Showing papers on "Kinetin published in 2014"
TL;DR: In this article, the authors investigated whether the foliar application of kinetin (KN), a kind of cytokinins alleviates cadmium toxicity in Solanum melongena L. seedlings.
109 citations
TL;DR: It is found that the expression of cytokinin-responsive type-A RESPONSE REGULATOR genes was higher in d10-1 and d14-1 mutants than in the wild type, suggesting that OsTCP5 contributes to the SL- and CK-controlled mesocotyl elongation in darkness.
Abstract: Strigolactones (SLs) are a group of phytohormones that control plant growth and development including shoot branching. Previous studies of the phenotypes of SL-related rice (Oryza sativa) dwarf (d) mutants demonstrated that SLs inhibit mesocotyl elongation by controlling cell division. Here, we found that the expression of cytokinin (CK)-responsive type-A RESPONSE REGULATOR (RR) genes was higher in d10-1 and d14-1 mutants than in the wild type. However, CK levels in mesocotyls of the d mutants were not very different from those in the wild type. On the other hand, application of a synthetic CK (kinetin) enhanced mesocotyl elongation in the d mutants and the wild type. d10-1 and d14-1 mesocotyls were more sensitive to CK than wild-type mesocotyls, suggesting that the up-regulation of the CK-responsive type-A RR genes and the higher elongation of mesocotyls in the d mutants are mainly due to the increased sensitivity of the d mutants to CK. Co-treatment with kinetin and a synthetic SL (GR24) confirmed the antagonistic functions of SL and CK on mesocotyl elongation. OsTCP5, which encodes a transcription factor belonging to the cell division-regulating TCP family, was also regulated by SL and CK and its expression was negatively correlated with mesocotyl length. These findings suggest that OsTCP5 contributes to the SL- and CK-controlled mesocotyl elongation in darkness.
64 citations
TL;DR: In vitro methods are good alternative for multiplication, propagation and germplasm conservation of this nutraceutically important plant and need for development of non-conventional methods for propagation and conservation of C. edulis.
59 citations
TL;DR: In vitro technique of shoot regeneration could be an efficient alternative means of propagating C. borivilianum through seeds and tubers, but conventional methods may take several months.
56 citations
TL;DR: It is suggested that plant growth regulators and in vitro culture conditions increased the antioxidant activity.
54 citations
TL;DR: In this article, the antagonistic effects of kinetin and spermine on stress imposed by seawater on leaf area, pigment, Hill reaction, 14 CO 2 fixation and chloroplast ultrastructure of wheat flag leaf were investigated.
Abstract: The antagonistic effects of kinetin and spermine on stress imposed by seawater on leaf area, pigment, Hill reaction, 14 CO 2 fixation and chloroplast ultrastructure of wheat flag leaf were investigated. Irrigation of wheat plants by seawater at 25% caused marked decrease in leaf area, pigment content, Hill activity and photosynthetic efficiency of wheat flag leaf at ear emergence. Grain priming with kinetin, spermine or their interaction alleviated the adverse effect of seawater stress by stimulating leaf area expansion, pigment production as well as photosynthetic activity. From transmission electron microscopy micrographs, a continuous “end-to-end” distribution of regular (oval or elliptical) chloroplasts around the cell's periphery was observed in flag leaf mesophyll cells of control wheat plants. Conversely for seawater-stressed plants, the irregular spherical chloroplasts appeared “bulbous” and discrete, the cells also displayed extensive but thin peripheral cytoplasmic regions devoid of chloroplasts. Grain presoaking in 0.1 mM kinetin caused the chloroplast of stressed wheat plants to be more regular, with organized membrane system, large starch grains and projections in the form of tails. Furthermore, ultrastructure analysis cleared that grain priming with spermine, either alone or in combination with kinetin, caused the chloroplast in flag leaf mesophyll cells of stressed wheat plants to be more regular in shape with more starch grains. The changes in pigment content and photosynthetic activity of flag leaf appeared to depend mainly on chloroplast ultrastructure and its numbers, showing a positive correlation between chloroplasts number and pigment content.
53 citations
TL;DR: A long-term system that useful for embryogenic culture maintenance and transformation was developed through recurrent cycles of secondary embryogenesis from Vitis vinifera L. cv.
