Rhizogenes Strain A4 Research Articles

Tapping the potential of Calotropis procera hairy roots for cardiac glycosides production and their identification using UHPLC/QTOF-MS.

The present work deals with the establishment of hairy root cultures from different explants of C. procera using Agrobacterium rhizogenes strain A4. A high transformation frequency (95%) was obtained from leaves followed by cotyledons (81.6%) and hypocotyls (38.3%). Genetic transformation of hairy roots was confirmed through PCR by amplifying a 400 bp fragment of the rolB gene. Hairy roots were highly branched, possessed plagiotropic and rapid growth on hormone-free ½ B5 medium. Ten cardiac glycosides, including calotropagenin, calotoxin, frugoside, coroglaucigenin, calotropin, calactin, uzarigenin, asclepin, uscharidin, and uscharin, based on their specific masses and fragmentation properties were identified in ethanolic extracts of hairy roots by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry UHPLC/QTOF-MS. This protocol could be used as a powerful tool for large-scale in vitro production of highly valued cardiac glycosides and for further transcriptomics or metabolomics studies.

Effect of silver nanoparticles on tropane alkaloid production of transgenic hairy root cultures of Hyoscyamus muticus L. and their antimicrobial activity

The utilization of nanotechnology and biotechnology for enhancing the synthesis of plant bioactive chemicals is becoming increasingly common. The hairy root culture technique can be used to increase secondary metabolites such as tropane alkaloids. Agrobacterium was used to induce hairy roots from various explants of Hyoscyamus muticus. The effect of nano-silver particles (AgNPs) at concentrations of 0, 25, 50, 100, and 200 mg/L on tropane alkaloids synthesis, particularly hyoscyamine and scopolamine, was studied in transgenic hairy root cultures. Different types of explants obtained from 10-day-old seedlings of H. muticus were inoculated with two strains of Agrobacterium rhizogenes (15,834 and A4). The antimicrobial activity of an ethanolic extract of AgNPs-induced hairy root cultures of H. muticus was tested. The frequency of hairy roots was higher in hypocotyl, root, leaf, and stem explants treated with A. rhizogenes strain A4 compared to those treated with strain 15,834. In transgenic hairy root cultures, AgNPs application at a concentration of 100 mg/L resulted in the highest total tropane alkaloid production, which exhibited broad-spectrum antimicrobial activity. The study demonstrated the potential of nano-silver as an elicitor for promoting the production of target alkaloids in Hyoscyamus muticus hairy root cultures, which exhibit high biological activity.

PECULIARITIES OF THE GROWTH OF Artemisia tilesii Ledeb. “HAIRY” ROOTS WITH DIFFERENT FOREIGN GENES

Aim. To compare Artemisia tilesii “hairy” root lines with different transferred genes in terms of the relationship between the total content of flavonoids, the levels of antioxidant activity (AOA) and reducing power (RP), as well as the activity of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), rolB and rolC genes. Methods. We compared the root lines Nos. 10 and 16, obtained by transformation with the wild Agrobacterium rhizogenes strain A4, lines Nos. 2 and 4, obtained using A. rhizogenes carrying pSV124 vector with ifn-α2b and nptII genes, as well as the roots of non-transformed plants that were cultivated in vitro. The presence and activity of rolB, rolC, PAL, and CHS genes were determined by PCR and real-time PCR, respectively. The content of flavonoids, AOA and RP were determined by standard tests with AlCl3, DPPH (2,2-diphenyl-1-picrylhydrazyl) and K3[Fe(CN)6] accordingly. Results. The content of flavonoids in most of the lines was higher than in the control, and correlated with AOA and RP. Roots No. 10 were characterized by the fastest growth, which coincided with higher activity of rolB and rolC genes. The activities of PAL and CHS in “hairy” roots were lower than those in non-transformed ones. Conclusions. Root lines carrying only rolB and rolC and lines with additional ifn-α2b and nptII genes had similar ranges of flavonoids concentration, AOA and RP levels that exceeded those in the control. The dependence of the root growth rate, and lack of the dependence of the flavonoids content with the activity of the rol genes were demonstrated. PAL activity inversely correlated with flavonoids content in all experimental lines, which may be the result of overproduction of compounds in transgenic roots.

