Stimulation of adventitious rooting of Taxus species by thiamine

Summary Results obtained from using root inducing compounds on Taxus species cuttings suggested that rooting could be significantly enhanced by the presence of thiamine. This observation was verified using a root inducing solution containing a set concentration of IBA (0.2%), NAA (0.1%), and supplemented with various concentrations of thiamine. The best rooting response for Taxus cuspidata stem cuttings was found using this solution supplemented with 0.08% thiamine. Rooted cuttings were easily established and developed into vigorous plants. In addition, Taxus brevifolia shoots obtained from tissue cultures via in vitro organogenesis also responded favorably to this 0.08% thiamine supplemented rooting solution.     

N,N′-bis-(2,3-Methylenedioxyphenyl)urea and N,N′-bis-(3,4-methylenedioxyphenyl)urea enhance adventitious rooting in Pinus radiata and affect expression of genes induced during adventitious rooting in the presence of exogenous auxin

We have analyzed the effect of N,N′-bis-(2,3-methylenedioxyphenyl)urea (2,3-MDPU) and N,N′-bis-(3,4-methylenedioxyphenyl)urea (3,4-MDPU), two symmetrically substituted diphenylurea derivatives with no auxin or cytokinin-like activity, on the rooting capacity of Pinus radiata stem cuttings. Results indicate that both diphenylurea derivatives enhance adventitious rooting in the presence of exogenous auxin (indole-3-butyric acid, IBA), even at low auxin concentration, in rooting-competent cuttings, but have no effect on the adventitious rooting of low or null competent-to-root cuttings. Histological analyses show that, in the simultaneous presence of MDPUs and low concentration of exogenous auxin, adventitious root formation is induced in the cell types that retain intrinsic competence to form adventitious roots in response to auxin. The time course of cellular events leading to root formation and the time of root emergence are closely similar to that observed in cuttings treated only with higher auxin concentration. In addition, the mRNA level of a P. radiata SCARECROW-LIKE gene, which is significantly induced in the presence of the optimal concentration (10 μM) of exogenous auxin needed for cuttings to root, is increased in the presence of MDPUs and low concentration of exogenous auxin (1 μM). The expression of a P. radiata SHORT-ROOT gene in rooting-competent cuttings during adventitious rooting is also affected by the presence of MDPUs when combined with auxin. As MDPUs do not affect the expression of either gene in the absence of exogenous auxin, but only in its presence, we suggest that MDPUs could interact, directly or indirectly, with the auxin-signalling pathways in rooting-competent cuttings during adventitious rooting.     

Promotion of adventitious root formation by 4-chlororesorcinol: A polyphenol oxidase inhibitor

The extent of rooting in cuttings of Phaseolus vulgaris L., and Vigna radiata Wilcz. was affected by 4-chlororesorcinol, a polyphenol oxidase inhibitor. More root primordia and more roots were formed after 4-chlororesorcinol treatment both with and without 10^-5M Indole butyric acid. Promotion of rooting was observed also in cuttings of Elaeagnus pungens, Gypsophilia elegans and Kalanchoe blossfeldiana. The enhancement in bean and mung bean was accompanied by a concomitant wider spatial distribution of the primordia and the resulting adventitious roots. The formation of primordia in the treated cuttings was delayed by 12–24 hours, compared to untreated cuttings. The treatment was effective only when given during the first hours after the preparation of the cutting of bean and mung bean, suggesting involvement in the initiation stage. Hypocotyl extracts of mung bean cuttings, pretreated with 4-chlororesorcinol, exhibited reduced polyphenol oxidase activity. The inhibition was not reversed by washing of the treated extract in 50% acetone or by an overnight dialysis, suggesting tight or maybe even irreversible binding of the inhibitor to the enzyme.Abbreviations 4-CR 4-chlororesorcinol - IBA Indole butyric acid - PPO polyphenol oxidase     

The effect of indole-3-acetylaspartic acid on adventitious root formation on bean cuttings

The influence of indole-3-acetylaspartic acid (IAAsp) on rooting of stem cuttings from bean plants (Phaseolus vulgaris L.) of different ages, cultivated at different temperatures (17°, 21° and 25°C) was studied and compared to that of indole-3-acetic acid (IAA). At a concentration of 10^–4 M, IAAsp only nonsignificantly stimulated adventitious root formation, approximately to the same level as IAA in all treatments. IAAsp at 5×10^–4 M further enhanced rooting, by up 200% of control values, with little influence of temperature conditions and stock plant age. This concentration of IAA usually stimulated rooting more than the conjugate. The largest differences between the effects of IAAsp and IAA occured at the highest cultivation temperature of 25°C where stock plant age also influenced the response. The number of roots produced in comparison with the control, was enhanced from 350% on cuttings from the youngest plants to more than 600% on cuttings from the oldest. In contrast to the conjugate, 5×10^–4 M IAA induced hypocotyl swelling and injury of the epidermis at the base of cuttings, in all treatments.     