Abstract: To establish an efficient regeneration protocol for functional validation and variety resistance improvement, a long-term system that useful for embryogenic culture maintenance and transformation was developed through recurrent cycles of secondary embryogenesis from Vitis vinifera L. cv. Thompson Seedless. Three media and five types of somatic embryo in secondary embryogenesis were evaluated. Somatic embryos (SE) in the torpedo and mid-cotyledonary stages gave the best embryogenic responses with re-induction rates of about 80 %. Embryogenic callus, proembryonic masses and SE produced in the system, could be propagated for over 3 years and all proved competent for Agrobacterium-mediated transformation. Based on this system, different transgenic selection regimes were compared. Addition of kanamycin at 4 weeks after co-cultivation was optimal for embryo recovery. Plant conversion was improved by alternating culture on two media: one containing 0.2 mg l−1 BA and the other 0.25 mg l−1 kinetin. To further test the efficiency of the system, a ubiquitin ligase gene (VpPUB23) from Chinese wild Vitis pseudoreticulata was transferred into Thompson Seedless for functional evaluation. Of the 351 transgenic plants obtained, those overexpressing VpPUB23 exhibited decreased resistance to powdery mildew compared with non-transgenic plants.
43 citations
01 Aug 2014
TL;DR: An efficient micropropagation protocol is developed on half strength Murashige and Skoog media, using two-stage culture procedures and a remarkable increase in stevioside content was noticed in the in vitro-raised plants as compared to in vivo grown plants.
Abstract: Stevia rebaudiana Bertoni, member of Asteraceae family, has bio-active compounds stevioside and rebaudioside which taste about 300 times sweeter than sucrose. It regulates blood sugar, prevents hypertension and tooth decay as well as used in treatment of skin disorders having high medicinal values, and hence there is a need for generating the plant on large scale. We have developed an efficient micropropagation protocol on half strength Murashige and Skoog (MS) media, using two-stage culture procedures. Varying concentrations of cytokinins, i.e., benzylaminopurine, kinetin and thidiazuron (TDZ) were supplemented in the nutrient media to observe their effects on shoot development. All the cytokinins promoted shoot formation, however, best response was observed in the TDZ (0.5 mg/l). The shoots from selected induction medium were sub-cultured on the multiplication media. The media containing 0.01 mg/l TDZ produced maximum number of shoot (11.00 ± 0.40) with longer shoots (7.17 ± 0.16) and highest number of leaves (61.00 ± 1.29). Rooting response was best observed in one-fourth strength on MS media supplemented with indole-3-butyric acid (1.0 mg/l) and activated charcoal (50 mg/l) with (11.00 ± 0.40) number of roots. The plantlets thus obtained were hardened and transferred to the pots with soil and sand mixture, where the survival rate was 80 % after 2 months. Quantitative analysis of stevioside content in leaves of in vivo mother plant and in vitro plantlets was carried out by high performance liquid chromatography. A remarkable increase in stevioside content was noticed in the in vitro-raised plants as compared to in vivo grown plants. The protocol reported here might be useful in genetic improvement and high stevioside production.
42 citations
TL;DR: The influence of plant growth regulators on biomass growth and the accumulation of medicinally-relevant isoflavone phytoestrogens, derivatives of genistein and daidzein in callus cultures of Genista tinctoria was examined.
Abstract: The influence of plant growth regulators on biomass growth and the accumulation of medicinally-relevant isoflavone phytoestrogens, derivatives of genistein and daidzein (8 compounds including aglycones, glucosides and glucoside esters) in callus cultures of Genista tinctoria (Fabaceae) was examined. The experiments included 10 auxins [2,4-dichlorophenoxyacetic acid (2,4-D), p-chlorophenoxyacetic acid, indole-3-acetic acid, indole-3-butyric acid, indole-3-propionic acid, 1-naphthaleneacetic acid, β-naphthoxyacetic acid, picloram, 2,3,5-triiodobenzoic acid (TIBA), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)] and 7 cytokinins [6-benzylaminopurine, forchlorfenuron, 1,3-diphenylurea, 2-isopentenyladenine, kinetin (KIN), thidiazuron, zeatin] applied at 0.5 and 5.0 mg l−1, jointly with 5.0 or 0.5 mg l−1 KIN or 2,4-D (for auxins and cytokinins, respectively—36 phytohormone combinations in total). Statistical analysis of the relationships between callus growth [expressed as growth index (Gi)] and the accumulation of isoflavones showed positive correlation in the cytokinin group (rxy values from 0.13 to 0.61) and negative correlation within auxins (rxy values from −0.31 to −0.39). Among the cytokinins tested, the highest isoflavone content (6,436.26 mg/100 g dry weight) and the fastest biomass growth (Gi = 892.46 %) were obtained for 0.5 mg l−1 KIN used jointly with 5.0 mg l−1 2,4-D. In the group of auxins, the combination of 0.5 mg l−1 TIBA and 5.0 mg l−1 KIN provided the fastest culture growth (Gi = 983.07 %) and the isoflavone concentration of 10,474.23 mg/100 g dry weight, which is so far the highest amount of these metabolites achieved in callus cultures of higher plants.