Agrobacterium rhizogenes-mediated genetic transformation of Musa acuminata cv. Vaibalhla (AAA)

Agrobacterium rhizogenes-mediated genetic transformation of Musa acuminata cv. Vaibalhla (AAA) was successfully carried out using A. rhizogenes strain A4 harboring the binary vector pCAMBIA2301with VrNHX1gene. In the study, male flowers of M. acuminata cv. Vaibalhla were used as explants to obtain white bud-like structures by culturing on MS basal medium supplemented with 2 mg/l 6-Benzylaminopurine (BAP) and 0.5 mg/l 1-Naphthaleneacetic acid (NAA). The subsequent shoot induction and plantlet regeneration were carried out in MS medium supplemented with Kinetin (2 mg/l) and NAA (0.5 mg/l). For the genetic transformation, in vitro raised plantlets were inoculated with A. rhizogenes strain A4 harboring pCAMBIA2301VrNHX1 for 30 min followed by 2 days of co-cultivation in the dark in a semi solid MS basal medium. The treated plants were then transferred and maintained in MS basal medium supplemented with ascorbic acid (75 mg/l), kanamycin (150 mg/l) and cefotaxime (400 mg/l). Initiation of hairy roots were observed within 2 days of transfer which were evaluated for GUS activity and the subsequent GUS+ roots were assayed for transient transformation by PCR using nptII and NHX1 gene specific primers. The transfer of the plasmid as well as the gene was confirmed with positive bands observed at 540 bp and 1.6 kb respectively.

Improving galegine production in transformed hairy roots of Galega officinalis L. via elicitation

Galega officinalis L. is an herbaceous legume used to treat symptoms associated with hyperglycemia or diabetes mellitus because of its dominant alkaloid, galegine. In this study, we induced hairy roots in this plant using Rhizobium rhizogenes strain A4, and investigated the effect of type, concentration, and duration of elicitor application on galegine content and some phytochemical characteristics in the hairy roots. Hence, the best growing hairy root line in terms of growth rate was selected and subcultured for treatment with elicitors. Then, at the end of the log phase of growth, chitosan (100, 200, and 400 mg/L), salicylic acid (100, 200, and 300 mM), and ultrasound (1, 2, and 4 min) were applied to hairy roots culture medium. High-performance liquid chromatography (HPLC) showed that the content of galegine was significantly increased after elicitation compared with the control. Thus, the highest content of galegine (14.55 mg/g FW) was obtained 2 days after elicitation when ultrasonic waves were applied to the hairy root culture medium for 4 min. Also, elicitation resulted in a significant increase in the content of total phenol, flavonoid, H2O2 and MDA compared with the control. So that the highest total flavonoid content was obtained in hairy roots that were treated with ultrasonic waves for 4 min and harvested 2 days after elicitation; while, application of 400 mg/L chitosan for 4 days resulted in the highest total phenol (16.84 mg/g FW).Graphical

Genetic engineering of tropane alkaloid biosynthesis of hyoscyamus reticulatus L. hairy roots by pmt gene overexpression and feeding with putrescine

