The super-pangenome of Populus unveils genomic facets for its adaptation and diversification in widespread forest trees

Understanding the underlying mechanisms and links between genome evolution and adaptive innovations stands as a key goal in evolutionary studies. Poplars, among the world's most widely distributed and cultivated trees, exhibit extensive phenotypic diversity and environmental adaptability. In this study, we present a genus-level super-pangenome comprising 19 Populus genomes, revealing the likely pivotal role of private genes in facilitating local environmental and climate adaptation. Through the integration of pangenomes with transcriptomes, methylomes, and chromatin accessibility mapping, we unveil that the evolutionary trajectories of pangenes and duplicated genes are closely linked to local genomic landscapes of regulatory and epigenetic architectures, notably CG methylation in gene-body regions. Further comparative genomic analyses have enabled the identification of 142 202 structural variants across species that intersect with a significant number of genes and contribute substantially to both phenotypic and adaptive divergence. We have experimentally validated a ∼180-bp presence/absence variant affecting the expression of the CUC2 gene, crucial for leaf serration formation. Finally, we developed a user-friendly web-based tool encompassing the multi-omics resources associated with the Populus super-pangenome (http://www.populus-superpangenome.com). Together, the present pioneering super-pangenome resource in forest trees not only aids in the advancement of breeding efforts of this globally important tree genus but also offers valuable insights into potential avenues for comprehending tree biology.

Harnessing the power of microbes: Enhancing soybean growth in an acidic soil through AMF inoculation rather than P-fertilization

The low phosphorus (P) availability of acidic soils severely limits leguminous plant growth and productivity. Improving the soil P nutritional status can be achieved by increasing the P-content through P-fertilization or stimulating the mineralization of organic P via arbuscular mycorrhizal fungi (AMF) application; however, their corresponding impacts on plant and soil microbiome still remain to be explored. Here, we examined the effects of AMF-inoculation and P-fertilization on the growth of soybean with different P-efficiencies, as well as the composition of rhizo-microbiome in an acidic soil. The growth of recipient soybean NY-1001, which has a lower P-efficiency, was not significantly enhanced by AMF-inoculation or P-fertilization. However, the plant biomass of higher P-efficiency transgenic soybean PT6 was significantly increased by 46.74%-65.22% through AMF-inoculation. Although there was no discernible difference in plant biomass between PT6 and NY-1001 in the absence of AMF-inoculation and P-fertilization, PT6 had approximately 1.9-2.5 times the plant biomass of NY-1001 after AMF-inoculation. Therefore, the growth advantage of higher P-efficiency soybean was achieved through the assistance of AMF rather than P-fertilization in available P-deficient acidic soil. Most nitrogen (N)-fixing bacteria and some functional genes related to N-fixation were abundant in endospheric layer, as were the P-solubilizing Pseudomonas plecoglossicida, and annotated P-metabolism genes. These N-fixing and P-solubilizing bacteria were positive correlated with each other. Lastly, the two most abundant phytopathogenic fungi species accumulated in endospheric layer, they exhibited positive correlations with N-fixing bacteria, but displayed negative interactions with the majority of the other dominant non-pathogenic genera with potential antagonistic activity.

A modified natural small molecule inhibits triple-negative breast cancer growth by interacting with Tubb3

BACKGROUND

Triple-negative breast cancer (TNBC) is a malignant tumor without specific therapeutic targets and a poor prognosis. Chemotherapy is currently the first-line therapeutic option for TNBC. However, due to the heterogeneity of TNBC, not all of TNBC patients are responsive to chemotherapeutic agents. Therefore, the demand for new targeted agents is critical. β-tubulin isotype III (Tubb3) is a prognostic factor associated with cancer progression, including breast cancer, and targeting Tubb3 may lead to improve TNBC disease control. Shikonin, the active compound in the roots of Lithospermun erythrorhizon suppresses the growth of various types of tumors, and its efficacy can be improved by altering its chemical structure.

PURPOSE

In this work, the anti-TNBC effect of a shikonin derivative (PMMB276) was investigated, and its mechanism was also investigated.

STUDY DESIGN/METHODS

This study combines flow cytometry, immunofluorescence staining, immunoblotting, immunoprecipitation, siRNA silencing, and the iTRAQ proteomics assay to analyze the inhibition potential of PMMB276 on TNBC. In vivo study was performed, Balb/c female murine models with or without the small molecule treatments.

RESULTS

Herein, we screened 300 in-house synthesized analogs of shikonin against TNBC and identified a novel small molecule, PMMB276; it suppressed cell proliferation, induced apoptosis, and arrested the cell cycle at the G2/M phase, suggesting that it could have a tumor suppressive role in TNBC. Tubb3 was identified as the target of PMMB276 using proteomic and biological activity analyses. Meanwhile, PMMB276 regulated microtubule dynamics in vitro by inducing microtubule depolymerization and it could act as a tubulin stabilizer by a different process than that of paclitaxel. Moreover, suppressing or inhibiting Tubb3 with PMMB276 reduced the growth of breast cancer in an experimental mouse model, indicating that Tubb3 plays a significant role in TNBC progression.

CONCLUSION

The findings support the therapeutic potential of PMMB276, a Tubb3 inhibitor, as a treatment for TNBC. Our findings might serve as a foundation for the utilization of shikonin and its derivatives in the development of anti-TNBC.

PMAT: an efficient plant mitogenome assembly toolkit using low-coverage HiFi sequencing data

Complete mitochondrial genomes (mitogenomes) of plants are valuable resources for nucleocytoplasmic interactions, plant evolution, and plant cytoplasmic male sterile line breeding. However, the complete assembly of plant mitogenomes is challenging due to frequent recombination events and horizontal gene transfers. Previous studies have adopted Illumina, PacBio, and Nanopore sequencing data to assemble plant mitogenomes, but the poor assembly completeness, low sequencing accuracy, and high cost limit the sampling capacity. Here, we present an efficient assembly toolkit (PMAT) for de novo assembly of plant mitogenomes using low-coverage HiFi sequencing data. PMAT has been applied to the de novo assembly of 13 broadly representative plant mitogenomes, outperforming existing organelle genome assemblers in terms of assembly accuracy and completeness. By evaluating the assembly of plant mitogenomes from different sequencing data, it was confirmed that PMAT only requires 1× HiFi sequencing data to obtain a complete plant mitogenome. The source code for PMAT is available at https://github.com/bichangwei/PMAT. The developed PMAT toolkit will indeed accelerate the understanding of evolutionary variation and breeding application of plant mitogenomes.

Phylogenomics reveals patterns of ancient hybridization and differential diversification that contribute to phylogenetic conflict in willows, poplars, and close relatives

Despite the economic, ecological, and scientific importance of the genera Salix L. (willows) and Populus L. (poplars, cottonwoods, and aspens) Salicaceae, we know little about the sources of differences in species diversity between the genera and of the phylogenetic conflict that often confounds estimating phylogenetic trees. Salix subgenera and sections, in particular, have been difficult to classify, with one recent attempt termed a "spectacular failure" due to a speculated radiation of the subgenera Vetrix and Chamaetia. Here, we use targeted sequence capture to understand the evolutionary history of this portion of the Salicaceae plant family. Our phylogenetic hypothesis was based on 787 gene regions and identified extensive phylogenetic conflict among genes. Our analysis supported some previously described subgeneric relationships and confirmed the polyphyly of others. Using an fbranch analysis, we identified several cases of hybridization in deep branches of the phylogeny, which likely contributed to discordance among gene trees. In addition, we identified a rapid increase in diversification rate near the origination of the Vetrix-Chamaetia clade in Salix. This region of the tree coincided with several nodes that lacked strong statistical support, indicating a possible increase in incomplete lineage sorting due to rapid diversification. The extraordinary level of both recent and ancient hybridization in both Salix and Populus have played important roles in the diversification and diversity in these two genera.

Expression Quantitative Trait Locus of Wood Formation-Related Genes in Salix suchowensis

Shrub willows are widely planted for landscaping, soil remediation, and biomass production, due to their rapid growth rates. Identification of regulatory genes in wood formation would provide clues for genetic engineering of willows for improved growth traits on marginal lands. Here, we conducted an expression quantitative trait locus (eQTL) analysis, using a full sibling F1 population of Salix suchowensis, to explore the genetic mechanisms underlying wood formation. Based on variants identified from simplified genome sequencing and gene expression data from RNA sequencing, 16,487 eQTL blocks controlling 5505 genes were identified, including 2148 cis-eQTLs and 16,480 trans-eQTLs. eQTL hotspots were identified, based on eQTL frequency in genomic windows, revealing one hotspot controlling genes involved in wood formation regulation. Regulatory networks were further constructed, resulting in the identification of key regulatory genes, including three transcription factors (JAZ1, HAT22, MYB36) and CLV1, BAM1, CYCB2;4, CDKB2;1, associated with the proliferation and differentiation activity of cambium cells. The enrichment of genes in plant hormone pathways indicates their critical roles in the regulation of wood formation. Our analyses provide a significant groundwork for a comprehensive understanding of the regulatory network of wood formation in S. suchowensis.

The Metasequoia genome and evolutionary relationships among redwoods

Redwood trees (Sequoioideae), including Metasequoia glyptostroboides (dawn redwood), Sequoiadendron giganteum (giant sequoia), and Sequoia sempervirens (coast redwood), are threatened and widely recognized iconic tree species. Genomic resources for redwood trees could provide clues to their evolutionary relationships. Here, we report the 8-Gb reference genome of M. glyptostroboides and a comparative analysis with two related species. More than 62% of the M. glyptostroboides genome is composed of repetitive sequences. Clade-specific bursts of long terminal repeat retrotransposons may have contributed to genomic differentiation in the three species. The chromosomal synteny between M. glyptostroboides and S. giganteum is extremely high, whereas there has been significant chromosome reorganization in S. sempervirens. Phylogenetic analysis of marker genes indicates that S. sempervirens is an autopolyploid, and more than 48% of the gene trees are incongruent with the species tree. Results of multiple analyses suggest that incomplete lineage sorting (ILS) rather than hybridization explains the inconsistent phylogeny, indicating that genetic variation among redwoods may be due to random retention of polymorphisms in ancestral populations. Functional analysis of ortholog groups indicates that gene families of ion channels, tannin biosynthesis enzymes, and transcription factors for meristem maintenance have expanded in S. giganteum and S. sempervirens, which is consistent with their extreme height. As a wetland-tolerant species, M. glyptostroboides shows a transcriptional response to flooding stress that is conserved with that of analyzed angiosperm species. Our study offers insights into redwood evolution and adaptation and provides genomic resources to aid in their conservation and management.