41 citations
TL;DR: A simple and efficient regeneration protocol was established for soybean and Cotyledonary node explants from 7-day-old in vitro seedlings were used as explants to investigate the effect of different plant growth regulators and polyamines on regeneration using direct organogenesis system.
Abstract: A simple and efficient regeneration protocol was established for soybean [Glycine max (L.) Merrill]. Cotyledonary node explants from 7-day-old in vitro seedlings were used as explants. The effect of different plant growth regulators [N
6 –benzyladenine (BA), kinetin (KT), thidiazuron (TDZ), gibberellic acid (GA3), zeatin riboside (ZTR), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA)] along with polyamines (Spermidine, spermine, and putrescine) were investigated at different stages of regeneration using direct organogenesis system. Exogenous spermidine (137.69 μM) in shoot induction medium containing optimal BA concentration (2.22 μM) induced maximum number of shoots (39.02 shoots/explant) compared to BA (2.22 μM) alone. Regenerated shoots elongated well in shoot elongation medium containing GA3 (1.45 μM) and spermine (74.13 μM), and developed profuse roots in root induction medium containing putrescine (62.08 μM). Rooted plantlets were successfully hardened and acclimatized with a survival rate of 92 %. The amenability of the standardized protocol using cultivar PK 416 was tested on four more Indian soybean cultivars JS 90–41, Hara soy, Co1, and Co2 of which PK 416 was found to be the best responding cultivar, with a maximum of 96.94 % shoot induction.
39 citations
TL;DR: In the present study, a protocol was developed for in vitro micropropagation using 6-benzylamino purine (BAP) and Kinetin (Kn) for the formation of multiple shoot proliferation and Indole-3-acetic acid (IAA), Indole -3-butyric acid (IBA) and 1-Naphthaleneacetic Acid (NAA) forThe induction of roots.
Abstract: Stevia rebaudiana Bertoni is a medicinal plants and commercially use as non-caloric sweetener for diabetic patient. In the present study, a protocol was developed for in vitro micropropagation using 6-benzylamino purine (BAP) and Kinetin (Kn) for the formation of multiple shoot proliferation and Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA) and 1-Naphthaleneacetic acid (NAA) for the induction of roots. Maximum shoot formation (7.82 ± 0.7 shoots per explants) was observed on a Murashige and Skoog (MS) medium supplemented with 0.5 mg L-1 BAP and 0.25 mg L-1 Kn. The maximum number of roots (30.12 ± 2.1 roots per explants) was obtained on a MS medium containing 1.0 mg L-1 IBA. The well rooted plantlets were successfully weaned and acclimatized in plant soil with survival rate of 83.3 %.
TL;DR: Homogeneity and phytochemical productivity of the in vitro regenerated plantlets were confirmed by random amplified polymorphic DNA (RAPD) profiles and high performance liquid chromatography (HPLC), respectively.
Abstract: Thymus persicus (Ronniger ex Rech. f.) Jalas is a valuable and endangered natural source of antitumor pentacyclic triterpenoids, i.e., betulinic acid, oleanolic acid and ursolic acid, which grows in northwest Iran. As the plant has a low propagation rate in nature, a suitable method for in vitro-propagation is needed. With the aim of identifying a suitable system for regenerating T. persicus via direct organogenesis, Murashige & Skoog (MS) medium supplemented with different plant growth regulators (PGRs) was tested. In vitro-grown shoot tips were exposed to the cytokinins 6-benzylaminopurine (BAP), kinetin (KN), and thidiazuron (TDZ), alone or in combination with the auxins 1-naphthalene-acetic acid (NAA), 2,4-dichlorophenoxyacetic (2,4-D), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA). The highest shoot formation (7.1 ± 0.9) was obtained with a medium fortified with 8.9 μM BAP plus 2.7 μM NAA. Regenerated shoots were easily rooted on the different tested media, with the most abundant (16.6 ± 1.4) and strongest roots obtained on half-strength MS medium containing 2.5 μM IBA. The rooted plantlets were successfully acclimatized (76.6%) in a greenhouse before transference to natural conditions. Homogeneity and phytochemical productivity of the in vitro regenerated plantlets were confirmed by random amplified polymorphic DNA (RAPD) profiles and high performance liquid chromatography (HPLC), respectively.
TL;DR: It is suggested that spatiotemporal manipulation of GhAGL15s expression may prove valuable in improving cotton transformation efficiency and enhances embryogenic potential of transgenic calli.
