Analysis of PROC mutations and clinical features in 22 unrelated families with inherited protein C deficiency.

Currently, limited information is available in the literature regarding the relationships between PROC mutations and clinical features in Chinese individuals. We aimed to characterize severe congenital Protein C deficiency in 22 unrelated Chinese families in a tertiary hospital by analyzing its clinical manifestation, associated risk factors, and gene mutations. We measured protein C activity and antigen levels for all participants, screened them for mutations in the PROC gene, and analyzed the clinical features of each family to identify commonalities and differences. The analysis revealed a total of 75 individuals with PCD and 16 different PROC mutations, including 12 missense mutations and 4 deletion mutations. Among them, 11 who were compound heterozygotes or homozygotes for mutations tended to develop symptoms at a younger age without any clear triggers. In contrast, the remaining 64 individuals who were heterozygotes for mutations often had clear triggers for their symptoms and experienced a milder course of the disease. It is worth noting that the mutation c.565C > T occurred most frequently, being identified in 8 out of 22 families (36%). Our team also reported five novel mutations, including c.742-744delAAG, c.383G > A, c.997G > A, c.1318C > T, and c.833T > C mutations. The identification of five novel mutations adds to the richness of the Human Genome Database. Asymptomatic heterozygotes are not uncommon, and they are prone to develop symptoms with obvious triggers. The evidence presented strongly suggest that asymptomatic individuals with family history of protein C deficiency can benefit from mutational analysis of PROC gene.

Arthrospira promotes plant growth and soil properties under high salinity environments.

Salt stress detrimentally impacts plant growth, imperiling crop yield and food quality. Ameliorating plant resilience and productivity in saline environments is critical for global food security. Here, we report the positive effect of Arthrospira (Spirulina) on plant growth and salt tolerance in Arabidopsis and sweet sorghum. Arthrospira application greatly promotes seed germination and seedling growth in both species under salt stress conditions in a dosage-dependent manner. Application of 6 mg Arthrospira per plate significantly enhances K+/Na+ equilibrium and reactive oxygen species (ROS) scavenging in Arabidopsis, reducing salt-induced toxicity. The primary root length, survival rate, chlorophyll content, photosynthesis, plant height, biomass and yield were all improved in both species. Concurrently, Arthrospira demonstrated the synthesis of compatible solutes, such as trehalose (Tre) and glucosylglycerol (GG), contributing to heightened stress tolerance when co-cultivated with Arabidopsis on plates. Transcriptome analysis revealed dramatic up-/down- regulation of genes involved in phytohormone signal transduction, chlorophyll and photosynthesis metabolism, and phenylpropanoid metabolism in Arabidopsis. Furthermore, the application of Arthrospira exerted a positive influence on the rhizosphere bacteriome structure in sweet sorghum, crucial for nutrient cycling and soil health enhancement. Our findings uncovered the underlying mechanisms of algae-plants interaction in saline soil, proposing strategies to enhance crop productivity and soil quality, thereby addressing the urgent need for sustainable agriculture practices to mitigate salinity's repercussions amidst climate change challenges.

Guiding the landscape patterns evolution is the key to mitigating river water quality degradation.

Consensus has emerged that landscape pattern evolution significantly impacts the river environment. However, there remains unclear how the landscape pattern evolves possible to achieve a balance between land resource use and water conservation. Thus, simulating future landscape patterns under different scenarios to predict river eutrophication level is critical to propose targeted landscape planning programs and alleviate river water quality degradation. Here, we coupled five water quality parameters (TOC, TN, NO3--N, NH4+-N, TP), collected from October 2020 to September 2021, to construct the river eutrophication index (EI) to assess river water quality. Meanwhile, based on redundancy analysis, patch-generating land use simulation model, and stepwise multiple linear regression model comprehensively analyze the Fengyu River watershed landscape patterns evolution and their impact on river eutrophication. Results indicated that current rivers reach eutrophic levels, and EI reaches 40.7. The landscape patterns explain 88.2 % of river eutrophication variation, while the LPI_Con metric is critical and individually explained 21.5 %. Furthermore, eutrophication in the watershed will increase in 2040 under the natural development (ND) scenario, and the EI will reach 44.4. In contrast, farmland protection (FP) scenarios and environmental protection (EP) scenarios contribute to mitigating eutrophication, the EI values are 38.2 and 38.1, respectively. The results provide a potential mechanistic explanation that river eutrophication is a consequence of unreasonable landscape pattern evolution. Guiding the landscape patterns evolution based on critical driver factors from a planning perspective is conducive to mitigating river water quality degradation.

