Hairy Root Formation Research Articles

Agrobacterium rhizogenes mediated transformation, initiation and multiplication of hairy roots in Spilanthes acmella Murr.

Spilanthes acmella is an important medicinal plant that belongs to the family Asteraceae. Traditionally, this plant has been used for years to cure toothaches, stammering, stomatitis and many other ailments. This plant is an important source of various medicinally important secondary metabolites like phenolics, coumarin, spilanthol, scopoletin, triterpenoids etc. The present study was carried out with the objective to transform this plant with Agrobacterium rhizogenes to initiate the hairy roots formation. This study demonstrated the transformation, initiation and multiplication of hairy roots from nodal segments and leaf explants taken from field grown and in vitro developed S. acmella plants. The hairy roots produced from different explants were white, slender, showed negative geotropism and lateral branching. PCR analysis of hairy root was performed that confirmed the bacterial transformation. Among the field grown and in vitro grown plants, the explants from the in vitro grown plants gave a high percentage of root induction. Nodal segments from in vitro grown plant gave 90% hairy root induction and leaf segments from in vitro grown plants with petiole gave the highest rate of root induction which was 92%. Nodal segments from field grown plants gave 85% and the leaves from field grown plants gave 80% of hairy root induction. This study offers great potential to establish the protocol for hairy root induction which can be used as an alternative source for the continuous production of this plant’s important secondary metabolites and active biocompounds.

Developing a direct organogenesis protocol to obtain compact Ri petunias

Ri plants characteristically exhibit a compact architectural growth habit, enhancing the economic value of ornamental varieties. These plants are obtained through the natural transformation of plant cells using wild strains of Rhizobium rhizogenes, which means they are not classified as genetically modified organisms (GMOs) in some countries, as USA or Japan. In the standard transformation protocol, rol genes are transferred to plant cells, resulting in the formation of hairy roots from which complete Ri plants can be regenerated. However, there are plant species, such as petunias, in which the regeneration of complete plantlets from hairy roots is not possible. In our research, we have developed a natural transformation protocol that enables the production of Ri petunias through direct organogenesis from leaves, bypassing the hairy root stage. The presence of rolB and rolC genes in these petunias was confirmed by PCR. The phenotypic characterization, both in vitro (laboratory-based experiments) and ex vitro (outside artificial tissue culture), showed that all Ri petunias had a more compact growth, with lower height due to reduced elongation of the internodes. Moreover, two of nine Ri petunia lines exhibited enhanced branching, resulting in an increased number of internodes, leaves, and flowers. These phenotypic changes, especially the increase in the number of flowers, represent an additional increase in their commercial value. However, there were no observable changes in the specific morphology of leaves or flowers of Ri petunias. The transformation protocol developed in this work could be adapted to other species or genotypes in which shoot regeneration from hairy roots is not possible.

Agrobacterium rhizogenes-Mediated Hairy Root Genetic Transformation Using Agrobacterium Gel Inoculation and RUBY Reporter Enables Efficient Gene Function Analysis in Sacha Inchi (Plukenetia volubilis).

Plukenetia volubilis L., a woody oilseed plant rich in α-linolenic acid, represents a promising source of polyunsaturated fatty acids. However, the lack of an efficient genetic transformation system has significantly hindered gene function research and molecular breeding in P. volubilis. In this study, we developed a highly efficient Agrobacterium rhizogenes-mediated hairy root transformation system for P. volubilis via the use of Agrobacterium gel in combination with the visually detectable RUBY reporter for gene function analysis in roots. The results indicate that the optimal transformation method involves infecting P. volubilis seedlings with Agrobacterium gel containing acetosyringone and inducing hairy root formation in perlite. This approach resulted in more than 18.97% of the seedlings producing positive hairy roots overexpressing the RUBY gene. Using this genetic transformation system, we successfully overexpressed the antimicrobial peptide-encoding gene CEMA in hairy roots, which enhanced the resistance of P. volubilis to Fusarium oxysporum. Furthermore, by combining this transformation system with the CRISPR-Cas9 tool, we validated the regulatory role of PvoSHR in the development of root epidermal cells in P. volubilis. Unexpectedly, a 123-bp DNA fragment from the T-DNA region of the A. rhizogenes Ri plasmid was found to be knocked in to the P. volubilis genome, replacing a 110-bp fragment of PvoSHR at CRISPR-Cas9 induced double-strand DNA breaks. Conclusively, this system provides a powerful tool for gene function research in P. volubilis and provides novel insights into the development of transformation and gene editing systems for other woody plants.

