In vitro somatic embryogenesis from callus culture of the timber yielding treeHardwickia binata Roxb.

Somatic embryogenesis was achieved in callus cultures derived from immature cotyledonary explants ofHardwickia binata Roxb., a multipurpose leguminous tree, on semisolid modified Murashige and Skoog's (mMS) medium containing 2900 mg/l potassium nitrate (KNO₃) supplemented with 4.64 µM kinetin (Kn) and 5.37µM a-naphthaleneacetic acid (NAA). Somatic embryos proliferated rapidly after transfer to MS basal medium supplemented with 2052.6 µM L-glutamine and 0.084 µM gibberellic acid (GA₃). Maturation of somatic embryos was achieved on half-strength MS basal medium supplemented with 1.23 µM IBA and 2% (w/v) sucrose. Histological studies confirmed different developmental stages of somatic embryogenesis inHardwickia binata. Abbreviations BA N⁶-benzyladenine - Kn kinetin - NAA a-naphthaleneacetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - IBA indole-3-butyric acid - GA₃ gibberellic acid - MS Murashige and Skoog (1962) medium - mMS modified Murashige and Skoog (1962) medium     

Somatic embryogenesis and in vitro flowering of 3 species of bamboo

Plant regeneration via somatic embryogenesis was achieved in callus cultures derived from nodal explants of in vitro grown seedlings and excised mature zygotic embryos of three bamboo species on Murashige and Skoog's (MS) basal medium supplemented with 0.5 mg/l kinetin (Kn), 2.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), 10 mg/l adenine sulphate (Ads) and 3% (w/v) sucrose incubated in the light or in the dark. Somatic embryos germinated (95–98%) into normal plants and were transferred to soil with 95% success. In vitro flowering was induced on shoots developed from nodal explants taken from somatic embryo regenerated plants of Bambusa vulgaris, Dendrocalamus giganteus and Dendrocalamus strictus on half-strength MS basal medium supplemented with 0.25 mg/l indole-3-butyric acid (IBA), 0.5 mg/l Ads, 0.5 mg/l gibberellic acid (GA₃) and 3% sucrose.Abbreviations BAP 6-benzylaminopurine - Kn kinetin - Ads adenine sulphate - IBA indole-3-butyric acid - NAA 1-naphthaleneacetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - MS Murashige and Skoog (1962) basal medium - GA₃ gibberellic acid     

Gibberellic acid improves water deficit tolerance in maize plants

The combination effects of water stress and gibberellic acid (GA₃) on physiological attributes and nutritional status of maize (Zea mays L. cv., DK 647 F1) were studied in a pot experiment. Maize plants were grown in the control (well watered WW) and water stress subjected to treated both water stress and two concentrations of gibberellic acid (GA₃ 25 mg L⁻¹, 50 mg L⁻¹). WS was imposed by maintaining the moisture level equivalent to 50 % pot capacity whereas the WW pots were maintained at full pot capacity. Water stress reduced the total dry weight, chlorophyll concentration, and leaf relative water content (RWC), but it increased proline accumulation and electrolyte leakage in maize plants and appears to affect shoots more than roots. Both concentrations of GA₃ (25 and 50 mg L⁻¹) largely enhanced the above physiological parameters to levels similar to control. WS reduced leaf Ca²⁺ and K⁺ concentrations, but exogenous application of GA₃ increased those nutrient levels similar or close to control. Exogenous application of GA₃ improved the water stress tolerance in maize plants by maintaining membrane permeability, enhancing chlorophyll concentration, leaf relative water content (LRWC) and some macro-nutrient concentrations in leaves.     

Factors influencing direct shoot regeneration from mature leaves of Jatropha curcas, an important biofuel plant