Effects of prenatal heat stress on birth weight and birth weight genetic parameters in German Holstein calves

The aim of this study was to infer the effects of heat stress (HS) during late gestation of dams on phenotypes and on direct and maternal genetic parameters for birth weight (BiW). We considered 171,221 Holstein calves kept in 56 large-scale co-operator herds. For a clear separation of maternal effects, only calves from dams with at least 3 offspring were included in the analyses. The genotype data set comprised 41,143 SNPs from 1,883 Holstein bulls. Temperature-humidity indices (THI) during the last 8 wk of gestation were calculated in each herd to reflect prenatal HS. A further prenatal HS descriptor was the first principal component (PC1) from principal component analysis considering the daily THI during the last 56 d of gestation. Regression coefficients of BiW on prenatal THI during the last 12 wk of gestation and PC1 were estimated in 13 consecutive phenotypic analyses. The strongest BiW decline was -0.63 kg per standardized THI, identified during 50 to 56 d before birth. A reaction norm model with weekly prenatal THI or PC1 nested within maternal genetic and maternal permanent environmental effects was defined to infer maternal sensitivity in response to prenatal THI alterations. Direct BiW heritabilities were close to 0.33 in the course of prenatal THI. Maternal BiW heritabilities marginally increased from 0.07 to 0.08 with increasing THI. Genetic correlations between maternal genetic effects at maximum HS levels and remaining THI were larger than 0.95, indicating the absence of genotype by time-lagged HS interactions. In contrast, maternal permanent environmental correlations between BiW at prenatal THI indicating HS with BiW at remaining THI substantially declined with increasing THI distances. Hence, from a herd management perspective, avoiding HS during the dry period of the dams will contribute to a slight increase in fetus growth.

Design, synthesis and biological evaluation of novel modified dual-target shikonin derivatives for colorectal cancer treatment

Warburg effect provides energy and material essential for tumor proliferation, the reverse of Warburg effect provides insights into the development of a novel anti-cancer strategy. Pyruvate kinase 2 (PKM2) and pyruvate dehydrogenase kinase 1 (PDK1) are two key enzymes in tumor glucose metabolism pathway that not only contribute to the Warburg effect through accelerating aerobic glycolysis, but also serve as druggable target for colorectal cancer (CRC). Considering that targeting PKM2 or PDK1 alone does not seem to be sufficient to remodel abnormal glucose metabolism and achieve significant antitumor activity, a series of novel benzenesulfonyl shikonin derivatives were designed to regulate PKM2 and PDK1 simultaneously. By means of molecular docking and antiproliferative screen, we found that compound Z10 could act as the combination of PKM2 activator and PDK1 inhibitor, thereby significantly inhibited glycolysis that reshaping tumor metabolism. Moreover, Z10 could inhibit proliferation, migration and induce apoptosis in CRC cell HCT-8. Finally, the in vivo anti-tumor activity of Z10 was evaluated in a colorectal cancer cell xenograft model in nude mice and the results demonstrated that Z10 induced tumor cell apoptosis and inhibited tumor cell proliferation with lower toxicity than shikonin. Our findings indicated that it is feasible to alter tumor energy metabolism through multi-target synergies, and the dual-target benzenesulfonyl shikonin derivative Z10 could be a potential anti-CRC agent.

Analyzing the Predictive Effects of PD-L1 Expression, Early Changes of bTMB and Circulated CD8+T Cells during Treatment for Responses of RT Combined with ICI in NSCLC

PURPOSE/OBJECTIVE(S)

The beneficial role of immunotherapy and the clinical relevance of current biomarkers remain inconclusive; thus, appropriate strategies and reliable predictors need further definition. A rational combination of biomarkers is needed. Here, we estimated potential predictive factors for responses of radiotherapy (RT) combined with immune checkpoint inhibitor (ICI) in a phase II trial to determine the efficacy and safety of combination of moderate hypofractionated RT with ICI in patients with oligometastatic NSCLC (NCT03557411).

MATERIALS/METHODS

Pretreatment tumor tissue samples and longitudinal blood were collected for immune and tumor biomarker analysis. We examined pre-treatment (pre-ICI) PD-L1 expression in tumor cells. Circulating tumor cell (CTC), PD-L1+CTC, blood tumor mutation burden (bTMB), CD8+T cells, CD4+T cells, NK cells, B cells in circulation were acquired pre-ICI and 1 month after ICI starting (1-mth). In addition, early changes of CTC (CTC), PD-L1+CTC (PD-L1+CTC), bTMB (bTMB), CD8+T cells (CD8+T cells), CD4+T cells (CD4+T cells), NK cells (NK cells), B cells (B cells) were also analyzed to estimate the predictive effects for treatment.

RESULTS

High pre-ICI bTMB and increased CD8+T cells at 1 month was associated with better PFS (p = 0.016; p = 0.006). Interaction analyses revealed that each combination of two markers in the 5 markers including PD-L1, pre-ICI bTMB, 1-mth bTMB, 1-mth CD8+T cells and CD8+T cells was significantly associated with PFS, except for CTC, PD-L1+CTC, CD4+T cells, NK cells and B cells in circulation due to low power. Unsupervised cluster analysis based on these markers revealed three sub-cohorts. Cohort-1 was overrepresented by patients with progressive disease (81%) of whom were negative for 3-4 of the 5 biomarkers. Cohort-3 was overrepresented by patients with partial response (70%) of whom were positive for 3-4 of the 5 biomarkers. Survival analyses of the 3 cohorts indicated a significant association with PFS (p = 0.017).

CONCLUSION

This study suggests that a combination of PD-L1 expression, early changes of bTMB and circulated CD8+T cells as a better predictive biomarker for response to RT combined with ICI. Consequently, refinement of this set of biomarkers and validation in a larger set of patients is warranted.

Genome-Wide Comparison and Functional Characterization of HMGR Gene Family Associated with Shikonin Biosynthesis in Lithospermum erythrorhizon

3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), as the rate-limiting enzyme in the mevalonate pathway, is essential for the biosynthesis of shikonin in Lithospermum erythrorhizon. However, in the absence of sufficient data, the principles of a genome-wide in-depth evolutionary exploration of HMGR family members in plants, as well as key members related to shikonin biosynthesis, remain unidentified. In this study, 124 HMGRs were identified and characterized from 36 representative plants, including L. erythrorhizon. Vascular plants were found to have more HMGR family genes than nonvascular plants. The phylogenetic tree revealed that during lineage and species diversification, the HMGRs evolved independently and intronless LerHMGRs emerged from multi-intron HMGR in land plants. Among them, Pinus tabuliformis and L. erythrorhizon had the most HMGR gene duplications, with 11 LerHMGRs most likely expanded through WGD/segmental and tandem duplications. In seedling roots and M9 cultured cells/hairy roots, where shikonin biosynthesis occurs, LerHMGR1 and LerHMGR2 were expressed significantly more than other genes. The enzymatic activities of LerHMGR1 and LerHMGR2 further supported their roles in catalyzing the conversion of HMG-CoA to mevalonate. Our findings provide insight into the molecular evolutionary properties and function of the HMGR family in plants and a basis for the genetic improvement of efficiently produced secondary metabolites in L. erythrorhizon.

[Apatinib Suppressed Macrophage-Mediated Malignant Behavior of Hepatocellular Carcinoma Cells via Modulation of VEGFR2/STAT3/PD-L1 Signaling]

Hepatocellular carcinoma (HCC) is the most frequently diagnosed primary liver tumor worldwide. Tumor-associated macrophages (TAMs) usually have a similar phenotype to M2-like macrophages and can participate in tumor progression by secreting cytokines to suppress the immune response and activity of tumor-infiltrating lymphocytes. We investigated the role of M2 macrophages in HCC progression and explored the effects of vascular endothelial growth factor receptor 2 inhibitor-apatinib. As a cellular model of HCC, Hepb3 cell line was used. M2 macrophages were obtained by differentiation of THP-1 cells. The Transwell chamber was used to co-culture M2 macrophages and Hepb3 cells. CCK-8 and EdU assays were conducted to measure cell viability and proliferation capacity. Transwell migration assay was performed to estimate cellular metastatic potential. Cytokine expression levels were assessed by ELISA. Western blotting was used to characterize activation of the VEGFR2/STAT3/PD-L1 axis. It has been shown that co-culture with M2 macrophages increased viability, cytokine production, promoted proliferation, invasion, and migration of Hepb3 cells. The secretion of TGF-β1, IL-6, MMP-9, and VEGF was significantly increased after co-culture. In contrast apatinib suppressed M2 macrophage-induced proliferation, cell viability, invasion, and migration of Hepb3 cells. Moreover, apatinib markedly decreased expression levels of p-VEGFR2, p-STAT3, and PD-L1 in Hepb3 cells under the co-culture conditions. In conclusion, apatinib treatment can suppress TAMs-mediated malignant behavior of HCC cells via modulation of the VEGFR2/STAT3/PD-L1 signaling pathway.

Function and molecular mechanism of a poplar placenta limited MIXTA gene in regulating differentiation of plant epidermal cells

The placenta in fruits of most plants either desiccate and shrink as the fruits mature or develop further to form the fleshy tissues. In poplars, placental epidermal cells protrude collectively to produce catkin fibers. In this study, three carpel limited MIXTA genes, PdeMIXTA02, PdeMIXTA03, PdeMIXTA04, were find to specifically expressed in carpel immediately after pollination. Heterologous expression of the three genes in Arabidopsis demonstrated that PdeMIXTA04 significantly promoted trichomes density and could restore trichomes in the trichomeless mutant. By contrast, such functions were not observed with PdeMIXTA02, PdeMIXTA03. In situ hybridization revealed that PdeMIXTA04 was explicitly expressed in poplar placental epidermal cells. We also confirmed trichome-specific expression of the PdeMIXTA04 promoter. Multiple experimental proofs have confirmed the interaction between PdeMIXTA04, PdeMYC and PdeWD40, indicating PdeMIXTA04 functioned through the MYB-bHLH-WD40 ternary complex. Our work provided distinctive understanding of the molecular mechanism triggering differentiation of poplar catkins.

The sex determination gene of Populus deltoides, PdFERR, interacts with ERF96 to promote the development of female flower organs

The FEMALE-SPECIFICALLY EXPRESSED RESPONSE REGULATOR (PdFERR) gene in Populus deltoides, a sex determination gene (an orthologous gene of ARR17 in P. tremula), was found to promote femaleness in heterologous expression lines of Arabidopsis. None of the genes in the Arabidopsis genome seem to be orthologous to PdFERR. Although originating from two evolutionarily distant plants, the dioecious poplar FERR might promote femaleness in the hermaphroditic Arabidopsis through an evolutionary consistent regulatory pathway. However, there is no molecular evidence to support this viewpoint. In this study, to identify the shared downstream orthologous gene of PdFERR, we used yeast two-hybrid (Y2H) to screen potential interactors of PdFERR in Arabidopsis. We identified the ETHYLENE RESPONSE FACTOR 96 (AtERF96) and confirmed the interaction via in vivo and in vitro assays. The ERF96 orthologous gene in P. deltoides was also experimentally confirmed to interact with PdFERR. PdFERR could then promote femaleness in poplar or Arabidopsis through interactions with ERF96, which provide a new perspective for understanding the PdFERR gene regulating sex differentiation. This article is protected by copyright. All rights reserved.