Unraveling the genetic basis of Rhizobium rhizogenes-mediated transformation and hairy root formation in rose using a genome-wide association study

Key MessageMultiple QTLs reveal the polygenic nature of R. rhizogenes-mediated transformation and hairy root formation in roses, with five key regions explaining 12.0–26.9% of trait variability and transformation-related candidate genes identified.Understanding genetic mechanisms of plant transformation remains crucial for biotechnology. This is particularly relevant for roses and other woody ornamentals that exhibit recalcitrant behavior in transformation procedures. Rhizobium rhizogenes-mediated transformation leading to hairy root (HR) formation provides an excellent model system to study transformation processes and host–pathogen interactions. Therefore, this study aimed to identify quantitative trait loci (QTLs) associated with HR formation and explore their relationship with adventitious root (AR) formation in rose as a model for woody ornamentals. A diversity panel of 104 in vitro grown rose genotypes was transformed with R. rhizogenes strain ATCC 15834 carrying a green fluorescent protein reporter gene. Phenotypic data on callus and root formation were collected for laminae and petioles. A genome-wide association study using 23,419 single-nucleotide polymorphism markers revealed significant QTLs on chromosomes one and two for root formation traits. Five key genomic regions explained 12.0–26.9% of trait variability, with some peaks overlapping previously reported QTLs for AR formation. This genetic overlap was supported by weak to moderate correlations between HR and AR formation traits, particularly in petioles. Candidate gene identification through literature review and transcriptomic data analysis revealed ten candidate genes involved in bacterial response, hormone signaling, and stress responses. Our findings provide new insights into the genetic control of HR formation in roses and highlight potential targets for improving transformation efficiency in ornamental crops, thereby facilitating future research and breeding applications.

Metabolic engineering of hairy root cultures in Beta vulgaris for enhanced production of vanillin, 4-hydroxybenzoic acid, and vanillyl alcohol.

The flavor of vanilla is a complex blend of compounds, with vanillin as the most prominent, along with vanillyl alcohol and 4-hydroxybenzoic acid. Natural vanillin extracted from vanilla beans is expensive, so researchers use heterologous synthesis to produce nature-identical vanillin in plant hosts. Consequently, alternative traditional farming and gathering methods are required to bridge the significant disparity between supply and demand. The current research successfully developed a method to induce hairy root formation from leaves. It integrated the Vanillin synthase (VpVAN) gene into transgenic hairy root lines of Beta vulgaris, synthesizing vanillin-related compounds. The presence of the VpVAN gene in transgenic roots was confirmed using PCR analysis. Additionally, RT-qPCR analysis demonstrated the expression of the VpVAN gene in the transgenic root lines. The transgenic hairy root clones H1, H2, and H5 showed enhanced vanillin production, vanillyl alcohol, and 4-hydroxybenzoic acid. Elicitation with methyl jasmonate (MJ) and salicylic acid (SA) further improved the production of these compounds in B. vulgaris hairy roots. The maximum hairy root biomass was observed after 60 days, with the maximum synthesis of vanillin and 4-hydroxybenzoic acid obtained from hairy root clones H5 and HR2, respectively. Vanillyl alcohol HR2 was obtained on the 45th day of cultivation. Elicitation with wound-associated hormone methyl jasmonate and salicylic acid enhanced the yield of vanillin, vanillyl alcohol, and 4-hydroxybenzoic acid, with a 215-fold increase in vanillin, a 13-fold increase in vanillyl alcohol, and a 21 fold increase in 4-hydroxybenzoic acid. The study results indicate that establishing transgenic hairy root cultures with the VpVAN gene is a promising alternative method for enhancing the production of vanilla flavor compounds such as vanillin, vanillyl alcohol, and 4-hydroxybenzoic acid. A cost-effective protocol has been developed to mass-produce phenolic compounds using a hairy root culture of B. vulgaris. This approach addresses the increasing demand for these substances while reducing the cost of natural vanillin production, making it suitable for industrial-scale applications.

