Evolutionary history and root trait coordination predict nutrient strategy in tropical legume trees.

Plants express diverse nutrient use and acquisition traits, but it is unclear how trait combinations at the species level are constrained by phylogeny, trait coordination, or trade-offs in resource investment. One trait - nitrogen (N) fixation - is assumed to correlate with other traits and used to define plant functional groups, despite potential confounding effects of phylogeny. We quantified growth, carbon metabolism, fixation rate, root phosphatase activity (RPA), mycorrhizal colonization, and leaf and root morphology/chemistry across 22 species of fixing and nonfixing tropical Fabaceae trees under common conditions. Belowground trait variation was high even among closely related species, and most traits displayed a phylogenetic signal, including N-fixation rate and nodule biomass. Across species, we observed strong positive correlations between physiological traits such as RPA and root respiration. RPA increased ~ fourfold per unit increase in fixation, supporting the debated hypothesis that N-fixers 'trade' N for phosphatases to enhance phosphorus acquisition. Specific root length and root N differed between functional groups, though for other traits, apparent differences became nonsignificant after accounting for phylogenetic nonindependence. We conclude that evolutionary history, trait coordination, and fixation ability contribute to nutrient trait expression at the species level, and recommend explicitly considering phylogeny in analyses of functional groupings.

Nutrient acquisition, soil phosphorus partitioning and competition among trees in a lowland tropical rain forest.

We hypothesized that dinitrogen (N2 )- and non-N2 -fixing tropical trees would have distinct phosphorus (P) acquisition strategies allowing them to exploit different P sources, reducing competition. We measured root phosphatase activity and arbuscular mycorrhizal (AM) colonization among two N2 - and two non-N2 -fixing seedlings, and grew them alone and in competition with different inorganic and organic P forms to assess potential P partitioning. We found an inverse relationship between root phosphatase activity and AM colonization in field-collected seedlings, indicative of a trade-off in P acquisition strategies. This correlated with the predominantly exploited P sources in the seedling experiment: the N2 fixer with high N2 fixation and root phosphatase activity grew best on organic P, whereas the poor N2 fixer and the two non-N2 fixers with high AM colonization grew best on inorganic P. When grown in competition, however, AM colonization, root phosphatase activity and N2 fixation increased in the N2 fixers, allowing them to outcompete the non-N2 fixers regardless of P source. Our results indicate that some tropical trees have the capacity to partition soil P, but this does not eliminate interspecific competition. Rather, enhanced P and N acquisition strategies may increase the competitive ability of N2 fixers relative to non-N2 fixers.

Plant diversity shapes microbe-rhizosphere effects on P mobilisation from organic matter in soil.

Plant species richness (PSR) increases nutrient uptake which depletes bioavailable nutrient pools in soil. No such relationship between plant uptake and availability in soil was found for phosphorus (P). We explored PSR effects on P mobilisation [phosphatase activity (PA)] in soil. PA increased with PSR. The positive PSR effect was not solely due to an increase in Corg concentrations because PSR remained significant if related to PA:Corg . An increase in PA per unit Corg increases the probability of the temporal and spatial match between substrate, enzyme and microorganism potentially serving as an adaption to competition. Carbon use efficiency of microorganisms (Cmic :Corg ) increased with increasing PSR while enzyme exudation efficiency (PA:Cmic ) remained constant. These findings suggest the need for efficient C rather than P cycling underlying the relationship between PSR and PA. Our results indicate that the coupling between C and P cycling in soil becomes tighter with increasing PSR.

Interactions among nitrogen fixation and soil phosphorus acquisition strategies in lowland tropical rain forests.

Paradoxically, symbiotic dinitrogen (N2 ) fixers are abundant in nitrogen (N)-rich, phosphorus (P)-poor lowland tropical rain forests. One hypothesis to explain this pattern states that N2 fixers have an advantage in acquiring soil P by producing more N-rich enzymes (phosphatases) that mineralise organic P than non-N2 fixers. We assessed soil and root phosphatase activity between fixers and non-fixers in two lowland tropical rain forest sites, but also addressed the hypothesis that arbuscular mycorrhizal (AM) colonisation (another P acquisition strategy) is greater on fixers than non-fixers. Root phosphatase activity and AM colonisation were higher for fixers than non-fixers, and strong correlations between AM colonisation and N2 fixation at both sites suggest that the N-P interactions mediated by fixers may generally apply across tropical forests. We suggest that phosphatase enzymes and AM fungi enhance the capacity of N2 fixers to acquire soil P, thus contributing to their high abundance in tropical forests.

