1.Screening of plant growth-promoting rhizobacteria and its effect on seed germination of Polygonum multiflorum.
Chang-Zheng LIU ; Xiao-Lin JIANG ; Qi-Zhong CAI ; Liang-Yun ZHOU ; Quan YANG
China Journal of Chinese Materia Medica 2021;46(20):5247-5252
In this study, the rhizobacteria and actinomycetes of Polygonum multiflorum were screened for the strains with indole acetic acid(IAA)-producing capacity by Salkowski method, the siderophore-producing strains by Chrome Azurol S(CAS) assay, and the strains with inorganic phosphorus-solubilizing capacity by PKO inorganic phosphorus medium. The strains were identified by morphological identification, physiological and biochemical characteristics, and 16 S rDNA sequences. Furthermore, the effect of growth-promoting strains on the seed germination and development of P. multiflorum was tested. The results showed that among 196 strains, two strains F17 and F42 were found to be capable of producing IAA and siderophore and solubilizing inorganic phosphorus simulta-neously. For F17 and F42, the results are listed below: 38.65 and 33.64 mg·L~(-1) for IAA production, 0.85 and 0.49 for siderophore-producing capacities(A_s/A_r), and 1.35 and 1.70 for inorganic phosphorus-solubilizing capacities(D/d), respectively. Comprehensive analysis revealed that strains F17 and F42 were identified as Pseudochrobactrum asacharolyticum and Bacillus aryabhattai, respectively, and both could significantly promote the seed germination of P. multiflorum.
Bacillus
;
Fallopia multiflora
;
Germination
;
Seeds
;
Soil Microbiology
2.Promoting tanshinone synthesis of Salvia miltiorrhiza root by a seed endophytic fungus, Phoma herbarum D603.
Hai-Min CHEN ; Hong-Xia WU ; Xiao-Yi HE ; Hai-Hua ZHANG ; Fang MIAO ; Zong-Suo LIANG
China Journal of Chinese Materia Medica 2020;45(1):65-71
The interaction of endophytes and host plant is an effective mean to regulate the growth and secondary metabolism of medicinal plants. Here we want to elucidate the effects and mechanism of Phoma herbarum D603 on the root development and tanshinone synthesis in root of Salvia miltiorrhiza by endophyte-plant coculture system. The mycelium of P. herbarum D603 was colonized in the root tissue space, and formed a stable symbiotic relationship with host plant. The in vitro activities analysis showed that the concentration of IAA produced by D603 can reach(6.45±0.23) μg·mL~(-1), and this strain had some abilities of phosphorus solubilization and siderophore production activities. The coculture experiment showed that strain D603 can significantly promote the synthesis and accumulation of tanshinones in the root of S. miltiorrhiza, in which after 8 weeks of treatment with D603, the content of tanshinone Ⅱ_A in the roots reached up to(1.42±0.59) mg·g~(-1). By the qRT-PCR analysis results, we found that D603 could improve the expression levels of some key genes(DXR, DXS, GGPP, HMGR, CPS) of tanshinone biosynthesis pathway in host plant S. miltiorrhiza, but the promoting effect mainly occurred in the early stage of the interaction, and the enzyme activity level decreased in varying degrees of the later stage. In summary, seed-associated endophyte P. herbarum D603 can promote the growth and root development of S. miltiorrhiza by producing hormones, promoting nutrient absorption and siderophore production, and promote the synthesis and accumulation of tanshinones by regulating the expression level of key genes in the synthetic pathway in S. miltiorrhiza.
Abietanes/biosynthesis*
;
Ascomycota/growth & development*
;
Endophytes/growth & development*
;
Plant Roots/microbiology*
;
Salvia miltiorrhiza/microbiology*
;
Seeds/microbiology*
3.Callus induction and regeneration from mature seeds of indica rice minghui 63 and anti-fungal assay of transgenic rice plants.