Enhanced production of withaferin A from the hairy root culture of Withania somnifera via synergistic effect of Methyl jasmonate and β-cyclodextrin

Enhanced production of withaferin A from the hairy root culture of Withania somnifera via synergistic effect of Methyl jasmonate and β-cyclodextrin

Injection-based hairy root induction and plant regeneration techniques in Brassicaceae

BackgroundHairy roots constitute a valuable tissue culture system for species that are difficult to propagate through conventional seed-based methods. Moreover, the generation of transgenic plants derived from hairy roots can be facilitated by employing carefully designed hormone-containing media.ResultsWe initiated hairy root formation in the rare crucifer species Asperuginoides axillaris via an injection-based protocol using the Agrobacterium strain C58C1 harboring a hairy root-inducing (Ri) plasmid and successfully regenerated plants from established hairy root lines. Our study confirms the genetic stability of both hairy roots and their derived regenerants and highlights their utility as a permanent source of mitotic chromosomes for cytogenetic investigations. Additionally, we have developed an effective embryo rescue protocol to circumvent seed dormancy issues in A. axillaris seeds. By using inflorescence primary stems of Arabidopsis thaliana and Cardamine hirsuta as starting material, we also established hairy root lines that were subsequently used for regeneration studies.ConclusionWe developed efficient hairy root transformation and regeneration protocols for various crucifers, namely A. axillaris, A. thaliana, and C. hirsuta. Hairy roots and derived regenerants can serve as a continuous source of plant material for molecular and cytogenetic analyses.

Simple method for transformation and gene editing in medicinal plants.

A sample delivery method, modified from cut-dip-budding, uses explants with robust shoot regeneration ability, enabling transformation and gene editing in medicinal plants, bypassing tissue culture and hairy root formation. This method has potential for applications across a wide range of plant species.

Hairy Root Transformation and Regeneration in Arabidopsis thaliana and Brassica napus.

Hairy root transformation represents a versatile tool for plant biotechnology in various species. Infection by an Agrobacterium strain carrying a Root-inducing (Ri) plasmid induces the formation of hairy roots at the wounding site after the transfer of T-DNA from the Ri plasmid into the plant genome. The protocol describes in detail the procedure of the injection-based hairy root induction in Brassica napus DH12075 and Arabidopsis thaliana Col-0. The hairy roots may be used to analyze a transgene of interest or processed for the generation of transgenic plants. Regeneration medium containing cytokinin 6-benzylaminopurine (5 mg/L) and auxin 1-naphthaleneacetic acid (8 mg/L) successfully elicits shoot formation in both species. The protocol covers the genotyping and selection of regenerants and T1 plants to obtain plants carrying a transgene of interest and free of T-DNA from the Ri plasmid. An alternative process leading to the formation of a composite plant is also depicted. In this case, hairy roots are kept on the shoot (instead of the natural roots), which enables the study of a transgene in hairy root cultures in the context of the whole plant.

Lessons learned from metabolic engineering in hairy roots: Transcriptome and metabolic profile changes caused by Rhizobium-mediated plant transformation in Cucurbitaceae species

Cucurbitaceae species are used in traditional medicine around the world. Cucurbitacins are highly oxygenated triterpenoids found in Cucurbitaceae species and exhibit potent anticancer activity alone and in combination with other existing chemotherapeutic drugs. Therefore, increasing production of these specialized metabolites is of great relevance. We recently showed that hairy roots of Cucurbita pepo can be used as a platform for metabolic engineering of cucurbitacins to modify their structure and increase their production. To study the changes in cucurbitacin accumulation upon formation of hairy roots, an empty vector (EV) control and Cucurbitacin inducing bHLH transcription factor 1 (CpCUCbH1)-overexpressing hairy roots of C. pepo were compared to untransformed (WT) roots. Whilst CpCUCbH1-overexpression increased production of cucurbitacins I and B by 5-fold, and cucurbitacin E by 3-fold when compared to EV lines, this increase was not significantly different when compared to WT roots. This indicated that Rhizobium rhizogenes transformation lowered the cucurbitacins levels in hairy roots, but that increasing expression of cucurbitacin biosynthetic genes by CpCUCbH1-overexpression restored cucurbitacin production to WT levels. Subsequent metabolomic and RNA-seq analysis indicated that the metabolic profile and transcriptome of hairy roots was significantly changed when compared to WT roots. Interestingly, it was observed that 11% of the differentially expressed genes were transcription factors. It was noteworthy that the majority of transcripts showing highest Pearson correlation coefficients to the Rhizobium rhizogenes genes rolB, rolC and ORF13a, were predicted to be transcription factors. In summary, hairy roots are an excellent platform for metabolic engineering of plant specialized metabolites, but these extensive transcriptome and metabolic profile changes should be considered in subsequent studies.