Managing landscape patterns at the riparian zone and sub-basin scale is equally important for water quality protection.

Widespread attention has been given to understanding the effect of the landscape pattern on river water quality. However, which spatial scale (riparian zone versus sub-basin) has the greater impact on water quality has long been controversial, since the key metrics that affect water quality varied with spatial scale. Thus, quantifying the spatial scale effects of key landscape metrics on water quality is critical to clarifying which scale of landscape pattern is more conducive to water quality conservation. Here, we adopted variation partitioning analysis (VPA) and random forest models to quantify the landscape pattern impact on water quality at northern Erhai Lake during the 2019 rainy season (early, mid, and late), and comprehensively analyze the key landscape metrics on different scales. The results revealed that the riparian zone and sub-basin scale landscape patterns explained similar water quality variations (difference only 0.9%) in the mid (August) and late rainy season (October), but exhibited a large difference (24.1%) during the early rainy season (June). Furthermore, rivers were primarily stressed by nitrogen pollution. Maintaining the Grassland_ED > 27.99 m/ha, Grassland_LPI > 4.19%, Farmland_LSI < 3.2 in the riparian zone, and Construction_ED < 1.69 m/ha, Construction_LSI < 2.46, Farmland_PLADJ < 89.0% at the sub-basin scale could significantly reduce the TN concentration in the stream. Meanwhile, managing of these metrics can effectively prevent rapid increases of TN in rivers. Moreover, due to the low phosphorus concentration in the rivers, none of the landscape metrics significantly explained the variation in TP. This study explored the spatial scale effect of landscape patterns on water quality and revealed the driving factors of nutrient variation. This study will provide a scientific basis for aquatic environmental management in plateau watersheds.

[Analysis of the molecular pathogenesis of hereditary protein C deficiency due to a p.Gly86Asp variant of the PROC gene].

OBJECTIVE: To explore the molecular pathogenesis of hereditary protein C (PC) deficiency due to a p.Gly86Asp variant of the PROC gene through in vitro expression experiment. METHODS: Wild type and Gly86Asp mutant expression plasmids of PC were constructed and respectively transfected into HEK 293FT cells. Total RNA was extracted from the transfected cells, and the expression of PROC gene was determined by quantitative real-time PCR (qRT-PCR). PC antigen (PC:Ag) in the supernatant of cell culture and cell lysate was determined by enzyme-linked immunosorbent assay (ELISA), and the level of PC protein was detected by Western blotting. RESULTS: qRT-PCR has detected no significant difference in the transcription level of wild-type and mutant-type PC. Compared with the wild type, the level of mutant PC:Ag in the supernatant and cell lysate were 81.3%±2.6% and 110.0%±2.8%, respectively. No difference was detected in the molecular weight between the wild-type and mutant-type PC by Western blotting. The PC content of mutant type was higher than wild-type in cell lysate, while the opposite was found with the cell culture supernatant. CONCLUSION: The impaired secretion by mutant PC may be the molecular mechanism of PC deficiency caused by the p.Gly86Asp variant.

Low-frequency electrical stimulation alleviates immobilization-evoked disuse muscle atrophy by repressing autophagy in skeletal muscle of rabbits.