In order to establish a highly efficient and sustainable regeneration system, we systematically researched the key factors affecting direct shoot regeneration from Jatropha curcas leaves that were collected from Hainan (HN1-1), Lijiang (LJ3-1), and Yuxi (YX2-12) provinces in China. The L₉(3⁴) orthogonal test of thidiazuron (TDZ), kinetin (Kn), and gibberellic acid (GA₃) were studied, and the explant type, growth age, and cultivar of leaves were subsequently investigated. Simultaneously, the combinations of plant growth regulators (PGRs) promoting shoot bud proliferation, elongation, and root establishment were examined. The results showed that the best medium for shoot bud induction was Murashige and Skoog (MS) medium supplemented with 1.0 mg/L TDZ, 0.5 mg/L Kn, and 0.5 mg/L GA₃. TDZ was the key PGR, while Kn and GA₃ played an important role in shoot bud elongation and the number of shoots per leaf disk, respectively. The induced shoot buds proliferated and readily elongated in MS medium with 0.3 mg/L 6-benzylaminopurine and 0.01 mg/L indole-3-butyric acid (IBA) and established roots in half-strength MS medium supplemented with 2.0 mg/L IBA. Using the previously described methods, the third to fifth leaves were found to be the best explant source for shoot bud induction, with a high induction rate, large shoot numbers per disk, excellent proliferation, and consistent rooting. With the use of this regeneration system, the shoot bud induction rate increased from the reported rate of 53.5% to more than 90% using different explants and cultivars, and the shoot number per leaf disk (shoot length?≥?0.5 cm) increased from 1.6 to 3.5. Thus, this optimized regeneration system will effectively promote the propagation and genetic transformation of J. curcas.     

Plant regeneration and ploidy variation in culture derived plants of Asclepias curassavica L

Clonal propagation of medicinal milkweed, Asclepias curassavica L. (Asclepiadaceae) was achieved by culturing excised nodes on MS medium (Murashige and Skoog, 1962) supplemented with different hormone combinations. Both BAP and Kn were found equally effective for shoot initiation. IAA and NAA were found suitable for root induction. Combinations of Kn and NAA induced both roots and shoots after 30 days of culture. Chromosomal variation was observed in the roots of in vitro regenerated plants. Regenerants with higher chromosome number (33; 2n=22) obtained on MS medium in response to 9.2 M Kn+10.7 M NAA showed vigorous growth and higher propagation rates in culture than the plants possessing less than the diploid chromosome number (2n–2=20, 2n–4=18). Such variations are more likely due to genetic fitness of different aneuploids grown on a particular nutrient medium.Abbreviations IAA 3-Indoleacetic acid - NAA Naphaleneacetic acid - 2,4-D 2,4-Dichlorophenoxyacetic acid - IBA Indolebutyric acid - Kn Kinetin - BAP Benzyladenine - GA₃ Gibberellic acid - S Shoot - R Root     

Synergistic effect of gibberellic acid and indole-3-acetic acid on rooting in stem cuttings of Abelmoschus esculentus Moench

Indole-3-acetic acid (IAA) and gibberellic acid (GA₃) enhanced the formation of roots on the stem cuttings of Abelmoschus esculentus. The effect increased considerably when both IAA and GA₃ were applied together.     

Effect of morphactin on certain plant growth substances in bean roots

The effect of morphactin (methyl-2-chloro-9-hydroxyfluorene-9-carboxylate) on the content of several plant growth substances in bean roots was determined. Beans (Phaseolus vulgaris L. cv. Spartan) were soaked in aqueous solutions of morphactin, 1 x 10^-4, 1 x 10^-5, and 1 x 10^-6M and grown in moist vermiculite. As controls were used beans grown in water-moistened vermiculite either intact or having the root tips removed (decapped). The roots, morphactin-treated, controls, and the decapped ones were analyzed for indol-3-yl acetic acid (IAA), indol-3-yl acrylic acid (IAcA), indol-3-yl pyruvic acid (IPyA), indol-3-yl lactic acid (1LA), abscisic acid (ABA), gibberellins GA₁, GA₃, GA₄, and GA₉ using gas-liquid chromatographic methods. Morphactin, while affecting the geotropical responses, changed also the growth substance content of roots. IAA, ABA, GA₁, and GA₉ contents decreased, IPyA, IAeA, GA₃, and GA₄ contents were not affected and ILA content increased slightly with increasing dosages of morphactin. Growth substance pattern of decapped roots resembled that of the roots treated with the highest dose, 1 x 10^-4M, of morphactin.     

Effects of ascorbic acid on axillary shoot induction in Tylophora indica (Burm. f.) Merrill.