Impact of different Agrobacterium rhizogenes strains on secondary metabolites accumulation in Nitraria schoberi L. hairy roots and antiviral activity of their extracts against influenza virus of subtypes A (H5N1) and A (H3N2).

To optimize protocol for obtaining hairy roots of Nitraria schoberi L. with high antiviral activities, factors such as four strain types of Agrobacterium rhizogenes (A4, ATCC15834, R-1601, 8196), two explant types, namely cotyledonous and primary leaves of seedlings, and different cultivation durations (30 and 90 d) were studied. The formation of hairy roots was observed after 2 to 4 wk of incubation, depending on the type of explant and the strain of A. rhizogenes used. The maximum transformation frequency (85.7%) was observed in the cotyledons genetically modified with the strain ATCC15834. The transgenic nature of hairy roots was revealed by PCR with primers to the Agrobacterium oncogenes rolB and rolC. The absence of contamination of the culture by A. rhizogenes was confirmed by primers to the virC and virD1 genes. Phytochemical analysis showed that accumulation of individual metabolites in the line samples exceeded their levels in the native Nitraria roots. Catechin content in the cultures of long-term cultivation (90 d) was found 1.4 to 2.2 times higher than the same samples of short cultivation (30 d) and 4.8 to 10.8 times higher in comparison with the native roots. The most productive in terms of catechin level were hairy roots of long-term cultivation obtained during the transformation of primary leaves of N. schoberi seedlings with ATCC15834 strain. These data were consistent with the highest antiviral activities against influenza viruses of A (H5N1) and A (H3N2) subtypes with neutralization indexes 6.5 to 6.75 log10, and selectivity index values were in the range 15.4 to 16.4.

Rhizogenic Agrobacterium protein RolB interacts with the TOPLESS repressor proteins to reprogram plant immunity and development

Rhizogenic Agrobacterium strains comprise biotrophic pathogens that cause hairy root disease (HRD) on hydroponically grown Solanaceae and Cucurbitaceae crops, besides being widely explored agents for the creation of hairy root cultures for the sustainable production of plant-specialized metabolites. Hairy root formation is mediated through the expression of genes encoded on the T-DNA of the root-inducing (Ri) plasmid, of which several, including root oncogenic locus B (rolB), play a major role in hairy root development. Despite decades of research, the exact molecular function of the proteins encoded by the rol genes remains enigmatic. Here, by means of TurboID-mediated proximity labeling in tomato (Solanum lycopersicum) hairy roots, we identified the repressor proteins TOPLESS (TPL) and Novel Interactor of JAZ (NINJA) as direct interactors of RolB. Although these interactions allow RolB to act as a transcriptional repressor, our data hint at another in planta function of the RolB oncoprotein. Hence, by a series of plant bioassays, transcriptomic and DNA-binding site enrichment analyses, we conclude that RolB can mitigate the TPL functioning so that it leads to a specific and partial reprogramming of phytohormone signaling, immunity, growth, and developmental processes. Our data support a model in which RolB manipulates host transcription, at least in part, through interaction with TPL, to facilitate hairy root development. Thereby, we provide important mechanistic insights into this renowned oncoprotein in HRD.

Transformation and Detection of Soybean Hairy Roots.

Agrobacterium rhizogenes is a soil bacteria with extensive infectivity, which can infect almost all dicotyledonous plants and a few monocotyledonous plants to induce root nodules. This is caused by the root-inducing plasmid, which contains genes responsible for the autonomous growth of root nodules and crown gall base synthesis. Structurally, it is similar to the tumor-inducing plasmid in that it mainly contains the Vir region, the T-DNA region, and the functional region of crown gall base synthesis. Its T-DNA is integrated into the nuclear genome of the plant with the assistance of Vir genes, causing hairy root disease in the host plant and the formation of hairy roots. The roots produced by Agrobacterium rhizogenes-infested plants are characterized by a fast growth rate, high degree of differentiation, physiological, biochemical, and genetic stability, and ease of manipulation and control. In particular, the hairy root system is an efficient and rapid research tool for plants that have no affinity for transformation by Agrobacterium rhizogenes and low transformation efficiency. The establishment of germinating root culture system for the production of secondary metabolites in the original plants through the genetic transformation of natural plants mediated by root-inducing plasmid in Agrobacterium rhizogenes has become a new technology combining plant genetic engineering and cell engineering. It has been widely used in a variety of plants for different molecular purposes, such as pathological analysis, gene function verification, and secondary metabolite research. Chimeric plants obtained by induction of Agrobacterium rhizogenes that can be expressed instantaneously and contemporarily are more rapidly obtained, compared to tissue culture and stably inheritable transgenic strains. In general, transgenic plants can be obtained in approximately one month.

