Transformation of Ginkgo Hairy Root and Establishment of Its Suspension Culture Clone

Tender leaves,buds and stems of ginkgo biloba L .were transformed successfully by Agrobacterium rhizogenes with Ri plasmid,and its suspension cultured clone was eastablished.The result of detection of opines suggested that A.rhizogenes had integrated the T DNA of the Ri plasmid into genomic DNA of ginkgo cells.A new way is offered to exploit ginkgo resources with biological technology.

Studies on Biological Characteristics of Ginkgo Hairy Root Culture

The comparative studies on properties of growth and cultivated conditions of seven transformed ginkgo hairy root clones were reported. Different clones display various phenotypes characterized by growth rate.The results show that the suitable inoculum is benefical to the growth of ginkgo hairy root.NH + 4/NO - 3, pH ,sucrose, and inositol have important effects on the growth of ginkgo hairy root.

Development of a rapid and efficient system for CR genes identification based on hairy root transformation in Brassicaceae

Many economically important crops and vegetables belonging to the cruciferous family are heavily endangered by clubroot disease caused by Plasmodiophora brassicae infection.Breeding of clubroot resistant cultivars based on mapping and cloning of resistant genes is commonly regarded as the most cost-effective and efficient way to fight against this disease.The traditional way of R gene functional validation requires stable transformation that is both time-and labor-consuming.In this study,a rapid and efficient hairy-root transgenic protocol mediated by Agrobacterium rhizogenes was developed.The transformation positive rate was over 80%in Brassica napus showed by GUS reporter gene and this transformation only took 1/6 of the time compared with stable transformation.The system was applicable to different B.napus varieties and other cruciferous crops including Brassica rapa and Brassica oleracea.In particular,two known CR genes,CRA3.7.1 and CRA8.2.4 were used respectively,as example to show that the system works well for CR gene study combined with subsequent P.brassicae infection in B.napus.Most importantly,it works both in over-expression that led to disease resistance,as well as in RNAi which led to disease susceptible phenotype.Therefore,this system can be used in batch-wise identification of CR genes,and also offered the possibility of manipulating key genes within the P.brassicae genome that could improve our knowledge on host-pathogen interaction.

In Vitro and in Silico Insights on the Biological Activities, Phenolic Compounds Composition of Hypericum perforatum L. Hairy Root Cultures

Three Hypericum perforatum hairy root lines(HR B,HR F and HR H)along with non-transformed roots were analyzed for phenolic compounds composition and in vitro enzyme inhibitory properties.In silico molecular modeling was performed to predict the interactions of the most representative phenolic compounds in HR clones with enzymes related to depression,neurodegeneration and diabetes.Chromatographic analyses revealed that HR clones represent an efficient source of quinic acid and hydroxybenzoic acids,epicatechin and procyanidin derivatives,quercetin and kaempferol glycosides,as well numerous xanthones.In vitro antidepressant activity of HR extracts through monoamine oxidase A(MAO-A)inhibition was attributed to the production of oxygenated and prenylated xanthones.The neuroprotective potential of HR extracts was related to the accumulation of quercetin 6-C-glucoside,epicatechin,procyanidins andγ-mangostin isomers as potential inhibitors of acetylcholinesterase(AChE)and butyrylcholinesterase(BChE).Vanillic acid and prenylated xanthones in HR clones as promising inhibitors of tyrosinase additionally contributed to the neuroprotective activity.Five preeminent xanthones in HR(γ-mangostin,mangiferin,garcinone C,garcinone E and 1,3,7-trihydroxy-6-metoxy-8-prenyl xanthone)along with the flavonol quercetin 6-C-glucoside effectively inhibitedα-amylase andα-glucosidase indicating the antidiabetic properties of HR extracts.Transgenic roots of H.perforatum can be exploited for the preparation of novel phytoproducts with multi-biological activities.

Effects of Fungal Elicitors on Cell Growth and Artemisinin Accumulation in Hairy Root Cultures of Artemisia annua

The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment.