Li-Jiang WANG ; Xiao-Tian MING ; Cheng-Cai AN ; Hua-Yi YUAN ; Zhang-Liang CHEN
Chinese Journal of Biotechnology 2002;18(3):323-326
A large number of callus from mature seeds of indica rice minghui 63 were obtained through pre-induction on medium with 2 mg/L 2,4-D but without inorganic and organic components for 9 days. Trichosanthin gene was transferred into indica rice minghui 63 by using agrobacterium with the help of bombardment and the transgenic plants were obtained by inducing regeneration. Southern and Western blot analysis showed that the trichosanthin gene had been transferred into genome of minghui 63 and expressed in rice plants. The anti-fungal assay suggested that transgenic rice plants enhanced resistance to infection of Pyricularia oryzae.
Mitosporic Fungi
;
drug effects
;
Oryza
;
genetics
;
microbiology
;
Plant Diseases
;
microbiology
;
Plants, Genetically Modified
;
Regeneration
;
Seeds
;
physiology
;
Trichosanthin
;
genetics
4.Screening and identification of GABA-producing microbes in fermentation process of Sojae Semen Praeparatum.
Jing-Jing XIONG ; Jia-Xiu REN ; Shu-Han ZHOU ; Ming-Sheng SU ; Li-Yuan WANG ; Mei-Zhi WENG ; Wei-Hua XIE ; Xiao-Mei XIE
China Journal of Chinese Materia Medica 2019;44(11):2266-2273
A high-content GABA was found in Sojae Semen Praeparatum(SSP), which is a famous traditional Chinese medicine and officially listed in Chinese Pharmacopoeia. To screen out and identify GABA-producing microbes from samples at different time points during the fermenting process of SSP, traditional microbiological methods combined with molecular biological methods were used to study the predominant GABA-producing microorganisms existing in the fermenting process of SSP. This study would lay a foundation for further studying the processing mechanism of SSP. The fermenting process of SSP was based on Chinese Pharmacopoeia(2010 edition), and samples were taken at different time points during the fermenting process of SSP. The bacteria and fungi from samples at different time points in the fermenting process of SSP were cultured, isolated and purified by selective medium, and dominant strains were selected. The dominant bacteria were cultured in the designated liquid medium to prepare the fermentation broths, and GABA in the fermentation broth was qualitatively screened out by thin-layer chromatography. The microbial fermentation broth with GABA spots in the primary screening was quantitatively detected by online pre-column derivatization and high performance liquid chromatography established in our laboratory. GABA-producing microorganisms were screened out from predominant strains, and their GABA contents in fermentation broth were determined. The DNA sequences of GABA-producing bacteria and fungi were amplified using 16S rDNA and 18S rDNA sequences by PCR respectively. The amplified products were sequenced, and the sequencing results were identified through NCBI homology comparison. Molecular biological identification was made by phylogenetic tree constructed by MEGA 7.0 software. Through the homology comparison of NCBI and the construction of phylogenetic tree by MEGA 7.0 software, nine GABA-producing microorganisms were screened out and identified in this study. They were Bacillus subtilis, Enterococcus faecium, E. avium, Aspergillus tamarii, A. flavus, A. niger, Cladosporium tenuissimum, Penicillium citrinum and Phanerochaete sordida respectively. For the first time, nine GABA-producing microorganisms were screened out and identified in the samples at different time points during the fermenting process of SSP in this study. The results indicated that multiple predominant GABA-producing microorganisms exist in the fermenting process of SSP and may play an important role in the formation of GABA.
Bacteria
;
classification
;
metabolism
;
Chromatography, High Pressure Liquid
;
Fermentation
;
Fungi
;
classification
;
metabolism
;
Phylogeny
;
Seeds
;
microbiology
;
Soybeans
;
microbiology
;
gamma-Aminobutyric Acid
;
biosynthesis
5.Investigation of aflatoxins,mycobiota,and toxigenic fungi during post-harvest handling of Ziziphi Spinosae Semen.
