In this study, eight-month-old ectomycorrhizae of Tuber borchii with Corylus avellana were synthesized to explore the influence of T. borchii colonization on the soil properties and the microbial communities associated with C. avellana during the early symbiotic stage. The results showed that the bacterial richness and diversity in the ectomycorrhizae were significantly higher than those in the control roots, whereas the fungal diversity was not changed in response to T. borchii colonization. Tuber was the dominant taxon (82.97%) in ectomycorrhizae. Some pathogenic fungi, including Ilyonectria and Podospora, and other competitive mycorrhizal fungi, such as Hymenochaete, had significantly lower abundance in the T. borchii inoculation treatment. It was found that the ectomycorrhizae of C. avellana contained some more abundant bacterial genera (e.g., Rhizobium, Pedomicrobium, Ilumatobacter, Streptomyces, and Geobacillus) and fungal genera (e.g., Trechispora and Humicola) than the control roots. The properties of rhizosphere soils were also changed by T. borchii colonization, like available nitrogen, available phosphorus and exchangeable magnesium, which indicated a feedback effect of mycorrhizal synthesis on soil properties. Overall, this work highlighted the interactions between the symbionts and the microbes present in the host, which shed light on our understanding of the ecological functions of T. borchii and facilitate its commercial cultivation.
Colon ; Corylus ; Fungi ; Magnesium ; Mycorrhizae ; Nitrogen ; Phosphorus ; Podospora ; Rhizobium ; Rhizosphere ; Soil ; Streptomyces

Agriculture ; Bibliography as Topic ; China ; Humans ; Rhizobium ; growth & development ; metabolism ; Soil Microbiology

The cis-epoxysuccinate hydrolase (CESH) from Rhizobium strain BK-20 is the key enzyme for L(+)-tartaric acid production. To establish a highly efficient and stable production process, we first optimized the enzyme production from Rhizobium strain BK-20, and then developed an immobilized cell-culture process for sustained production of L(+)-tartaric acid. The enzyme activity of free cells reached (3 498.0 +/- 142.6) U/g, and increased by 643% after optimization. The enzyme activity of immobilized cells reached (2 817.2 +/- 226.7) U/g, under the optimal condition with sodium alginate as carrier, cell concentration at 10% (W/V) and gel concentration at 1.5% (W/V). The immobilized cells preserved high enzyme activity and normal structure after 10 repeated batches. The conversion rate of the substrate was more than 98%, indicating its excellent production stability.
Alginates ; chemistry ; Cells, Immobilized ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Hydrolases ; metabolism ; Rhizobium ; enzymology ; metabolism ; Tartrates ; metabolism

To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%.
Agrobacterium ; Chromatography, Thin Layer ; Culture Media ; Dianthus ; growth & development ; Plant Growth Regulators ; Plant Leaves ; Plant Roots ; growth & development ; Plants, Genetically Modified ; Rhizobium ; Tissue Culture Techniques ; Transformation, Genetic

Two strains of bean rhizobia, Rhizobium vigna 01 (slow-growing Rhizobium) and Rh. vigna 03 (fast-growing Rhizobium), were adopted to study allelopathic effect of artemisinin on the rhizobia. The results showed a significant inhibition of the reproduction and growth of rhizobium by artemisinin. After about 8 hours by adding 40 mg x L(-1) artemisinin into the culture medium, the number of rhizobia was less than half of those in normal culture. The utilization of sucrose and glucose by rhizobia decreased significantly as the concentration of artemisinin increased in the culture medium, which could be one of the main reasons for the inhibition of reproduction and growth of rhizobia by artemisinin. In addition, the activities of extracellular protease and acid phosphatase released from rhizobia decreased significantly as the concentrations of artemisinin increased. Artemisinin refluxed from Artemisia annua could thus inhibit the formation of root nodules and interfered with energy supply and reception between bacteroid and host cells. y = e(-ax) + b reflected the relationships between nitrogenase activities (y) and concentrations of artemisinin (x). In the culture medium with 48 mg x L(-1) of artemisinin, nitrogenase activities were about zero, resulting in the inactivation of nitrogenase in nodules formed. In general, artemisin in A. annua grown soils may inhibit the reproduction and growth of rhizobia, nodule formation and nitrogen biofixation, leading to less nitrogen supply, poor growth and development, and low yields of beans.
Acid Phosphatase ; metabolism ; Artemisinins ; pharmacology ; Carbon ; metabolism ; Peptide Hydrolases ; metabolism ; Rhizobium ; drug effects ; growth & development

OBJECTIVETo establish a culture system for Psammosilene tunicoides hairy roots, and provide technological aid for the large-scale production of P. tunicoides material.

METHODThe young leaves and stem segments of sterile plantlets were infected with ACCC10060 strain, and subsequently a culture system suitable for hairy roots growth was further established.

