cross-species activity of ALKs with the Anopheles LK receptor was consistent with a critical role for the FXXWX-amide motif in receptor activity. Furthermore, we showed, through alanine substitution of ALK1, the highly conserved phenylalanine (F), tryptophan (W), and C-terminal amidation were each essential for receptor activation. Finally, we used an artificial intelligence-based protein structure prediction server (Robetta) and Autodock Vina to predict the ligand-bound conformation of ALKR. Our model predicted several interactions (i.e., hydrophobic interactions, hydrogen bonds, and amide-pi stacking) between ALK peptides and ALKR, and several of our substitution and mutagenesis experiments were consistent with the predicted model. In conclusion, our results provide important information defining possible interactions between ALK peptides and their receptors. The workflow utilized here may be useful for studying other ligand-receptor interactions for a neuropeptide signaling system, particularly in protostomes.

[Exploration and example interpretation of real-world herbal prescription classification based on similarity matching algorithm].

In observational studies, herbal prescriptions are usually studied in the form of "similar prescriptions". At present, the classification of prescriptions is mainly based on clinical experience judgment, but there are some problems in manual judgment, such as lack of unified criteria, labor consumption, and difficulty in verification. In the construction of a database of integrated traditional Chinese and western medicine for the treatment of coronavirus disease 2019(COVID-19), our research group tried to classify real-world herbal prescriptions using a similarity matching algorithm. The main steps include 78 target prescriptions are determined in advance; four levels of importance labeling shall be carried out for the drugs of each target prescription; the combination, format conversion, and standardization of drug names of the prescriptions to be identified in the herbal medicine database; calculate the similarity between the prescriptions to be identified and each target prescription one by one; prescription discrimination is performed based on the preset criteria; remove the name of the prescriptions with "large prescriptions cover the small". Through the similarity matching algorithm, 87.49% of the real prescriptions in the herbal medicine database of this study can be identified, which preliminarily proves that this method can complete the classification of herbal prescriptions. However, this method does not consider the influence of herbal dosage on the results, and there is no recognized standard for the weight of drug importance and criteria, so there are some limitations, which need to be further explored and improved in future research.

Novel Nitric Oxide Donor Dinitroazetidine-Coumarin Hybrids as Potent Anti-Intrahepatic Cholangiocarcinoma Agents.

Intrahepatic cholangiocarcinoma (iCC) is a serious liver cancer threatening human health. However, there are a few chemotherapeutic drugs for the treatment of iCC in the clinic. It is extremely urgent to develop new drugs for iCC. In this study, twenty dinitroazetidine and coumarin hybrids were synthesized and evaluated anti-iCC bioactivity as a new type of nitric oxide (NO) donors. Among them, compounds 2-5 and 21 showed a higher antiproliferative activity against RBE cell lines (human intrahepatic cholangiocarcinoma cell lines) and low cytotoxicity in nontumor cells (HOSEpiC and T29). The preliminary study of pharmacology mechanism indicated that compounds 2-5 and 21 could release effective concentration of NO in RBE cell lines, which leaded to inhibit the proliferation of RBE cell lines. The research results revealed that compound 3 inhibited the proliferation of RBE cell lines by inducing apoptosis and arresting cell cycle at G2/M phase. Additionally, compound 3 had acceptable metabolic stability. Therefore, compound 3 was merited to further explore for developing a desirable NO donor lead with anti-iCC activity.

Mobility Extraction in 2D Transition Metal Dichalcogenide Devices-Avoiding Contact Resistance Implicated Overestimation.

Schottky barrier (SB) transistors operate distinctly different from conventional metal-oxide semiconductor field-effect transistors, in a unique way that the gate impacts the carrier injection from the metal source/drain contacts into the channel region. While it has been long recognized that this can have severe implications for device characteristics in the subthreshold region, impacts of contact gating of SB in the on-state of the devices, which affects evaluation of intrinsic channel properties, have been yet comprehensively studied. Due to the fact that contact resistance (RC ) is always gate-dependent in a typical back-gated device structure, the traditional approach of deriving field-effect mobility from the maximum transconductance (gm ) is in principle not correct and can even overestimate the mobility. In addition, an exhibition of two different threshold voltages for the channel and the contact region leads to another layer of complexity in determining the true carrier concentration calculated from Q = COX * (VG -VTH ). Through a detailed experimental analysis, the effect of different effective oxide thicknesses, distinct SB heights, and doping-induced reductions in the SB width are carefully evaluated to gain a better understanding of their impact on important device metrics.