BACKGROUND: The study aimed to investigate the effect of low-frequency electrical stimulation (LFES) on disuse muscle atrophy and its mechanism in a rabbit model of knee extension contracture. METHODS: This study involved two experiments. In the time-point experiment, 24 rabbits were randomly divided into 4 groups: Control 1 (Ctrl1 group), immobilization for 2 weeks (I-2 group), immobilization for 4 weeks (I-4 group), and immobilization for 6 weeks (I-6 group). In the intervention experiment, 24 rabbits were randomly divided into 4 groups: Control 2 (Ctrl2 group), electrical stimulation (ESG group), natural recovery (NRG group), and electrical stimulation treatment (ESTG group). All intervention effects were assessed by evaluating the knee joint range of motion (ROM), cross-sectional area (CSA) of the rectus femoris muscle, and expression of autophagy-related proteins. RESULTS: The time-point experiment showed that immobilization reduced the knee ROM, reduced the rectus femoris muscle CSA, and activated autophagy in skeletal muscle. The levels of five autophagy-related proteins [mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), autophagy-related protein 7 (Atg7), p62, and microtubule-associated protein light chain 3B-II (LC3B-II)] were significantly elevated in the skeletal muscle of the I-4 group. The intervention experiment further showed that LFES significantly improved the immobilization-induced reductions in ROM and CSA. Additionally, LFES resulted in a significant decrease in the protein expression of mTOR, p-mTOR, Atg7, p62, and LC3B-II in the rectus femoris muscle. CONCLUSIONS: LFES alleviates immobilization-evoked disuse muscle atrophy possibly by inhibiting autophagy in the skeletal muscle of rabbits.

Evidence for conifer sucrose transporters' functioning in the light-dependent adjustment of sugar allocation.

Sucrose is the central unit of carbon and energy in plants. Active intercellular transport of sucrose is mediated by sucrose transporters (SUTs), genes for which have been found in the genomes of all land plants. However, they have only been assigned functions in angiosperm species. Here, we cloned two types of SUTs from two gymnosperms, the conifers Cedrus deodara (Roxb. G. Don) and Pinus massoniana Lambert, and analyzed their sucrose transport activities. Uptake of the fluorescent sucrose-analog esculin into tobacco epidermis cells expressing the conifer SUT confirmed their transport ability. To determine their function in planta, we investigated their mRNA abundance in relation to photosynthesis and sugar levels in leaves, inner bark, wood and roots. Combined with measurements of protein abundance and immunolocalization of C. deodara SUTs, our results suggest a role for CdSUT1G and CdSUT2 in supporting phloem transport under varying environmental conditions. The implications of these findings regarding conifer physiology and SUT evolution are discussed.

Coupled effects of landscape structures and water chemistry on bacterioplankton communities at multi-spatial scales.

Bacterioplankton communities in rivers are strongly influenced by the surrounding landscape, yet the relationships between land use and bacterioplankton communities at multi-spatial scales and the mechanisms that shape bacterioplankton communities remain unclear. Here, we collected surface water samples from 14 tributaries of the Yuan River, a secondary tributary of the Yangtze River, which has been heavily impacted by human activities. We characterized the bacterioplankton communities by high-throughput sequencing techniques, and managed to identify the mechanisms governing bacterioplankton community assembly. The results showed that, in general, both landscape compositions and landscape configurations had significant effects on bacterial communities, and the effects were greater at the buffer scale than at the sub-basin scale. Additionally, there was no distinct distance-decay pattern for the effects of landscape structures on bacterial communities from the near-distance (100 m) to the long-distance (1000 m) buffer zones, with the maximal effects occurring in the 1000 m circular buffer (wet season) and 500 m riparian buffer (dry season) zone, respectively. Land use influenced the bacterioplankton community both directly through exogenous inputs (mass effect) and indirectly by affecting water chemistry (species sorting). Variance partitioning analyses showed that the total explanations of bacterial community variations by water chemistry and the intersections of water chemistry and land use (56.2% in wet season and 50.4% in dry season) were higher than that of land use alone (6.1% in wet season and 25.4% in dry season). These suggest that mass effects and species sorting jointly shaped bacterial community assembly, but that the effects of species sorting outweighed those of mass effects. Nevertheless, more biotic and abiotic factors need to be considered to better understand the microbial assembly mechanisms in anthropogenically influenced riverine ecosystems.