Discrepancies in rhizobacterial assembly caused by glyphosate application and herbicide-tolerant soybean Co-expressing GAT and EPSPS

There are concerns that the innovation of genetically modified herbicide-tolerant (GMHT) plants, as well as the application of herbicide to such GMHT plants, could have an impact on ecological interactions and unintentionally harm non-targeted organisms. Consequently, we intend to use full-length 16 S rDNA amplicon sequencing to examine changes in the bacterial community in the rhizosphere of GMHT soybean (Z106) harboring 5-enolpyruvylshikimate-3-phosphate synthase and Glyphosate N-acetyltransferase genes and GMHT soybean treated with glyphosate (Z106G). Glyphosate application significantly impacted bacterial alpha diversity (species richness, and Shannon diversity). Permutational multivariate analysis of variance of beta diversity demonstrated that soil compartments and growth stages had a substantial impact on soybean rhizobacterial communities (soil compartments, growth stages, P = 0.001). Community composition revealed that Z106G soils were abundant in Taibaiella and Arthrobacter pascens at maturity, while Chryseobacterium joostei and Stenotrophomonas maltophilia predominated in Z106 soils during flowering. Nitrogen-fixing and phosphate-solubilizing microbes were found in higher proportions in the rhizosphere than in bulk soil, with Sinorhizobium being more abundant in Z106 and Bacillus and Stenotrophomonas being more prevalent in Z106G rhizosphere soils. Collectively, our findings suggest glyphosate application and glyphosate-tolerant soybean as potential regulators of soybean rhizobacterial composition.

The proposed role of MSL-lncRNAs in causing sex lability of female poplars

Labile sex expression is frequently observed in dioecious plants, but the underlying genetic mechanism remains largely unknown. Sex plasticity is also observed in many Populus species. Here we carried out a systematic study on a maleness-promoting gene, MSL, detected in the Populus deltoides genome. Our results showed that both strands of MSL contained multiple cis-activating elements, which generated long non-coding RNAs (lncRNAs) promoting maleness. Although female P. deltoides did not have the male-specific MSL gene, a large number of partial sequences with high sequence similarity to this gene were detected in the female poplar genome. Based on sequence alignment, the MSL sequence could be divided into three partial sequences, and heterologous expression of these partial sequences in Arabidopsis confirmed that they could promote maleness. Since activation of the MSL sequences can only result in female sex lability, we propose that MSL-lncRNAs might play a role in causing sex lability of female poplars.

Genome-Wide Analysis of the Expansin Gene Family in Populus and Characterization of Expression Changes in Response to Phytohormone (Abscisic Acid) and Abiotic (Low-Temperature) Stresses

Expansins are a group of cell wall enzyme proteins that help to loosen cell walls by breaking hydrogen bonds between cellulose microfibrils and hemicellulose. Expansins are essential plant proteins that are involved in several key processes, including seed germination, the growth of pollen tubes and root hairs, fruit ripening and abscission processes. Currently, there is a lack of knowledge concerning the role of expansins in woody plants. In this study, we analyzed expansin genes using Populus genome as the study target. Thirty-six members of the expansin gene family were identified in Populus that were divided into four subfamilies (EXPA, EXPB, EXLA and EXLB). We analyzed the molecular structure, chromosome localization, evolutionary relationships and tissue specificity of these genes and investigated expression changes in responses to phytohormone and abiotic stresses of the expansin genes of Populus tremula L. (PtEXs). Molecular structure analysis revealed that each PtEX protein had several conserved motifs and all of the PtEXs genes had multiple exons. Chromosome structure analysis showed that the expansin gene family is distributed on 14 chromosomes. The PtEXs gene family expansion patterns showed segmental duplication. Transcriptome data of Populus revealed that 36 PtEXs genes were differently expressed in different tissues. Cis-element analysis showed that the PtEXs were closely associated with plant development and responses to phytohormone and abiotic stress. Quantitative real-time PCR showed that abscisic acid (ABA) and low-temperature treatment affected the expression of some PtEXs genes, suggesting that these genes are involved in responses to phytohormone and abiotic stress. This study provides a further understanding of the expansin gene family in Populus and forms a basis for future functional research studies.

Mycorrhizae Enhance Soybean Plant Growth and Aluminum Stress Tolerance by Shaping the Microbiome Assembly in an Acidic Soil

Strongly acidic soils are characterized by high aluminum (Al) toxicity and low phosphorus (P) availability, which suppress legume plant growth and nodule development. Arbuscular mycorrhizal fungi (AMF) stimulate rhizobia and enhance plant P uptake. However, it is unclear how this symbiotic soybean-AMF-rhizobial trio promotes soybean growth in acidic soils. We examined the effects of AMF and rhizobium addition on the growth of two soybean genotypes, namely, Al-tolerant and Al-sensitive soybeans as well as their associated bacterial and fungal communities in an acidic soil. With and without rhizobial addition, AMF significantly increased the fresh shoot and root biomass of Al-tolerant soybean by 47%/87% and 37%/24%, respectively. This increase in plant biomass corresponded to the enrichment of four plant growth-promoting rhizobacteria (PGPR) in the rhizospheric soil, namely, Chitinophagaceae bacterium 4GSH07, Paraburkholderia soli, Sinomonas atrocyanea, and Aquincola tertiaricarbonis. For Al-sensitive soybean, AMF addition increased the fresh shoot and root biomass by 112%/64% and 30%/217%, respectively, with/without rhizobial addition. Interestingly, this significant increase coincided with a decrease in the pathogenic fungus Nigrospora oryzae as well as an increase in S. atrocyanea, A. tertiaricarbonis, and Talaromyces verruculosus (a P-solubilizing fungus) in the rhizospheric soil. Lastly, the compartment niche along the soil-plant continuum shaped microbiome assembly, with pathogenic/saprotrophic microbes accumulating in the rhizospheric soil and PGPR related to nitrogen fixation or stress resistance (e.g., Rhizobium leguminosarum and Sphingomonas azotifigens) accumulating in the endospheric layer. IMPORTANCE Taken together, this study examined the effects of arbuscular mycorrhizal fungi (AMF) and rhizobial combinations on the growth of Al-tolerant and Al-sensitive soybeans as well as their associated microbial communities in acidic soils and concluded that AMF enhances soybean growth and Al stress tolerance by recruiting PGPR and altering the root-associated microbiome assembly in a host-dependent manner. In the future, these findings will help us better understand the impacts of AMF on rhizosphere microbiome assembly and will contribute to the development of soybean breeding techniques for the comprehensive use of PGPR in sustainable agriculture.

PKM2/PDK1 dual-targeted shikonin derivatives restore the sensitivity of EGFR-mutated NSCLC cells to gefitinib by remodeling glucose metabolism

Pyruvate kinase 2 (PKM2) and pyruvate dehydrogenase kinase 1 (PDK1) are two key enzymes in tumor glucose metabolism pathway that not only promote tumor growth and proliferation through accelerating aerobic glycolysis, but also contribute to drug resistance of non-small cell lung cancer (NSCLC). Considering that targeting PKM2 or PDK1 alone seems insufficient to remodel abnormal glucose metabolism to achieve significant antitumor activity, we proposed a "two-step approach" that regulates PKM2 and PDK1 synchronously. Firstly, we found that the combination of ML265 (PKM2 activator) and AZD7545 (PDK1 inhibitor) could synergistically inhibit proliferation and induce apoptosis in H1299 cells. Base on this, we designed a series of novel shikonin (SK) thioether derivatives as PKM2/PDK1 dual-target agents, among which the most potent compound E5 featuring a 2-methyl substitution on the benzene ring exerted significantly increased inhibitory activity toward EGFR mutant NSCLC cell H1975 (IC₅₀ = 1.51 μmol/L), which was 3 and 17-fold more active than the lead compound SK (IC₅₀ = 4.56 μmol/L) and the positive control gefitinib (IC₅₀ = 25.56 μmol/L), respectively. Additionally, E5 also showed good anti-tumor activity in xenografted mouse models, with significantly lower toxicity side effects than SK. Moreover, E5 also inhibited the entry of PKM2 into nucleus to regulate the transcriptional activation of oncogenes, thus restoring the sensitivity of H1975 cell to gefitinib. Collectively, these data demonstrate that E5, a dual inhibitor of PKM2/PDK1, may be a promising adjunct to gefitinib in the treatment of EGFR-TKIs resistant NSCLC, deserving further investigation.

The host niches of soybean rather than genetic modification or glyphosate application drive the assembly of root-associated microbial communities

Plant roots significantly influence soil microbial diversity, and soil microorganisms play significant roles in both natural and agricultural ecosystems. Although the genetically modified (GM) crops with enhanced insect and herbicide resistance are thought to have unmatched yield and stress resistance advantages, thorough and in-depth case studies still need to be carried out in a real-world setting due to the potential effects of GM plants on soil microbial communities. In this study, three treatments were used: a recipient soybean variety Jack, a triple transgenic soybean line JD321, and the glyphosate-treated JD321 (JD321G). Three sampling stages (flowering, seed filling and maturing), as well as three host niches of soybean rhizosphere [intact roots (RT), rhizospheric soil (RS) and surrounding soil (SS)] were established. In comparison to Jack, the rhizospheric soil of JD321G had higher urease activity and lower nitrite reductase at the flowering stage. Different treatments and different sampling stages existed no significant effects on the compositions of microbial communities at different taxonomic levels. However, at the genus level, the relative abundance of three plant growth-promoting fungal genera (i.e. Mortierella, Chaetomium and Pseudombrophila) increased while endophytic bacteria Chryseobacterium and pathogenic bacteria Streptomyces decreased from the inside to the outside of the roots (i.e. RT → RS → SS). Moreover, two bacterial genera, Bradyrhizobium and Ensifer were more abundant in RT than in RS and SS, as well as three species, Agrobacterium radiobacter, Ensifer fredii and Ensifer meliloti, which are closely related to nitrogen-fixation. Furthermore, five clusters of orthologous groups (COGs) associated to nitrogen-fixation genes were higher in RT than in RS, whereas only one COG annotated as dinitrogenase iron-molybdenum cofactor biosynthesis protein was lower. Overall, the results imply that the rhizosphere host niches throughout the soil-plant continuum largely control the composition and function of the root-associated microbiome of triple transgenic soybean.