The WOX family transcriptional regulator SlLAM1 controls compound leaf and floral organ development in Solanum lycopersicum.

Plant-specific WOX family transcription factors play important roles ranging from embryogenesis to lateral organ development. The WOX1 transcription factors, which belong to the modern clade of the WOX family, are known to regulate outgrowth of the leaf blade specifically in the mediolateral axis; however, the role of WOX1 in compound leaf development remains unknown. Phylogenetic analysis of the whole WOX family in tomato (Solanum lycopersicum) indicates that there are 10 members that represent the modern, intermediate, and ancient clades. Using phylogenetic analysis and a reverse genetic approach, in this study we identified SlLAM1 in the modern clade and examined its function and tissue-specific expression pattern. We found that knocking out SlLAM1 via CRISPR/Cas9-mediated genome editing led to narrow leaves and a reduced number of secondary leaflets. Overexpression of tomato SlLAM1 could rescue the defects of the tobacco lam1 mutant. Anatomical and transcriptomic analyses demonstrated that floral organ development, fruit size, secondary leaflet initiation, and leaf complexity were altered due to loss-of-function of SlLAM1. These findings demonstrate that tomato SlLAM1 plays an important role in the regulation of secondary leaflet initiation, in addition to its conserved function in blade expansion.

The F-box protein MIO1/SLB1 regulates organ size and leaf movement in Medicago truncatula.

The size of leaf and seed organs, determined by the interplay of cell proliferation and expansion, is closely related to the final yield and quality of forage and crops. Yet the cellular and molecular mechanisms underlying organ size modulation remain poorly understood, especially in legumes. Here, MINI ORGAN1 (MIO1), which encodes an F-box protein SMALL LEAF AND BUSHY1 (SLB1) recently reported to control lateral branching in Medicago truncatula, was identified as a key regulator of organ size. We show that loss-of-function of MIO1/SLB1 severely reduced organ size. Conversely, plants overexpressing MIO1/SLB1 had enlarged organs. Cellular analysis revealed that MIO1/SLB1 controlled organ size mainly by modulating primary cell proliferation during the early stages of leaf development. Biochemical analysis revealed that MIO1/SLB1 could form part of SKP1/Cullin/F-box (SCF) E3 ubiquitin ligase complex, to target BIG SEEDS1 (BS1), a repressor of primary cell division, for degradation. Interestingly, we found that MIO1/SLB1 also played a key role in pulvinus development and leaf movement by modulating cell proliferation of the pulvinus as leaves developed. Our study not only demonstrates a conserved role of MIO1/SLB1 in the control of organ size in legumes, but also sheds light on the novel function of MIO1/SLB1 in leaf movement.

Syphilis-associated septic cardiomyopathy: case report and review of the literature.

BACKGROUND: Septic cardiomyopathy has been observed in association with influenza, indicating that not only bacteria but also other infective agents can cause this condition. There has been no systematic study as to whether Treponema pallidum infection induces septic cardiomyopathy, and we are the first to report this possibility. CASE PRESENTATION: We report two cases of a 48-year-old man and a 57-year-old man who were diagnosed with syphilis-related septic cardiomyopathy. The diagnosis of cardiomyopathy was made based on elevation of cardiogenic markers and decrease in ejection fraction evaluated by echocardiography. Screen for infective pathogens was negative except for syphilis, which supported our diagnosis. The two patients recovered following effective anti-syphilis treatment and advanced life support technology. Syphilis serology became negative after treatment. CONCLUSION: Syphilis has the potential to cause septic cardiomyopathy. Clinicians should consider Treponema pallidum in cases of septic cardiomyopathy with unknown pathogens. However, the specific pathophysiological mechanism of syphilis-associated septic cardiomyopathy has not been elucidated, and more specific studies are needed.

Identification of four insertion sites for foreign genes in a pseudorabies virus vector.