New Perspectives of Therapies in Osteogenesis Imperfecta-A Literature Review.

(1) Background: Osteogenesis imperfecta (OI) is a rare skeletal dysplasia characterized as a heterogeneous disorder group with well-defined phenotypic and genetic features that share uncommon bone fragility. The current treatment options, medical and orthopedic, are limited and not efficient enough to improve the low bone density, bone fragility, growth, and mobility of the affected individuals, creating the need for alternative therapeutic agents. (2) Methods: We searched the medical database to find papers regarding treatments for OI other than conventional ones. We included 45 publications. (3) Results: In reviewing the literature, eight new potential therapies for OI were identified, proving promising results in cells and animal models or in human practice, but further research is still needed. Bone marrow transplantation is a promising therapy in mice, adults, and children, decreasing the fracture rate with a beneficial effect on structural bone proprieties. Anti-RANKL antibodies generated controversial results related to the therapy schedule, from no change in the fracture rate to improvement in the bone mineral density resorption markers and bone formation, but with adverse effects related to hypercalcemia. Sclerostin inhibitors in murine models demonstrated an increase in the bone formation rate and trabecular cortical bone mass, and a few human studies showed an increase in biomarkers and BMD and the downregulation of resorption markers. Recombinant human parathormone and TGF-ß generated good results in human studies by increasing BMD, depending on the type of OI. Gene therapy, 4-phenylbutiric acid, and inhibition of eIF2α phosphatase enzymes have only been studied in cell cultures and animal models, with promising results. (4) Conclusions: This paper focuses on eight potential therapies for OI, but there is not yet enough data for a new, generally accepted treatment. Most of them showed promising results, but further research is needed, especially in the pediatric field.

Enhancing the effectiveness of Alkaline Phosphatase and bone matrix proteins by tunable metal-organic composite for accelerated mineralization.

The irregular expression of bone matrix proteins occurring during the mineralization of bone regeneration results in various deformities which poses a major concern of orthopedic reconstruction. The limitations of the existing reconstruction practice paved a way for the development of a metal-organic composite [TQ-Sr-Fe] with Metal ions strontium [Sr] and iron [Fe] and a biomolecule Thymoquinone [TQ] in an attempt to enhance the bone mineralization due to their positive significance in osteoblast differentiation, proliferation and maturation. TQ-Sr-Fe was synthesized by in-situ coprecipitation and subjected to various characterization to determine their nature, compatibility and osteogenic efficiency. The crystallographic and electron microscopy analysis reveals sheet like structure of the composite. The negative cytotoxicity of TQ-Sr-Fe in the MG 63 cell line signified their biocompatibility. Cell adhesion and proliferation rate affirmed osteoconductive and osteoinductive nature of the composites and it was further supported by the gene expression of osteoblastic differentiation. The sequential expression of bone matrix proteins such as OCN, SPARC, COL 1, and Alkaline Phosphatase elevate the calcium deposition of MG-63 osteoblast like cells and initiates mineralization compared to control. Thus, the metal-organic composite TQ-Sr-Fe would make a suitable composite for accelerating mineralization process which would leads to faster bone regeneration.

Insights into enzyme activity and phosphorus conversion during kitchen waste composting utilizing phosphorus-solubilizing bacterial inoculation.

The main objective of this research was to investigate the effects of Phosphorus-Solubilizing Bacterial (PSB) inoculant on the bacterial structure and phosphorus transformation during kitchen waste composting. High throughput sequencing, topological roles, and multiple analysis methods were conducted to explain the links between phosphorus fractions, enzyme contents, and microbial community structure and function. The findings indicated that bacterial inoculant improved environmental parameters and increased the concentration of total phosphorus, Olsen phosphorus, citric acid phosphorus, OM decomposition, and bacterial diversity. Network analysis concluded that the inoculation treatment was more complex (nodes and edges) and contained more positive links than the control, implying the inoculation effect. The structural equation model also displayed that pH and enzyme activity directly enhanced the phosphorus conversion and bacterial structure. Overall, these results suggest that bacterial inoculation may considerably increase enzyme activity, thus improving biological phosphorus transformation and nutrient content in composting products.

Role of Organic Anions and Phosphatase Enzymes in Phosphorus Acquisition in the Rhizospheres of Legumes and Grasses Grown in a Low Phosphorus Pasture Soil.