Genome-Wide Identification of LeBAHDs in Lithospermum erythrorhizon and In Vivo Transgenic Studies Confirm the Critical Roles of LeBAHD1/LeSAT1 in the Conversion of Shikonin to Acetylshikonin

The BAHD acyltransferase family is a unique class of plant proteins that acylates plant metabolites and participates in plant secondary metabolic processes. However, the BAHD members in Lithospermum erythrorhizon remain unknown and uncharacterized. Although the heterologously expressed L. erythrorhizon BAHD family member LeSAT1 in Escherichia coli has been shown to catalyze the conversion of shikonin to acetylshikonin in vitro, its in vivo role remains unknown. In this study, the characterization, evolution, expression patterns, and gene function of LeBAHDs in L. erythrorhizon were explored by bioinformatics and transgenic analysis. We totally identified 73 LeBAHDs in the reference genome of L. erythrorhizon. All LeBAHDs were phylogenetically classified into five clades likely to perform different functions, and were mainly expanded by dispersed and WGD/segmental duplication. The in vivo functional investigation of the key member LeBAHD1/LeSAT1 revealed that overexpression of LeBAHD1 in hairy roots significantly increased the content of acetylshikonin as well as the conversion rate of shikonin to acetylshikonin, whereas the CRISPR/Cas9-based knockout of LeBAHD1 in hairy roots displayed the opposite trend. Our results not only confirm the in vivo function of LeBAHD1/LeSAT1 in the biosynthesis of acetylshikonin, but also provide new insights for the biosynthetic pathway of shikonin and its derivatives.

Differential assembly of root-associated bacterial and fungal communities of a dual transgenic insect-resistant maize line at different host niches and different growth stages

Transgenic technology has been widely applied to crop development, with genetically modified (GM) maize being the world’s second-largest GM crop. Despite the fact that rhizosphere bacterial and fungal populations are critical regulators of plant performance, few studies have evaluated the influence of GM maize on these communities. Plant materials used in this study included the control maize line B73 and the mcry1Ab and mcry2Ab dual transgenic insect-resistant maize line 2A-7. The plants and soils samples were sampled at three growth stages (jointing, flowering, and maturing stages), and the sampling compartments from the outside to the inside of the root are surrounding soil (SS), rhizospheric soil (RS), and intact root (RT), respectively. In this study, the results of alpha diversity revealed that from the outside to the inside of the root, the community richness and diversity declined while community coverage increased. Morever, the different host niches of maize rhizosphere and maize development stages influenced beta diversity according to statistical analysis. The GM maize line 2A-7 had no significant influence on the composition of microbial communities when compared to B73. Compared to RS and SS, the host niche RT tended to deplete Chloroflexi, Gemmatimonadetes and Mortierellomycota at phylum level. Nitrogen-fixation bacteria Pseudomonas, Herbaspirillum huttiense, Rhizobium leguminosarum, and Sphingomonas azotifigens were found to be enriched in the niche RT in comparison to RS and SS, whilst Bacillus was found to be increased and Stenotrophomonas was found to be decreased at the maturing stage as compared to jointing and flowering stages. The nitrogen fixation protein FixH (clusters of orthologous groups, COG5456), was found to be abundant in RT. Furthermore, the pathogen fungus that causes maize stalk rot, Gaeumannomyces radicicola, was found to be abundant in RT, while the beneficial fungus Mortierella hyalina was found to be depleted in RT. Lastly, the abundance of G. radicicola gradually increased during the development of maize. In conclusion, the host niches throughout the soil-plant continuum rather than the Bt insect-resistant gene or Bt protein secretion were primarily responsible for the differential assembly of root-associated microbial communities in GM maize, which provides the theoretical basis for ecological agriculture.

Repeated turnovers keep sex chromosomes young in willows

Background

Salicaceae species have diverse sex determination systems and frequent sex chromosome turnovers. However, compared with poplars, the diversity of sex determination in willows is poorly understood, and little is known about the evolutionary forces driving their turnover. Here, we characterized the sex determination in two Salix species, S. chaenomeloides and S. arbutifolia, which have an XY system on chromosome 7 and 15, respectively.

Results

Based on the assemblies of their sex determination regions, we found that the sex determination mechanism of willows may have underlying similarities with poplars, both involving intact and/or partial homologs of a type A cytokinin response regulator (RR) gene. Comparative analyses suggested that at least two sex turnover events have occurred in Salix, one preserving the ancestral pattern of male heterogamety, and the other changing heterogametic sex from XY to ZW, which could be partly explained by the “deleterious mutation load” and “sexually antagonistic selection” theoretical models. We hypothesize that these repeated turnovers keep sex chromosomes of willow species in a perpetually young state, leading to limited degeneration.

Conclusions

Our findings further improve the evolutionary trajectory of sex chromosomes in Salicaceae species, explore the evolutionary forces driving the repeated turnovers of their sex chromosomes, and provide a valuable reference for the study of sex chromosomes in other species.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-022-02769-w.

Natural shikonin and acetyl-shikonin improve intestinal microbial and protein composition to alleviate colitis-associated colorectal cancer

BACKGROUND

Colorectal cancer (CRC) and inflammatory bowel disease (IBD) are the most common diseases of human digestive system. Nowadays, the influence of the inflammatory microenvironment on tumorigenesis has become a new direction, and the exploration of relative molecular mechanism will facilitate the discovery and identification of novel potential anti-cancer molecules.

METHODS

Natural shikonin (SK) and acetyl-shikonin (acetyl-SK) was administered to azoxymethane (AOM)/dextran sodium sulphate (DSS)-induced colitis-associated colorectal cancer (CAC) mice model by gavage to investigate their therapeutic effects. Moreover, fresh feces and colon tissues were collected for determining the function of SK and acetyl-SK on the gut microbes and protein expression, respectively.

RESULTS

Both SK and acetyl-SK decreased AOM/DSS-induced CAC, and regulated the intestinal flora structure in CAC mouse model. They, especially SK, improved species richness, evenness and diversity of intestinal flora, recovered the upregulated ratio of Firmicutes to Bacteroidota (F/B ratio) which symbolizes gut microbiota dysbiosis. SK and its derivative increased the beneficial bacteria g__norank_f__Muribaculaceae, Lactobacillus, Lachnospiraceae_NK4A136_Group, and reduced those harmful ones including Ileibacterium and Coriobacteriaceae UCG-002. Notably, AOM/DSS caused significant increase in the abundance of Ileibaterium valens and g__norank_f__norank_o__Clostridia_UCG-014, which were not previously reported in studies of colonic inflammation or cancer, and the disorder was reversed by 20 mg/kg of SK. In our current study, the action of SK and acetyl-SK is dose-dependent, and 20 mg/kg SK exhibited the most effective functions, even better than the positive drug mesalazine. Moreover, differential proteomics and ELISA results showed that SK could recover the increase of pro-inflammatory cytokines (including IL-1β, IL-6 and TNF-α), the upregulation of pyruvate kinase isozyme type M2 (PKM2) and some other proteins (mainly concentrated in transcriptional mis-regulation in cancer and IL-17 signaling pathways), and the downregulation of Aldh1b1-Acc3-Maoa and Μgt2b34-Aldh1a1-Aldh1a7 involved in Wnt/β-catenin signaling pathway.

CONCLUSION

Our study identified SK and acetyl-SK, especially SK, as potential preventive agents for CAC through regulating both gut microbes and pathways involved in inflammation and cancer such as Wnt/β-catenin signaling pathway.

First Report of Diaporthe cercidis and D. nobilis Causing Leaf Blotch on Populus davidiana × P. bolleana in China

Shanxin yang (Populus davidiana × P. bolleana) is a commercially valuable hybrid poplar that is widely planted in northern China. Efficient genetic transformation and gene-editing systems have been established for this hybrid poplar (Wang et al., 2011; Wang et al., 2020). However, records of fungal diseases on Shanxin yang are very limited. In July 2020, large necrotic lesions were observed on 16 one-year-old Shanxin yang seedlings planted in a greenhouse of Nanjing Forestry University, Nanjing, China. The disease symptoms appeared mostly on the leaves and not on the stems. Symptoms first manifested as differently sized and shaped brown spots, having clearly demarcated margins. As the disease progressed, the spots coalesced, and large lesions were present on the leaves. Severe infections resulted in whole-plant defoliation and eventually plant death. Small leaf samples (5 mm2) cut from lesion margins were surface sterilized with 75% ethanol for 30 s, followed by 1% NaClO for 90 s and then washed three times with sterile distilled water. After drying on sterilized filter paper, the cut tissues were plated on potato dextrose agar (PDA) supplemented with ampicillin (100 μg/mL) and incubated at 25°C in the dark. Three isolates (named as SX-1, SX-2 and SX-3, respectively) were obtained after 5 days. The isolation frequency was low, which might be due to the greenhouse microclimate that was unfavorable for pathogen spread. Mycelial plugs (5 mm) cut from the leading edge of the mycelia were transferred onto fresh PDA and synthetic nutrient-poor agar (SNA) plates to obtain pure cultures. On both media, colonies of the isolates were white on the front and light yellowish on the back, with concentric zonation. Abundant aerial mycelia developed; the hyphae were hyaline, non-septate, and approximately 0.794-2.961 µm in diameter. On the SNA medium, SX-1 and SX-3 produced globose to subglobose, black pycnidia after 18 days under a 12 h photoperiod. The alpha conidia were fusoid, aseptate, hyaline, smooth, and 6.4 ± 1.2 × 2.4 ± 0.6 µm (n = 50) in size. Under the same conditions, SX-2 produced pycnidia after 20 days, and the conidia were 2.8 ± 0.7 × 7.5 ± 1.3 µm. Beta conidia were not observed on any colony. Based on the morphological characteristics, the isolated mycelia resembled Diaporthe spp. (Gomes et al., 2013). To determine the species identity, genomic DNA from each isolate was extracted, and five loci were amplified, namely, part of the internal transcribed spacer (ITS) amplified with primers ITS1/ITS4 (White et al. 1990); part of the translation elongation factor 1-alpha (EF1-α) with primers EF1-728F/EF1-986R (Carbone and Kohn, 1999); part of the calmodulin (CAL) with primers CAL-228F/CAL-737R (Carbone and Kohn, 1999); part of the β-tubulin (β-tub) with primers Bt2a/Bt2b (Glass and Donaldson, 1995), and part of the histone H3 (HIS) with primers CYLH3F/H3-1b (Glass and Donaldson 1995, Crous et al., 2004). The obtained sequences were deposited in GenBank (accession numbers are listed in Table S1). BLAST analyses showed that the all the amplified fragments were highly homologous to Diaporthe spp. (Table S1). Based on concatenated sequences of the amplicons, a phylogenetic tree was constructed by using Maximum-likelihood and Bayesian inference methods. The multi-locus phylogenetic analyses distinguished SX-1 and SX-3 as D. cercidis, and SX-2 as D. nobilis. To complete Koch's postulates, the pathogenicity of SX-1, as well as SX-2, was tested on both detached and attached leaves of one-year-old Shanxin yang seedlings grown under greenhouse conditions. Healthy leaves were pierced with a sterile needle and then inoculated independently with 5-mm mycelial plugs cut from the edge of the 4-day-old colonies of SX-1 and SX-2 colonies. Controls were inoculated with noncolonized PDA plugs. Three replicates were prepared for each isolate. For the in-vitro tests, detached leaves were placed on wet filter paper in parafilm-sealed Petri dishes and cultured at 25 °C in the dark. For the attached leaf assays, the plants were kept in an 85% humidity chamber immediately after inoculation. All the inoculated leaves developed dark or brown necrotic lesions at 5 days after inoculation, whereas the control leaves showed no symptoms. D. cercidis and D. nobilis were separately reisolated from the inoculated leaves. The former was first described by Yang et al. (2018) as occurring on twigs and branches of Cercis chinensis, and very recently, this pathogen was reported to cause leaf blotch on Acer pictum subsp. mono (Wan et al., 2021). The latter infects some fruit trees (Yu et al., 2018; Sun et al., 2019; Ma et al., 2019) and chestnut (Zhang et al., 2018). All of these studies were conducted in China where there is a great diversity of Diaporthe species (Yang et al., 2018). To our knowledge, this is the first report of both D. cercidis and D. nobilis causing leaf blotch on poplar. The identification of these pathogens is essential for understanding the range of their host species and to manage the resulting fungal diseases, which may cause severe economic damage.