RESULTWhen explants were co-cultured with ACCC10060 (A600 0.8) on B5 media containing 20 mg x L(-1) Acetosyringo (AS) for 48 h, the hairy roots could be successfully induced, and it could achieve a higher induction rate using young leaves as explants than that of stem segments. The transfected hairy roots possessed the ability of kanamycin resistance and growth on hormone-free media, and synthesis of opines. All above results demonstrated that the present hairy roots originated in the infection of P. tunicoides tissues by ACCC10060 strains. After 35 d culture in liquid hormone-free MS (1/2 strength), the biomass of hairy roots increased 14.11 times (fresh weight) and 8. 39 times (dry weight), respectively, and the content of total saponins in hairy roots reached to 0.857% (DW), by contrast, it's only 0.388% and 0.217% in callus and seedlings respectively.

CONCLUSIONEstablishment of hairy roots culture of P. tunicoides provided a foundation for industrial production of active components from P. tunicoides culture.

Biomass ; Caryophyllaceae ; growth & development ; microbiology ; Culture Techniques ; Plant Roots ; growth & development ; microbiology ; Rhizobium ; physiology ; Saponins ; analysis

To study the possibilities for improvement of the ornamental character and production of secondary metabolites by using Wedelia trilobata hairy roots, we investigated the induction of W. trilobata L. hairy roots and its consumption changes of carbon resource, nitrogen resource, phosphate and calcium in the medium during liquid culture. The results showed that hairy roots could be incited from the cut edges of leaf explants 7 days after inoculation with Agrobacterium rhizogenes ATCC15834 and could have an autonomous growth on the medium without phytohormones. The PCR amplification showed that rol genes of Ri plasmid of A. rhizogenes was integrated and expressed into the genome of transformed hairy roots. The hairy root line grew very slowly in 0-7 days, very fast from 7 to 21 days. During the liquid culture of hairy roots, sucrose, NO3(-)-N, PO4(3-) and Ca2+ in the medium could be gradually absorbed and utilized with time. The content of NO3(-)-N in the medium was 5.8% of the initial amount at day 7, while sucrose content was about 50% of the initial amount. At day 35, the NO3(-)-N and sucrose content in the medium was 1.82% and 3.39% of the initial amount, respectively. In combination with Ca2+ consumption, PO4(3-) of the medium was rapidly absorbed and utilized. At day 7, the content of PO4(3-) in the spent medium was only 1.76% of the initial amount; but even at day 35, the content of Ca2+ in the spent medium was still 61.3% of the initial amount. The results presented here had provided the possibilities on improvement the ornamental character and how to prepare optimum medium for large scale cultivation and production of secondary metabolites from W. trilobata L. hairy roots.
Culture Techniques ; methods ; Plant Roots ; cytology ; growth & development ; Plants, Genetically Modified ; genetics ; growth & development ; metabolism ; Rhizobium ; genetics ; physiology ; Transformation, Genetic ; Wedelia ; genetics ; growth & development ; microbiology

Recently, more research about the plant bioreactor expressing genes encoding human proteins was reported. In the present study, the cDNA of the human gene keratinocyte growth factor 2 (KGF2) was replaced with plant preferred codons by PCR, and the modified full-length cDNA was cloned into the plant expression vector pCAMBIA-YO containing the oil-body promoter. The fusion construct pCAMBIA-YO-KGF2 was transformed into Brassica napus by Agrobacterium tumefacien-mediated cotyledon transformation method. The transgenic seedlings were identified by PCR, Southern and western blot analysis all showed that KGF2 gene was successfully expressed in in transgenic Brassica napus.
Brassica napus ; genetics ; metabolism ; Cloning, Molecular ; DNA, Complementary ; genetics ; Fibroblast Growth Factor 7 ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Plants, Genetically Modified ; genetics ; Rhizobium ; genetics ; Transformation, Genetic

Rhizobium species, aerobic Gram-negative rods found in soils worldwide, are well-known tumor-inducing pathogens in plants. Since 1980, when the first case of prosthetic valve endocarditis caused by Rhizobium radiobacter was reported, R. radiobacter has been recognized as an opportunistic human pathogen. In Korea, three cases of infection by this organism have been reported. Recently, we experienced a case of R. radiobacter bacteremia in a patient who underwent chemotherapy for lymphoma. Here, we report the case with a review of the literature.
Agrobacterium tumefaciens ; Bacteremia ; Endocarditis ; Humans ; Korea ; Lymphoma ; Rhizobium ; Soil

A system for the Agrobacterium rhizogenes-mediated transformation and plant regeneration of A. venetum has been developed. The highest transformation frequency was 100%, achieved by using strain LBA9402 with root explants. The highest density of hairy roots reached 22 when root explants transformed by R1000 cultured in the dark. Adventitious shoots were obtained from profusely branched, fast-growing (type PBF) hairy roots, and the adventitious shoot induction frequency was 20%. Regenerated shoots rooted easily on hormone-free 1/2 MS solid medium in 2 weeks. Approximately 1/3 regenerated plants derived from hairy roots exhibited prolific roots with shortened internodes. Whereas other regenerated plants showed another phenotype: long intemodes, strong stems, and fleshy blades. However, all regenerated plants displayed a relatively fast development procedure and stronger than the aseptic seedlings. Polymerase chain reaction (PCR) analyses confirmed the hairy root lines and regenerated plants were induced by A. rhizogenes.
Apocynum ; genetics ; growth & development ; Plant Roots ; growth & development ; Regeneration ; Rhizobium ; genetics ; Tissue Culture Techniques ; Transformation, Genetic