A procedure for rapid in vitro multiplication of Tylophora indica (Burm. f.) Merrill., an important indigenous medicinal plant, has been developed. Addition of ascorbic acid was essential to induce sprouting of axillary buds. Optimum multiplication was observed on MS medium containing 6-benzylamino purine (5.0 mg l^–1), -naphathalene-acetic acid (0.5 mg l^–1) and ascorbic acid (100 mg l^–1). Rooting of in vitro produced shoots was readily achieved with indole-3-acetic acid alone (1.0 mg l^–1) in MS. The plantlets thus obtained were successfully transferred to pots in large numbers which grew normally.Abbreviations BAP 6-benzylamino purine - 2,4-D 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2ip 2-isopentenyladenine - Kn kinetin - MS Murashige & Skoog media - NAA -naphthalene acetic acid     

Effects of ascorbic acid and gibberellin A3 on alleviation of salt stress in common bean (Phaseolus vulgaris L.) seedlings

Salinity, a severe environmental factor, has limited the growth and productivity of crops. Many compounds have been applied to minimize the harmful effects of salt stress on plant growth. An experiment was conducted to investigate the interactive effects of exogenous ascorbic acid (AsA) and gibberellic acid (GA₃) on common bean (Phaseolus vulgaris L. cv. Naz) seedlings under salt stress. The changes of growth parameters, photosynthetic and non-photosynthetic pigments and potassium content showed that the addition of 1 mM AsA and/or 0.05 mM GA₃ considerably decreased the oxidative damage in common bean plants treated with 200 mM NaCl. The NaCl-stressed seedlings exposed to AsA or GA₃, specifically in their combination, exhibited an improvement in sodium accumulation in both roots and shoots, as compared to NaCl-treated plants. NaCl treatment increased hydrogen peroxide (H₂O₂) content and lipid peroxidation indicated by accumulation of malondialdehyde (MDA), whereas the interaction of AsA with GA₃ decreased the amounts of MDA and H₂O₂. In the meantime, interactive effect of these substances enhanced protein content and the activity of the antioxidant enzyme, guaiacol peroxidase, in common bean plants under salt stress. It was concluded that synergistic interaction between AsA and GA₃ could alleviate the adverse effects of salinity on P. vulgaris seedlings.     

Effects of gibberellic acid on hairy root cultures of Artemisia annua: Growth and artemisinin production

Summary Artemisinin (AN), a potent antimalarial drug that has been used for centuries as a folk remedy in China, is an effective treatment against quinine-resistant strains of Plasmodium. It can be produced through the in vitro culture of genetically transformed (hairy) roots. The effect of gibberellic acid (GA₃) on the growth and secondary metabolite production of hairy roots of Artemisia annua was investigated. Six different concentrations of GA₃ were tested in shaker flasks to determine the optimum concentration. GA₃ levels of 0.01–0.001 mg/l (28.9–2.89 μM) provided the most significant increase in biomass, and 0.01 mg/l (28.9 μM) produced the highest amount of AN. Investigation of growth kinetics showed that the use of GA₃ at 0.01 mg/l (28.9 μM) increased the growth rate of hairy roots of A. annua by 24.9%. Thus, the cultures treated with GA₃ reached stationary phase faster than control cultures.     

Effects of potassium and gibberellic acid on stem growth of whole sunflower plants

Abstract The effects of gibberellic acid (GA₃) on whole sunflower (Helianthus annuus L.) plants grown at three potassium (K) levels (0.0, 0.5 and 5.0 mM) were studied. A tenfold increase in the length of the first internode was observed when plants grown without K were treated with GA₃. The uneven K distribution along the plant (higher K content in the higher internodes) was enhanced by GA₃ treatment. Gibberellic acid increased the content of reducing sugars, especially in K-deficient plants. An increase in the K level in the nutrient solution resulted in a decrease of the osmotic potential of stem segments. Osmotic potential differences within the elongating first internode were increased by GA₃ treatment.     

