Interactions of rhizosphere microbiota-environmental factors-pharmacological active ingredients of Eucommia ulmoides.

MAIN CONCLUSION: The composition, diversity and co-occurrence patterns of the rhizosphere microbiota of E. ulmoides were significantly influenced by environmental factors, and which were potentially associated with the contents of pharmacological active ingredients. Eucommia ulmoides is an important perennial medicinal plant. However, little is known about the interactions among microbiota, environmental factors (EFs), and pharmacological active ingredients (PAIs) of E. ulmoides. Herein, we analyzed the interactions among rhizosphere microbiota-EFs-PAIs of E. ulmoides by amplicon sequencing and multi-analytical approach. Our results revealed variations in the dominant genera, diversity, and co-occurrence networks of the rhizosphere microbiota of E. ulmoides across different geographical locations. Notably, available nitrogen exerted the strongest influence on fungal dominant genera, while pH significantly impacted bacterial dominant genera. Rainfall and relative humidity exhibited pronounced effects on the α-diversity of fungal groups, whereas available phosphorus influenced the number of nodes in fungal co-occurrence networks. Altitude and total phosphorus had substantial effects on the average degree and nodes in bacterial co-occurrence networks. Furthermore, the dominant genera, diversity and co-occurrence network of rhizosphere microbiota of E. ulmoides were significantly correlated with the content of PAIs. Specifically, the abundance of rhizosphere dominant genera Filobasidium, Hannaella and Nitrospira were significantly correlated with the content of pinoresinol diglucoside (PD). Similarly, the abundance of Vishniacozyma and Bradyrhizobium correlated significantly with the content of geniposidic acid (GC), while the abundance of Gemmatimonas was significantly correlated with the content of aucubin. Moreover, the bacterial co-occurrence network parameters including average degree, density, and edge, were significantly correlated with the content of GC and aucubin. The α-diversity index Chao1 also displayed a significant correlation with the content of PD. These findings contribute to a more comprehensive understanding of the interactions between medicinal plants and microbes.

A systematic discussion and comparison of the construction methods of synthetic microbial community.

Synthetic microbial community has widely concerned in the fields of agriculture, food and environment over the past few years. However, there is little consensus on the method to synthetic microbial community from construction to functional verification. Here, we review the concept, characteristics, history and applications of synthetic microbial community, summarizing several methods for synthetic microbial community construction, such as isolation culture, core microbiome mining, automated design, and gene editing. In addition, we also systematically summarized the design concepts, technological thresholds, and applicable scenarios of various construction methods, and highlighted their advantages and limitations. Ultimately, this review provides four efficient, detailed, easy-to-understand and -follow steps for synthetic microbial community construction, with major implications for agricultural practices, food production, and environmental governance.

Differential responses of the phyllosphere abundant and rare microbes of Eucommia ulmoides to phytohormones.

Phyllosphere microbiota play a crucial role in plant productivity and adaptation, and the abundant and rare microbial taxa often possess distinct characteristics and ecological functions. However, it is unclear whether the different subcommunities of phyllosphere microbiota respond variably to the factors that influence their formation, which limits the understanding of community assembly. The effects of two phytohormones, namely, indole-3-acetic acid (IAA) and N6-(delta 2-isopentenyl)-adenine (IP), on the phyllosphere microbial subcommunities of Eucommia ulmoides were investigated using potted experiments. The results demonstrated that the phytohormones induced significant variations in the composition, diversity, and function of the abundant microbial subcommunity in the phyllosphere of E. ulmoides, however, their effects on the rare subcommunity were negligible, and their effects on the moderate subcommunity were between those of the abundant and rare taxa. The phytohormones also induced significant alterations in the phenotypic and physiological properties of E. ulmoides, which indirectly affected the phyllosphere microbial community. Leaf thickness and average leaf area were the main phenotypic variables that affected the composition of the phyllosphere microbial community. The total alkaloid content and activity of superoxide dismutase (SOD) were the main physiological variables that affected the composition of the phyllosphere microbial community. The phenotypic and physiological indices of E. ulmoides explained the variations in the phyllosphere microbial subcommunities in descending order: abundant > moderate > rare taxa. These variables explained a significant proportion of the variations in the abundant taxa, and an insignificant proportion of the variations in the rare taxa. This study improves our understanding of the assembly of the phyllosphere microbiota, which provides important theoretical knowledge for future sustainable agriculture and forestry management based on the precise regulation of phyllosphere microbiota.