The use of biotechnology strategies to increase the production of natural products in medicinal plants, can be very useful and commercially profitable. In this study, control and transgenic hairy roots were obtained from Agrobacterium rhizogenes strain A4 and Agrobacterium tumefaciens strain C58C1(pRiA4-pBMI) carrying the pmt gene C58C1, respectively. The effect of pmt gene overexpression on growth, biochemical traits, and phytochemical ingredients were determined in Hyoscyamus reticulatus hairy roots, which were also fed with different concentrations of the precursor compound putrescine (0, 1, 2, 3, and 4 mM) for two exposure times (24 and 48 h). The growth rate was higher in transgenic hairy roots. The maximum total content of phenol, flavonoid, and alkaloid were obtained in transgenic hairy roots fed with putrescine (4, 3 and 1 mM, respectively) after 48 h. According to the half maximal inhibitory concentration (IC50) values, the antioxidant activity was lower in the control than transgenic hairy roots. High performance liquid chromatography indicated that the hyoscyamine content (125.09 μg g−1 DW with 3 mM putrescine after 24 h; 203.83 % compared with the control) was higher in control hairy roots, whereas scopolamine levels (161.88 μg g−1 DW with 3 mM putrescine after 48 h; 207.34 %) was higher in transgenic hairy roots. The highest increase in the expression level of the pmt (2.6-fold with 3 mM putrescine) and h6h (2.83-fold with 2 mM putrescine) genes occurred after 48 h in both transgenic and control hairy roots, respectively. The combination of genetic engineering and precursor feeding strategies improved the accumulation of secondary metabolites in vitro.

Establishment of hairy root cultures of Salvia bulleyana Diels for production of polyphenolic compounds

This study was to obtain stable transformed roots of Salvia bulleyana using A. rhizogenes strain A4 and then evaluate their phytochemical profile and selected the most productive clone. Our results indicated that the type of explant and medium used for bacterium and explant incubation had an influence on the frequency of hairy root formation. The best response was obtained on leaves infected with bacteria cultivated on YMB medium supplemented with acetosyringone. Of the four selected transformed root clones, after five-week cultivation in Woody Plant (WP) medium, the highest growth indexes were demonstrated for line C1: i.e. 13 for fresh and 15 for dry weight (81.4 and 8.2 g/l fresh and dry weight, respectively). The qualitative analysis of hydromethanolic extracts of hairy roots of S. bulleyana using UPLC-PDA-ESI-MS/MS method showed the presence of 10 polyphenolic compounds including predominant rosmarinic acid (RA), its derivatives (hexoside and methyl rosmarinate), caffeic acid, its derivatives and several salvianolic acids: K, E and F. Their production varied among the four root clones studied; the highest RA (39.6 mg/g dry weight) and total polyphenol (48.9 mg/g dry weight) level were found in the roots of C4 clone. These values were significantly higher than those of the roots of plants grown for several years under field conditions. The transformation of the obtained root cultures was confirmed by polymerase chain reaction using aux1, aux2, rolB, rolC and rolD primers.

Establishment of hairy root cultures by Agrobacterium rhizogenes mediated transformation of Trachyspermum ammi L. for the efficient production of thymol.

Trachyspermum ammi is an important medicinal plant that contains a bioactive compound namely thymol. In the study, T. ammi was transformed by Agrobacterium rhizogenes strains. Seedling stem explants were inoculated with A. rhizogenes strains A4, LBA 9402, ATCC 15834, and the effect of different co-cultivation media along with incorporation of acetosyringone (100 µM) was evaluated comparatively on the frequency of hairy root induction. The polymerase chain reaction using rolB and virD specific primers was served to confirm the putative transformed hairy roots. All strains established hairy root with various frequencies, among which strain ATCC 15834 was significantly the most efficient strain for hairy root induction (84.3%). Half-strength B5 medium and incorporation of acetosiryngone (100 µM) were also significantly optimal for hairy root induction. Hairy roots culture induced by ATCC 15834 using half-strength B5 liquid medium supplemented with 30 g L-1 sucrose indicated the highest accumulation of biomass (99.05 g L-1 FW and 10.95 g L-1 DW) and thymol content (11.30 mg g-1 DM) at 20days. Nearly 4.9-fold and 5.3-fold increment of biomass and thymol accumulation was observed, respectively, at 20days in comparison with the untransformed control roots. The results showed the high potential of T. ammi hairy roots for the biosynthesis of thymol.