Preventive effect and possible mechanisms of ultrashort wave diathermy on myogenic contracture in a rabbit model.

The purpose of this study was to determine the preventive effect of ultrashort wave diathermy on immobilization-induced myogenic contracture and to explore its underlying mechanisms. Forty-two rabbits were randomly assigned into control (Group C), immobilization (Group I, which was further divided into one week, Group I-1; two weeks, Group I-2; and four weeks, Group I-4, subgroups by the length of immobilization) and ultrashort wave prevention (Group U, which was further divided into one week, Group U-1; two weeks, Group U-2; and four weeks, Group U-4, by time of treatment) groups. Intervention effects were assessed by evaluating rectus femoris cross-sectional area (CSA), knee range of motion, and the protein levels for myogenic differentiation (MyoD) and muscle atrophy F-box (MAFbx-1) in the rectus femoris. Compared with those of Group C, in Groups I and U, total contracture, myogenic contracture, MyoD and MAFbx-1 levels were significantly elevated, and CSA was significantly smaller (p < 0.05). Compared with those of Group I at each time point, MyoD levels were significantly elevated, MAFbx-1 levels were significantly lower, CSA was significantly larger, and myogenic contracture was significantly alleviated in Group U (p < 0.05). In the early stages of contracture, ultrashort wave diathermy reduces muscle atrophy and delays the process of myogenic contracture during joint immobilization; the mechanism of this may be explained as increased expression of MyoD triggered by suppression of the MAFbx-1-mediated ubiquitin-proteasome pathway.

Two heterozygous mutations associated with type I protein C deficiency in two Chinese independent families.

To explore the pathogenesis of protein C (PC) deficiency in two independent families by mutations detection and bioinformatics analysis. The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and ELISA, respectively. The PROC sequencing was performed to identify the mutational sites. The molecular pathogenesis of the mutations were studied by the conservation, bioinformatics and model analysis. The PC:A and PC:Ag of the proband 1 were observably reduced at 35 and 44%, respectively. Gene sequencing analysis revealed the p.Leu278Pro derived from a heterozygous c.833T>C point mutations in exon 9 of PROC gene. For proband 2, the PC:A and PC:Ag were decreased to 40 and 51%, respectively, caused p.Ala178Pro missense mutation by a heterozygous point mismatch of c.532G>C in exon 5 of PROC gene. Bioinformatics and model analysis indicated that it was the Leu278Pro and Ala178Pro that caused clinical PC deficiency (PCD). The heterozygous mutations Leu278Pro and Ala178Pro were observed in two independent families. The Leu278Pro mutation in the PROC gene has not been described elsewhere. The two mutations can both lead to the type I hereditary PCD, and probably be the major causes of PCD in the families.

Sugar export from Arabidopsis leaves: actors and regulatory strategies.

Plant acclimation and stress responses depend on the dynamic optimization of carbon balance between source and sink organs. This optimization also applies to the leaf export rate of photosynthetically produced sugars. So far, investigations into the molecular mechanisms of how the rate is controlled have focused on sugar transporters responsible for loading sucrose into the phloem sieve element-companion cell complex of leaf veins. Here, we take a broader view of the various proteins with potential direct influence on the leaf sugar export rate in the model plant Arabidopsis thaliana, helped by the cell type-specific transcriptome data that have recently become available. Furthermore, we integrate current information on the regulation of these potential target proteins. Our analysis identifies putative control points and units of transcriptionally and post-transcriptionally co-regulated genes. Most notable is the potential regulatory unit of sucrose transporters (SUC2, SWEET11, SWEET12, and SUC4) and proton pumps (AHA3 and AVP1). Our analysis can guide future research aimed at understanding the regulatory network controlling leaf sugar export by providing starting points for characterizing regulatory strategies and identifying regulatory factors that link sugar export rate to the major signaling pathways.