Effect of abscisic acid on endogenous IAA, auxin protector levels and peroxidase activity during adventitious root initiation in Vigna radiata cuttings

Endogenous levels of free and conjugated IAA, auxin protectors (Prs) and peroxidase (PER) activity and their relation to adventitious root initiation (ARI) were investigated at the potential sites of adventitious rooting in relation to exogenous application of 250 μM ABA during the first 120 h after treatment. Cuttings from 7-day-old mung bean [Vigna radiata (L.) Wilcz.] seedlings were treated with 125, 250, and 500 μM ABA for 24 h. ABA significantly stimulated ARI but extremely inhibited epicotyl growth as compared to control. Free and conjugated IAA were measured by reversed-phase high performance liquid chromatography while Prs and PER activities were measured spectrophotometrically. The present results also indicate that endogenous free IAA levels peaked later in ABA-treated cuttings than that in control, suggesting that ABA extended the length of the induction phase of rooting process in treated cuttings and that might explain the significant delay of the appearance of roots at the treated cuttings. Higher level of IAA conjugates was found in ABA-treated cuttings than that in untreated ones. Pr level also peaked later in ABA-treated cuttings than that in control, indicating that ABA extended the period of Pr activity. An initial temporary decrease of PER activity was found in associating with high levels of free IAA and Prs during most of the primary events, while the opposite occurred during the secondary events of adventitious rooting process in both treated and untreated cuttings. Thus, ABA may stimulate ARI in mung bean Vigna radiata cuttings by regulating the concentration and /or activities of endogenous IAA, Prs, and PER activity in favor of inducing a large number of adventitious roots at their potential sites of adventitious rooting.     

Methyl gallate and its 3-glucoside promote rooting in bean cuttings

Methyl gallate stimulated adventitious root formation in cuttings of bean (Phaseolus vulgaris L.). This polyphenol was quickly metabolized into 3-glucosyl methyl gallate to such an extent that 4 h after application no methyl gallate was detected. The isolated glucoside when supplied exogenously at 0.5 mM also enhanced rooting; the effect was 2-fold greater than that of methyl gallate. The glucoside persisted in the cuttings for 72 h after treatment. Because methyl gallate is rapidly transformed to a stable glucoside, we suggest that the root stimulation effect could be ascribed to its glucoside.     

Leaf number and position effects on the survival and performance of grape microcuttings in vitro,and the sensitivity of the cut nodal region to the medium

The presence of leaf in microcuttings of grape cvs. Arka Neelamani and Thompson Seedless promoted rooting in vitro (MS, 1 μM IAA, 0.1 μM GA₃, 3% sucrose) but the effect varied depending on the number of leaves and position of the leaf on the cutting. Single node cuttings with a full-length lower internode and a lamina at top (LAT) showed earlier rooting and more root and shoot growth than cuttings with lamina positioned at the middle (LAM), while cuttings with a leaf at the base (LAB) of the cutting and full-length upper internode exhibited a lower percent rooting and sprouting, poor root and shoot growth, and low survival. Partial or complete removal of the upper internodal segment in LAB cuttings improved rooting and sprouting suggesting the possible operation of an inhibitory effect by the upper internode. Retaining an upper leaf in LAB cuttings (LAB+UL) resulted in necrosis of the upper leaf often followed by the lower one. The extent of necrotic damage was influenced by the leaf area and position or age of the cutting on the stock shoot. Retaining the lower internode in LAB and LAB+UL cuttings which held the node–leaf junction away from the medium, or reducing the concentration of MS medium helped significantly in improving the survival and performance of these cuttings. The difference in reaction between LAB and LAT cuttings was attributable mainly to the difference in the sensitivity of the stem part that came in contact with the medium. Removal of the leaf in LAB cuttings reduced this sensitivity. The majority of the LAB and LAB+UL cuttings, as well as non-rooting or delayed rooting LAT and LAM cuttings, exhibited high purple pigmentation of leaf, petiole and stem. Two-leafed cuttings in vitro showed poor survival, less rooting and low plantlet output compared to single-leafed cuttings. This revised version was published online in June 2006 with corrections to the Cover Date.     