BACKGROUND: Pseudorabies virus (PRV) is a preferred vector for recombinant vaccine construction. Previously, we generated a TK&gE-deleted PRV (PRVΔTK&gE-AH02) based on a virulent PRV AH02LA strain. It was shown to be safe for 1-day-old piglets with maternal PRV antibodies and 4 ~ 5 week-old PRV antibody negative piglets and provide rapid and 100 % protection in weaned pigs against lethal challenge with the PRV variant strain. It suggests that PRVTK&gE-AH02 may be a promising live vaccine vector for construction of recombinant vaccine in pigs. However, insertion site, as a main factor, may affect foreign gene expression. RESULTS: In this study, we constructed four recombinant PRV-S bacterial artificial chromosomes (BACs) carrying the same spike (S) expression cassette of a variant porcine epidemic diarrhea virus strain in different noncoding regions (UL11-10, UL35-36, UL46-27 or US2-1) from AH02LA BAC with TK, gE and gI deletion. The successful expression of S gene (UL11-10, UL35-36 and UL46-27) in recombinant viruses was confirmed by virus rescue, PCR, real-time PCR and indirect immunofluorescence. We observed higher S gene mRNA expression level in swine testicular cells infected with PRV-S(UL11-10)ΔTK/gE and PRV-S(UL35-36)ΔTK/gE compared to that of PRV-S(UL46-27)ΔTK/gE at 6 h post infection (P < 0.05). Moreover, at 12 h post infection, cells infected with PRV-S(UL11-10)ΔTK/gE exhibited higher S gene mRNA expression than those infected with PRV-S(UL35-36)ΔTK/gE (P = 0.097) and PRV-S(UL46-27)ΔTK/gE (P < 0.05). Recovered vectored mutant PRV-S (UL11-10, UL35-36 and UL46-27) exhibited similar growth kinetics to the parental virus (PRVΔTK&gE-AH02). CONCLUSIONS: This study focuses on identification of suitable sites for insertion of foreign genes in PRV genome, which laids a foundation for future development of recombinant PRV vaccines.

Research on the fate of polymeric nanoparticles in the process of the intestinal absorption based on model nanoparticles with various characteristics: size, surface charge and pro-hydrophobics.

BACKGROUND: The use of drug nanocarriers to encapsulate drugs for oral administration may become an important strategy in addressing the challenging oral absorption of some drugs. In this study-with the premise of controlling single variables-we prepared model nanoparticles with different particle sizes, surface charges, and surface hydrophobicity/hydrophilicity. The two key stages of intestinal nanoparticles (NPs) absorption-the intestinal mucus layer penetration stage and the trans-intestinal epithelial cell stage-were decoupled and analyzed. The intestinal absorption of each group of model NPs was then investigated. RESULTS: Differences in the behavioral trends of NPs in each stage of intestinal absorption were found to result from differences in particle properties. Small size, low-magnitude negative charge, and moderate hydrophilicity helped NPs pass through the small intestinal mucus layer more easily. Once through the mucus layer, an appropriate size, positive surface charge, and hydrophobic properties helped NPs complete the process of transintestinal epithelial cell transport. CONCLUSIONS: To achieve high drug bioavailability, the basic properties of the delivery system must be suitable for overcoming the physiological barrier of the gastrointestinal tract.

Primary Cardiac Angiosarcoma.

In this study, we present the case of a 34-year-old man who was diagnosed with primary cardiac angiosarcoma 1 month after hospital admission. Cardiac angiosarcoma is a relatively rare disease that can be easily misdiagnosed as pneumonia or other diseases. Although surgery is the preferred treatment to prolong survival time, highly malignant tumors with local infiltration and systemic metastasis can lead to poor prognosis.

A study of male fertility control in Medicago truncatula uncovers an evolutionarily conserved recruitment of two tapetal bHLH subfamilies in plant sexual reproduction.

Male sterility is an important tool for plant breeding and hybrid seed production. Male-sterile mutants are largely due to an abnormal development of either the sporophytic or gametophytic anther tissues. Tapetum, a key sporophytic tissue, provides nutrients for pollen development, and its delayed degeneration induces pollen abortion. Numerous bHLH proteins have been documented to participate in the degeneration of the tapetum in angiosperms, but relatively little attention has been given to the evolution of the involved developmental pathways across the phylogeny of land plants. A combination of cellular, molecular, biochemical and evolutionary analyses was used to investigate the male fertility control in Medicago truncatula. We characterized the male-sterile mutant empty anther1 (ean1) and identified EAN1 as a tapetum-specific bHLH transcription factor necessary for tapetum degeneration. Our study uncovered an evolutionarily conserved recruitment of bHLH subfamily II and III(a + c)1 in the regulation of tapetum degeneration. EAN1 belongs to the subfamily II and specifically forms heterodimers with the subfamily III(a + c)1 members, which suggests a heterodimerization mechanism conserved in angiosperms. Our work suggested that the pathway of two tapetal-bHLH subfamilies is conserved in all land plants, and likely was established before the divergence of the spore-producing land plants.