Effect of Radial Extracorporeal Shock Wave Combined With Ultrashort Wave Diathermy on Fibrosis and Contracture of Muscle.

OBJECTIVE: The purpose of this study was to examine the intervention effect of radial extracorporeal shock wave combined with ultrashort wave diathermy on immobilization-induced fibrosis and contracture of muscle. DESIGN: The groups included male rabbits for the group (control group). To cause joint contracture, rabbits underwent plaster fixation of a left knee joint at full extension. After immobilization for 4 wks, all rabbits were randomly divided into five groups: model group, natural recovery group, radial extracorporeal shock wave treatment group, ultrashort wave diathermy group, and radial extracorporeal shock wave combined with ultrashort wave diathermy group. All intervention effects were assessed by evaluating the cross-sectional area and the collagen deposition of muscle, the knee joint range of motion and the protein levels for transforming growth factor ß1 and hypoxia-inducible factor 1α. RESULTS: The combined treatment group got the best recovery of the knee joint function. The combined treatment was more effective than radial extracorporeal shock wave or ultrashort wave diathermy alone against the fibrosis and contracture of muscle, as well as the overexpression of transforming growth factor ß1 and hypoxia-inducible factor 1α. CONCLUSIONS: Radial extracorporeal shock wave combined with ultrashort wave diathermy was effective in alleviating immobilization-induced contracture and fibrosis of muscle, as well as reducing the molecular manifestations of muscle fibrosis.

Type II antithrombin deficiency caused by a novel missense mutation (p.Leu417Gln) in a Chinese family.

THE AIM OF THE REPORT WAS T: o explore the phenotype and genotype of a hereditary antithrombin deficient Chinese family. Functional and molecular analysis of the proband and his family members was performed. Online bioinformatics software was used to predict the pathogenicity of the novel mutation. ClustalX-2.1-win and PyMol software were applied to conservative analysis and generate molecular graphic images, respectively. Functional analysis had shown that the antithrombin (AT):A of the proband was reduced to 32% whereas AT:Ag was normal. Molecular analysis revealed a heterozygous missense mutation p. Leu417Gln in exon 7 of SERPINC1 gene. Bioinformatics and model analysis indicated that this mutation could affect the integrity of local intermolecular structures, resulting in a mild type of antithrombin deficiency but when combined with other genetic or acquired thrombophilic factors, patients may develop venous thrombosis. The p.Leu417Gln mutation was responsible for the decrease of AT:A in this family and caused type II antithrombin deficiency.

Analysis of an Inherited Dysfibrinogenemia Pedigree Associated with a Heterozygous Mutation in the FGA Gene.

OBJECTIVE: This article aims to analyze the phenotype and genotype of an inherited dysfibrinogenemia pedigree associated with a heterozygous mutation in the FGA gene, and to investigate the pathogenesis of this disease. CLINICAL PRESENTATION: The proband of interest is a 29-year-old woman. She was in her 37 weeks of gestation. Routine coagulation tests showed low fibrinogen activity (0.91 g/L; normal range: 2.0-4.0 g/L) and normal fibrinogen antigen (FIB:Ag) level (2.09 g/L; normal range: 2.0-4.0 g/L). TECHNIQUES: The prothrombin time, activated partial thromboplastin time, thrombin time, and activity of plasma fibrinogen (FIB:C) were detected by the one-stage clotting method. The FIB:Ag, D-dimer, and fibrinogen degradation products were tested by the immunoturbidimetry method. To identify the novel missense mutation, fibrinogen gene sequencing and molecular modeling were performed. We used ClustalX-2.1-win and online bioinformatic software to analyze the conservation and possible effect of the amino acid substitution on fibrinogen. RESULTS: Phenotypic analysis revealed that the FIB:C of the proband was significantly reduced while the FIB:Ag was normal. Sequencing analysis detected a heterozygous C.2185G > A point mutation in the FGA gene (AαGlu710Lys). Bioinformatic and modeling analyses indicated that the mutation probably caused harmful effects on fibrinogen. CONCLUSION: The heterozygous mutation of Glu710Lys in the FGA gene was identified that could cause the reduction of the FIB structure stability and result in the dysfibrinogenemia.