Abstract: Somatic embryogenesis is a useful tool for gene transfer and propagation of plants. AGAMOUS-LIKE15 (AGL15) promotes somatic embryogenesis in many plant species. In this study, three homologous AGL15 genes were isolated from Gossypium hirsutum L., namely GhAGL15-1, GhAGL15-3, and GhAGL15-4. Their putative proteins contained a highly conserved MADS-box DNA-binding domain and a less conserved K domain. Phylogenetic analysis suggested that the three GhAGL15s clustered most closely with AGL15 proteins in other plants. Subcellular location analyses revealed that three GhAGL15s were localized in the nucleus. Furthermore, their expression levels increased following embryogenic callus induction, but sharply decreased during the embryoid stage. GhAGL15-1 and GhAGL15-3 were significantly induced by 2,4-D and kinetin, whereas GhAGL15-4 was only responsive to 2,4-D treatment. Over-expression of the three GhAGL15s in cotton callus improved callus quality and significantly increased the embryogenic callus formation rate, while GhAGL15-4 had the highest positive effect on the embryogenic callus formation rate (an increase from 38.1 to 65.2 %). These results suggest that over-expression of GhAGL15s enhances embryogenic potential of transgenic calli. Therefore, spatiotemporal manipulation of GhAGL15s expression may prove valuable in improving cotton transformation efficiency.
TL;DR: The combined effect of anther incubation time on CP induction medium and 2 concentrations of kinetin in R1 regeneration medium on the effectiveness of androgenesis was investigated in 17 genotypes of Capsicum grown in Poland.
Abstract: The combined effect of anther incubation time on CP induction medium (12, 14, and 16 days) and 2 concentrations of kinetin in R1 regeneration medium (0.1 and 0.3 mg/L) on the effectiveness of androgenesis was investigated in 17 genotypes of Capsicum grown in Poland. Plant material consisted of breeding lines and intraspecific hybrids of C. annuum; the species of C. frutescens, C. chinense, and C. baccatum var. pendulum; interspecific hybrids F1 (C. frutescens × C. chinense) and F1 (C. frutescens × C. baccatum); and doubled haploid lines derived from the hybrids. The results of the tested variants of the experiment were compared with the androgenic response of the control anthers cultured according to the standard protocol previously developed for pepper (12 days incubation on CP, 0.1 mg/L kinetin in R1). Under control conditions, androgenic embryos regenerated only from anthers of 3 of the tested genotypes, whereas application of the selected modifications promoted embryo development in an additional 12 genotypes. The highest effectiveness of androgenesis was observed after 16 days of anther incubation on CP medium combined with 0.1 mg/L kinetin in R1 medium. Twelve- and 14-day-long anther incubation was more effective when followed by transferring anthers onto R1 medium supplemented with 0.3 mg/L kinetin.
TL;DR: Application of these protocols would be helpful in reducing stress in natural habitat, and in long-term storage of elite genotypes through synthetic seed production of S. chirayita.
Abstract: An efficient protocol for plant regeneration through somatic embryogenesis was established from in vivo leaf explants of Swertia chirayita, a critically endangered medicinal herb. The highest frequency (76%) of embryogenic callus was induced on Murashige & Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L kinetin (Kn) from in vivo leaf explants. Globular somatic embryos were induced and further matured from such embryogenic calli by subsequent culture on the same medium. The highest number of somatic embryos (48.83 ± 4.6) was recovered from embryogenic calli derived from leaf explants after 6 weeks of culture. Synthetic seeds were produced by encapsulating of torpedo stage embryos in sodium alginate (4% W/V) gel, dropped into 100 mM calcium chloride (CaCl2 · 2H2O) solution. The synthetic seeds were germinated on MS medium. The highest frequency of synthetic seed germination (84%) was observed on MS medium supplemented with 1.0 mg/L BA and 0.5 mg/L NAA. Regenerants were successfully acclimatized under ex vitro condition. This is the first report on synthetic seed production of S. chirayita. Application of these protocols would be helpful in reducing stress in natural habitat, and in long-term storage of elite genotypes through synthetic seed production.
TL;DR: The genetic fidelity of micropropagated plantlets was confirmed by ISSR analysis confirming that in vitro plants obtained from callus showed genetic variation during the period of culturing, whereas those from nodal segments did not.