Changing root and shoot architecture with the rolA gene from Agrobacterium rhizogenes: Interactions with gibberellic acid and polyamine metabolism

The effects of rolA on root and shoot architecture have been ascribed to a deficiency in gibberellic acid (GA₃) and to changes in polyamine metabolism. Using tobacco, we examined interactions among GA₃, a polyamine accumulation inhibitor (α-DL-difluoromethylornithine or DFMO) and the rolA gene controlled by the 35S CaMV promoter. We measured the effects of these three agents on architecture and polyamine accumulation in excised roots and whole plants grown in vitro. Previous work showed that DFMO or genetic transformation with the rolA gene from Agrobacterium rhizogenes, controlled by the 35S promoter (P_35S-rolA), caused excised tobacco roots to grow faster with altered root system architecture. We show that gibberellic acid (GA₃) reversed the effects of DFMO on the architecture of excised root systems, but neither reversed the effects of DFMO on growth, nor the changes in growth and architecture associated with P_35S-rolA. GA₃ treatment alone resulted in increased agmatine levels, suggesting that the inhibition of the effects of DFMO on architecture was through a stimulation of the arginine decarboxylase (ADC) pathway, GA₃ alone also inhibited the accumulation of putrescine and tyramine conjugates in excised roots. In tobacco plants growing in vitro DFMO and P_35S-rolA were associated with reduced shoot height, which was partially restored by GA₃ treatment; however, GA₃ also stimulated shoot height in the controls. GA₃ did not lessen the leaf wrinkling associated with P_35S-rolA. P_35S-rolA increased root number in young seedlings in vitro, and increased root system length in seedlings grown in soil. As in excised roots, the developmental changes linked to DFMO and P_35S-rolA were accompanied by reductions in putrescine titers. GA₃ treatment stimulated putrescine accumulation in stems and leaves, and partially reversed the negative effects of DFMO and P_35S-rolA on putrescine accumulation in roots, stems and leaves. Again, the restoration of putrescine pools appeared to be through a stimulation of the ADC pathway, since agmatine accumulated in plants exposed to GA₃. In general, the effects of DFMO and P_35S-rolA on phenotype and polyamine metabolism were coordinated, and in many cases these effects were similarly modulated by GA₃, reinforcing the previous conclusion that the phenotypic effects of rolA in roots and shoots occur through interference with polyamine metabolism and that the putrescine conjugates are particularly important in regulating root system growth and architecture. We were unable, however, to discem consistent evidence for a direct role for GA₃ in establishing the RolA phenotype.     

Higher Production of Forskolin in Genetically Transformed Cultures of Coleus forskohlii Briq Induced by Growth Regulators

Increased forskolin yield was obtained in transformed root, rhizogenic calli and cell suspension cultures of Coleus forskohlii when treated alone with various concentrations of auxins (IAA, IBA, NAA, 2,4-0), auxin conjugates ( IAA-ala, IAA-gly, IAA-phe, IAA-asp), cytokinins (Kn, BAP) and gibberellic acid (GA₃). An 8.9-fold stimulation in forskolin production was achieved in transformed rhizogenic line GCO-RCH-10 in presence of 1.0 mg I^-1 GA₃, 6-fold in cell suspension line GSO-5/7-k in presence of 2 mg I^-1 BAP and 4.3-fold in root line RC-ST -2/16 in presence of 0.5 mg I^-1 GA₃ at the end of a culture period of 4 weeks. Growth and morphology was found to be influenced by the growth regulators studied. A seven fold increase in biomass was obtained in rhizogenic line GCO-RCH-10 with 0.5 mg I^-1 GA₃ In root line RC-ST-2/16, different concentrations of IAA, IAA conjugates and GA3 stimulated growth while cytokinins inhibited growth of roots. The shoot culture line ST -2/51/d, showed prolific growth in the presence of all cytokinins but no forskolin was detected in the shoot cultures treated with any of these hormones.     

Stimulation of putrescine biosynthesis via the ornithine decarboxylase pathway by gibberellic acid in the in vitro rooting of globe artichoke (Cynara scolymus)