Direct genetic effects, maternal genetic effects, and maternal genetic sensitivity on prenatal heat stress for calf diseases and corresponding genomic loci in German Holsteins

The aim of this study was to infer the effects of heat stress (HS) of dams during late gestation on direct and maternal genetic parameters for pneumonia (PNEU, 112,563 observations), diarrhea (DIAR, 176,904 observations), and omphalitis (OMPH, 176,872 observations) in Holstein calves kept in large-scale co-operator herds. The genotype dataset included 41,135 SNPs from 19,247 male and female cattle. Temperature-humidity indices (THI) during the last 8 wk of pregnancy were calculated, using the climate data from the nearest public weather station for each herd. Heat load effects were considered for average weekly THI larger than 60. Phenotypically, regression coefficients of calf diseases on prenatal THI during the last 8 wk of gestation were estimated in 8 consecutive runs. The strongest detrimental effects of prenatal HS on PNEU and DIAR were identified for the last week of pregnancy (wk 1). Thus, only wk 1 was considered in ongoing genetic and genomic analyses. In an advanced model considering prenatal HS, random regression coefficients on THI in wk 1 nested within maternal genetic effects (maternal slope effects for heat load) were considered as parameters to infer maternal sensitivity in response to prenatal THI alterations. Direct heritabilities from the advanced model ranged from 0.10 (THI 60) to 0.08 (THI 74) for PNEU and were close to 0.16 for DIAR. Maternal heritabilities for PNEU increased from 0.03 to 0.10 along the THI gradient. For DIAR, the maternal heritability was largest (0.07) at the minimum THI (THI = 60) and decreased to 0.05 at THI 74. Genetic correlations smaller than 0.80 for PNEU and DIAR recorded at THI 60 with corresponding diseases at THI 74 indicated genotype by climate interactions for maternal genetic effects. Genome-wide associations studies were performed using de-regressed proofs of genotyped sires for direct genetic, maternal genetic, and maternal slope effects. Thirty suggestive and 2 significant SNPs were identified from the GWAS. Forty-three genes located close to the suggestive SNPs (±100 kb) were annotated as potential candidate genes. Three biological processes were inferred on the basis of the these genes, addressing the negative regulation of the viral life cycle, innate immune response, and protein ubiquitination. Hence, the genetics of prenatal heat stress mechanisms are associated with immune physiology and disease resistance mechanisms.

Deciphering the Multi-Chromosomal Mitochondrial Genome of Populus simonii

Mitochondria, inherited maternally, are energy metabolism organelles that generate most of the chemical energy needed to power cellular various biochemical reactions. Deciphering mitochondrial genome (mitogenome) is important for elucidating vital activities of species. The complete chloroplast (cp) and nuclear genome sequences of Populus simonii (P. simonii) have been reported, but there has been little progress in its mitogenome. Here, we assemble the complete P. simonii mitogenome into three circular-mapping molecules (lengths 312.5, 283, and 186 kb) with the total length of 781.5 kb. All three molecules of the P. simonii mitogenome had protein-coding capability. Whole-genome alignment analyses of four Populus species revealed the fission of poplar mitogenome in P. simonii. Comparative repeat analyses of four Populus mitogenomes showed that there were no repeats longer than 350 bp in Populus mitogenomes, contributing to the stability of genome sizes and gene contents in the genus Populus. As the first reported multi-circular mitogenome in Populus, this study of P. simonii mitogenome are imperative for better elucidating their biological functions, replication and recombination mechanisms, and their unique evolutionary trajectories in Populus.

Time-sequential detection of quantitative trait loci and candidate genes underlying the dynamic growth of Salix suchowensis

Elucidating the genetic factors underlying long-term biological processes remains challenging since the relevant genes and their effects may vary across different developmental stages. In this study, we carried out a large-scale field trial of the progeny of an F1 full-sib pedigree of Salix suchowensis and measured plant height and ground diameter periodically over a time course of 240 days. With the obtained data, we characterized plant growth rhythms and performed time-sequential analyses of quantitative trait loci underlying the dynamic growth of the plants. The dynamic mapping of quantitative trait loci revealed that stem height and ground diameter were under the control of four quantitative trait loci, and the effects of these quantitative trait loci varied greatly throughout the growth process, in which two quantitative trait loci were found to exert a pleiotropic effect determining the correlation between stem height and ground diameter. The analysis of candidate genes in the target genetic intervals showed that the pleiotropic effect of the two quantitative trait loci arises from the colocalization of genes with independent effects on stem height and ground diameter. Further examination of the expression patterns of the candidate genes indicated that height and circumference growth involve different activities of leaf and cambium tissues. This study provides unprecedented information to help us understand the dynamic growth of plants and presents an applicable strategy for elucidating the genetic mechanism underlying a long-term biological process by using plant growth as an example.

A Selection of Reliable Reference Genes for Gene Expression Analysis in the Female and Male Flowers of Salix suchowensis

Salix is a dioecious plant. Research on the molecular regulation mechanism of male and female inflorescence differentiation and development is necessary to analyze sex differentiation in the willow and the underlying mechanisms of unisexual flower development. However, at present, there are no reference genes suitable for stable expression in the process of willow inflorescence development. In this study, Salix suchowensis was used as the research material, nine candidate reference genes (α-TUB1, α-TUB2, ACT, H2A, DnaJ, CDC2, GAPDH, TIP41, β-TUB) were selected, and qRT-PCR technology was used to detect the expression of each candidate reference gene in female and male flowers at different developmental stages and using five algorithms (geNorm, Normfinder, Delta Ct, BestKeeper, and RefFinder) to comprehensively evaluate the stability of candidate reference genes. The results showed that ACT and DnaJ were stably expressed in all samples and could be used as reference genes. In addition, the reliability of the screening results was further verified via an expression pattern analysis of the CFS gene that encodes flower specific transcription factor in different samples. The stable reference genes selected in this study provide the basis for future research on the expression analysis of functional genes related to the development of male and female flowers of S. suchowensis.

Genome-wide associations for heat stress response suggest potential candidate genes underlying milk fatty acid composition in dairy cattle

Contents of milk fatty acids (FA) display remarkable alterations along climatic gradients. Detecting candidate genes underlying such alterations might be beneficial for the exploration of climate sensitivity in dairy cattle. Consequently, we aimed on the definition of FA heat stress indicators, considering FA breeding values in response to temperature-humidity index (THI) alterations. Indicators were used in GWAS, in ongoing gene annotations and for the estimation of chromosome-wide variance components. The phenotypic data set consisted of 39,600 test-day milk FA records from 5,757 first-lactation Holstein dairy cows kept in 16 large-scale German cooperator herds. The FA traits were C18:0, polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and unsaturated fatty acids (UFA). After genotype quality control, 40,523 SNP markers from 3,266 cows and 930 sires were considered. Meteorological data from the weather station in closest herd distance were used for the calculation of maximum hourly daily THI, which were allocated to 10 different THI classes. The same FA from 3 stages of lactation were considered as different, but genetically correlated traits. Consequently, a 3-trait reaction norm model was used to estimate genetic parameters and breeding values for FA along THI classes, considering either pedigree (A) or genomic (G) relationship matrices. De-regressed proofs and genomic estimated breeding values at the intermediate THI class 5 and at the extreme THI class 10 were used as pseudophenotypes in ongoing genomic analyses for thermoneutral (TNC) and heat stress conditions (HSC), respectively. The differences in de-regressed proofs and in genomic estimated breeding values from both THI classes were pseudophenotypes for heat stress response (HSR). Genetic correlations between the same FA under TNC and HSC were smallest in the first lactation stage and ranged from 0.20 for PUFA to 0.87 for SFA when modeling with the A matrix, and from 0.35 for UFA to 0.86 for SFA when modeling with the G matrix. In the first lactation stage, larger additive genetic variances under HSC compared with TNC indicate climate sensitivity for C18:0, PUFA, and UFA. Climate sensitivity was also reflected by pronounced chromosome-wide genetic variances for HSR of PUFA and UFA in the first stage of lactation. For all FA under TNC, HSC, and HSR, quite large genetic variance proportions were explained by BTA14. In GWAS, 30 SNP (within or close to 38 potential candidate genes) overlapped for HSR of the different FA. One unique potential candidate gene (AMFR) was detected for HSR of PUFA, 15 for HSR of SFA (ADGRB1, DENND3, DUSP16, EFR3A, EMP1, ENSBTAG00000003838, EPS8, MGP, PIK3C2G, STYK1, TMEM71, GSG1, SMARCE1, CCDC57, and FASN) and 3 for HSR of UFA (ENSBTAG00000048091, PAEP, and EPPK1). The identified unique genes play key roles in milk FA synthesis and are associated with disease resistance in dairy cattle. The results suggest consideration of FA in combination with climatic responses when inferring genetic mechanisms of heat stress in dairy cows.

[Emergency psychological intervention of acute ammonia leakage event]

Objective: To analyze the situation of emergency psychological intervention in an acute ammonia leakage event, and to provide reference for emergency response. Methods: In August 2020, the emergency treatment of 65 patients admitted by Zhangqiu District People's Hospital Affiliated to Jining Medical College of Shandong Province in June 2019 in the ammonia tank car leakage incident was analyzed, the psychological intervention in emergency after the incident was collected, the anxiety and depression were evaluated by symptom checklist 90 (SCL-90) , and targeted psychological intervention was implemented according to the psychological evaluation results, And analyze the intervention efficiency. Results: Among the 65 patients, there were 52 cases of ammonia stimulation reaction, 11 cases of mild poisoning and 2 cases of moderate poisoning. There were 60 cases of chest tightness and dyspnea, 11 cases of bloody sputum, 58 cases of sore throat, 43 cases of hoarseness, 28 cases of photophobia and tears, 13 cases of blurred vision, 18 cases of nausea and vomiting, and 2 cases of dry and wet rales in the lungs. The scores of somatization, depression, anxiety, hostility, phobia, paranoia and negative coping in patients with mild and moderate poisoning were higher than those in patients with stimulus response (P<0.05) . The effective rate of intervention was 98.7%. Conclusion: Emergency psychological evaluation and intervention in mass public health events are helpful to the treatment of patients.