Abstract: A reliable protocol for micropropagation was developed for an anti-diabetic medicinal plant species, Stevia rebaudiana. In the present investigation the highest percentage of response was shown by nodal segment (98.00 ± 1.22) and both MS full and half strength performed well and were almost equally effective. Callus along with multiple shoots was obtained from nodal segments of S. rebaudiana on half strength Murashige and Skoog (MS) media supplemented with various concentrations of benzyl amino purine (BAP) and indole-3-butyric acid (IBA) (0.2, 0.5, 1.0, 1.5 mg l−1 each). The in vitro shoots produced along with callus were re-cultured on one-fourth strength MS media supplemented with kinetin (Kn) (0.5 mg l−1), IBA (1.0 mg l−1), activated charcoal (50 mg l−1), polyvinylpolypyrrolidone (100 mg l−1) and gibberellic acid (1 mg l−1) to obtain optimum shoot regeneration. Shoot multiplication and simultaneous rooting of S. rebaudiana was observed. The results obtained showed multiple shooting (18–20) with shoot length (6.5–7.2 cm), number of leaves (42–50), number of roots (12–14) and root length (5.8–6.2 cm), after 4 weeks of re-culturing of callus. Among different auxins and cytokinins used for secondary callus formation in half strength MS media. 2, 4-D (0.5 mg l−1) showed maximum growth index (266.384), after 8 weeks of callus culture. In vitro raised plantlets were transferred for hardening in plastic pots containing garden soil and perlite (1:1). A total of 80 % survival rate was observed. Quantitative analysis of stevioside content of in vitro and field grown plants was carried out by HPLC which showed increase of about 2 % stevioside content in the regenerants as compared to field grown plants. The genetic fidelity of micropropagated plantlets was confirmed by ISSR analysis confirming that in vitro plants obtained from callus showed genetic variation during the period of culturing, whereas those from nodal segments did not. Overall, this system results in mass multiplication of S. rebaudiana with simultaneous production of callus within short period. The high stevioside content in micropropagated plants may be of immense use to the pharmaceutical industry.
01 Jan 2014
TL;DR: A feasible and efficient method for indirect regeneration of S. marianum for production of consistent plantlets is established and contributes to a better understanding of the different mechanisms involved in morphogenesis and production of biologically active principle in Silybum Marianum.
Abstract: Silybum marianum, of family Asteraceae is renowned for production of biologically important silymarin, which has shown multi-dimensional medicinal properties. It has a high protective role against jaundice and hepatitis C worldwide. We hereby established a feasible and efficient method for indirect regeneration of S. marianum for production of consistent plantlets. Calli were induced from leaf explants of seed-derived plantlets on Murashige and Skoog (MS) medium supplemented with several concentrations of different plant growth regulators (PGRs). Highest callogenic response (89%) was recorded for 4.4µM Thidiazuron (TDZ) in combination with 6.6µM Kinetin (Kn). Subsequent sub-culturing of callus after 4 weeks of culture, on medium with similar compositions of PGRs induced shoot organogenesis. Highest shoot induction frequency (86%) with maximum mean multiple shoots (26 shoots per explant) were recorded for 11µM TDZ after 4 weeks of transfer. Longest shoots (4.1 cm) were recorded for MS medium augmented with 6.6µM TDZ and 4.4µM αnaphthalene acetic acid (NAA). Furthermore, rooted plantlets were developed on MS medium containing different concentrations of indole acetic acid (IAA). Silymarin was determined by High performance liquid chromatography (HPLC) and 8.47 mg/g DW silymarin was detected in the regenerated plantlets. This study contributes to a better understanding of the different mechanisms involved in morphogenesis and production of biologically active principle in Silybum marianum.
TL;DR: It is concluded that MS medium containing 15 g/L sucrose, 1.1 μM NAA + 2.2 μM BAP hormone combination, and a pH of 5.7 was highly effective for inducing friable callus from leaf explants of A. malaccensis for the purpose of establishing cell suspension culture.
Abstract: The endangered tropical tree, Aquilaria malaccensis, produces agarwood for use in fragrance and medicines. Efforts are currently underway to produce valuable agarwood compoundsn tissue culture. The purpose of this study was to develop an optimal growth medium, specifically, the best hormone combination for callus suspension culture. Using nursery-grown A. malaccensis, sterilized leaf explants were first incubated on basic Murashige and Skoog (MS) gel medium containing 15g/L sucrose and at pH 5.7. Different auxin types including 1-naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and indole-3-butyric acid (IBA), were tested at various concentrations (0.55, 1.1 and 1.65 μM) using the basic medium. Leaf explants were incubated for 30 days in the dark. Callus induced by 1.1 μM NAA had the highest biomass dry weight (DW) of 17.3 mg; however the callus was of a compact type. This auxin concentration was then combined with either 6-benzylaminopurine (BAP) or kinetin at 0.55, 1.1, 2.2 or 3.3 μM to induce growth of friable callus. The 1.1μM NAA + 2.2μM BAP combination produced friable callus with the highest biomass (93.3mg DW). When testing the different carbon sources and pHs, sucrose at 15g/L and pH at 5.7 yielded highest biomasses at 87.7mg and 83mg DW, respectively. Microscopic observations revealed the arrangement of the friable cells as loosely packed with relatively large cells, while for the compact callus, the cells were small and densely packed. We concluded that MS medium containing 15 g/L sucrose, 1.1 μM NAA + 2.2 μM BAP hormone combination, and a pH of 5.7 was highly effective for inducing friable callus from leaf explants of A. malaccensis for the purpose of establishing cell suspension culture.