Effect of EuCl_3 on Hairy Root Growth of Cassia Obtusifolia and Production of Its Active Principle

Treated with extremely low EuCl 3 (0 001, 0 01, 1 0 mg·L -1 ) in MS medium, the hairy root growth of Cassia obtusifolia was inhibited. The inhibition was strongest at the treatment with 0 001 mg·L -1 EuCl 3, and the dry weight of hairy roots was 22% lower than that of control. Treated with rather low EuCl 3 (10 mg·L -1 ) in Murashige and Skoog(MS) medium, the hairy root growth was enhanced, and the dry weight of hairy roots was 27% higher than that of control. In the each treatment with 0 001 to 1 0 mg·L -1 EuCl 3 in MS medium, the total content of six free anthraquinones was lower than that of control. While treated with 10 mg·L -1 EuCl 3, the total content of six free anthraquinones was 26% higher than that of control, 97% higher than the treatment of 1 0 g·L -1 EuCl 3. Treatment with 10 mg·L -1 EuCl 3 in MS medium enhances the growth of hairy root of Cassia obtusifolia and improves the total content and production of six free anthraquinones in them.

Biotransformation of Artemisinin by Hairy Root Cultures of Rheum palmatum L.

The biotransformation of artemisinin by hairy root cultures ofRheum palmatum L. was investigated for the first time. The main product, deoxyartemisinin, was isolated and characterized on the basis of its spectral data.

Gm NAC15 overexpression in hairy roots enhances salt tolerance in soybean

The NAC （NAM, ATAF1/2 and CUC2） transcription factor family plays a key role in plant development and responses to abiotic stress. GmNAC15 （Glyma 15g40510.1）, a member of the NAC transcription factor family in soybean, was functionally characterized, especially with regard to its role in salt tolerance. In the present study, qRT-PCR （quantitative reverse transcription PCR） analysis indicated that GmNAC15 was induced by salt, drought, low temperature stress, and ABA treatment in roots and leaves. GmNAC15 overexpression in soybean （Glycine max） hairy roots enhanced salt tolerance. Transgenic hairy roots improved the survival of wild leaves; however, overexpression of GmNAC15 in hairy root couldn＇t influnce the expression level of GmNAC15 in leaf. GmNAC15 regulates the expression levels of genes responsive to salt stress. Altogether, these results provide experimental evidence of the positive effect of GmNAC15 on salt tolerance in soybean and the potential application of genetic manipulation to enhance the salt tolerance of important crops.

Two new coumarin glucosides biosynthesized by transgenic hairy roots of Polygonum multiflorum

The glycosylation of hydroxylcoumarin was investigated by using suspension cultures of hairy roots of Polygonum multiflorum. Two new coumarin glucosides （3 and 4） were biosysthesized by regioselectively glycosylation of corresponding substrates （1 and 2） in the system. The structures of two products were identified as 7-hydroxy-4-methylcoumarin 5-O-β-D-glucopyranoside and 7- hydroxy-3,4-dimethylcoumarin 5-O-β-D-glucopyranoside on the ground of chemical and spectroscopic methods, respectively. 2007 Rong Min Yu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Overexpression of GmBIN2,a soybean glycogen synthase kinase 3 gene,enhances tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots

Glycogen synthase kinase 3 （GSK3） is a kind of sedne/threonine kinase widely found in eukaryotes. Many plant GSK3 kinases play important roles in regulating stress responses. This study investigated BRASSINOSTEROID-INSENSITIVE 2 （GmBIN2） gene, a member of the GSK3 protein kinase family in soybean and an orthologue of Arabidopsis BIN2/AtSK21. GmBIN2 expression was increased by salt and drought stresses, but was not significantly affected by the ABA treatment. To examine the function of GrnBIN2, transgenic Arabidopsis and transgenic soybean hairy roots were generated. Overexpression of GmBIN2 in Arabidopsis resulted in increased germination rate and root length compared with wild-type plants under salt and mannitol treatments. Overexpression of GmBIN2 increased cellular Ca2~ content and reduced Na~ content, enhancing salt tolerance in transgenic Arabidopsis plants. In the soybean hairy root assay, overexpression of GmBIN2 in transgenic roots also showed significantly higher relative root growth rate than the control when subjected to salt and mannitol treatments. Measurement of physiological indicators, including proline content, superoxide dismutase （SOD） activity, and relative electrical conductivity, supported this conclusion. Furthermore, we also found that GmBIN2 could up-regulate the expression of some stress-related genes in transgenic Arabidopsis and soybean hairy roots. Overall, these results indicated that GmBIN2 improved tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots.