[ ≥ ]

Objective: To investigate the safety and efficacy of retroperitoneal laparoscopic selective renal artery branch occlusion with nephron sparing surgery in patients with renal carcinoma of stage ≥ T1b. Methods: From July 2016 to September 2020, 35 patients with renal cancer ≥T1b underwent retroperitoneoscopic nephron sparing surgery in the First Affiliated Hospital of Shenzhen University. The surgical methods were retroperitoneoscopic nephron sparing surgery with total renal artery occlusion (group A) or selective renal artery branch occlusion (group B). Operation time, heat ischemia time, blood transfusion rate, positive margin rate, intraoperative blood loss, postoperative complications and length of hospital stay were compared between the two groups, and the total glomerular filtration rate (GFR) and the single-nephron glomerular filtration rate (sGFR) of the offected kidneys were compared between the two groups before, 3 months after and 12 months after surgery. Results: Among the 35 patients, 19 were male and 16 were female, aged (55.7±8.4) years and the body mass index is (24.6±3.1) kg/m². The tumor diameter was (54.7±10.3) mm. The difference was statistically significant of operative time between group A and B [(103.5±14.3) vs (123.2±14.1) min,P=0.003]. There were no significant differences in thermal ischemia time, blood transfusion rate, positive margin, intraoperative blood loss, incidence of postoperative complications and length of hospital stay between the two groups (all P>0.05). The decrease of renal sGFR in the group A was significantly higher than group B at 3 months and 12 months after surgery [(23.1±3.6) vs (29.1±7.1) ml/min;(25.9±4.7) vs (30.7±7.2),both P<0.05]. Conclusion: Retroperitoneal laparoscopic selective renal artery branch occlusion and neon-sparing surgery for patients with ≥ T1b stage renal carcinoma is a safe and effective surgical method, which can well protect the renal function of patients in the early postoperative stage without increasing intraoperative blood loss and postoperative complications.

Shikonin N-benzyl matrinic acid ester derivatives as novel telomerase inhibitors with potent activity against lung cancer cell lines

In this study, a series of novel shikonin N-benzyl matrinic acid ester derivatives (PMMB-299-PMMB-310) were synthesized and tested for their ability to inhibit the proliferation of cancer cells. Compared with shikonin and matrine, some of the ester derivatives were found to exhibit better anti-proliferative activity against seven different cancer cell lines, with less cytotoxicity toward non-cancerous cells. The strongest anti-proliferative activity was exhibited by PMMB-302, which had an IC₅₀ value of 2.71 μM against A549 cells. The compound caused cell cycle arrest in the G2/M phase and induced apoptosis. Effects on the expression of apoptosis-related molecules such as Bcl2, Bcl-XL, caspase-3, caspase-9 and FADD suggested that PMMB-302 has tumor suppressive roles in lung cancer cells. In addition, PMMB-302 inhibited expression of telomerase core proteins, dyskerin and NHP2, and telomerase reverse transcriptase RNA. Moreover, molecular docking of PMMB-302 was subsequently conducted to determine the probable binding mode with telomerase. Taken together, the results indicate that PMMB-302 acts as a tumor suppressor in lung cancer cells by negatively regulating telomerase expression.

Effect of TNF-alpha on endometrial glucose transporter-4 expression in patients with polycystic ovary syndrome through nuclear factor-kappa B signaling pathway activation

The present study aimed to investigate the possible mechanism of action of tumor necrosis factor-alpha (TNF-α) in endometrial glucose transporter-4 (GLUT-4) expression regulation by detecting the expression levels of endometrial inflammatory factors and GLUT-4 in patients with polycystic ovary syndrome (PCOS). A total of 140 patients were included in this study and divided into four groups: the PCOS group, the obesity + PCOS group, the normal group, and the obesity group (n = 35 each). The general clinical data of all patients were collected, and their expression levels of TNF-α, nuclear factor kappa B p65 (NF-κBp65), and GLUT-4 in the endometrium were tested via immunohistochemistry. Endometrial stromal cells were cultured in vitro and treated with TNF-α or pyrrolidine dithiocarbamate (PDTC) + TNF-α, and the expression levels of NF-κBp65, phospho-NF-κBp65 (p-NF-κBp65), and GLUT-4 were tested using Western blotting (WB) before and after treatment. As a result, we got: 1) Compared with the normal group, the abundance of the protein for TNF-α and NF-κBp65 in the endometrium of the patients with PCOS was elevated, while the expression level of GLUT-4 was decreased; the difference was statistically different (P < 0.05). The comparison between the obesity + PCOS group and the PCOS group yielded the same results. 2) According to the WB results, compared with the normal group, the abundance of the protein for endometrial GLUT-4 was decreased in the PCOS group, and the expression levels of p-NF-κBp65 and NF-κBp65 were increased in the obesity + PCOS group; the differences were statistically different (P < 0.05). The addition of TNF-α could decrease the abundance of the protein for GLUT-4 and increase the abundance of the protein for p-NF-κBp65. After treatment with PDTC + TNF-α, the abundance of the protein for p-NF-κBp65 decreased and GLUT-4 increased compared with the TNF-α group; these values were close to those of the control group. We concluded that the abundance of the proteins for local inflammatory factors in the endometrial cells of patients with PCOS was increased, indicating that TNF-α could affect the expression of endometrial GLUT-4 in such patients by activating the p-NF-κBp65 signaling pathway.

Deciphering the rhizobacterial assemblages under the influence of genetically engineered maize carrying mcry genes

Genetically engineered (GE) maize has been thoroughly studied regarding its agro-environmental impact; however, its concerns for the soil environment remain. This work was aimed to decode rhizosphere microbe interactions and potential ecological hazards associated with GE maize. Rhizobacterial communities of field grown transgenic insect-resistant 2A5 maize carrying mcry1Ab and mcry2Ab genes were compared with control Z58 using PacBio sequencing platform. Also full-length 16S rDNA gene sequencing was used to verify the partial (V3-V4) sequencing results obtained in 2017. Measures of α-diversity displayed transgenic 2A5 to be significantly lower in species richness at the flowering stage; however, diversity remained undisturbed. β-diversity was least affected by genetic modifications where similar community profiles were shared by transgenic 2A5 and control Z58. In addition, root exudation patterns were found to drive variations in bacterial assemblages based on developmental stages. For example, genus Massilia successfully colonized the rhizosphere at jointing stage, while Mucilaginobacter showed higher relative abundance in flowering stages of both 2A5 and Z58. These members are known to possess attributes related to plant growth. The impact of dual-transgene insertion on nifH gene abundance was also analyzed where no apparent significant difference in nifH gene copy number was observed. Our results confirmed that full-length 16S rDNA sequencing was sufficient to provide higher taxonomic resolution. Also, results of our 2-year field trials confirmed that there is no significant impact of mcry gene integration on belowground biomasses. Therefore, GE insect-resistant 2A5 maize carrying mcry1Ab and mcry2Ab genes can continue to benefit human populations by increasing crop productivity. In future, further research needs to be catalyzed to analyze the impact of Bt-insertion on microbial community structure across the years for ecosystem sustainability.

Single-step genomic best linear unbiased predictor genetic parameter estimations and genome-wide associations for milk fatty acid profiles, interval from calving to first insemination, and ketosis in Holstein cattle

Milk fatty acids (FA) have been suggested as biomarkers for early-lactation metabolic diseases and for female fertility status. The aim of the present study was to infer associations between FA, the metabolic disorder ketosis (KET), and the interval from calving to first insemination (ICF) genetically and genomically. In this regard, we focused on a single-step genomic BLUP approach, allowing consideration of genotyped and ungenotyped cows simultaneously. The phenotypic data set considered 38,375 first-lactation Holstein cows, kept in 45 large-scale co-operator herds from 2 federal states in Germany. The calving years for these cows were from 2014 to 2017. Concentrations in milk from the first official milk recording test-day for saturated, unsaturated (UFA), monounsaturated (MUFA), polyunsaturated, palmitic, and stearic (C18:0) FA were determined via Fourier-transform infrared spectroscopy. Ketosis was defined as a binary trait according to a veterinarian diagnosis key, considering diagnoses within a 6-wk interval after calving. A subset of 9,786 cows was genotyped for 40,989 SNP markers. Variance components and heritabilities for all Gaussian distributed FA and for ICF, and for binary KET were estimated by applying single-step genomic BLUP single-trait linear and threshold models, respectively. Genetic correlations were estimated in series of bivariate runs. Genomic breeding values for the single-step genomic BLUP estimations were dependent traits in single-step GWAS. Heritabilities for FA were moderate in the range from 0.09 to 0.20 (standard error = 0.02-0.03), but quite small for ICF (0.08, standard error = 0.01) and for KET (0.05 on the underlying liability scale, posterior standard deviation = 0.02). Genetic correlations between KET and UFA, MUFA, and C18:0 were large (0.74 to 0.85, posterior standard deviation = 0.14-0.19), and low positive between KET and ICF (0.17, posterior standard deviation = 0.22). Genetic correlations between UFA, MUFA, and C18:0 with ICF ranged from 0.34 to 0.46 (standard error = 0.12). In single-step GWAS, we identified a large proportion of overlapping genomic regions for the different FA, especially for UFA and MUFA, and for saturated and palmitic FA. One identical significantly associated SNP was identified for C18:0 and KET on BTA 15. However, there was no genomic segment simultaneously significantly affecting all trait categories ICF, FA, and KET. Nevertheless, some of the annotated potential candidate genes DGKA, IGFBP4, and CXCL8 play a role in lipid metabolism and fertility mechanisms, and influence production diseases in early lactation. Genetic and genomic associations indicate that Fourier-transform infrared spectroscopy FA concentrations in milk from the first official test-day are valuable predictors for KET and for ICF.

Genotype by heat stress interactions for production and functional traits in dairy cows from an across-generation perspective

The aim of this study was to analyze time-lagged heat stress (HS) effects during late gestation on genetic co(variance) components in dairy cattle across generations for production, female fertility, and health traits. The data set for production and female fertility traits considered 162,492 Holstein Friesian cows from calving years 2003 to 2012, kept in medium-sized family farms. The health data set included 69,986 cows from calving years 2008 to 2016, kept in participating large-scale co-operator herds. Production traits were milk yield (MKG), fat percentage (fat%), and somatic cell score (SCS) from the first official test-day in first lactation. Female fertility traits were the nonreturn rate after 56 d (NRR56) in heifers and the interval from calving to first insemination (ICFI) in first-parity cows. Health traits included clinical mastitis (MAST), digital dermatitis (DD), and endometritis (EM) in the early lactation period in first-parity cows. Meteorological data included temperature and humidity from public weather stations in closest herd distance. The HS indicator was the temperature-humidity index (THI) during dams' late gestation, also defined as in utero HS. For the genetic analyses of production, female fertility, and health traits in the offspring generation, a sire-maternal grandsire random regression model with Legendre polynomials of order 3 for the production and of order 2 for the fertility and health traits on prenatal THI, was applied. All statistical models additionally considered a random maternal effect. THI from late gestation (i.e., prenatal climate conditions), influenced genetic parameter estimates in the offspring generation. For MKG, heritabilities and additive genetic variances decreased in a wave-like pattern with increasing THI. Especially for THI >58, the decrease was very obvious with a minimal heritability of 0.08. For fat% and SCS, heritabilities increased slightly subjected to prenatal HS conditions at THI >67. The ICFI heritabilities differed marginally across THI [heritability (h²) = 0.02-0.04]. For NRR56, MAST, and DD, curves for heritabilities and genetic variances were U-shaped, with largest estimates at the extreme ends of the THI scale. For EM, heritability increased from THI 25 (h² = 0.13) to THI 71 (h² = 0.39). The trait-specific alterations of genetic parameters along the THI gradient indicate pronounced genetic differentiation due to intrauterine HS for NRR56, MAST, DD, and EM, but decreasing genetic variation for MKG and ICFI. Genetic correlations smaller than 0.80 for NRR56, MAST, DD, and EM between THI 65 with corresponding traits at remaining THI indicated genotype by environment interactions. The lowest genetic correlations were identified when considering the most distant THI. For MKG, fat%, SCS, and ICFI, genetic correlations throughout were larger than 0.80, disproving concerns for any genotype by environment interactions. Variations in genetic (co)variance components across prenatal THI may be due to epigenetic modifications in the offspring genome, triggered by in utero HS. Epigenetic modifications have a persistent effect on phenotypic responses, even for traits recorded late in life. However, it is imperative to infer the underlying epigenetic mechanisms in ongoing molecular experiments.

