In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins.
Fungi ; drug effects ; growth & development ; physiology ; Fungicides, Industrial ; pharmacology ; Glycyrrhiza uralensis ; chemistry ; growth & development ; microbiology ; physiology ; Mycorrhizae ; drug effects ; growth & development ; physiology ; Plant Extracts ; chemistry ; Symbiosis ; drug effects

OBJECTIVEIn this review, to illustrate the resistance mechanism for pathogen insult, we discussed the role of the intestinal microbiome in promoting resistance to local gastrointestinal tract infections and to respiratory tract infections.

DATA SOURCESThe review was based on data obtained from the published research articles.

STUDY SELECTIONA total of 49 original articles were selected in accordance with our main objective to illustrate the resistance mechanism(s) by which commensal microbiota can contribute to host defense against local and systemic infections.

RESULTSDiverse microorganisms colonize human environmentally exposed surfaces such as skin, respiratory tract, and gastrointestinal tract. Co-evolution has resulted in these microbes with extensive and diverse impacts on multiple aspects of host biological functions. During the last decade, high-throughput sequencing technology developed has been applied to study commensal microbiota and their impact on host biological functions. By using pathogen recognition receptors pathway and nucleotide binding oligomerization domain-like receptors pathway, the commensal microbiome promotes resistance to local and systemic infections, respectively. To protect against the local infections, the microbiome functions contain the following: the competing for sites of colonization, direct production of inhibition molecules or depletion of nutrients needed for pathogens, and priming immune defenses against pathogen insult. At the same time, with the purpose to maintain homeostasis, the commensal bacteria can program systemic signals toward not only local tissue but also distal tissue to modify their function for infections accordingly.

CONCLUSIONSCommensal bacteria play an essential role in protecting against infections, shaping and regulating immune responses, and maintaining host immune homeostasis.

Disease Resistance ; Humans ; Infection ; microbiology ; Intestines ; microbiology ; Symbiosis ; physiology

The epiphytic orchid, Dendrobium aphyllum and D. devonianum are used as traditional Chinese medicine, and became locally endangered in recent years because of over-collection. We test the effect of inoculations of endophytic fungi FDaI7 (Tulasnella sp.), FDd1 (Epulorhiza sp. ) and FCb4 (Epulorhiza sp.), which isolated from D. aphyllum, D. denonianum and Cymbidium mannii, respectively, on artificial substrate in these two Dendrobium species. In the symbiotic germination experiment, FDaI7 and FDd1 were effective for protocorm formation and seedling development of D. aphyllum and D. denonianum separately. After 60 days, 14.46% of the D. aphyllum seeds grown to protocorms and 12.07% developed to seedlings inoculated only with FDaI7, while contrasted with 0 when inoculated the other two isolates and non-inoculation treatment. However, in D. denonianum, seeds only grown to protocorms and developed to seedlings when inoculated with FDd1, the percentages were 44.36% and 42.91% distinguishingly. High specificity was shown in symbiotic germination on artificial substrate of Dendrobium. Protocorms could further develop to seedlings within or without light when inoculated the compatible fungi. However, light condition (12/12 h Light/Dark) produced the normal seedlings, while dark condition (0/24 h L/D) produced the abnormal seedlings. These may suggest that the development of young seedlings require light based on the effective symbiotic fungi. These findings will aid in seedling production of simulation-forestry ecology cultivation, conservation and reintroduction of Dendrobium.
Basidiomycota ; classification ; physiology ; Darkness ; Dendrobium ; classification ; growth & development ; microbiology ; Germination ; Host-Pathogen Interactions ; Light ; Plants, Medicinal ; classification ; growth & development ; microbiology ; Seedlings ; growth & development ; microbiology ; radiation effects ; Seeds ; growth & development ; microbiology ; Species Specificity ; Symbiosis