Dwarf and Increased Branching 1 controls plant height and axillary bud outgrowth in Medicago truncatula.

Optimizing plant architecture is an efficient approach for breeders to increase crop yields, and phytohormones such as gibberellins (GAs) play an important role in controlling growth. Medicago truncatula is a model legume species, but the molecular mechanisms underlying its architecture are largely unknown. In this study, we examined a tobacco retrotransposon Tnt1-tagged mutant collection of M. truncatula and identified dwarf and increased branching 1 (dib1), which exhibited extreme dwarfism and increased numbers of lateral branches. By analysis of the flanking sequences of Tnt1 insertions in different alleles of the tagged lines, we were able to clone DIB1. Linkage analysis and reverse screening of the flanking-sequence tags identified Medtr2g102570 as the gene corresponding to the DIB1 locus in the dib1 loss-of-function mutants. Phylogenetic analysis indicated that DIB1 was the ortholog of PsGA3ox1/Le in Pisum sativum. Expression analysis using a GUS-staining reporter line showed that DIB1 was expressed in the root apex, pods, and immature seeds. Endogenous GA4 concentrations were markedly decreased whilst some of representative GA biosynthetic enzymes were up-regulated in the dib1 mutant. In addition, exogenous application of GA3 rescued the dib1 mutant phenotypes. Overall, our results suggest that DIB1 controls plant height and axillary bud outgrowth via an influence on the biosynthesis of bioactive GAs. DIB1 could therefore be a good candidate gene for breeders to optimize plant architecture for crop improvement.

Intelligent Escape System for the Oral Delivery of Liraglutide: A Perfect Match for Gastrointestinal Barriers.

Epithelial cells are known to impede the oral delivery of polypeptides, and the accumulation of mucus and regular dynamic renewal also significantly impede drug absorption. In this work, we prepared a core-shell (COS) nanosystem using poly-N-(2-hydroxypropyl)methacrylamide (pHPMA)/chitosan (CTS). Liraglutide (NN2211) was isolated from the gastrointestinal environment and smoothly passes through the mucous layer. CSKSSDYQC (CSK) peptide and hemagglutinin-2 (HA2) were introduced into the COS nanosystem to establish a complete path from the oral cavity to the epithelial basal side. The fate of nanocapsules in vivo was studied by fluorescence detection. The results showed that the nanocapsules escaped smoothly from the mucus. Taking into account the characteristics of CSK targeting goblet cells, we conducted cell-level studies, and the results showed that after the modification of CSK and pHPMA, more nanocapsules entered the cells. In vitro and in vivo evaluation results showed that the system successfully established a complete path from mucus to epithelial cells by responding to the gastrointestinal environment multiple times.

Cloning and Functional Analysis of Dwarf Gene Mini Plant 1 (MNP1) in Medicago truncatula.

Plant height is a vital agronomic trait that greatly determines crop yields because of the close relationship between plant height and lodging resistance. Legumes play a unique role in the worldwide agriculture; however, little attention has been given to the molecular basis of their height. Here, we characterized the first dwarf mutant mini plant 1 (mnp1) of the model legume plant Medicago truncatula. Our study found that both cell length and the cell number of internodes were reduced in a mnp1 mutant. Using the forward genetic screening and subsequent whole-genome resequencing approach, we cloned the MNP1 gene and found that it encodes a putative copalyl diphosphate synthase (CPS) implicated in the first step of gibberellin (GA) biosynthesis. MNP1 was highly homologous to Pisum sativum LS. The subcellular localization showed that MNP1 was located in the chloroplast. Further analysis indicated that GA3 could significantly restore the plant height of mnp1-1, and expression of MNP1 in a cps1 mutant of Arabidopsis partially rescued its mini-plant phenotype, indicating the conservation function of MNP1 in GA biosynthesis. Our results provide valuable information for understanding the genetic regulation of plant height in M. truncatula.