Xi-Mei ZHANG ; Wei-Wei GAO ; Yan-Hong HAO ; Xiao-Lin JIAO ; Bao-Lin GUO ; Ya-Lin XUE ; Jian-Ting BAI ; Zhen-Hong LEI
China Journal of Chinese Materia Medica 2019;44(10):2009-2014
Ziziphi Spinosae Semen is one of the Chinese herbal medicine being susceptible to aflatoxins contamination. To investigate the sources of aflatoxins contamination and toxigenic fungi species on Ziziphi Spinosae Semen,32 samples were collected from multiple steps during the post-harvest processing in this study. Aflatoxins in these samples were determined by immunoaffinity column and HPLC coupled with post-column photochemical derivatization. The dilution-plate method was applied to the fungi isolation. The isolated fungi strains were identified by morphological characterization and molecular approaches. The results showed that aflatoxins were detected in 28 samples from every step during the processing of Ziziphi Spinosae Semen. Three samples were detected with aflatoxin B_1 and 2 samples with both aflatoxin B_1 and total aflatoxin exceeding the limit of Chinese Pharmacopoeia. Especially the samples from the washing step,with the highest detected amounts of AFB_1 and AFs were reached 94. 79,121. 43 μg·kg~(-1),respectively. All 32 samples were contaminated by fungi. The fungal counts on the newly harvested samples were 2. 20 × 10~2 CFU·g~(-1). Moreover,it increased as tphreocessing progresses,and achieved 1. 16×10~6 CFU·g~(-1) after washing. A total of 321 isolates were identified to 17 genera. Aspergillus flavus was the main source of aflatoxins during the processing and storage of Ziziphi Spinosae Semen. One isolate of A. flavus was confirmed producing AFB_1 and AFB_2. The fungal count was significantly increased by composting,and Aspergillus was the predominant genus after shell breaking. The contamination level of aflatoxins was increased by composting and washing.
Aflatoxins
;
analysis
;
Aspergillus
;
Chromatography, High Pressure Liquid
;
Fungi
;
isolation & purification
;
Seeds
;
chemistry
;
microbiology
;
Ziziphus
;
chemistry
6.Suppression of Meloidogyne javanica by antagonistic and plant growth-promoting rhizobacteria.
Bin LI ; Guan-lin XIE ; A SOAD ; J COOSEMANS
Journal of Zhejiang University. Science. B 2005;6(6):496-501
Four rhizobacteria selected out of over 500 isolates from rhizosphere of the vegetables in China were further studied for suppression of the root-knot nematode and soil-borne fungal pathogens in laboratory and greenhouse in Belgium. They were identified as Brevibacillus brevis or Bacillus subtilis by Biolog test and partial 16s rDNA sequence comparison. They not only inhibited the radial growth of the root-infecting fungi Rhizoctonia solani SX-6, Pythium aphanidermatum ZJP-1 and Fusarium oxysporum f.sp. cucumerinum ZJF-2 in vitro, but also exhibited strong nematicidal activity by killing the second stage larvae of Meloidogyne javanica to varying degrees in the greenhouse. The toxic principles of bacterium B7 that showed the highest juvenile mortality were partially characterized. The active factors were heat stability and resistance to extreme pH values. B7 used either as seed dressing or soil drench significantly reduced the nematode populations in the rhizosphere and enhanced the growth of mungbean plants over the controls in the presence or absence of R. solani.
Alphaproteobacteria
;
physiology
;
Animals
;
Pest Control, Biological
;
methods
;
Phaseolus
;
microbiology
;
parasitology
;
Seeds
;
microbiology
;
parasitology
;
Survival Analysis
;
Survival Rate
;
Symbiosis
;
physiology
;
Tylenchoidea
;
microbiology
;
pathogenicity
7.Fungal detection of American ginseng seeds from Beijing and northeast area in China.
Guo-zhen ZHANG ; Shu-feng ZHANG
China Journal of Chinese Materia Medica 2002;27(9):658-661
OBJECTIVEThe quantity and genus of fungi on 13 samples of American ginseng seed from Beijing and Northeast area in China were detected.
METHODWashing and surface sterilization were used to isolate the fungi existed on seed surface and inside of the seed, respectively.
RESULTThe genera of the fungi in embryo and shell of the seeds mainly belonged to Fusarium spp., Alternaria spp., Penicilium spp., Cephalosporium sp., Rhizopus spp., and a small quantity of Mucor, Aspergillus, Tritroderma, Doratomyces and so on. The isolated fungal frequencies on the shell and in the embryo were 36%-100% and 40%-100% respectively.