A novel heterozygous mutation (γIIe367Thr) causes congenital dysfibrinogenemia in a Chinese family.

: The aim of this study was to elucidate the molecular defects in a Chinese family with dysfibrinogenemia. The fibrinogen activity was measured by the one-stage clotting method. The fibrinogen antigen was measured with immunoturbidimetry. The fibrinogen gene was amplified by PCR with direct sequencing. Suspected mutation was confirmed by reverse sequencing. Bioinformatics and model analysis were used to study the conservatism and harm of the mutation. The proband had a history of menorrhagia. Study showed fibrinogen activity at 0.35 g/l and fibrinogen antigen at 2.05 g/l. Sequencing analysis detected a heterozygous c.1178T>C missense mutation in exon 9 of FGG gene resulting in p.IIe367Thr. The bioinformatics and model analysis indicated that the IIe367Thr mutation may disrupt the activation of the fibrinogen. We detected a novel IIe367Thr missense mutation in the FGG. To our knowledge this is causative mutation has not been reported so far.

Phenotypic and Genotypic Analysis of a Hereditary Antithrombin Deficiency Pedigree Due to a Novel SERPINC1 Mutation (p.Met281Thr).

Antithrombin (AT) is one of the physiological anticoagulants that are mainly synthesized in the liver. As a protease inhibitor belonging to the serpin superfamily, AT is able to inactivate thrombin and inhibit activated coagulation factors IX, X, XI, and XII (FIXa, FXa, FXIa, and FXIIa).1 Moreover, it has been found that AT can inhibit activated FVII (FVIIa) by accelerating dissociation of FVIIa-tissue factor complex and preventing it from recombining.2 The AT gene (SERPINC1), located on chromosome 1 at q23.1-23.9 and spreads 13.5 kb, is composed of seven extrons and six introns.3 Hereditary AT deficiency is a rare thrombotic disorder caused by defects in SERPINC1 gene.4 It is inherited in an autosomal-dominant manner with an incidence of roughly 0.02 to 0.25% in the general population and 2 to 5% in patients with a history of venous thromboembolism (VTE).1 5 The most common thrombotic manifestations of patients with AT deficiency are VTEs, and their risks of VTE are approximately 20 times higher than those of nondeficient individuals.6 And the consequences of thrombophilia caused by AT deficiency are more severe than those of protein C and S protein deficiency,2 so it should be given sufficient attention.

Directionality of Plasmodesmata-Mediated Transport in Arabidopsis Leaves Supports Auxin Channeling.

The plant hormone auxin serves as central regulator of growth and development. Auxin transporters in the plasma membrane are assumed to define tissue-level patterns of auxin distribution [1, 2]. However, auxin is small enough to diffuse through the plasmodesmata that connect neighboring cells [3], presenting an alternative pathway, whose contribution to auxin transport remained largely unexplored [4]. Here, photoactivation microscopy [5, 6] was used to measure the capacity for small-molecule diffusion in the epidermis of Arabidopsis thaliana leaves. In the elongated epidermis cells covering the midrib and petiole, the plasmodesmata-mediated cell-wall permeability was found to be several times higher in the longitudinal than in the transverse direction. The physiological relevance of this asymmetry was tested through quantification of the shade-avoidance response, which depends on auxin transport from the leaf tip to the petiole in the abaxial side of the leaf [7], with the hypothesis that directionality of diffusion supplements transporter-mediated auxin movement [8]. Triggering the response by auxin application at the tip led to stronger leaf movement in wild-type plants than in gsl8 mutants [9], which lack the callose synthase necessary to establish directionality. The results match the predictions of a mathematical model of auxin transport based on the permeabilities measured in wild-type and mutant plants. It is concluded that plasmodesmata permeability can be selectively modulated within a plant cell and that the conferred directionality in diffusion can influence the tissue-specific distribution patterns of small molecules, like auxin. VIDEO ABSTRACT.