Hairy root cultures of Salvia viridis L. for production of polyphenolic compounds

Salvia viridis is a containing bioactive phenols plant, which has been used in Turkish medicine. The aim of the study was to establish hairy root culture of the species in order to increase the production of the compounds with pharmacological activity. Transformed roots are promising biotechnological systems that produce great amounts of secondary metabolites; this is attributed to their fast growth and their genetic and biosynthetic stability. Stable hairy root lines of S. viridis were established from shoot explants using Agrobacterium rhizogenes strain A4. The highest frequency of transformation (45%) was achieved when the shoot was inoculated at the node or internode by bacteria cultivated on Yeast/Mannitol/Broth (YMB) medium supplemented with acetosyringone. The transformation of the root clones was confirmed by polymerase chain reaction using aux1, aux2, rolB and rolC primers. Of the five obtained transformed root clones, the highest biomass was achieved for clone K3 (13.63 ± 0.5 g/L after 5 weeks) grown in Woody Plant (WP) medium in darkness. The UPLC-PDA-ESI–MS analysis of hydromethanolic extracts of transformed roots of S. viridis revealed the presence of 10 compounds identified as caffeic acid derivatives. Quantitative analysis showed that rosmarinic acid (RA) was the predominant compound in all clones. The highest RA (35.8 mg/g dry weight) and total polyphenol (41.24 mg/g dry weight) content were evaluated in clone K3 cultured in WP medium. These values were 8-fold higher than those of the non-transformed roots, indicating that hairy root cultivation could be a promising technique for the production of valuable compounds from S. viridis.

Growth kinetics and withanolide production in novel transformed roots of Withania somnifera and measurement of their antioxidant potential using chemiluminescence

Markedly increased withanolide content was found in transformed roots (TR) of Withania somnifera germplasm grown in low mineral minimal media and withanolides showed high antioxidant potential when analysed using acidic potassium permanganate chemiluminescence. Transformation frequency of explants infected with Agrobacterium rhizogenes strain A4 varied between the three germplasms tested with the highest observed as 75 ± 0.9. Transformed root production was explant specific with leaves being the most productive among the different explants used. Withanolides, namely withaferin A, withanolide A, withanolide B and 12-deoxywithastramonolide were detected in TR cultures and differences in their content were found between germplasms. The highest concentrations of secondary metabolites were found in 4-week-old cultures and concentrations declined by the 8th and 12th week of culture. In 4-week-old cultures, the biomass of TR cultures was 4.5 fold higher than their respective non-transformed roots (NTR). Withaferin A was found in TR at levels that were 28–34 times higher than that found in NTR. A rapid method for the determination of the antioxidant potential of W. somnifera TR extracts was developed using post-column acidic potassium permanganate chemiluminescence (APPC) detection. The APPC chromatographic peaks for extract constituents showed strong alignment with those found for ultraviolet absorbance detection. The methods developed in this study for TR culture establishment and the use of a fast and sensitive way for the qualitative and quantitative determination of the antioxidant activity of their metabolites provides a new platform that will have use for similar studies in other species.

Pyrethrin accumulation in elicited hairy root cultures of Chrysanthemum cinerariaefolium