Enhancement of adventitious root formation in mung bean cuttings by 3,5-dihalo-4-hydroxybenzoic acids and 2,4-dinitrophenol

3,5-Dihalo-4-hydroxybenzoic acids enhanced adventitious root formation in mung bean (Vigna radiata L.) cuttings. 3,5-Diiodo-4-hydroxybenzoic acid was more active than 3,5-dichloro-4-hydroxybenzoic acid, increasing the number of roots formed by about 4-fold. 2,4-Dinitrophenol also enhanced significantly adventitious root formation in mung bean cuttings. The phenolic compounds were active with or without indole-3-acetic acid. The possible mechanism by which these phenolic compounds enhance rooting is discussed.Abbreviations CCCP carbonyl cyanide 3-chlorophenylhydrazone - DIHB 3,5-diiodo-4-hydroxybenzoic acid - DNP 2,4-dinitrophenol     

IBA浓度、扦插时间对江西杜鹃和百合花杜鹃扦插生根的影响

为探明有鳞大花亚组杜鹃扦插生根的最佳IBA浓度和扦插时间,该研究以江西杜鹃、百合花杜鹃为材料,分别采用腐叶土+河沙(1:1)、泥炭+珍珠岩+蛭石(3:1:1)基质,开展了4个IBA浓度和4个扦插时间的生根试验.结果表明:IBA浓度对除老叶留存数外的所有指标有显著影响,其中100 mg·L-1 IBA处理生根率、新梢长最大,腐烂率最低,其它指标也表现良好,为最佳生根浓度;50 mg·L-1 IBA处理根幅、新梢率最大,但不定根数最少,效果其次;200 mg·L-1 IBA处理促进根系生长,但生根率较低、特别是显著抑制新梢发育;对照处理生根效果最差.扦插时间对所有生根指标均有显著影响,早春(04-18)木质化硬枝扦插除老叶留存数较差外,其它指标均表现极佳,为最适扦插时间;秋季(10-19)半木质-木质化过渡枝扦插效果其次;夏季(06-21)嫩枝及(08-16)半木质化枝生根效果极差,不宜进行扦插育苗.物种、基质对生根指标也有显著影响,百合花杜鹃扦插生根能力强于江西杜鹃,泥炭+珍珠岩+蛭石(3:1:1)基质生根效果优于腐叶土+河沙(1:1).该研究结果首次发现早春新梢萌发前采用木质化硬枝扦插可以显著提高两种杜鹃的生根效果,为该亚组杜鹃的扦插育苗提供了科学依据.     

Stimulation of in vitro root and shoot growth of potato by increasing sucrose concentration in the presence of fluridone,an inhibitor of abscisic acid synthesis

Fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, strongly stimulated rooting of nodal stem segments of potato (Solanum tuberosum L.) cultivar Arran Banner cultured in darkness on tuberisation medium. Inclusion of 10^-6 M ABA in the culture medium prevented this rooting response, indicating that root proliferation in the presence of fluridone could be due to inhibition of ABA synthesis. The rooting response to fluridone (increased total root number and root fresh weight) was obtained only at high sucrose concentrations (0.175 and 0.234 M) and was demonstrated with two potato cultivars and two culture media; one which favoured tuberisation and one which did not. Shoot numbers were also increased, but to a lesser extent than root numbers, and total fresh weight of plant material per culture was greatly increased by inclusion of both fluridone (10^-6 or 10^-5 M) and 0.234 M sucrose in the culture medium. The role of sucrose was not simply osmotic because when the osmolarity of fluridone medium was increased using mixtures of mannitol and sucrose, no root proliferation occurred unless sucrose predominated in the mixture.     

Abscisic acid and Ethrel abolish the inhibition of adventitious root formation of paclobutrazol-treated bean primary leaf cuttings

Paclobutrazol (PB), a triazole growth retardant and an inhibitor of gibberellin biosynthesis, reduced at 17 μM concentration the adventitious root formation of bean primary leaf cuttings. Treatments with 5 μM ABA or 4 μM Ethrel, an ethylenereleasing compound, restored the rooting of PB-treated cuttings. Ethylene production and the content of the precursor 1-aminocyclopropane-l-carboxylic acid (ACC) were enhanced in root-forming tissues of PB-treated petioles 48 h after ABA application. The effect of ABA could be abolished by 10 μM CoCl₂, an inhibitor of ACC oxidase. Thus, ABA might stimulate rooting through its effect on ethylene release. 2 mM silver thiosulphate, an inhibitor of ethylene action, decreased the rooting of PB-treated cuttings similarly to Co²⁺, but failed to negate the ABA effect. These data indicate that the effect of PB on rhizogenesis is not associated directly with the inhibition of the biosynthesis of gibberellins Acknowledgements: We are grateful to Gabriella Biró. This work was supported by the Hungarian National Science Research Foundation (OTKA), Project No. 462.     