Regeneration of plants from callus tissues of hairy roots induced by Agrobacterium rhizogenes on Alhagi pseudoalhagi

The legume forage Alhagi pseudoalhagi was transformed by the Agrobacterium rhizogenes strain A4 using cotyledon and hypocotyl segments as infection materials. Regenerated plants were achieved from sterile calli derived from hairy roots, which occurred at or near the infection sites. The regenerated plants from hairy root were characterized by normal leaf morphology and stem growth but a shallow and more extensive root system than normal plants. Opine synthesis, PCR and Southern blot confirmed that T- DNA had been integrated into the A. pseudoalhagi genome. Acetosyringone (AS) was found to be vital for successful transformation of A. pseudoalhagi.

Effects of Rare Earth Elements on Promoting Isoflavonoid Production and Release of Pueraria Lobata Hairy Roots in Vitro

The effects of various rare earth elements on growth and isoflavonoid production in hairy root cultures of Pueraria lobata (Willd.) Ohwi (strain TR2) cultured in 500 ml flasks were studied. After 32 days of culture, the biomass of hairy roots increase 15 times and reach 3.2 g dry weight. Hairy root growth was inhibited by Y_2O_3, NaSeO_3 and Sm^(3+) because of brown formation. But significant promoting effect on root growth due to callus formation was observed in La^(3+) treatments. It is the most noteworthy that the production of total isoflavonoids and puerarin was enhanced greatly by La^(3+) treatment. A major portion of increased total isoflavonoids and puerarin was released into medium in La^(3+) treatment while the hairy root viabilities were preserved. Some specific secondary metabolite release processes could be induced by La^(3+) and their possible mechanism is discussed.

Ficus carica hairy roots:In vitro anti-leishmanial activity against Leishmania major promastigotes and amastigotes

Objective:To investigate the biochemical capacity,and in vitro inhibitory effects of hairy roots from two cultivars of Ficus carica L.(Sabz and Siah)on Leishmania major promastigotes and amastigotes.Methods:In the hairy roots,the activity of antioxidant enzymes compared to normal leaves and roots,and the presence of some phenolic compounds in comparison with fruits were investigated.The IC_(50) values of hairy roots in promastigotes was determined by tetrazolium-dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trypan blue assays.By calculating the infectivity index of peripheral blood mononuclear cells(PBMCs),the leishmanicidal activity(IC_(50) values)of hairy roots for amastigotes was estimated.The effects of hairy roots(IC_(50) values)treatment on the levels of IFN-γ and iNOS expression,intracellular reactive oxygen species,and iNOS protein expression in infected-PBMCs were determined.Results:Based on antioxidant enzyme assays and high performance liquid chromatography analysis,hairy roots exhibited high antioxidant capacity and contained high levels of phenolic compounds.According to the results of tetrazolium-dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trypan blue assays,the hairy root extracts of both cultivars showed considerable dose-dependent inhibitory effects against Leishmania major promastigotes.Depending on the concentration and exposure time,treatment of infected-PBMCs with hairy root extracts caused the generation of a significant reactive oxygen species,up-regulation of IFN-γ and iNOS genes expression,and high value of iNOS protein compared to controls.Conclusions:The findings of this study suggest that the hairy roots of Ficus carica can be considered as a promising natural source of antileishmanial agents.

Establishment of Rhodiola quadrifida Hairy Roots and Callus Culture to Produce Bioactive Compounds

Rhodiola quadrifida is a rare mountain medicinal plant whose root extracts are used in traditional Chinese medicine as a hemostatic,antitussive,and tonic in the treatment of gynecological diseases.The aim of the study was to obtain R.quadrifida cultures at different degrees of differentiation in vitro and compare their growth characteristics and the content of salidroside and rosavin.Hairy roots were obtained by incubating cotyledons and hypocotyls in a suspension of Agrobacterium rhizogenes strain A4.The presence of the rolB and rolC genes was proven by polymerase chain reaction.The obtained roots were cultivated in Murashige-Skoog medium(MS).Calluses were obtained from the hairy roots in MS medium with the addition of hormones:3 mg/L 2,4 D and 0.5 mg/L BAP.The presence of the main secondary metabolites of R.quadrifida,salidroside and rosavin,in calluses and salidroside in hairy roots by HPLC/MS was confirmed.The content of salidroside in callus culture was significantly higher than in hairy roots,0.158 and 0.047%,respectively.The content of rosavin in callus culture was 0.07%.The content of rosavin and salidroside in callus culture was close to the level of these substances in the rhizomes of R.quadrifida plants growing in vivo,making this culture promising for its possible biotechnological use.