The flowers of Pyrethrum (Chrysanthemum cinerariaefolium) are known to contain Pyrethrins that are naturally occurring potential insecticide. Hairy roots were induced from leaves of C. cinerariaefolium using Agrobacterium rhizogenes strain A4. The root clones were characterized in to four groups i.e. thick, unbranched (D2 and D5), thin, highly branched (D3), thick, branched (B2) and thick, highly branched (D1, D6). Six established hairy root clones showed the presence of pyrethrin and were selected for elicitation studies. Growth kinetics studies revealed highest growth index in hairy root clone D1 (592.0) followed by D6 and D3 on dry weight basis after 40 days of culture. The maximum pyrethrin content was found in the clone D3 (7.2 mg/g dw) which is comparable to the flowers obtained from the variety “Avadh”. Hairy root clone D2 (5.2 mg/g dw) and D6 (1.3 mg/g dw) contained pyrethrin but in less amount as compared to clone D3. The PCR analysis showed the presence of rol B and rol C genes in all the six hairy root clones while rol A was detected only in D2 clone. The methanolic extract of D3 clone showed antifungal activities against phytopathogenic fungal strains which were found maximum against Curvuleria andropogonis followed by Colletotrichum acutatum and Rhizoctonia solani. Hairy root clones D2, D3 and D6 were elicited with culture filtrate of endophytic fungus (Fusarium oxysporum) and bacteria (Bacillus subtilis). The culture filtrate (4.0 %v/v) of both the fungal and bacterial origin was found to be effective in enhancing the pyrethrin content in all the tested hairy root clones. Clone D3 showed maximum pyrethrin content on elicitation with F. oxysporum (9.7 mg/g dw) and B. subtilis (9.7 mg/g dw) culture filtrate, which is 32 % higher than the non elicited D3 hairy roots (7.2 mg/g dw). F. oxysporum also enhanced the hairy root growth resulting into the higher biomass yield of D3 (50 %) and D2 (76 %) in comparison to control non elicited hairy root clones of D3 and D2, respectively leading to higher pyrethrin yield.

The identification and quantitative determination of rosmarinic acid and salvianolic acid B in hairy root cultures of Dracocephalum forrestii W.W. Smith

Dracocephalum forrestii, an important plant in Tibetan medicine, was transformed with Agrobacterium rhizogenes strain A4 to obtain hairy root culture. A maximum transformation frequency of 82% after seven weeks was obtained by inoculation of internodal stem segments. Six lines of hairy roots were obtained and cultured in darkness in Woody Plant (WPM) liquid medium. The transgenic nature of the hairy roots was investigated by PCR and RT-PCR. Three main compounds: rosmarinic acid (RA), salvianolic acid B (SAB) and caffeic acid (CA) were identified in extracts of D. forrestii hairy roots by UPLC-PDA-ESI-MS analysis. Quantitative HPLC analysis showed that RA levels were greatly increased in hairy roots (max. 19.97mg/g DW) compared with the roots of one-year-old field grown plants (4.7mg/g DW), but SAB levels were significantly lower in transformed roots (max. 11.7mg/g DW) than in untransformed roots (16.4mg/g DW). Caffeic acid was detected only in transformed roots. A time course experiment with the most productive hairy root line showed that a culture period of 30days and a medium supplemented with 3% of sucrose was optimal for biomass and production of analysed phenolic compounds. Production remained stable over at least 3.5 years of continuous subculturing of the hairy roots.

The influence of methyl jasmonate, cholesterol and l‐arginine on solasodine production in hairy root culture of Solanum mammosum

The increasing demand of diosgenin for high‐revenue synthesis of steroid hormones by the pharmaceutical industries has driven researchers to look for other alternatives. Solasodine which was reported to be present in Solanum mammosum is known to be a potential source. The present study highlighted that added methyl jasmonate, cholesterol and l‐arginine into the modified liquid full‐strength Murashige and Skoog (MS) medium (with ammonium to nitrate ratio 10.3 mM: 39.4 mM, and 4% (w/v) sucrose) could influence the solasodine production in the hairy roots of S. mammosum. The findings showed that both hairy root line‐ATCC31798 and line‐A4 (which were separately induced by Agrobacterium rhizogenes strain ATCC31798 and A4) acquired solasodine productivity of 4.5 mg/g dry weight roots with average dry biomass of 190 mg after 32 days culture, when using 50 mg fresh weight roots as initial inoculum size, with 100 mM cholesterol, 1000 μM l‐arginine and 300 μM methyl jasmonate added simultaneously into the culture medium on day 20 of culture. The amount of solasodine obtained was five times higher than those without both the elicitor and precursor treatment. The improved solasodine production with a high‐biomass growth could reduce the production cost of steroid synthesis in the long run.