Effect of auxins on adventitious rooting from stem cuttings of candidate plus tree Pongamia pinnata (L.), a potential biodiesel plant

Pongamia pinnata, commercially important tree species used to produce biofuels, is known for its multipurpose benefits and its role in agro-forestry. Present study examines the amenability of vegetative propagation and effect of maturation in candidate plus tree P. pinnata through rooting of stem cuttings treated with varying concentrations and combinations of auxins. The performance of the cuttings was evaluated using SAS GLM software and the data were analyzed as a one-way classified data with and without sub sampling for inferring auxin concentration that can be included in programmes aimed at genetic improvement of the tree species. All auxin treatments promoted sprouting and at lower concentrations triggered/enhanced rooting of cuttings. The effectiveness was in the order of IBA > NAA > IAA when applied singly. IBA at 4.92 mM was found to be most effective where rooting percentage and number of roots were significantly higher (P < 0.01) than in control. However higher concentrations of auxins above 7 mM in general inhibited the rooting of cuttings. The interaction among auxins was found to be effective in root induction and differentiation and the most stimulating effects were observed in three-component mixture. The effect of other cutting characteristics such as juvenility and cutting position on rooting is also discussed.     

Degradation of exogenous indole-3-butyric acid and riboflavin and their influence on rooting response of papaya in vitro

Varying concentrations of riboflavin were added to a De Fossard et al. (1974) basal medium containing 10 µM IBA and the effect on adventitious root initiation on shoots of Carica papaya L. was studied. Ninety percent root initiation occurred in 11 days when 1 µM riboflavin was added to the culture medium. Smaller rooting percentages were observed and roots emerged more slowly with riboflavin concentrations greater and less than 1 µM. Tissue culture media were maintained at 27°±1°C in either darkness or 12-h photoperiods for 28 days, and concentrations of riboflavin and IBA were measured at regular intervals using HPLC analysis. In a De Fossard et al. (1974) basal medium, riboflavin concentrations (0.1, 1.0, 10.0 µM) decreased rapidly in light and were independent of the presence of IBA. IBA concentration steadily decreased when media was placed in light, and increasing riboflavin concentrations accelerated the reduction of IBA levels. Concentrations of IBA and riboflavin were stable with dark incubation.Abbreviations IAA indole-3-acetic acid - IBA indole-3-butyric acid     

Microcutting leaf area,weight and position on the stock shoot influence root vigour,shoot growth and incidence of shoot tip necrosis in grape plantlets in vitro

The physiological parameters of microcuttings, namely leaf area, weight (wt) and position on the stock shoot, had significant effects on root vigour, microshoot growth and incidence of shoot tip necrosis (STN) in cultures of grape (Vitis vinifera L.) ‘Arka Neelamani’. Single-node leafy cuttings cultured in MS medium containing 1 μM IAA and 0.1 μM GA₃ generally rooted first and subsequently sprouted into a single shoot. Small leafed cuttings exhibited slow root emergence, poor quality roots, early sprouting and weak shoot growth. Large leafed cuttings on the other hand, showed early rooting, vigorous roots, delayed sprouting and healthier shoots. Significant correlations were observed between fresh root wt per plantlet at 1 month in culture and wt of lamina, total wt and leaf area of the cuttings in that order. A significant correlation also existed between wt of roots and height or wt of the sprout that developed. The study suggests that the weight or area of the leaf governed the root growth in a microcutting. STN was observed in some plantlets particularly those derived from large leafed cuttings. Such cuttings showed vigorous roots and delayed but fast sprout growth that ended in STN. Plantlets showing STN had less Ca⁺⁺ and Mg⁺⁺ in the shoot tissue than in the shoots of normal plantlets while the roots showed similar Ca⁺⁺ or higher Mg⁺⁺ contents. Both had comparable amounts of cytokinins in shoot and root tissues. This revised version was published online in June 2006 with corrections to the Cover Date.     