S-Adenosyl-L-methionine decarboxylase (SAMDC) is a key enzyme in the polyamines biosynthesis, thus is essential for basic physiological and biochemical processes in plant. In the present study, a full length cDNA of DoSAMDC1 gene was obtained from symbiotic germinated seeds of an endangered medicinal orchid species Dendrobium officinale, using the rapid amplification of cDNA ends (RACE)-PCR technique for the first time. The full length cDNA was 1 979 bp, with three open reading frames, i.e. tiny-uORF, small-uORF and main ORF (mORF). The mORF was deduced to encode a 368 amino acid (aa) protein with a molecular mass of 40.7 kD and a theoretical isoelectric point of 5.2. The deduced DoSAMDC1 protein, without signal peptide, had two highly conserved function domains (proenzyme cleavage site and PEST domain) and a 22-aa transmembrane domain (89-110). Multiple sequence alignments and phylogenetic relationship analyses revealed DoSAMDC1 had a higher level of sequence similarity to monocot SAMDCs than those of dicot. Expression patterns using qRT-PCR analyses showed that DoSAMDC1 transcripts were expressed constitutively without significant change in the five tissues (not infected with fungi). While in the symbiotic germinated seeds, the expression level was enhanced by 2.74 fold over that in the none-germinated seeds, indicating possible involvement of the gene in symbiotic seed germination of D. officinale.
Adenosylmethionine Decarboxylase ; genetics ; isolation & purification ; Amino Acid Sequence ; Basidiomycota ; physiology ; Cloning, Molecular ; DNA, Complementary ; genetics ; Dendrobium ; enzymology ; genetics ; microbiology ; Germination ; Open Reading Frames ; Phylogeny ; Plants, Medicinal ; enzymology ; genetics ; microbiology ; Seeds ; genetics ; growth & development ; microbiology ; Sequence Alignment ; Symbiosis ; physiology

Calcium-dependent protein kinases (CDPKs) play an important regulatory role in the plantarbuscular mycorrhiza/rhizobium nodule symbiosis. However, the biological action of CDPKs in orchid mycorrhiza (OM) symbiosis remains unclear. In the present study, a CDPK encoding gene, designated as DoCPK1 (GenBank accession No. JX193703), was identified from D. officinale roots infected by an OM fungus-Mycena sp. using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, for the first time. The full length cDNA of DoCPK1 was 2137 bp in length and encoded a 534 aa protein with a molecular weight of 59.61 kD and an isoelectric point (pI) of 6.03. The deduced DoCPK1 protein contained the conserved serine/threonine-protein kinase catalytic domain and four Ca2+ binding EF hand motifs. Multiple sequence alignment demonstrated that DoCPK1 was highly homologous (85%) to the Panax ginseng PgCPK1 (ACY78680), followed by CDPKs genes from wheat, rice, and Arabidopsis (ABD98803, ADM14342, Q9ZSA2, respectively). Phylogenetic analysis showed that DoCPK1 was closely related to CDPKs genes from monocots, such as wheat, maize and rice. Real time quantitative PCR (qPCR) analysis revealed that DoCPK1 was constitutively expressed in the included tissues and the transcript levels were in the order of roots > stems > seeds > leaves. Furthermore, DoCPK1 transcripts were significantly accumulated in roots 30 d after fungal infection, with 5.16 fold compared to that of the mock roots, indicating involvement of DoCPK1 during the early interaction between D. officinale and Mycena sp., and a possible role in the symbiosis process. This study firstly provided important clues of a CDPK gene associated with OM symbiosis, and will be useful for further functional determination of the gene involving in D. officinale and Mycena sp. symbiosis.
Agaricales ; growth & development ; physiology ; Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; genetics ; Dendrobium ; enzymology ; genetics ; microbiology ; Gene Expression Regulation, Plant ; Molecular Weight ; Mycorrhizae ; growth & development ; physiology ; Phylogeny ; Plant Leaves ; enzymology ; genetics ; microbiology ; Plant Roots ; enzymology ; genetics ; microbiology ; Plant Stems ; enzymology ; genetics ; microbiology ; Plants, Medicinal ; enzymology ; genetics ; microbiology ; Protein Kinases ; genetics ; metabolism ; Seeds ; enzymology ; genetics ; microbiology ; Sequence Alignment ; Symbiosis

The existence of symbiotic relationships between Acanthamoeba and a variety of bacteria is well-documented. However, the ability of Acanthamoeba interacting with host bacterial pathogens has gained particular attention. Here, to understand the interactions of Escherichia coli K1 and E. coli K5 strains with Acanthamoeba castellanii trophozoites and cysts, association assay, invasion assay, survival assay, and the measurement of bacterial numbers from cysts were performed, and nonpathogenic E. coli K12 was also applied. The association ratio of E. coli K1 with A. castellanii was 4.3 cfu per amoeba for 1 hr but E. coli K5 with A. castellanii was 1 cfu per amoeba for 1 hr. By invasion and survival assays, E. coli K5 was recovered less than E. coli K1 but still alive inside A. castellanii. E. coli K1 and K5 survived and multiplied intracellularly in A. castellanii. The survival assay was performed under a favourable condition for 22 hr and 43 hr with the encystment of A. castellanii. Under the favourable condition for the transformation of trophozoites into cysts, E. coli K5 multiplied significantly. Moreover, the pathogenic potential of E. coli K1 from A. castellanii cysts exhibited no changes as compared with E. coli K1 from A. castellanii trophozoites. E. coli K5 was multiplied in A. castellanii trophozoites and survived in A. castellanii cysts. Therefore, this study suggests that E. coli K5 can use A. castellanii as a reservoir host or a vector for the bacterial transmission.
Acanthamoeba castellanii/*microbiology ; Animals ; Disease Reservoirs/*microbiology ; Disease Vectors ; Escherichia coli/growth & development/pathogenicity/*physiology ; Oocysts/microbiology ; Symbiosis/*physiology ; Trophozoites/microbiology

OBJECTIVETo investigate the effects of endophytic fungal elicitors on the growth and atractylodin accumulation of cell suspension cultures of Atractylodes lancea.