Rooting and growth of globe artichoke (Cynarascolymus) cuttings were improved by supplementing the rooting mediumwith 10 M gibberellic acid(GA₃). Exogenous putrescine (Put) (0.5mM) raised the percentage of rooting to thesame level as GA₃, but decreased the number of roots per plant.Addition of Put to GA₃ produced the same effects on growthparametersand rooting percentage as Put alone. Changes in endogenous contents of freepolyamines (PAs) were determined in plants cultured 4 weeks in a rootingmedium.Whatever the treatments, rooting caused a large decrease in Put, the largelypredominant PA, in the leaves. GA₃ increased the free Put content ofthe leaves and roots. DL--difluoromethylarginine (DFMA), which inhibitsarginine decarboxylase (ADC), did not affect rooting while Put content wasdecreased by 12–15%. DFMA changed neither GA₃ effectsnor those from DFMO when used in combination. An inhibitor of ornithinedecarboxylase (ODC), DL--difluoromethylornithine (DFMO), inhibited leafgrowth as well as rooting and decreased the Put content; these effects werepartially reversed by addition of Put. GA₃ combined with DFMO didnotalleviate the inhibitory effects of DFMO. The GA₃ treatment caused aclear stimulation of ODC activity in the leaves; it also stimulated¹⁴C-putrescine uptake (2.8-fold) by leaves and its translocationtowards roots. These results indicate that the ODC pathway mediates thehormone-induced rooting response in globe artichoke. Moreover, a release of Putfrom its conjugates could contribute to the increase of free-Put levels in theroots under GA₃ treatment. Thus, Put can be considered to be a goodmarker of rhizogenesis.     

In vitro regeneration of plants from hypocotyl segments of Amaranthus paniculatus

Hypocotyl segments, 5 to 8 mm length from 4 to 7 day old seedlings, callused on B₅ medium supplemented with Kn (0.5 ppm) and NAA (0.1 ppm). Even without transfer, shoots were formed in such cultures. About 20% of the cultures produced multiple shoots. In medium with 1 ppm each of Kn and NAA direct shoots were formed at one end of the hypocotyl segment and callusing was initiated at the other end. The plants obtained in either medium formed roots and could be transferred to soil for further growth.Abbreviations BA benzyladenine - 2,4-D 2,4-dichlorophenoxy acetic acid - GA₃ gibberellic acid - Kn Kinetin - NAA naphthalene acetic acid     

Interactive effects of gibberellin A<Subscript>3</Subscript> and ascorbic acid on lipid peroxidation and antioxidant enzyme activities in <Emphasis Type="Italic">Glycine max</Emphasis> seedlings under nickel stress

The effects of nickel in combination with ascorbic acid (AsA) and gibberellin on 7-day-old soybean seedlings were examined. Exposure to 0.25 mM NiCl₂ × 6H₂O for 5 days resulted in toxicity symptoms, such as formation of reddish-brown mottled spots on the leaf blade. Addition of 0.05 mM GA₃ or 1 mM AsA reduced toxic effects of nickel. After their simultaneous application, these symptoms did not appear. Ni decreased dry weights of roots and shoots and reduced chlorophyll content in leaves. An enhanced level of lipoxygenase activity and malondialdehyde, and changes in the activities of the antioxidant enzymes, catalase, guaiacol peroxidase and ascorbate peroxidase, in both roots and leaves indicated that Ni caused an oxidative stress in soybean plants. The Ni-stressed seedlings exposed to AsA or GA₃, especially to GA₃ plus AsA, exhibited an improved growth as compared to Ni-treated plants. GA₃ decreased Ni uptake by roots, while ascorbic acid considerably reduced root-to-shoot translocation of Ni. Interaction of AsA plus GA₃ prevented the decrease in chlorophyll content and lipid peroxidation as well as increased the activities of the antioxidant enzymes. These results suggest that GA₃ plus AsA treatment counteracts the negative effects of Ni on soybean seedlings. Published in Russian in Fiziologiya Rastenii, 2007, Vol. 54, No. 1, pp. 85–91. The text was submitted by the authors in English.     

Control of macaw palm seed germination by the gibberellin/abscisic acid balance

The hormonal mechanisms involved in palm seed germination are not fully understood. To better understand how germination is regulated in Arecaceae, we used macaw palm (Acrocomia aculeata (Jacq.) Lodd. Ex Mart.) seed as a model. Endogenous hormone concentrations, tocopherol and tocotrienol and lipid peroxidation during germination were studied separately in the embryo and endosperm. Evaluations were performed in dry (D), imbibed (I), germinated (G) and non‐germinated (NG) seeds treated (+GA₃) or not treated (control) with gibberellins (GA). With GA₃ treatment, seeds germinated faster and to a higher percentage than control seeds. The +GA₃ treatment increased total bioactive GA in the embryo during germination relative to the control. Abscisic acid (ABA) concentrations decreased gradually from D to G in both tissues. Embryos of G seeds had a lower ABA content than NG seeds in both treatments. The GA/ABA ratio in the embryo was significantly higher in G than NG seeds. The +GA₃ treatment did not significantly affect the GA/ABA ratio in either treatment. Cytokinin content increased from dry to germinated seeds. Jasmonic acid (JA) increased and 1‐aminocyclopropane‐1‐carboylic acid (ACC) decreased after imbibition. In addition, α‐tocopherol and α‐tocotrienol decreased, while lipid peroxidation increased in the embryo during germination. We conclude that germination in macaw palm seed involves reductions in ABA content and, consequently, increased GA/ABA in the embryo. Furthermore, the imbibition process generates oxidative stress (as observed by changes in vitamin E and MDA).     