Root-promoting Substances in Salix alba

Root-promoting substances were extracted from softwood cuttings of Salix alba L. by centrifuging them with water or by shaking the ground freeze-dried stems with water. Rooting substances were partitioned by paper chromatography or chemical fractionation and their rooting activity was tested by mung bean cuttings. Both extracts indicated three major root -promoting fractions at Rf 0-0.1, 0.7-0.8, and 0.3-0.4 in a decreasing order of their activities when paper chromatographed with isopropanol:ammonia:water 8:1:1 v/v. The strongest one indicated an apparent synergistic rooting effect with indol-3yl-acetic acid (IAA) regardless of the extraction method. These results indicate that water can extract from freeze -dried sample the similar rooting substances found in the centrifugal diffusates. The Rf 0–0.1 fraction consisted of at least four fractions and the strongest one did not move from the starting line on the chromatogram when isopropanol:ammonia:water 8:1:1 was used. This starting line fraction was extremely strong in rooting activity and its highest concentration resulted in 8.7 times as many roots as controls. More thain additive rooting effect between IAA and the fraction was found only at the highest concentration. The fraction was very soluble in water but insoluble in chloroform or ethyl ether and only stimulated rooting of mung bean cuttings when it was applied within 3 days after cuttings were made. It had no effect in lengthening roots. The starting line fraction was further found to have four root-promoting subfractions at Rf 0.05, 0.35, 0.65, and 0.85 when it was chromatographed in 60 % isopropanol. Among these four, the subfractions at Rf 0.65 and 0.35 were strongly root promotive and displayed more than additive root promotion with IAA at the highest concentrations studied.     

Chemical induction of adventitious root formation in Taxus baccata cuttings

The effect of some auxins (IBA and NAA), phenolic compounds (phloroglucinol, gentisic acid and coumarin), a combination of auxins and phenolics, and a systemic fungicide (Bavistin) have been examined for stimulatory effects on adventitious root formation in stem cuttings (current season's growth) of Taxus baccata L. In general lower concentration (0.25 mM) of both IBA and NAA was more effective in inducing rooting of cuttings taken from both male and female trees. The combined treatment of IBA+NAA (0.25 mM each) showed some success in cuttings from male trees only (55%, compared to 15% rooting in cuttings from female trees). Generally, the callus formation was quite high (70%) in all auxin treatments (alone or in combination). Among the phenolics, 40% rooting success was achieved with phloroglucinol only, while coumarin and gentisic acid were ineffective. The combined treatment of auxins and phenolics also failed to promote rooting. On the other hand, Bavistin was extremely effective for callusing (90%) as well as rooting (80%). The effectiveness of various compounds tested for rooting of young stem cuttings declined in the order: 0.25 mM IBA>0.05% Bavistin>0.25 mM NAA>1.25 mM IBA>15 mM phloroglucinol>IBA+NAA (0.25 mM each). In addition to the auxins, IBA and NAA that are widely used for commercial propagation, the auxin-like properties of the fungicide Bavistin could be exploited for adventitious rooting in T. baccata, and in other plant species.     

Rhizogenesis and root growth ofCarica papaya L.in vitro in relation to auxin sensitive phases and use of riboflavin

High rooting percentages and high-quality adventitious root systems for papaya (Carica papaya L.) were obtainedin vitro by appropriate auxin source, duration of exposure to auxin and use of riboflavin. Root initiation of papaya shoots was higher using IBA than IAA, NAA or PCPA. Maximum rooting percentage (96%) was achieved by exposure of shoots to a medium containing 10 µM IBA for 3 days before transfer to a hormone-free medium. However, the resultant plants had small shoots and callused roots. Shoot and root growth were improved when shoots were transferred after 2 days from medium containing 10 µM IBA to hormone-free medium containing 10 µM riboflavin. Good root initiation, and root and shoot growth were also obtained when shoots were incubated for 2 days in darkness on a medium containing 10 µM IBA and 31 µM riboflavin before transfer to light. Alternatively, cultures could be placed in the light on medium containing 10 µM IBA, and after 1 day the medium overlaid with 300 µM riboflavin (1 ml over 10 ml of medium).     