Hairy Root Induction in Helicteres isora L.and Production of Diosgenin in Hairy Roots

Mature seeds of Helicteres isora L.were collected from seven geographical locations of Maharashtra and Goa(India)and evaluated for diosgenin(a bioactive steroidal sapogenin of prime importance)extraction and quantification.Chemotypic variations were evidenced with diosgenin quantity ranging from 33 lg g^(-1)seeds(Osmanabad forests)to 138 lg g^(-1)(Khopoli region).Nodal and leaf explants from in vitro-raised seedlings were used for callus and Agrobacterium-mediated transformation,respectively.Compact,hard,whitish-green callus(2.65 g explant-1)was obtained on MS?13.32 lM BAP?2.32 lM Kin after 30 days of inoculation.Various parameters including types of explant and Agrobacterium strain,culture density,duration of infection and various medium compositions were optimized for hairy root production.A.rhizogenes strain ATCC-15834 successfully induced hairy roots from leaf explants(1 cm2)with 42%efficiency.Transgenic status of the roots was confirmed by PCR using rolB and VirD specific primers.Hairy roots showed an ability to synthesize diosgenin.Diosgenin yield was increased*8 times in hairy roots and*5 times in callus than the seeds of wild plants.Enhanced diosgenin content was associated with proline accumulation in hairy roots.This is the first report on induction of hairy roots in H.isora.

Rapid,Efficient and High-Performance Protocol for Agrobacterium rhizogenes-Mediated Hairy Root Transformation of the Common Bean Phaseolus vulgaris

A rapid, efficient and high-performance transformation protocol employing Agrobacterium rhizogenes was developed for the common bean Phaseolus vulgaris. In this study, we examined competencies of various protocols to induce and explants that respond to hairy root transformation in bean plants. Utilizing young seedlings with severed radicles/hypocotyls, we developed a highly efficient procedure for achieving hairy root transformation frequencies as high as 100% as visualized by GUS reporter gene expression system. Transgenic hairy roots in these young composite plants were susceptible to nodulation by rhizobia, and form an excellent system for high throughput genomic analysis to study root biology and endosymbiosis in common bean.

Development of a single transcript CRISPR/Cas9 toolkit for efficient genome editing in autotetraploid alfalfa

Alfalfa(Medicago sativa.L.)is a globally significant autotetraploid legume forage crop.However,despite its importance,establishing efficient gene editing systems for cultivated alfalfa remains a formidable challenge.In this study,we pioneered the development of a highly effective ultrasonic-assisted leaf disc transformation system for Gongnong 1 alfalfa,a variety widely cultivated in Northeast China.Subsequently,we created a single transcript CRISPR/Cas9(CRISPR_2.0)toolkit,incorporating multiplex gRNAs,designed for gene editing in Gongnong 1.Both Cas9 and gRNA scaffolds were under the control of the Arabidopsis ubiquitin-10 promoter,a widely employed polymeraseⅡconstitutive promoter known for strong transgene expression in dicots.To assess the toolkit’s efficiency,we targeted PALM1,a gene associated with a recognizable multifoliate phenotype.Utilizing the CRISPR_2.0 toolkit,we directed PALM1 editing at two sites in the wild-type Gongnong 1.Results indicated a 35.1%occurrence of editing events all in target 2 alleles,while no mutations were detected at target 1 in the transgenic-positive lines.To explore more efficient sgRNAs,we developed a rapid,reliable screening system based on Agrobacterium rhizogenes-mediated hairy root transformation,incorporating the visible reporter MtLAP1.This screening system demonstrated that most purple visible hairy roots underwent gene editing.Notably,sgRNA3,with an 83.0%editing efficiency,was selected using the visible hairy root system.As anticipated,tetra-allelic homozygous palm1 mutations exhibited a clear multifoliate phenotype.These palm1 lines demonstrated an average crude protein yield increase of 21.5%compared to trifoliolate alfalfa.Our findings highlight the modified CRISPR_2.0 system as a highly efficient and robust gene editing tool for autotetraploid alfalfa.