13 Aug 2014
TL;DR: The direct regeneration protocol will be useful for the production of true to type plants of this medicinally important plant and will go a long way in reducing the pressure on the natural populations for the secondary metabolite production, especially for extraction of essential oils.
Abstract: The present investigations were made attempting to develop a rapid, reliable, and reproducible in vitro regeneration protocol for Artemisia absinthium L., a medicinal plant of Kashmir Himalayas. Out of several auxin-cytokinin combinations tested, Murashige and Skoog’s (MS) medium supplemented with 0.5 mgL−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mgL−1 kinetin (Kn) was found to be the best for the callus induction. On the other hand, 4.5 mgL−1 6-benzylaminopurine (BAP) and 0.5 mgL−1 1-α-naphthaleneacetic acid (NAA) in the medium resulted in maximum shoot induction from the callus. Similarly, BAP and NAA at a concentration of 1.5 mgL−1 and 0.5 mgL−1, respectively, proved to be the best for the multiple shoot induction from nodal explants. Numerous shoots were obtained from nodal explants after third subculture. In vitro rooting was maximum on medium containing indole-3-butyric acid (IBA) at 0.5 mgL−1. The genetic stability of the in vitro raised plants of Artemisia absinthium was assessed using the intersimple sequence repeat (ISSR) and sequence-specific amplification polymorphism (SSAP) molecular markers. Both markers were able to detect the somaclonal variations in the callus regenerated plants, while no variation was detected in the plants regenerated from the nodal explants. SSAP has been found to be more useful in detection of variability as compared to ISSR molecular marker. The results of present study concluded that the direct regeneration protocol will be useful for the production of true to type plants of this medicinally important plant. This will go a long way in reducing the pressure on the natural populations for the secondary metabolite production, especially for extraction of essential oils.
TL;DR: A twofold increase in maturation and germination of somatic embryos was observed in the media containing seaweed extracts than the control, and the plantlets transferred from plant growth chamber to greenhouse conditions exhibited higher survival rate (90 %) than directly shifted plantlets.
Abstract: In the present study a simple and efficient somatic embryogenesis system was developed from leaf explants of Lycopersicon esculentum L. The protocol has been developed by using plant growth regulators and seaweed extracts a natural biostimulant. The leaf sections were initially cultured on to leaf embryogenic callus induction medium fortified with various concentration and combinations of 2,4-dichlorophenoxy acetic acid (0.2–1.0 mg L−1), picloram (0.2–1.0 mg L−1), and kinetin (0.1–0.5 mg L−1). The best responding concentration in induction of friable embryogenic callus was tested for the proliferation. The friable cultures were detached from the mother culture and inoculated in three different media supplemented with plant growth regulators, plus 0–25 % Caulerpa scalpelliformis or 0–25 % Gracilaria corticata extracts for embryo development. A twofold increase in maturation and germination of somatic embryos was observed in the media containing seaweed extracts (MSMG2 and MSMG3) than the control (MSMG1). The plantlets transferred from plant growth chamber to greenhouse conditions exhibited higher survival rate (90 %) than directly shifted plantlets.
TL;DR: It is concluded that reduction of abscisic acid levels by enhanced absc isic acid catabolism strongly contributes to cytokinin-mediated resistance effects and is a novel regulatory mechanism in plant immunity.