Carbon export from leaves is controlled via ubiquitination and phosphorylation of sucrose transporter SUC2.

All multicellular organisms keep a balance between sink and source activities by controlling nutrient transport at strategic positions. In most plants, photosynthetically produced sucrose is the predominant carbon and energy source, whose transport from leaves to carbon sink organs depends on sucrose transporters. In the model plant Arabidopsis thaliana, transport of sucrose into the phloem vascular tissue by SUCROSE TRANSPORTER 2 (SUC2) sets the rate of carbon export from source leaves, just like the SUC2 homologs of most crop plants. Despite their importance, little is known about the proteins that regulate these sucrose transporters. Here, identification and characterization of SUC2-interaction partners revealed that SUC2 activity is regulated via its protein turnover rate and phosphorylation state. UBIQUITIN-CONJUGATING ENZYME 34 (UBC34) was found to trigger turnover of SUC2 in a light-dependent manner. The E2 enzyme UBC34 could ubiquitinate SUC2 in vitro, a function generally associated with E3 ubiquitin ligases. ubc34 mutants showed increased phloem loading, as well as increased biomass and yield. In contrast, mutants of another SUC2-interaction partner, WALL-ASSOCIATED KINASE LIKE 8 (WAKL8), showed decreased phloem loading and growth. An in vivo assay based on a fluorescent sucrose analog confirmed that SUC2 phosphorylation by WAKL8 can increase transport activity. Both proteins are required for the up-regulation of phloem loading in response to increased light intensity. The molecular mechanism of SUC2 regulation elucidated here provides promising targets for the biotechnological enhancement of source strength.

Studying Phloem Loading with EDTA-Facilitated Phloem Exudate Collection and Analysis.

Sugars that are produced by photosynthesis in the leaves are transported in the phloem to heterotrophic sink tissues like roots, fruit, or flowers. Since sugars inside the highly specialized cells of the phloem move by bulk flow, it is the loading and unloading of sugars that determines the rates of allocation between organs. Here, a method is described for the relative quantification of sugars that are loaded into the phloem in leaves. It is based on EDTA-facilitated phloem exudate collection and, therefore, requires control experiments to exclude measurement artifacts. It can be applied to a wide range of plant species, including dicots, monocots, and trees.

BMP signaling is required for amphioxus tail regeneration.

Amphioxus, a cephalochordate, is an ideal animal in which to address questions about the evolution of regenerative ability and the mechanisms behind the invertebrate to vertebrate transition in chordates. However, the cellular and molecular basis of tail regeneration in amphioxus remains largely ill-defined. We confirmed that the tail regeneration of amphioxus Branchiostoma japonicum is a vertebrate-like epimorphosis process. We performed transcriptome analysis of tail regenerates, which provided many clues for exploring the mechanism of tail regeneration. Importantly, we showed that BMP2/4 and its related signaling pathway components are essential for the process of tail regeneration, revealing an evolutionarily conserved genetic regulatory system involved in regeneration in many metazoans. We serendipitously discovered that bmp2/4 expression is immediately inducible by general wounds and that expression of bmp2/4 can be regarded as a biomarker of wounds in amphioxus. Collectively, our results provide a framework for understanding the evolution and diversity of cellular and molecular events of tail regeneration in vertebrates.