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.

Effects of Medicinal Plants on Fungal Community Structure and Function in Hospital Grassplot Soil.

Hospital grassplot soil is an important repository of pathogenic fungi exposed to the hospital environment, and the diffusion of these fungi-containing soil particles in the air increases the risk of nosocomial fungal infections. In this study, from the perspective of soil microbes-plant holobiont, four medicinal plants Mirabilis jalapa, Artemisia argyi, Viola philippica, and Plantago depressa were used as materials, based on ITS high-throughput amplicon sequencing and simulated pot experiments to explore the effect of medicinal plants on the fungal community in hospital grassplot soil, in order to provide a new exploration for hospital grassplot soil remediation. The results showed that the fungal community ecological guilds in primary test soil was mainly pathogen, and the abundance of animal pathogen with potential threats to human reached 61.36%. After planting medicinal plants, the composition and function of soil fungal community changed significantly. Although this change varied with plant species and growth stages, all samples collected in the pot experiment showed that the pathogen abundance decreased and the saprotroph abundance increased. In addition, 45 of the 46 core fungal genera defined in all potted samples were present in primary test soil, and many of them were human potential pathogens. These findings imply that the idea of enhancing soil quality in hospital grassplot soil by planting specific plants is feasible. However, the initial fungal community of the hospital grassplot soil has a certain stability, and it is difficult to completely eliminate the threat of pathogenic fungi by planting medicinal plants.

Assembly, Core Microbiota, and Function of the Rhizosphere Soil and Bark Microbiota in Eucommia ulmoides.

Medicinal plants are inhabited by diverse microbes in every compartment, and which play an essential role in host growth and development, nutrient absorption, synthesis of secondary metabolites, and resistance to biological and abiotic stress. However, the ecological processes that manage microbiota assembly and the phenotypic and metabolic characteristics of the core microbiota of Eucommia ulmoides remain poorly explored. Here, we systematically evaluated the effects of genotypes, compartment niches, and environmental conditions (climate, soil nutrition, and secondary metabolites) on the assembly of rhizosphere soil and bark associated bacterial communities. In addition, phenotypic and metabolic characteristics of E. ulmoides core microbiota, and their relationship with dominant taxa, rare taxa, and pharmacologically active compounds were deciphered. Results suggested that microbiota assembly along the two compartments were predominantly shaped by the environment (especially pH, relative humidity, and geniposide acid) and not by host genotype or compartment niche. There were 690 shared genera in the rhizosphere soil and bark, and the bark microbiota was mainly derived from rhizosphere soil. Core microbiota of E. ulmoides was a highly interactive "hub" microbes connecting dominant and rare taxa, and its phenotypic characteristics had a selective effect on compartment niches. Metabolic functions of the core microbiota included ammonia oxidation, nitrogen fixation, and polyhydroxybutyrate storage, which are closely related to plant growth or metabolism. Moreover, some core taxa were also significantly correlated with three active compounds. These findings provide an important scientific basis for sustainable agricultural management based on the precise regulation of the rhizosphere soil and bark microbiota of E. ulmoides.

[Community composition and ecological functional structural analysis of endophytic fungi in bark of Eucommia ulmoides in different areas].