METHODThe endophytic fungal elicitors were added to the medium with different concentrations and culture period. Their effects on biomass, atractylodin content and relevant enzyme activities in suspension cultured cells were studied.

RESULTThe cell growth was not affected by elicitors at low concentration and obviously inhibited at high concentration. Inhibition rate reached 46.7% by 100 mg L(-1) elicitor. In addition, six strains from A. lancea, among which Rhizoctonia SP1 activity was higher, had distinctly promoted the accumulation of atractylodin. Atractylodin biosynthesis was notably promoted by 20-60 mg L(-1) Rhizoctonia SP1 elicitor. When 40 mg L(-1) Rhizoctonia SP1 elicitor was added in the medium at the 12 day, the maximum content of atractylodin was 28.06 microg L(-1) at the 21 day with 48.3% higher than that of the control and PPO, POD and CAT activities remarkably increased.

CONCLUSIONAdding the endophytic elicitors to the medium is able to be effective approaches to enhance atractylodin yield in the suspension culture cell of A. lancea.

Atractylodes ; growth & development ; microbiology ; physiology ; Cell Culture Techniques ; Cells, Cultured ; Fungi ; physiology ; Furans ; metabolism ; Symbiosis

Applications of arbuscular mycorrhizal fungi in research of medicinal plant cultivation are increased in recent years. Medicinal plants habitat is complicated and many inclusions are in root, however crop habitat is simple and few inclusions in root. So appraisal methods and key technologies about the symbiotic system of crop and arbuscular mycorrhizal fungi can't completely suitable for the symbiotic system of medicinal plants and arbuscular mycorrhizal fungi. This article discuss the appraisal methods and key technologies about the symbiotic system of medicinal plant and arbuscular mycorrhizal fungi from the isolation and identification of arbuscular mycorrhiza, and the appraisal of colonization intensity. This article provides guidance for application research of arbuscular mycorrhizal fungi in cultivation of medicinal plants.
Agriculture ; methods ; Fungi ; physiology ; Mycorrhizae ; physiology ; Plant Roots ; microbiology ; physiology ; Plants, Medicinal ; growth & development ; microbiology ; physiology ; Soil Microbiology ; Symbiosis

In previous studies, four endophytic fungi were isolated from different swollen roots of Rehmannia glutinosa. It's thought that Ceratobasidium sp. , one of the discovered endophytic fingi, was a major promoter for the growth of the roots. In this study, symbiotic experiments were performed to measure the effects of different endophytic fingi cultivated with R. glutinosa. The results showed that the R. glutinosa had significant increases in the size of roots and amount of chlorophyll cultivated with Ceratobasidium sp. And it was tested that indoleacetic acid secreted by Ceratobasidium sp. maybe the effective factor for the promotion of the growth.
Fungi ; metabolism ; physiology ; Indoleacetic Acids ; metabolism ; Plant Roots ; growth & development ; microbiology ; Rehmannia ; growth & development ; microbiology ; Symbiosis ; physiology

We isolated 30 Trichomonas vaginalis for the PCR detection from the gynecological outpatients in the Affiliated Hospital of Zhengzhou University using the specific 16s rDNA primers of Mycoplasma hominis. The results showed that there were 25 cases of Mycoplasma hominis infection, with the infection rate of 83.33%. This gave a clew that the symbiosis of Trichomonas vaginalis with Mycoplasma hominis may be of certain generality in China. We sequenced the ferredoxin gene of 10 Trichomonas vaginalis where 5 Mycoplasma hominis were positive and five negative, and found that the ferredoxin (Fd) gene of the 10 Trichomonas vaginalis were exactly the same. But compared to the genes in the GenBank, a comparative analysis of the gene revealed that there were 3 more ctg bases at the 200th position of encoding leucine, but this did not lead to changes in reading frame. The gene homology was 99%.
Amino Acid Sequence ; Base Sequence ; Female ; Ferredoxins ; genetics ; Humans ; Molecular Sequence Data ; Mycoplasma hominis ; genetics ; physiology ; Symbiosis ; genetics ; Trichomonas vaginalis ; genetics ; physiology