CONCLUSIONThe fungal frequency of American ginseng seed was higher. There were significant differences among different seed samples, the main fungal genera and isolation frequency in the seed embryo were identical with the results from the seed shell.
Alternaria ; isolation & purification ; China ; Fusarium ; isolation & purification ; Mitosporic Fungi ; isolation & purification ; Panax ; classification ; microbiology ; Plants, Medicinal ; microbiology ; Rhizopus ; isolation & purification ; Seeds ; microbiology
8.Determination of aflatoxin B1, B2, G1, G2 in armeniacae semen amarum by high-performance liquid chromatography-tandem mass spectrometry.
Run-Sheng ZHENG ; Hui XU ; Wen-Li WANG ; Ruo-Ting ZHAN ; Wei-Wen CHEN
China Journal of Chinese Materia Medica 2013;38(20):3534-3538
A simple, rapid and cost-effective high-performance liquid chromatography-tandem mass spectrometry (LC-MS/ MS) method was established for simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, AFG2) in Armeniacae Semen Amarum and the application was performance in 11 samples collected from different markets, medical stores and hospitals. The sample was extracted with 84% acetonitrile/water and 250 microL extraction was directly injected into a LC-MS/MS system without further purification procedure after being redissolved with methanol. The LC separation was performed on a C18 column with a linear gradient elution program of 4 mmol x L(-1) NH4 Ac-0.1% formic acid solution and menthol as the mobile phase. Selected reaction monitoring (SRM) was used for selective determination of the four aflatoxins on a triple quadruple mass spectrometer, which was operated in positive ionization modes. All the four aflatoxins showed a good linear relationship with r > 0.999 0, the average recoveries were between 87.88% and 102.9% and the matrix effect was ranged from 90.71% to 99.30% in low, intermediate and high levels. Furthermore, the higher recovery was obtained by the method reported in this study, comparing to the cleanup procedure with the Mycosep 226 purification column. Eleven samples collected were detected and the contamination levels of the AFB1 were between 1.590-2.340 microg x kg(-1) and the AF (B1 + B2 + G1 + G2) was ranged from 2.340 to 3.340 microg x kg(-1). In summary, the developed method was suitable to detect and screen AFB1, AFB2, AFG1, AFG2 in Armeniacae Semen Amarum.
Aflatoxins
;
analysis
;
metabolism
;
Chromatography, High Pressure Liquid
;
methods
;
Drug Contamination
;
Fungi
;
metabolism
;
Prunus
;
chemistry
;
microbiology
;
Seeds
;
chemistry
;
microbiology
;
Tandem Mass Spectrometry
;
methods
9.Effects of different fungi on symbiotic seed germination of two Dendrobium species.
China Journal of Chinese Materia Medica 2014;39(17):3238-3244
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
10.Pathogenicity of fungi isolated from American ginseng seeds and bioassay of fungicides against the pathogenic fungi.
Guo-zhen ZHANG ; Shu-feng ZHANG
China Journal of Chinese Materia Medica 2004;29(2):138-141
OBJECTIVEDetect the pathogenicity of fungi isolated from American ginseng seeds and select new fungicides against the pathogenic seed-born fungi.
METHODinoculate the isolates to American ginseng seedlings to detect the pathogenicity, and seeded the hyphae disk at the center of agar plate containing chemicals to do fungicide bioassay.
RESULTFusarium sp. isolate 5 and Alternara sp. isolate 13 had pathogenicity to American ginseng seedling. Sportak had the strongest inhibition to the two isolates, Carbendazim had better inhibition and Celest had weak inhibition.
CONCLUSIONSportak and Celest could be used as efficacious candidate chemicals to treat or coat the American ginseng seeds, and substitute Carbendazim, which has been used for many years, to control the diseases occurring in seedling stage of American ginseng.
Alternaria ; drug effects ; isolation & purification ; Benzimidazoles ; pharmacology ; Carbamates ; pharmacology ; Fungicides, Industrial ; pharmacology ; Fusarium ; drug effects ; isolation & purification ; Panax ; growth & development ; microbiology ; Plants, Medicinal ; growth & development ; microbiology ; Seedlings ; growth & development ; microbiology ; Seeds ; growth & development ; microbiology