Rhizosphere processes play a critical role in phosphorus (P) acquisition by plants and microbes, especially under P-limited conditions. Here, we investigated the impacts of nutrient addition and plant species on plant growth, rhizosphere processes, and soil P dynamics. In a glasshouse experiment, blue lupin (Lupinus angustifolius), white clover (Trifolium repens L.), perennial ryegrass (Lolium perenne L.), and wheat (Triticum aestivum L.) were grown in a low-P pasture soil for 8 weeks with and without the single and combined addition of P (33 mg kg-1) and nitrogen (200 mg kg-1). Phosphorus addition increased plant biomass and total P content across plant species, as well as microbial biomass P in white clover and ryegrass. Alkaline phosphatase activity was higher for blue lupin. Legumes showed higher concentrations of organic anions compared to grasses. After P addition, the concentrations of organic anions increased by 11-,10-, 5-, and 2-fold in the rhizospheres of blue lupin, white clover, wheat, and ryegrass, respectively. Despite the differences in their chemical availability (as assessed by P fractionation), moderately labile inorganic P and stable organic P were the most depleted fractions by the four plant species. Inorganic P fractions were depleted similarly between the four plant species, while blue lupin exhibited a strong depletion of stable organic P. Our findings suggest that organic anions were not related to the acquisition of inorganic P for legumes and grasses. At the same time, alkaline phosphatase activity was associated with the mobilization of stable organic P for blue lupin.

Nutrient acquisition strategies augment growth in tropical N2 -fixing trees in nutrient-poor soil and under elevated CO2.

Tropical forests play a dominant role in the global carbon (C) cycle, and models predict increases in tropical net primary productivity (NPP) and C storage in response to rising atmospheric carbon dioxide (CO2 ) concentrations. The extent to which increasing CO2 will enhance NPP depends in part on the availability of nitrogen (N) and phosphorus (P) to support growth. Some tropical trees can potentially overcome nutrient limitation by acquiring N via symbiotic dinitrogen (N2 ) fixation, which may provide a benefit in acquiring P via investment in N-rich phosphatase enzymes or arbuscular mycorrhizal (AM) fungi. We conducted a seedling experiment to investigate the effects of elevated CO2 and soil nutrient availability on the growth of two N2 -fixing and two non-N2 -fixing tropical tree species. We hypothesized that under elevated CO2 and at low nutrient availability (i.e., low N and P), N2 fixers would have higher growth rates than non-N2 fixers because N2 fixers have a greater capacity to acquire both N and P. We also hypothesized that differences in growth rates between N2 fixers and non-N2 fixers would decline as nutrient availability increases because N2 fixers no longer have an advantage in nutrient acquisition. We found that the N2 fixers had higher growth rates than the non-N2 fixers under elevated CO2 and at low nutrient availability, and that the difference in growth rates between the N2 and non-N2 fixers declined as nutrient availability increased, irrespective of CO2 . Overall, N2 fixation, root phosphatase activity, and AM colonization decreased with increasing nutrient availability, and increased under elevated CO2 at low nutrient availability. Further, AM colonization was positively related to the growth of the non-N2 fixers, whereas both N2 fixation and root phosphatase activity were positively related to the growth of the N2 fixers. Though our results indicate all four tree species have the capacity to up- or down-regulate nutrient acquisition to meet their stoichiometric demands, the greater capacity for the N2 fixers to acquire both N and P may enable them to overcome nutritional constraints to NPP under elevated CO2 , with implications for the response of tropical forests to future environmental change.

Targeting Lysophosphatidic Acid in Cancer: The Issues in Moving from Bench to Bedside.

Since the clear demonstration of lysophosphatidic acid (LPA)'s pathological roles in cancer in the mid-1990s, more than 1000 papers relating LPA to various types of cancer were published. Through these studies, LPA was established as a target for cancer. Although LPA-related inhibitors entered clinical trials for fibrosis, the concept of targeting LPA is yet to be moved to clinical cancer treatment. The major challenges that we are facing in moving LPA application from bench to bedside include the intrinsic and complicated metabolic, functional, and signaling properties of LPA, as well as technical issues, which are discussed in this review. Potential strategies and perspectives to improve the translational progress are suggested. Despite these challenges, we are optimistic that LPA blockage, particularly in combination with other agents, is on the horizon to be incorporated into clinical applications.