The nearly complete genome of Ginkgo biloba illuminates gymnosperm evolution

Gymnosperms are a unique lineage of plants that currently lack a high-quality reference genome due to their large genome size and high repetitive sequence content. Here, we report a nearly complete genome assembly for Ginkgo biloba with a genome size of 9.87 Gb, an N50 contig size of 1.58 Mb and an N50 scaffold size of 775 Mb. We were able to accurately annotate 27,832 protein-coding genes in total, superseding the inaccurate annotation of 41,840 genes in a previous draft genome assembly. We found that expansion of the G. biloba genome, accompanied by the notable extension of introns, was mainly caused by the insertion of long terminal repeats rather than the recent occurrence of whole-genome duplication events, in contrast to the findings of a previous report. We also identified candidate genes in the central pair, intraflagellar transport and dynein protein families that are associated with the formation of the spermatophore flagellum, which has been lost in all seed plants except ginkgo and cycads. The newly obtained Ginkgo genome provides new insights into the evolution of the gymnosperm genome.

Aux/IAA and ARF Gene Families in Salix suchowensis: Identification, Evolution, and Dynamic Transcriptome Profiling During the Plant Growth Process

The phytohormone auxin plays a pivotal role in the regulation of plant growth and development, including vascular differentiation and tree growth. The auxin/indole-3-acetic acid (Aux/IAA) and auxin response transcription factor (ARF) genes are key components of plant auxin signaling. To gain more insight into the regulation and functional features of Aux/IAA and ARF genes during these processes, we identified 38 AUX/IAA and 34 ARF genes in the genome of Salix suchowensis and characterized their gene structures, conserved domains, and encoded amino acid compositions. Phylogenetic analysis of some typical land plants showed that the Aux/IAA and ARF genes of Salicaceae originated from a common ancestor and were significantly amplified by the ancestral eudicot hexaploidization event and the "salicoid" duplication that occurred before the divergence of poplar and willow. By analyzing dynamic transcriptome profiling data, some Aux/IAA and ARF genes were found to be involved in the regulation of plant growth, especially in the initial plant growth process. Additionally, we found that the expression of several miR160/miR167-ARFs was in agreement with canonical miRNA-ARF interactions, suggesting that miRNAs were possibly involved in the regulation of the auxin signaling pathway and the plant growth process. In summary, this study comprehensively analyzed the sequence features, origin, and expansion of Aux/IAA and ARF genes, and the results provide useful information for further studies on the functional involvement of auxin signaling genes in the plant growth process.

Differential microbial assemblages associated with shikonin-producing Borage species in two distinct soil types

Shikonin and its derivatives are the main components of traditional Chinese medicine, Zicao. The pharmacological potential of shikonin and its derivatives have been extensively studied. Yet, less is known about the microbial assemblages associated with shikonin producing Borage plants. We studied microbial profiles of two Borage species, Echium plantagineum (EP) and Lithospermum erythrorhizon (LE), to identify the dynamics of microbial colonization pattern within three rhizo-compatments and two distinct soil types. Results of α and β-diversity via PacBio sequencing revealed significantly higher microbial richness and diversity in the natural soil along with a decreasing microbial gradient across rhizosphere to endosphere. Our results displayed genotype and soil type-dependent fine-tuning of microbial profiles. The host plant was found to exert effects on the physical and chemical properties of soil, resulting in reproducibly different micro-biota. Analysis of differentially abundant microbial OTUs displayed Planctomycetes and Bacteroidetes to be specifically enriched in EP and LE rhizosphere while endosphere was mostly prevailed by Cyanobacteria. Network analysis to unfold co-existing microbial species displayed different types of positive and negative interactions within different communities. The data provided here will help to identify microbes associated with different rhizo-compartments of potential host plants. In the future, this might be helpful for manipulating the keystone microbes for ecosystem functioning.

Sex determination through X-Y heterogamety in Salix nigra

The development of non-recombining sex chromosomes has radical effects on the evolution of discrete sexes and sexual dimorphism. Although dioecy is rare in plants, sex chromosomes have evolved repeatedly throughout the diversification of angiosperms, and many of these sex chromosomes are relatively young compared to those found in vertebrates. In this study, we designed and used a sequence capture array to identify a novel sex-linked region (SLR) in Salix nigra, a basal species in the willow clade, and demonstrated that this species has XY heterogamety. We did not detect any genetic overlap with the previously characterized ZW SLRs in willows, which map to a different chromosome. The S. nigra SLR is characterized by strong recombination suppression across a 2 MB region and an excess of low-frequency alleles, resulting in a low Tajima's D compared to the remainder of the genome. We speculate that either a recent bottleneck in population size or factors related to positive or background selection generated this differential pattern of Tajima's D on the X and autosomes. This discovery provides insights into factors that may influence the evolution of sex chromosomes in plants and contributes to a large number of recent observations that underscore their dynamic nature.

Design, synthesis and biological evaluation of anilide (dicarboxylic acid) shikonin esters as antitumor agents through targeting PI3K/Akt/mTOR signaling pathway

Triple-negative breast cancer (TNBC) has an unfavorable prognosis attribute to its low differentiation, rapid proliferation and high distant metastasis rate. PI3K/Akt/mTOR as an intracellular signaling pathway plays a key role in the cell proliferation, migration, invasion, metabolism and regeneration. In this work, we designed and synthesized a series of anilide (dicarboxylic acid) shikonin esters targeting PI3K/Akt/mTOR signaling pathway, and assessed their antitumor effects. Through three rounds of screening by computer-aided drug design method (CADD), we preliminarily obtained sixteen novel anilide (dicarboxylic acid) shikonin esters and identified them as excellent compounds. CCK-8 assay results demonstrated that compound M9 exhibited better antiproliferative activities against MDA-MB-231, A549 and HeLa cell lines than shikonin (SK), especially for MDA-MB-231 (M9: IC₅₀ = 4.52 ± 0.28 μM; SK: IC₅₀ = 7.62 ± 0.26 μM). Moreover, the antiproliferative activity of M9 was better than that of paclitaxel. Further pharmacological studies showed that M9 could induce apoptosis of MDA-MB-231 cells and arrest the cell cycle in G2/M phase. M9 also inhibited the migration of MDA-MB-231 cells by inhibiting Wnt/β-catenin signaling pathway. In addition, western blot results showed that M9 could inhibit cell proliferation and migration by down-regulating PI3K/Akt/mTOR signaling pathway. Finally, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model was also constructed to provide a basis for further development of shikonin derivatives as potential antitumor drugs through structure-activity relationship analysis. To sum up, M9 could be a potential candidate for TNBC therapy.

Heat-killed Lactobacillus brevis KB290 attenuates visceral fat accumulation induced by high-fat diet in mice

AIMS

This study aimed to evaluate the anti-adiposity effect of heat-killed Lactobacillus brevis KB290 originating from traditional Japanese fermented pickles in mice fed a high-fat diet (HFD).

METHODS AND RESULTS

C57BL/6J mice were fed a normal-fat diet, HFD or HFD supplemented with heat-killed KB290 for 8 weeks. Epididymal and renal adipose tissue weights, as well as areas of epididymal adipocytes, were significantly lower in the mice fed a HFD supplemented with KB290 than in those fed an unsupplemented HFD. Mice whose diets were supplemented with KB290 had elevated adiponectin and β3-adrenergic receptor expression in epididymal adipose tissue and an accompanying higher serum free fatty acid level. Furthermore, the HFD-induced elevations in serum glucose, insulin and HOMA-IR were significantly suppressed by dietary supplementation with KB290. Amplicon sequencing of 16S rRNA genes revealed that KB290 ingestion altered the composition of the intestinal microbiota.

CONCLUSIONS

Heat-killed L. brevis KB290 suppressed diet-induced visceral fat accumulation and ameliorated diet-induced metabolic symptoms and intestinal gut microbiota modifications, suggesting possibility of novel paraprobiotic.

SIGNIFICANCE AND IMPACT OF THE STUDY

Heat-killed L. brevis KB290 is useable as a material to develop functional foods that attenuate visceral fat accumulation.

Climate sensitivity of milk production traits and milk fatty acids in genotyped Holstein dairy cows

The aim of this study was the evaluation of climate sensitivity via genomic reaction norm models [i.e., to infer cow milk production and milk fatty acid (FA) responses on temperature-humidity index (THI) alterations]. Test-day milk traits were recorded between 2010 and 2016 from 5,257 first-lactation genotyped Holstein dairy cows. The cows were kept in 16 large-scale cooperator herds, being daughters of 344 genotyped sires. The longitudinal data consisted of 47,789 test-day records for the production traits milk yield (MY), fat yield (FY), and protein yield (PY), and of 20,742 test-day records for 6 FA including C16:0, C18:0, saturated fatty acids (SFA), unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). After quality control of the genotypic data, 41,057 SNP markers remained for genomic analyses. Meteorological data from the weather station in closest herd distance were used for the calculation of maximum hourly daily THI. Genomic reaction norm models were applied to estimate genetic parameters in a single-step approach for production traits and FA in dependency of THI at different lactation stages, and to evaluate the model stability. In a first evaluation strategy (New_sire), all phenotypic records from daughters of genotyped sires born after 2010 were masked, to mimic a validation population. In the second strategy (New_env), only daughter records of the new sires recorded in the most extreme THI classes were masked, aiming at predicting sire genomic estimated breeding values (GEBV) under heat stress conditions. Model stability was the correlation between GEBV of the new sires in the reduced data set with respective GEBV estimated from all phenotypic data. Among all test-day production traits, PY responded as the most sensitive to heat stress. As observed for the remaining production traits, genetic variances were quite stable across THI, but genetic correlations between PY from temperate climates with PY from extreme THI classes dropped to 0.68. Genetic variances in dependency of THI were very similar for C16:0 and SFA, indicating marginal climatic sensitivity. In the early lactation stage, genetic variances for C18:0, MUFA, PUFA, and UFA were significantly larger in the extreme THI classes compared with the estimates under thermoneutral conditions. For C18:0 and MUFA, PUFA, and UFA in the middle THI classes, genetic correlations in same traits from the early and the later lactation stages were lower than 0.50, indicating strong days in milk influence. Interestingly, within lactation stages, genetic correlations for C18:0 and UFA recorded at low and high THI were quite large, indicating similar genetic mechanisms under stress conditions. The model stability was improved when applying the New_env instead of New_sire strategy, especially for FA in the first stage of lactation. Results indicate moderately accurate genomic predictions for milk traits in extreme THI classes when considering phenotypic data from a broad range of remaining THI. Phenotypically, thermal stress conditions contributed to an increase of UFA, suggesting value as a heat stress biomarker. Furthermore, the quite large genetic variances for UFA at high THI suggest the consideration of UFA in selection strategies for improved heat stress resistance.