Multiple Shoot Induction from Cotyledonary Node Explants of Terminalia chebula

A protocol for multiple shoot induction from cotyledonary node explants of Terminalia chebula Retz. has been developed. Germination frequency of embryos (up to 100 %) was obtained on Murashige and Skoog (MS) medium supplemented with 0.5 mg dm^–3 gibberellic acid (GA₃). Maximum number of shoots (6.4 shoots per cotyledonary node) was obtained on half-strength MS + 0.3 mg dm^–3 GA₃+ 1.0 mg dm^–3 indole-3-butyric acid (IBA) + 10.0 mg dm^–3 benzylaminopurine (BAP) after 4 weeks of culture. When the cotyledonary nodes along with the axillary shoot buds were allowed to grow in the same medium upto 19.2 shoots were obtained after 8 – 9 weeks. Best rooting (100 %, 5.5 roots per shoot) was observed when shoots were excised and transferred to half-strength MS medium containing 1.0 mg dm^–3 IBA + 1 % mannitol and 1.5 % sucrose. Survival of rooted plants in vivo was low (35 – 40 %) when they were directly transferred to soil in glasshouse. However, transfer to soil with MS nutrients and 1.0 mg dm^–3 IBA in culture room for a minimum duration of 2 weeks increased the survival percentage of plants to 100 %.     

Shoot and root organogenesis of Camellia sasanqua

In vitro-derived shoot tips, (10 mm) taken from primary cultures of Camellia sasanqua L., were evaluated for organogenesis when cultured on a half-strength MS medium supplemented with various concentrations of NAA, IBA, BA and GA₃. Maximum shoot proliferation and growth for juvenile and mature tissue was obtained when 0.54 M NAA, 8.8 M BA plus 14.4 to 28.9 M GA₃ was added to the culture media, with a pH between 4.5 and 5.0. In vitro-derived shoots (20 mm) from mature C. sasanqua Day Dream and juvenile C. sasanqua cultures initiated roots in vitro after immersion in 2.5 mM IBA for 30 min. Sixty percent of the mature shoots and 90% of the juvenile shoots initiated roots within 3 weeks of treatment with IBA.Abbreviations MS Murashige and Skoog (1962) - IBA lH-indole-3-butanoic acid - BA N-(phenyl-methyl)-lH-purine-6-amine - GA₃ gibberellic acid - kinetin N-(Z-furanyl-methyl)-lH-purine-6-amine - NAA l-naphthaleneacetic acid - L Linear - Q Quadratic     

Traditional and non-traditional plant growth regulators alters phytochemical constituents in Catharanthus roseus

The effect of different plant growth regulators (PGR) and elicitor treatments on the alkaloid profile variation of Catharanthus roseus was investigated in the present study. The PGR used were paclobutrazol (PBZ), gibberellic acid (GA₃) and Pseudomonas fluorescens elicitors (PF Elicitors). The estimated alkaloids were ajmalicine, catharanthine, tabersonine, serpentine and vindoline. In roots, the ajmalicine content increased significantly under all the treatments on all sampling days. In roots, the catharanthine contents increased with the age in control and growth regulator treatments, but the increase was not prominent and significant in PGR treatments when compared to controls. The serpentine contents of the plant increased with PGR treatments, but the increase was more prominent in PBZ treatments when compared to other treatments. The increase was in the order PBZ > PF Elicitors > GA₃. C. roseus never showed any significant increase in tabersonine contents in the roots under GA₃ treatments, but it increased significantly under PBZ and PF Elicitors when compared to control plants. The root vindoline contents increased with PBZ and PF Elicitors treatments but the decreased under GA₃ treatments when compared to control plants. Our results have good significance, as these increases the secondary metabolites of this traditional medicinal plant.