Scale-Up of Agrobacterium rhizogenes-Mediated Hairy Root Cultures of Rauwolfia serpentina: A Persuasive Approach for Stable Reserpine Production.

Roots of Rauwolfia serpentina, also known as "Sarpagandha" possess high pharmaceutical value due to the presence of reserpine and other medicinally important terpene indole alkaloids. Ever increasing commercial demand of R. serpentina roots is the major reason behind the unsystematic harvesting and fast decline of the species from its natural environment. Considering Agrobacterium rhizogenes-mediated hairy root cultures as an alternative source for the production of plant-based secondary metabolites, the present optimized protocol offers a commercially feasible method for the production of reserpine, the most potent alkaloid from R. serpentina roots. This end-to-end protocol presents the establishment of hairy root culture from the leaf explants of R. serpentina through the infection of A. rhizogenes strain A4 in liquid B5 culture medium and its up-scaling in a 5 L bench top, mechanically agitated bioreactor. The transformed nature of roots was confirmed through PCR-based rol A gene amplification in genomic DNA of putative hairy roots. The extraction and quantification of reserpine in bioreactor grown roots has been done using monolithic reverse phase high-performance liquid chromatography (HPLC).

Synergistic effects of polyploidization and elicitation on biomass and hyoscyamine content in hairy roots of Datura stramonium

Description of the subject. The hyoscyamine, a tropane alkaloid, widely used in medicine, can be produced from Datura sp. (Solanaceae). However, its content in the spontaneous roots remains low; therefore, hairy roots (HRs) were envisaged as a potential alternative to improve its biosynthesis. The hairy roots are characterized by a good genetic stability and a rapid growth. Indeed, Datura stramonium HRs have widely been studied in the perspective of improving the yield of hyoscyamine. This study is part of this same perspective. Objectives. This paper aims to study the effects of polyploidization of HRs induced by colchicine in synergy with elicitation (with acetylsalicylic [ASA] or salicylic acids [SA]) on the hyoscyamine content in D. stramonium. Method. Colchicine was applied at different concentrations and periods, on a selected hairy root line (LDS) of D. stramonium obtained by infection with Agrobactrium rhizogenes strain A4. The selection of tetraploid HR lines was performed by the cytogenetic analysis using light microscopy. The effect of polyploidization and elicitation was studied on the biomass (dry weight) and hyoscyamine content of HRs. Results. The untreated HR line (control) shows a diploid level with 2n = 24 chromosomes. However, the HR lines treated with colchicine show, in most cases, an endoreduplication of their genetic material. The survival rate of endoreduplicated lines varies between 30% and 93%, depending on concentration and exposure time to colchicine. Moreover, the tetraploid HR line shows an increase in its biomass and hyoscyamine content in comparison to the diploid HR line (LDS). Further, elicitation of HRs by ASA or AS at the 10-4 M concentration causes a low decrease or increase in dry weight, respectively. However, the same treatments show a significant increase in the yield of hyoscyamine in elicited HR lines. Consequently, our work indicates that the combination of polyploidy and elicitation can lead to significant improvements in hyoscyamine biosynthesis and content due to their synergistic effects. Conclusions. Elicitation of tetraploid hairy root lines improves significantly their content of hyoscyamine.

Enhanced trans-resveratrol production in genetically transformed root cultures of Peanut (Arachis hypogaea L.)