A General Model to Explain Repeated Turnovers of Sex Determination in the Salicaceae

Dioecy, the presence of separate sexes on distinct individuals, has evolved repeatedly in multiple plant lineages. However, the specific mechanisms by which sex systems evolve and their commonalities among plant species remain poorly understood. With both XY and ZW sex systems, the family Salicaceae provides a system to uncover the evolutionary forces driving sex chromosome turnovers. In this study, we performed a genome-wide association study to characterize sex determination in two Populus species, P. euphratica and P. alba. Our results reveal an XY system of sex determination on chromosome 14 of P. euphratica, and a ZW system on chromosome 19 of P. alba. We further assembled the corresponding sex-determination regions, and found that their sex chromosome turnovers may be driven by the repeated translocations of a Helitron-like transposon. During the translocation, this factor may have captured partial or intact sequences that are orthologous to a type-A cytokinin response regulator gene. Based on results from this and other recently published studies, we hypothesize that this gene may act as a master regulator of sex determination for the entire family. We propose a general model to explain how the XY and ZW sex systems in this family can be determined by the same RR gene. Our study provides new insights into the diversification of incipient sex chromosomes in flowering plants by showing how transposition and rearrangement of a single gene can control sex in both XY and ZW systems.

Associations between minerals and metabolic indicators in maternal blood pre- and postpartum with ewe body condition, methane emissions, and lamb body weight development

In sheep production, economic efficiency strongly depends on the maternal health and feed efficiency status and on weaning performances of their offspring. Accordingly, an optimal level for the supply with macro- and microelements and the ewe energy status has impact on the fetal development during gestation and on maternal milk production during lactation. Furthermore, this study addressed intergenerational aspects, i.e., on associations between maternal energy metabolism profiles considering the macro- and microelement status, metabolic indicators (e.g. β-hydroxybutyrate (BHB)), body condition and methane (CH4) emissions with lamb BW (LBW) in two sheep breeds. Traits were recorded at the beginning of gestation (ewe traits), at lambing, three weeks postpartum, and at weaning (ewe and lamb traits). Trait recording included CH4 emissions (recorded via laser methane detector (LMD)), ewe BW (EBW), backfat thickness (BFT), and body condition score (BCS) from 46 ewes (24 Merinoland- (ML), 22 Rhönsheep (RH)), and LBW of their 87 (35 ML, 52 RH) purebred lambs. Serum levels of the following ewe blood parameters were determined: calcium (Ca), sodium (Na), potassium (K), phosphate (P), nonesterified fatty acids (NEFA), BHB, glutamate dehydrogenase (GLDH), selenium (Se), copper (Cu), iron (Fe), zinc (Zn), and magnesium (Mg). Mixed models were applied to infer associations between ewe blood parameters with EBW, BFT, BCS, and CH4 and with LBW recorded in offspring. At weaning, a maternal serum Mg level > 1.0 mmol/L was significantly associated with an increase of 13% in LBW in ML, compared to offspring from ML ewes with a serum Mg concentration within the lower reference range (0.8 mmol/L). Furthermore, higher Cu levels were favorably associated with ewe BCS and BFT at weaning in both breeds. In RH ewes, a Se level > 2.4 μmol/l was significantly associated with increased BCS. In the ML breed, high Zn levels during lactation were associated with reduced CH4 emissions. Ewe EBW was significantly larger for ML ewes representing low Ca levels. A low BHB level was associated with decreasing CH4 emissions in RH and ML. Serum levels for Na, K, P, GLDH, and Fe did not significantly affect the traits of interest. Trait associations from the present study indicate the importance of the mineral supply and metabolic status of the ewe with regard to body condition, CH4 emissions, and LBW development, but depending on the breed. Identified associations might contribute to energy efficiency in sheep production systems.

Proofs for genotype by environment interactions considering pedigree and genomic data from organic and conventional cow reference populations

The aim of the present study was to prove genotype by environment interactions (G × E) for production, longevity, and health traits considering conventional and organic German Holstein dairy cattle subpopulations. The full data set included 141,778 Holstein cows from 57 conventional herds and 7,915 cows from 9 organic herds. The analyzed traits were first-lactation milk yield and fat percentage (FP), the length of productive life (LPL) and the health traits mastitis, ovarian cycle disorders, and digital dermatitis in first lactation. A subset of phenotyped cows was genotyped and used for the implementation of separate cow reference populations. After SNP quality controls, the cow reference sets considered 40,830 SNP from 19,700 conventional cows and the same 40,830 SNP from 1,282 organic cows. The proof of possible G × E was made via multiple-trait model applications, considering same traits from the conventional and organic population as different traits. In this regard, pedigree (A), genomic (G) and combined relationship (H) matrices were constructed. For the production traits, heritabilities were very similar in both organic and conventional populations (i.e., close to 0.70 for FP and close to 0.40 for milk yield). For low heritability health traits and LPL, stronger heritability fluctuations were observed, especially for digital dermatitis with 0.05 ± 0.01 (organic, A matrix) to 0.33 ± 0.04 (conventional, G matrix). Quite large genetic correlations between same traits from the 2 environments were estimated for production traits, especially for high heritability FP. For LPL, the genetic correlation was 0.67 (A matrix) and 0.66 (H matrix). The genetic correlation between LPL organic with LPL conventional was 0.94 when considering the G matrix, but only 213 genotyped cows were included. For health traits, genetic correlations were throughout lower than 0.80, indicating possible G × E. Genetic correlations from the different matrices A, G, and H for health and production traits followed the same pattern, but the estimates from G for health traits were associated with quite large standard errors. In genome-wide association studies, significantly associated SNP for production traits overlapped in the conventional and organic population. In contrast, for low heritability LPL and health traits, significantly associated SNP and annotated potential candidate genes differed in both populations. In this regard, significantly associated SNP for mastitis from conventional cows were located on Bos taurus autosomes 6 and 19, but on Bos taurus autosomes 1, 10, and 22 in the organic population. For the remaining health traits and LPL, different potential candidate genes were annotated, but the different genes reflect similar physiological pathways. We found evidence of G × E for low heritability functional traits, suggesting different breeding approaches in organic and conventional populations. Nevertheless, for a verification of results and implementation of alternative breeding strategies, it is imperative to increase the organic cow reference population.

Differential relieving effects of shikonin and its derivatives on inflammation and mucosal barrier damage caused by ulcerative colitis

Background

Ulcerative colitis (UC) is one of the most challenging human diseases. Natural shikonin (SK) and its derivatives (with have higher accumulation) isolated from the root of Lithospermum erythrorhizon have numerous beneficial effects, such as wound healing and anti-inflammatory activities. Some researchers have reported that hydroxynaphthoquinone mixture (HM) and SK attenuate the acute UC induced by dextran sulfate sodium (DSS). However, no existing study has systemically investigated the effectiveness of SK and other hydroxynaphthoquinone natural derivative monomers on UC.

Methods

In this study, mice were treated with SK and its derivatives (25 mg/kg) and mesalazine (200 mg/kg) after DSS administration daily for one week. Disease progression was monitored daily by observing the changes in clinical signs and body weight.

Results

Intragastric administration natural single naphthoquinone attenuated the malignant symptoms induced by DSS. SK or its derivatives remarkably suppressed the serum levels of pro-inflammatory cytokines while increasing the inflammatory cytokine interleukin (IL)-10 . Additionally, both SK and alkanin restrained the activities of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) in serum and colonic tissues. SK and its derivatives inhibited the activation of nucleotide binding oligomerization domain-like receptors (NLRP3) inflammasome and NF-κB signaling pathway, thereby relieving the DSS-induced disruption of epithelial tight junction (TJ) in colonic tissues.

Conclusions

Our findings shed more lights on the pharmacological efficacy of SK and its derivatives in UC against inflammation and mucosal barrier damage.

Genome-Wide Comparative Analysis of R2R3 MYB Gene Family in Populus and Salix and Identification of Male Flower Bud Development-Related Genes

The MYB transcription factor (TF) family is one of the largest plant transcription factor gene family playing vital roles in plant growth and development, including defense, cell differentiation, secondary metabolism, and responses to biotic and abiotic stresses. As a model tree species of woody plants, in recent years, the identification and functional prediction of certain MYB family members in the poplar genome have been reported. However, to date, the characterization of the gene family in the genome of the poplar's sister species willow has not been done, nor are the differences and similarities between the poplar and willow genomes understood. In this study, we conducted the first genome-wide investigation of the R2R3 MYB subfamily in the willow, identifying 216 R2R3 MYB gene members, and combined with the poplar R2R3 MYB genes, performed the first comparative analysis of R2R3 MYB genes between the poplar and willow. We identified 81 and 86 pairs of R2R3 MYB paralogs in the poplar and willow, respectively. There were 17 pairs of tandem repeat genes in the willow, indicating active duplication of willow R2R3 MYB genes. A further 166 pairs of poplar and willow orthologs were identified by collinear and synonymous analysis. The findings support the duplication of R2R3 MYB genes in the ancestral species, with most of the R2R3 MYB genes being retained during the evolutionary process. The phylogenetic trees of the R2R3 MYB genes of 10 different species were drawn. The functions of the poplar and willow R2R3 MYB genes were predicted using reported functional groupings and clustering by OrthoFinder. Identified 5 subgroups in general expanded in woody species, three subgroups were predicted to be related to lignin synthesis, and we further speculate that the other two subgroups also play a role in wood formation. We analyzed the expression patterns of the GAMYB gene of subgroup 18 (S18) related to pollen development in the male flower buds of poplar and willow at different developmental stages by qRT-PCR. The results showed that the GAMYB gene was specifically expressed in the male flower bud from pollen formation to maturity, and that the expression first increased and then decreased. Both the specificity of tissue expression specificity and conservation indicated that GAMYB played an important role in pollen development in both poplar and willow and was an ideal candidate gene for the analysis of male flower development-related functions of the two species.