Hairy Root Induction of Taxus baccata L. by Natural Transformation with Rhizobium rhizogenes

Paclitaxel (Taxol®) is a potent anticancer agent, but the widespread pharmaceutical use of paclitaxel is hampered by its limited availability due to low accumulation levels in the native yew (Taxus spp.) plants. Currently, hairy root culture is an emerging biotechnological tool that presents several advantages such as reduced costs and higher specialized metabolite production, therefore, its application to paclitaxel production can be of commercial and medicinal interest. The objective of present study was to induce hairy root in Taxus baccata L. by transformation with the wild type Rhizobium rhizogenes A4 strain. Thus, T. baccata was inoculated by three different inoculation methods: (a) ex vitro seedlings inoculation by direct injection of a liquid bacterial culture; (b) ex vitro needles inoculation by liquid co-culturing with bacteria; (c) ex vitro shoots inoculation by dipping liquid bacterial culture. Hairy roots were formed only from ex vitro seedlings inoculated by the direct inoculation method, with transformation efficiency of 14.3%. Formation of hairy roots was observed two months after inoculation. This project forms the basis for the establishment of hairy root cultures from T. baccata for the production of paclitaxel.

Developing a robust in vivo hairy root system for assessing transgene expression and genome editing efficiency in papaya

Papaya is one of the most important fruits in tropical and subtropical countries. However, genetic improvement has had limited success to date due to time-consuming and complex transformation and regeneration technologies, as well as a lack of reproducible and efficient transient gene expression assays. Here, we report the development of a highly efficient Rhizobium rhizogenes-based in vivo hairy root system for evaluating transgene expression and activity including CRISPR/Cas gene editing reagents in the Vietnamese papaya cultivar Linhan. To optimize the papaya transformation parameters, we introduced the R. rhizogenes strain K599 into papaya hypocotyls at 1-, 5- and 10-mm below the cotyledon nodes by a needle using 5-, 7- and 10-day old seedlings and then monitored the frequency of hairy root formation at 18 days post infection. We found that the age of the seedlings and the distance of the infection site from the cotyledon node were inversely correlated with the efficacy of hairy root induction, being 5-day-old plants and 1-mm distance the best parameters. The etablished protocol was then employed to investigate transformation frequency using the gus reporter gene. Of the tested hairy roots, 47.22% were positive for GUS staining, which indicates a high level of transgene transfer and stability. Finally, we introduced a dual guide RNA CRISPR/Cas9 cassette targeting eukaryotic translation initiation factor isoform 4E (eIF(iso)4E) gene into papaya by R. rhizogenes and then screened for gene editing events by heteroduplex analysis and Sanger sequencing. Our analysis revealed that 50% of induced roots contained the expected mutations in the eIF(iso)4E gene, which makes our system ideal for testing transgene activity prior making stable transgenic papaya lines.

Efficient Editing of SoCSLD2 by CRISPR/Cas9 Affects Morphogenesis of Root Hair in Spinach

CRISPR/Cas9 is a valuable tool and has been extensively employed to perform gene editing in plants. However, CRISPR/Cas9 has not been successfully used in spinach, an important leafy vegetable crop. Here, we established a CRISPR/Cas9-based gene-editing system for spinach hairy roots and edited two cellulose synthase-like D (CSLD) genes (SoCSLD2 and SoCSLD3) that were involved in root-hair formation of spinach hairy roots. Four mutation types (i.e., replacement, insertion, deletion, and combined mutations) were observed, among which the replacement accounted for the vast majority (about 64.1%). Mutation rate differed largely among different targets. Seven homozygous/bi-allelic and eight heterozygous/chimeric mutants of SoCSLD2 were obtained from 15 independent transgenic hairy root lines. All of the seven homozygous/bi-allelic mutant lines displayed bulking and short root hairs, which resembled the characteristics of Arabidopsis atcsld2 mutants. The transcriptomic analysis further revealed that multiple gene expressions for cell-wall modulation and membrane trafficking were disturbed, which might result in the inhibition of root hair growth in socsld2 mutants. This indicates that SoCSLD2 was successfully knocked out in spinach root hairs using the CRISPR/Cas9-based gene editing system.