Abstract: Phytohormones are known as essential regulators of plant defenses, with ethylene, jasmonic acid, and salicylic acid as the central immunity backbone, while other phytohormones have been demonstrated to interact with this. Only recently, a function of the classic phytohormone cytokinin in plant immunity has been described in Arabidopsis, rice, and tobacco. Although interactions of cytokinins with salicylic acid and auxin have been indicated, the complete network of cytokinin interactions with other immunity-relevant phytohormones is not yet understood. Therefore, we studied the interaction of kinetin and abscisic acid as a negative regulator of plant immunity to modulate resistance in tobacco against Pseudomonas syringae. By analyzing infection symptoms, pathogen proliferation, and accumulation of the phytoalexin scopoletin as a key mediator of kinetin-induced resistance in tobacco, antagonistic interaction of these phytohormones in plant immunity was identified. Kinetin reduced abscisic acid levels in tobacco, while increased abscisic acid levels by exogenous application or inhibition of abscisic acid catabolism by diniconazole neutralized kinetin-induced resistance. Based on these results, we conclude that reduction of abscisic acid levels by enhanced abscisic acid catabolism strongly contributes to cytokinin-mediated resistance effects. Thus, the identified cytokinin-abscisic acid antagonism is a novel regulatory mechanism in plant immunity.
01 Mar 2014
TL;DR: This process of micropropagation of A. nilotica, can be utilized for plant production on a large-scale and about ten times increase in shoot number in liquid culture medium was achieved.
Abstract: A micropropagation method using liquid culture medium has been developed for mature Acacia nilotica (L.) Del. ssp. indica. Nodal segments obtained from 15 to 20 years old mature trees were used as explants and cultured on 0.8 % agar-gelled Murashige and Skoog medium containing 6-benzylaminopurine for shoot bud induction. Once culture got established, explants were transferred to Murashige and Skoog liquid medium containing 6-benzylaminopurine or kinetin for shoot multiplication. Shoot multiplication was influenced by plant growth regulators, size of vessels, amount of medium in culture vessels and repeated transfer of mother explants. Murashige and Skoog liquid medium containing 4.4 μM 6-benzylaminopurine was found to be the best for shoot multiplication. The performance of liquid and agar-gelled medium for shoot multiplication was compared. About ten times increase in shoot number in liquid culture medium was achieved. Micropropagated shoots were rooted ex vitro. Shoots treated with 2.46 mM indole-3-butyric acid solution for 1 h followed by 1.41 mM chlorogenic acid for 5 min exhibited highest percent of rooting in the green house. This process of micropropagation of A. nilotica, can be utilized for plant production on a large-scale.
TL;DR: The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species.
Abstract: An efficient in vitro regeneration protocol from seed culture has been established successfully for Dendrobium chrysotoxum, an epiphytic orchid having tremendous ornamental and medicinal values. Seed germination response was encouraging in Mitra (M) medium enriched with different combinations of auxins and cytokinins. Medium supplemented with 0.4% activated charcoal (AC), 2 mg/L 6-benzyl amino purine (BAP), and 2 mg/L indole-3-acetic acid (IAA) produced best seed germination percentage in 2 weeks of culture. Incorporation of higher concentration of kinetin (KN) or BAP in combination with low auxin in medium induced pronounced shooting and leaf formation. Reduction in leaf development was evident when cytokinins exist singly in medium indicating synergistic effect of auxin and cytokinin in leaf induction. Presence of elevated level of indole-3-butyric acid (IBA) or 1-naphthalene acetic acid (NAA) with low cytokinin content in medium generated more in vitro rooting, though IBA was found to be more effective in rooting induction as compared to NAA. The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species.
TL;DR: The results suggested that the optimized medium of cell suspension cultures possibly be used for scale-up studies in bioreactors to offer a high content of bioactive isoflavones.
Abstract: Glycine max contains potential therapeutic isoflavones, and its productivity in plants is considerably influenced worldwide by several biotic and abiotic factors. Optimization of soybean cell suspension cultures (Indian variety, JS 335) to maximize the cell growth and isoflavone production in the present study was performed using response surface methodology (RSM) with three independent variables of plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (α-NAA), and kinetin (Kn). The maximum biomass achieved was 70.62 g/L dry weight (dw) using the optimized medium of 2.10 mg/L 2,4-D, 5.52 mg/L α-NAA, and 0.35 mg/L Kn supplemented in the Murashige and Skoog (MS) basal medium. The total isoflavone content of 38.59 mg/g of dw was obtained in the medium with optimized conditions of 1.33 mg/L 2,4-D, 1.76 mg/L α-NAA, and 0.15 mg/L Kn. In comparison to field-grown soybean seeds, the cell suspension cultures profoundly augmented isoflavone concentrations. The optimized conditio...
TL;DR: An efficient protocol was developed for the rapid in vitro multiplication of an endemic and critically endangered medicinal herb, Ceropegia noorjahaniae Ans.