Development of an Agrobacterium-mediated CRISPR/Cas9 gene editing system in jute(Corchorus capsularis)

Jute(Corchorus capsularis L.)is the second most important natural plant fiber source after cotton.However,developing an efficient gene editing system for jute remains a challenge.In this study,the transgenic hairy root system mediated by Agrobacterium rhizogenes strain K599 was developed for Meifeng 4,an elite jute variety widely cultivated in China.The transgenic hairy root system for jute was verified by subcellular localization and bimolecular fluorescence complementation(BiFC)assays.The CHLOROPLASTOS ALTERADOS 1(CcCLA1)gene,which is involved in the development of chloroplasts,was targeted for editing at two sites in Meifeng 4.Based on this hairy root transformation,the gRNA scaffold was placed under the control of cotton ubiquitin GhU6.7 and-GhU6.9 promoters,respectively,to assess the efficiency of gene editing.Results indicated the 50.0%(GhU6.7)and 38.5%(GhU6.9)editing events in the target 2 alleles(gRNA2),but no mutation was detected in the target 1 allele(gRNA1)in transgenic-positive hairy roots.CcCLA1 gene editing at gRNA2 under the control of GhU6.7 in Meifeng 4 was also carried out by Agrobacterium tumefaciens-mediated transformation.Two CcCLA1 mutants were albinic,with a gene editing efficiency of 5.3%.These findings confirm that the CRISPR/Cas9 system,incorporating promoter GhU6.7,can be used as a gene editing tool for jute.

Transcriptome-Wide Identification and Functional Analysis of PgSQE08-01 Gene in Ginsenoside Biosynthesis in Panax ginseng C.A.Mey.

Panax ginseng C.A.Mey.is an important plant species used in traditional Chinese medicine,whose primary active ingredient is a ginsenoside.Ginsenoside biosynthesis is not only regulated by transcription factors but also controlled by a variety of structural genes.Nonetheless,the molecular mechanism underlying ginsenoside biosynthesis has always been a topic in the discussion of ginseng secondary metabolites.Squalene epoxidase(SQE)is a key enzyme in the mevalonic acid pathway,which affects the biosynthesis of secondary metabolites such as terpenoid.Using ginseng transcriptome,expression,and ginsenoside content databases,this study employed bioinformatic methods to systematically analyze the genes encoding SQE in ginseng.We first selected six PgSQE candidates that were closely involved in ginsenoside biosynthesis and then identified PgSQE08-01 to be highly associated with ginsenoside biosynthesis.Next,we constructed the overexpression vector pCAMBIA3301-PgSQE08-01 and the RNAi vector pART27-PgSQE08-01 and transformed ginseng adventitious roots using Agrobacterium rhizogenes,to obtain positive hairy-root clones.Thereafter,quantitative reverse transcriptionpolymerase chain reaction and high-performance liquid chromatography were used to determine the expression of relevant genes and ginsenoside content,respectively.Then,we focused on the function of PgSQE08-01 gene,which was noted to be involved in ginsenoside biosynthesis.Thus,these findings not only provided a molecular basis for the identification of important functional genes in ginseng but also enriched genetic resources for the biosynthesis of ginsenosides using synthetic biology.

Effects of Ag-carrying Zirconium Phosphate on the Kinetics of Growth of the Roots of Culture Artemisia annua

在植物组织和细胞培养过程中 ,尤其是在生物反应器培养中的染菌问题 ,一直是制约植物细胞培养工业化的难题。通过比较各种防腐剂的抑菌效果 ,确定银型磷酸锆盐抗菌粉为青蒿根培养的最佳防腐剂。银型磷酸锆盐抗菌粉在浓度为 30mg/L时 ,既能降低培养液的染菌几率 ,又不明显抑制青蒿根的生长及青蒿素的生物合成。在添加 30mg/L抗菌粉的培养液中进行的青蒿根生长、pH值变化以及残糖、铵离子和硝酸根离子消耗的动力学研究表明 ,在 4 0d内青蒿根在培养液中生长良好 ,营养成分的消耗和对照呈相似的趋势。