Structures of fructan and galactan from Polygonatum cyrtonema and their utilization by probiotic bacteria.

Polygonatum cyrtonema is a known tonic herb in Chinese Materia Medica, extensively consumed in China, but the structure and activity of its polysaccharide components remain to be clarified. Herein, two new polysaccharides (a fructan and a galactan) were purified from the dried and the processed P. cyrtonema rhizome, respectively. Structural analysis suggested that the fructan consisted of a (2 â†’ 6) linked ß-d-Fruf residues backbone with an internal α-d-Glcp residue and two (2 â†’ 1) linked ß-d-Fruf residues branches, and that the galactan was a (1 â†’ 4)-ß-d-galactan branched with a single ß-d-galactose at C-6 at about every nine residues in its main chain. The bioactive assay showed that the fructan and the galactan remarkably promoted growth of Bifidobacterium and Lactobacillus strains, indicating that they possess prebiotic activity. These findings may help expand the application of the polysaccharides from the tonic herb P. cyrtonema as functional ingredients in food products.

RAD51 supports DMC1 by inhibiting the SMC5/6 complex during meiosis.

Meiosis is a fundamental process for sexual reproduction in most eukaryotes and the evolutionarily conserved recombinases RADiation sensitive51 (RAD51) and Disrupted Meiotic cDNA1 (DMC1) are essential for meiosis and thus fertility. The mitotic function of RAD51 is clear, but the meiotic function of RAD51 remains largely unknown. Here we show that RAD51 functions as an interacting protein to restrain the Structural Maintenance of Chromosomes5/6 (SMC5/6) complex from inhibiting DMC1. We unexpectedly found that loss of the SMC5/6 partially suppresses the rad51 knockout mutant in terms of sterility, pollen inviability, and meiotic chromosome fragmentation in a DMC1-dependent manner in Arabidopsis thaliana. Biochemical and cytological studies revealed that the DMC1 localization in meiotic chromosomes is inhibited by the SMC5/6 complex, which is attenuated by RAD51 through physical interactions. This study not only identified the long-sought-after function of RAD51 in meiosis but also discovered the inhibition of SMC5/6 on DMC1 as a control mechanism during meiotic recombination.

Huangyusang decoction for Type 2 diabetes: A protocol for systematic review and meta analysis.

BACKGROUND: Diabetes is a chronic metabolic disease characterized by elevated blood glucose levels due to insulin resistance and ß-cell dysfunction. In China, Huangyusang decoction (HYS) has been widely used to treat Type 2 diabetes. However, there is no systematic review found. In order to evaluate the efficacy and safety of HYS in the treatment of Type 2 diabetes, we need to conduct a meta-analysis and systematic evaluation. METHODS: We will enroll the randomized controlled trials (RCTs) evaluating the effectiveness and safety of HYS in the treatment of Type 2 diabetes. Data come mainly from 4 Chinese databases (CNKI, Wanfang, CBM, and VIP Database) and 4 English databases (PubMed, Embase, Cochrane Library, and Web of science). The enrollment of RCTs is from the starting date of database establishment till January 30, 2021. Fasting blood glucose is considered as the main indicator of the dyslipidemia, while the body mass index, glycated hemoglobin, fasting insulin, triglycerides, and cholesterol are regarded as the secondary indicators. There are safety indicators including liver enzyme and kidney function. The work such as selection of literature, data collection, quality evaluation of included literature, and assessment of publication bias will be conducted by 2 independent researchers. Meta-analysis will be performed by RevMan 5.0 software. RESULTS: This study will provide high-quality evidence for the effectiveness and safety of HYS in the treatment of type 2 diabetes. CONCLUSION: The results of the study will help us determine whether HYS can effectively treat type 2 diabetes. ETHICS AND DISSEMINATION: This study does not require ethical approval. We will disseminate our findings by publishing results in a peer-reviewed journal. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/AXBRV.

The DYT1-interacting proteins bHLH010, bHLH089 and bHLH091 are redundantly required for Arabidopsis anther development and transcriptome.

The anther is the male reproductive organ of flowering plants, and the Arabidopsis bHLH transcription factors encoded by DYSFUNCTIONAL TAPETUM1 (DYT1) and ABORTED MICROSPORE (AMS) are required for control of the complex transcriptional networks regulating anther development. Knowledge of the mechanisms by which the bHLH proteins affect this diverse gene expression is quite limited. We examine here three recently duplicated Arabidopsis bHLH genes, bHLH010, bHLH089 and bHLH091, using evolutionary, genetic, morphological and transcriptomic approaches, and uncover their redundant functions in anther development. These three genes are relatively highly expressed in the tapetum of the Arabidopsis anther; single mutants at each of the bHLH010, bHLH089 and bHLH091 loci are developmentally normal, but the various double and triple combinations progressively exhibit increasingly defective anther phenotypes (abnormal tapetum morphology, delayed callose degeneration, and aborted pollen development), indicating their redundant functions in male fertility. Further transcriptomic and molecular analyses suggest that these three proteins act slightly later than DYT1, and also form protein complexes with DYT1, subsequently affecting the correct expression of many DYT1 target genes in the anther development transcriptional network. This study demonstrated that bHLH010, bHLH089 and bHLH091 together are important for the normal transcriptome of the developing Arabidopsis anther, possibly by forming a feed-forward loop with DYT1.

Overexpressing AtPAP15 enhances phosphorus efficiency in soybean.

Low phosphorus (P) availability is a major constraint to crop growth and production, including soybean (Glycine max), on a global scale. However, 50% to 80% of the total P in agricultural soils exists as organic phosphate, which is unavailable to plants unless hydrolyzed to release inorganic phosphate. One strategy for improving crop P nutrition is the enhanced activity of acid phosphatases (APases) to obtain or remobilize inorganic phosphate from organic P sources. In this study, we overexpressed an Arabidopsis (Arabidopsis thaliana) purple APase gene (AtPAP15) containing a carrot (Daucus carota) extracellular targeting peptide in soybean hairy roots and found that the APase activity was increased by 1.5-fold in transgenic hairy roots. We subsequently transformed soybean plants with AtPAP15 and studied three homozygous overexpression lines of AtPAP15. The three transgenic lines exhibited significantly improved P efficiency with 117.8%, 56.5%, and 57.8% increases in plant dry weight, and 90.1%, 18.2%, and 62.6% increases in plant P content, respectively, as compared with wild-type plants grown on sand culture containing phytate as the sole P source. The transgenic soybean lines also exhibited a significant level of APase and phytase activity in leaves and root exudates, respectively. Furthermore, the transgenic lines exhibited improved yields when grown on acid soils, with 35.9%, 41.0%, and 59.0% increases in pod number per plant, and 46.0%, 48.3%, and 66.7% increases in seed number per plant. Taken together, to our knowledge, our study is the first report on the improvement of P efficiency in soybean through constitutive expression of a plant APase gene. These findings could have significant implications for improving crop yield on soils low in available P, which is a serious agricultural limitation worldwide.