Based on high-throughput sequencing and metagenomic technology,the community composition and ecological functions of endophytic fungi in the bark of Eucommia ulmoides from three producing areas,Fengxiang town in Zunyi county of Guizhou province,Lingyang town of Cili county of Hunan province and Mumen town of Wangcang county of Sichuan province,were analyzed. A total of110 865 effective sequences of endophytic fungi were obtained in the study. The corresponding fungal group of OTUs after clustering belonged to 3 phyla( Ascomycota,Basidiomycota,Zygomycota),10 classes,25 orders,41 families,57 genera and 74 species. Among them,the dominant genera of Sichuan Wangcang Bark of E. ulmoides( EWP) was an unclassified genus in the Nectriaceae of the Crimsonaceae,with a relative abundance of 54. 79%; The dominant species of Hunan Cili Bark of E. ulmoides( ECP) was the unclassified genus of Ascomycota,with a relative abundance of 39. 97% and the dominant species of Guizhou Zunyi bark( EZP) was Lophiostoma,and its relative abundance was 47. 07%. The analysis of α diversity indicated that the shannon diversity index of endophytic fungi from different places was as follows: ECP: 1. 340 2>EZP: 1. 380 4 > EWP: 1. 168 3. The simpson diversity index was: EWP( 0. 427 3) >EZP( 0. 332 5) > ECP( 0. 313 6). FUNGuild software platform analysis displayed that endophytic fungi of E. ulmoides bark from three producing areas contained the following 14 functional groups: plant pathogen,animal pathogen and endophyte et al.,the number of functional groups in the 3 samples of E. ulmoides reached up 8 genera and exceeded one half of the total number. Correlation analysis of Canonical correspondence analysis( CCA) between endophytic fungal community diversity and four active compounds of E. ulmoides were analyzed,the results showed that the contents of pinoresinol diglucoside and chlorogenic acid,to a certain extend,had a positive correlation with an unclassified genus of Davidiellaceae,Mortierella,Chaetomium and Pestalotiopsis from the endophytic fungi in EWP sample.

Effect of synergistic inducement on the production of laccase by a novel Shiraia bambusicola strain GZ11K2.

In this study, an easily detectable method was employed for screening laccase-producing microorganisms by using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) as laccase secretion indicator. A novel laccase-producing strain was isolated and identified as Shiraia bambusicola Henn. strain GZ11K2 according to the morphological characteristics and the comparison of internal transcribed spacer ribosomal DNA gene sequences. In further investigation, the production of laccase by S. bambusicola GZ11K2 was greatly enhanced by the nontoxic inducers of copper sulfate and rhodamine B. Copper and rhodamine B were added into the cultivation medium at 24 and 12 h, respectively, and the maximum laccase production was obtained. Under the induction of 2.0 mM copper sulfate and 35 µM rhodamine B, an increment of about 80 times of laccase activity compared with that in the inducer-free medium and about 20 times compared with that in the single copper-supplemented medium was observed. Compared with other species, S. bambusicola GZ11K2 exhibits better laccase-producing characteristics with an activity of 16,400 U/L after 108 h, suggesting its potential ability for industrial application.

[Cluster analysis on hypocrellin A content in anamorphs of Shiraia bambusicola].

OBJECTIVE: By examining the colony growth rate, colony texture, substrate mycelium color and separation method of 40 anamorph strains of Shiraia bambusicola to investigate the relationship between these indexes and content of hypocrellin A. METHOD: In UV-spectrophotometry and microscopic observation were applied in the experiments. The results were analyzed by the clustering and variance analysis. RESULT: SPSS clustering analysis showed that the colony characters of S. bambusicola anamorph strains had significant differences with hypocrellin A content. CONCLUSION: In the tested conditions, substrate mycelium color of S. bambusicola anamophs has the most distinct correlation with the yield of hypocrellin A.

[Isolation and determination of anamorph of Shiraia bambusicola].

OBJECTIVE: To isolate and identify the anamorph of Shiraia bambusicola. METHOD: Fungus strains were isolated from mature ascospores and stroma. They were identified by means of morphological identification including colony and microscope characteristic, the molecular identification was done by 5.8S-ITS rDNA. RESULT: The strains GZDXIFR-171 and GZDXIFR-181 were isolated and obtained with the separation of different methods, which had the same colony morphology. With the universal primers of the ITS1-5.8S rDNA-ITS2, the 5.8S-ITS rDNA sequence of GZDXIFR-171 and GZDXIFR-181 were obtained by the PCR amplification and sequencing. Compared with the published nucleotide sequence of 5.8S-ITS rDNA in NCBI (National Center for Biotechnology Information), GZDXIFR-171 and GZDXIFR-181 were highly identical with S. bambusicola. CONCLUSION: The isolated strains GZDXIFR-171 and GZDXIFR-181 were confirmed to be the true anamorph of S. bambusicola.