The Effects of Ascorbate on Root Regeneration in Seedling Cuttings of Tomato

The changes in ascorbate (ASC) and dehydroascorbate (DHA) levels and the activities of ascorbate metabolising enzymes were examined during adventitious root formation in cuttings of tomato (Lycopersicon esculentum Mill. cv. Paw) seedlings. The effects of ASC, DHA and the immediate ascorbate precursor – galactono-γ-lactone (GalL) supplemented to the culture medium on the rooting response, ascorbate content and the activities of the ASC-metabolising enzymes were also investigated. The cuttings treated with abovementioned compounds formed more roots then control plants. However, in contrast to the number of regenerated organs, the elongation of newly formed roots was markedly inhibited. Treatment with auxin (IAA) resulted in a similar phenotype. The inhibitor of auxin polar transport-TIBA (2,3,5-triiodobenzoic acid) effectively blocked rooting. The inhibitory effect of TIBA was reversed by auxin and ASC treatments, while DHA and GalL were ineffective. Both auxin and ASC stimulated cell divisions in an area of pericycle layer of TIBA-treated rooting zones, that enabled cuttings to form roots in the presence of the inhibitor of auxin polar transport. It has been found that the first stages of rooting, preceding the emergence of roots, are accompanied by an increase in endogenous content of ASC with a peak in the 3rd day of rooting. Subsequent stages, when elongation of newly formed roots occurs, are characterised by low level of ASC. The activities of the ascorbate peroxidase (APX), ascorbate oxidase (AOX), ascorbate free radical reductase (AFRR) and dehydroascorbate reductase (DHR) increased in the first 3 days of root formation. The initial period of rooting was also accompanied by the increase of the hydrogen peroxide content and the activities of catalase (CAT) and guaiacol peroxidase (GPX) in the rooting zones. IAA, ASC, DHA as well as Gal stimulated the APX activity, however the rise of the enzyme's activity induced by ASC, DHA and Gal was reversed by TIBA, which was found to inhibit APX. Only exogenous IAA was able to maintain the high level of APX activity in the TIBA-treated cuttings. AOX was strongly affected by ASC and GalL – treatments, its activity increased in the cuttings grown on the media containing ASC in the absence as well as in the presence of TIBA. On the other hand, GalL-dependent stimulation of its activity was suppressed if TIBA was present in a rooting medium.     

A simple and efficient method for clonal propagation of Casuarina sumatrana (de Vriese) L. Johnson

A new and efficient method for clonal propagation of Casuarina sumatrana by rooting stem cuttings is described. High percentage (about 60–70%) of rooting was achieved with mature softwood stem cuttings. A quick-dip of 5 s in NAA (1–10mM) solution followed by sand culture under high humidity were required for a high rate of survival and rooting of stem cuttings. A simple, closed chamber propagation system, using fluorocarbon polymer (tetrafluoroethyleneperfluoroalkyl vinyl ether) film (Neoflon PFA film), was successfully developed for the rooting of stem cuttings without mist. Rooted cuttings inoculated with Frankia were easily transplanted and established in field conditions with very low (about 3%) mortality. The significance of these findings for mass clonal propagation of C. sumatrana is discussed.Abbreviations IBA indole-3-butyric acid - NAA -naphthaleneacetic acid     

l-DOPA (l-3,4-dihydroxyphenylalanine) affects rooting potential and associated biochemical changes in hypocotyl of mung bean, and inhibits mitotic activity in onion root tips

A study was undertaken to explore the effect of l-DOPA (l-3,4-dihydroxyphenylalanine) on the rooting potential of hypocotyl cuttings of mung bean (Phaseolus aureus Roxb. var. SML-32) and related biochemical changes at the post-expression phase. At lower concentrations of (0.0001–0.1 mM) l-DOPA, there was no change in rooting potential, though the average number of roots per cutting and root length were significantly decreased (except at 0.0001 mM). However, at 1.0 mM concentration, a 50% inhibition in rooting potential was noticed and the root number and length were severely reduced. In contrast, at 2.5 mM l-DOPA, none of the hypocotyl cutting rooted. The decrease in rooting potential was associated with a significant effect on the biochemical changes measured in terms of protein and carbohydrate metabolism and activity of peroxidases. In the l-DOPA treated hypocotyl cuttings, there was a significant reduction in the protein and carbohydrate content, whereas activities of associated enzymes proteases and amylases decreased, particularly at higher treatment concentration (>1.0 mM). It indicated negative effect of l-DOPA on these two important metabolic processes. Likewise, activity of peroxidases also decreased in the l-DOPA treated hypocotyl mung bean cuttings thereby indicating its role in suppressing rhizogenesis as the enzyme is involved in lignification process during cell division. l-DOPA suppressed mitotic activity in the root tip cells of onion indicating thereby its interference with the cell division, which is required for the formation of new meristematic tissue during rhizogenesis. Based on the obtained results, it is concluded that l-DOPA interferes with the various biochemical processes in the mung bean hypocotyl cuttings thereby affecting their rooting potential.