In the present study, 30 Ri-transformed root lines of peanut (Arachis hypogaea) cv. JL-24, a popular Indian cultivar, obtained following infection with Agrobacterium rhizogenes strains LBA9402, A4 and R1000 were selected on the basis of growth index and maintained in vitro for 3 years. The root lines showed high degree of branching and rapid, plagiotropic growth on phytohormone free solid N/5 medium but were devoid of root hairs. Trans-resveratrol was isolated by preparative HPLC from Ri-transformed roots and identified by ESI–MS/MS. Strain independent variability was observed among 30 Ri-transformed root lines on the basis of lateral root density per cm (7.60 ± 0.30 to 4.5 ± 0.5), relative thickness (0.54 ± 0.07 to 1.54 ± 0.1 mm), growth index (9.16 ± 1.1 to 17.79 ± 1.35 FW basis and 10.77 ± 0.95 to 19.46 ± 1.78 DW basis) and trans-resveratrol content 0.27 ± 0.03 (root line R1000-1) to 0.969 ± 0.141 mg g DW−1 (root line RIX-19) in solid N/5 medium, which was 4.1–14 fold greater than in excised non-transformed root cultures (0.06 ± 0.01 mg g DW−1). Optimum growth and productivity in liquid culture was achieved in N/5 medium supplemented with 0.01 % activated charcoal. Root line RIX-19 showed maximum trans-resveratrol accumulation (1.21 ± 0.09 mg g DW−1) and productivity (0.37 ± 0.08 mg per flask), which was 19 fold higher than non-transformed root cultures. This optimized protocol can be utilized for large scale cultivation of transformed root cultures in industrial bioreactors for mass synthesis of trans-resveratrol.

Iridoid and phenylethanoid glycoside production and phenotypical changes in plants regenerated from hairy roots of Rehmannia glutinosa Libosch.

Spontaneous shoot regeneration was obtained from the hairy roots of Rehmannia glutinosa cultured in liquid woody plant medium for 4 weeks in darkness after induction by Agrobacterium rhizogenes strain A4. These shoots were proliferated on solid Murashige and Skoog (MS) medium in 300 mL glass jars and in liquid MS medium in a 5 L nutrient sprinkle bioreactor. These media were supplemented with 0.1 mg L−1 of indole-3-acetic acid (IAA) and 1.0 mg L−1 of 6-benzylaminopurine. All shoots became rooted on MS agar medium containing IAA or indole-3-butyric acid within 4 weeks. The plantlets were then transferred into soil and grew in a greenhouse. The transgenic nature of the plants was confirmed by polymerase chain reaction (PCR) and reverse-transcriptase PCR analyses. The pRi-regenerated transformants demonstrated a few phenotypical alterations. Production of six iridoid (catalpol, aucubin, loganin, catalposide, harpagide, harpagoside) and two phenylethanoid (verbascoside and isoverbascoside) glycosides was determined in shoots cultured in vitro and leaves and roots of 6- and 12-month-old plants by ultra high performance liquid chromatography. The shoot culture was able to synthesize low amounts of catalpol, verbascoside and isoverbascoside. Leaves and roots of pRi-regenerants accumulated similar (harpagoside, isoverbascoside), higher (catalposide, aucubin, harpagide, verbascoside) or lower (catalpol, loganin) levels of the metabolites in comparison with untransformed R. glutinosa plants and their content varied with the age of the plants and the organ analyzed. However, the increase in shoot and root biomass of transformed plants resulted in a significantly greater yield of all analyzed compounds.

Evaluation of Total Phenolic Compounds and Insecticidal and Antioxidant Activities of Tomato Hairy Root Extract

Tomatoes are one of the most consumed crops in the whole world because of their versatile importance in dietary food as well as many industrial applications. They are also a rich source of secondary metabolites, such as phenolics and flavonoids. In the present study, we described a method to produce these compounds from hairy roots of tomato (THRs). Agrobacterium rhizogenes strain A4 was used to induce hairy roots in the tomato explants. The Ri T-DNA was confirmed by polymerase chain reaction amplification of the rolC gene. Biomass accumulation of hairy root lines was 1.7-3.7-fold higher compared to in vitro grown roots. Moreover, THRs efficiently produced several phenolic compounds, such as rutin, quercetin, kaempferol, gallic acid, protocatechuic acid, ferulic acid, colorogenic acid, and caffeic acid. Gallic acid [34.02 μg/g of dry weight (DW)] and rutin (20.26 μg/g of DW) were the major phenolic acid and flavonoid produced by THRs, respectively. The activities of reactive oxygen species enzymes (catalase, ascorbate peroxidase, and superoxide dismutase) were quantified. The activity of catalase in THRs was 0.97 ± 0.03 mM H2O2 min(-1) g(-1), which was 1.22-fold (0.79 ± 0.09 mM H2O2 min(-1) g(-1)) and 1.59-fold (0.61 ± 0.06 mM H2O2 min(-1) g(-1)) higher than field grown and in vitro grown roots, respectively. At 100 μL/g concentration, the phenolic compound extract caused 53.34 and 40.00% mortality against Helicoverpa armigera and Spodoptera litura, respectively, after 6 days. Surviving larvae of H. armigera and S. litura on the phenolic compound extract after 6 days showed 85.43 and 86.90% growth retardation, respectively.