Generation of Thyroid Tissues From Embryonic Stem Cells via Blastocyst Complementation In Vivo.

The generation of mature, functional, thyroid follicular cells from pluripotent stem cells would potentially provide a therapeutic benefit for patients with hypothyroidism, but in vitro differentiation remains difficult. We earlier reported the in vivo generation of lung organs via blastocyst complementation in fibroblast growth factor 10 (Fgf10), compound, heterozygous mutant (Fgf10 Ex1mut/Ex3mut) mice. Fgf10 also plays an essential role in thyroid development and branching morphogenesis, but any role thereof in thyroid organogenesis remains unclear. Here, we report that the thyroids of Fgf10 Ex1mut/Ex3mut mice exhibit severe hypoplasia, and we generate thyroid tissues from mouse embryonic stem cells (ESCs) in Fgf10 Ex1mut/Ex3mut mice via blastocyst complementation. The tissues were morphologically normal and physiologically functional. The thyroid follicular cells of Fgf10 Ex1mut/Ex3mut chimeric mice were derived largely from GFP-positive mouse ESCs although the recipient cells were mixed. Thyroid generation in vivo via blastocyst complementation will aid functional thyroid regeneration.

Generation of Lungs by Blastocyst Complementation in Apneumic Fgf10-Deficient Mice.

The shortage of donor lungs hinders lung transplantation, the only definitive option for patients with end-stage lung disease. Blastocyst complementation enables the generation of transplantable organs from pluripotent stem cells (PSCs) in animal models. Pancreases and kidneys have been generated from PSCs by blastocyst complementation in rodent models. Here, we report the generation of lungs using mouse embryonic stem cells (ESCs) in apneumic Fgf10 Ex1mut/Ex3mutmice by blastocyst complementation. Complementation with ESCs enables Fgf10-deficient mice to survive to adulthood without abnormalities. Both the generated lung alveolar parenchyma and the interstitial portions, including vascular endothelial cells, vascular and parabronchial smooth muscle cells, and connective tissue, largely originate from the injected ESCs. These data suggest that Fgf10 Ex1mut/Ex3mutblastocysts provide an organ niche for lung generation and that blastocyst complementation could be a viable approach for generating whole lungs.

Trachea Engineering Using a Centrifugation Method and Mouse-Induced Pluripotent Stem Cells.

The outcomes of tracheal transplantation for the treatment of airway stenosis are unsatisfactory. We investigated the feasibility of regeneration of the trachea using a rat decellularized tracheal scaffold and mouse-induced pluripotent stem (iPS) cells for in vivo transplantation. The rat trachea was first decellularized using a detergent/enzymatic treatment method. We successfully established a centrifugation method that can transplant cells onto the luminal surface of the decellularized rat tracheal scaffold circumferentially. Two types of mouse iPS cells were differentiated into definitive endoderm cells and transplanted onto the luminal surface of the decellularized tracheal matrix scaffold using this centrifugation method. For in vivo study, normal rat tracheas, no-cell rat tracheal scaffolds, or rat tracheal scaffolds recellularized with rat tracheal epithelial cells (EGV-4T) were orthotopically transplanted on F344 rats, and rat tracheal scaffolds recellularized with mouse iPS cells were transplanted on F344/NJc1-rnu/rnu rats. Rats transplanted with no-cell scaffolds or scaffolds recellularized with EGV-4T survived for 1 month, although airway stenosis was observed. One of the F344/NJc1-rnu/rnu rats transplanted with rat trachea regenerated using mouse iPS cells survived over 5 weeks. Histological analysis indicated the cause of death was airway stenosis due to colonic cellular proliferation of undifferentiated iPS cells. Re-epithelialization with numerous ciliated epithelial cells was observed in one of the rats transplanted with trachea bioengineered using iPS cells. In this study, we present a simple and efficient tracheal tissue engineering model using a centrifugation method in a small-animal model. Tissue-engineered trachea using decellularized tracheal scaffolds and iPS cells is potentially applicable for tracheal transplantation.