Altered carbon status in Glycine max hairy roots induced by Agrobacterium rhizogenes

ABSTRACT Plants fix CO2 into carbohydrates through photosynthesis, and various organisms interact with plants to obtain carbohydrates. Agrobacterium rhizogenes is a soil bacterium known as a plant pathogen that induces hairy root disease. Through A. rhizogenes-plant interactions, transfer-DNA (T-DNA) of the Ri plasmid is inserted into the host plant genome, leading to excessive formation of hairy roots and the synthesis of opines that are carbon and nitrogen sources for A. rhizogenes. In this study, we analyzed the carbohydrate contents in soybean (Glycine max) hairy roots. We found that the starch content was strongly increased in hairy roots, whereas the glucose was significantly decreased. On the other hand, no significant differences were observed in sucrose levels between the main roots and hairy roots of A. rhizogenes-inoculated plants. This result suggests that A. rhizogenes infection caused a change in primary carbon metabolism in the host plant cells.

Rhizobium rhizogenes infection in threatened Indian orchid Dendrobium ovatum mobilises ‘Moscatilin’ to enhance plant defensins

The present study illustrates the transformation ability of two wild-type bacterial strains of Rhizobium rhizogenes (MTCC 532 and MTCC 2364) on the embryogenic callus and callus-derived plantlets of a threatened Indian orchid, Dendrobium ovatum. Co-culture of the bacterium with the explants gave marginal hairy root phenotype that failed to multiply in the culture medium. Some primary and secondary metabolites were subdued in infected explants. Moscatilin, the stilbenoid active principle in D. ovatum, was found below the detection limit. The presence of two metabolites viz., Laudanosine, a benzyltetrahydroisoquinoline alkaloid and Lyciumin B, a cyclic peptide, were detected exclusively in the infected explants. The subjugated amino acids and phenolics in the infected plantlets were routed to produce phytoanticipins, and phenanthrenes, strengthening the defence mechanism in infected tissues. This research implies that the plant's defence mechanism activation could have prevented the extensive hairy root formation in the explants, even though nodulations and phenotype transitions were witnessed. Moscatilin has a structural resemblance with Resveratrol, a phytoalexin that combats bacterial and fungal pathogens. The study favours the possibility of Moscatlin being a precursor for phenanthrene compounds, thereby serving as a ‘phytoanticipin’ during the infection phase.

Study of hairy root formation and plant regeneration in Nicotiana tabaccum

Study of hairy root formation and plant regeneration in Nicotiana tabaccum

An Efficient Root Transformation System for Recalcitrant Vicia sativa.

Common vetch (Vicia sativa) is a multi-purpose legume widely used in pasture and crop rotation systems. Vetch seeds have desirable nutritional characteristics and are often used to feed ruminant animals. Although transcriptomes are available for vetch, problems with genetic transformation and plant regeneration hinder functional gene studies in this legume species. Therefore, the aim of this study was to develop a simple, efficient and rapid hairy root transformation system for common vetch to facilitate functional gene analysis. At first, we infected the hypocotyls of 5-day-old in vitro or in vivo, soil-grown seedlings with Rhizobium rhizogenes K599 using a stabbing method and produced transgenic hairy roots after 24 days at 19 and 50% efficiency, respectively. We later improved the hairy root transformation in vitro by infecting different explants (seedling, hypocotyl-epicotyl, and shoot) with R. rhizogenes. We observed hairy root formation at the highest efficiency in shoot and hypocotyl-epicotyl explants with 100 and 93% efficiency, respectively. In both cases, an average of four hairy roots per explant were obtained, and about 73 and 91% of hairy roots from shoot and hypocotyl-epicotyl, respectively, showed stable expression of a co-transformed marker β-glucuronidase (GUS). In summary, we developed a rapid, highly efficient, hairy root transformation method by using R. rhizogenes on vetch explants, which could facilitate functional gene analysis in common vetch.