Hairy roots of Dracocephalum moldavica: rosmarinic acid content and antioxidant potential

Hairy roots of Dracocephalum moldavica L. were induced using Agrobacterium rhizogenes strain A4. Transformed roots were obtained from shoot explants with low transformation frequency of up to 3 %. The effects of different liquid media: Murashige and Skoog (MS), Gamborg et al. (B5) and Woody Plant (WP) with full- and half-strength (½MS, ½B5, ½WP), on biomass accumulation and rosmarinic acid (RA) content were investigated. The hairy roots were cultured in photoperiod (16 h light/8 h dark) and darkness. Biomass of D. moldavica hairy roots was the highest (7.23 g flask−1 of fresh weight and 0.89 g flask−1 of dry weight) in the cultures grown in WP medium under periodic light. Ultra performance liquid chromatography analysis revealed the highest RA content (78 mg g−1 dry wt) in roots cultured in ½B5 medium under photoperiod conditions. It was about tenfold higher compared to roots of field-grown mother plants. Antioxidant activities and total phenolic contents of methanolic extracts of D. moldavica hairy roots cultured in ½B5 and WP media under photoperiod and darkness and roots of field grown plants were compared. All extracts were investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging and phosphomolybdenum reduction assays. Total phenolic contents were estimated by the Folin–Ciocalteu method. The methanolic extract of D. moldavica hairy roots grown in ½B5 medium under photoperiod possessed the strongest effects on reducing Mo and DPPH radical scavenging. The activities were significantly higher (p ≤ 0.05) than those of methanolic extract of roots of intact plants grown in the field. The most active methanolic extract of hairy roots was characterized by the highest level of rosmarinic acid and total content of phenolic compounds.

Effects of Phytohormones and Jasmonic Acid on Glucosinolate Content in Hairy Root Cultures of Sinapis alba and Brassica rapa

Although some study have established hairy root cultures from brassicaceous plants with glucosinolates (GS) as characteristic secondary metabolite, studies are missing which compare hairy roots with the corresponding mother plants. Therefore, two different plant species-Sinapis alba and Brassica rapa subsp. rapa pygmeae teltoviensis-were transformed with the Agrobacterium rhizogenes strain A4. Aliphatic and indolyl GS were present in B. rapa, exhibiting larger quantities in leaves than in roots. Aromatic p-hydroxybenzyl GS were found particularly in the leaves of S. alba. However, the proportion of indolyl GS increased suddenly in transformed hairy roots of S. alba and B. rapa. Cultivation with the phytohormone kinetin (0.5 mg L(-1)) enhanced GS accumulation in B. rapa hairy roots, however not in S. alba, but 2,4-D (0.4 mg L(-1)) induced de-differentiation of roots in both species and reduced GS levels. GS levels especially of 1-methoxyindol-3ylmethyl GS increased in hairy roots in response to JA, but root growth was inhibited. While 2 weeks of cultivation in 100 to 200 μM JA were determined at optimum for maximum GS yield in S. alba hairy root cultures, 4 weeks of cultivation in 50 to 100 μM JA was the optimum for B. rapa.