Abstract: An efficient protocol was developed for the rapid in vitro multiplication of an endemic and critically endangered medicinal herb, Ceropegia noorjahaniae Ans., via enhanced axillary bud proliferation from nodal explants. The effects of phytohormones [6-benzylaminopurine (BAP), kinetin (Kin) thidiazuron (TDZ), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA)] on in vitro regeneration were investigated. The highest number of shoots (18.3 ± 1.3), maximum shoot length (10.1 ± 0.8 cm) and the highest response of shoot induction (95 %) were recorded on MS medium supplemented with 2.0 mg/l BAP. Rooting was best achieved on half-strength MS medium augmented with IBA (1.0 mg/l). Half-strength MS medium supplemented with BAP (4 mg/l) and sucrose (5 %, w/v) produced an average of 5.6 flower buds per microshoots with highest (90 %) flower bud induction response. The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing sterile sand and coco peat (1:1) and grown in a greenhouse with 85 % survival rate. The regenerated plants did not show any detectable morphological variation. The developed method can be successfully employed for large-scale multiplication and conservation of C. noorjahaniae.
TL;DR: The present standardised protocol will find application in mass production, conservation and genetic transformation studies of this commercially important bananas of Mizoram, India.
Abstract: An efficient in vitro propagation method has been developed for the first time for Musa acuminata (AAA) cv. Vaibalhla, an economically important banana cultivar of Mizoram, India. Immature male flowers were used as explants. Murashige and Skoog's (MS) medium supplemented with plant growth regulators (PGRs) were used for the regeneration process. Out of different PGR combinations, MS medium supplemented with 2 mg L(-1) 6-benzylaminopurine (BAP) + 0.5 mg L(-1) α-naphthalene acetic acid (NAA) was optimal for production of white bud-like structures (WBLS). On this medium, explants produced the highest number of buds per explant (4.30). The highest percentage (77.77) and number (3.51) of shoot formation from each explants was observed in MS medium supplemented with 2 mg L(-1) kinetin + 0.5 mg L(-1) NAA. While MS medium supplemented with a combination of 2 mg L(-1) BAP + 0.5 mg L(-1) NAA showed the maximum shoot length (14.44 cm). Rooting efficiency of the shoots was highest in the MS basal medium without any PGRs. The plantlets were hardened successfully in the greenhouse with 96% survival rate. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were employed to assess the genetic stability of in vitro regenerated plantlets of M. acuminata (AAA) cv. Vaibalhla. Eight RAPD and 8 ISSR primers were successfully used for the analysis from the 40 RAPD and 30 ISSR primers screened initially. The amplified products were monomorphic across all the regenerated plants and were similar to the mother plant. The present standardised protocol will find application in mass production, conservation and genetic transformation studies of this commercially important banana.
TL;DR: In vitro rooted plants were successfully acclimatized and established in soil and RAPD analysis showed no variation suggesting true-to-type nature of the micropropagated plants, suggesting this protocol can effectively reduce the cost of in vitro multiplication of plants.
Abstract: The effect of plant growth regulators and natural supplements on the morphogenetic response of Pogostemon cablin Benth. was investigated. Murashige and Skoog (MS) media supplemented with 0.5 mg L−1 benzyl-6-adenine and 0.5 mg L−1 kinetin was effective in inducing multiple shoots (63.20 ± 0.15) with an average shoot length of 5.27 ± 0.15 cm and biomass of 5.20 ± 0.10 g shoot−1. Among the natural supplements, 10% coconut water supplemented to MS media showed a better response in all the morphological parameters studied. The use of 10% tomato extract, 20% banana extract, 10% carrot extract, and 10% papaya extract in MS medium have efficiently increased multiple shoots, shoot length, and fresh weight of the shoots. The natural supplements also effectively increased the chlorophyll content, total protein, and total carbohydrate content in the plant. The frequency of rooting (93%) was highest when shoots were implanted on 1/2 strength MS media with 100 mg L−1 activated charcoal. The in vitro rooted plants were successfully acclimatized and established in soil. Also, RAPD analysis showed no variation suggesting true-to-type nature of the micropropagated plants. Hence, this protocol can effectively reduce the cost of in vitro multiplication of plants.
TL;DR: An efficient protocol has been developed for the in vitro plant regeneration established from nodal explants of stevia, which showed 65% survival in the field with normal growth.
Abstract: Stevia rebaudiana, a medicinal plant normally used as a natural herbal sweetener, has documented properties of antimicrobial, antihypertensive and anti-hyperglycemic and hence a boon to diabetic people. An efficient protocol has been developed for the in vitro plant regeneration established from nodal explants of stevia. Best shoot proliferation was observed when nodal explants were inoculated on Murashige and Skoog (MS) medium supplemented with Kinetin (9.3 µM) and adenine sulphate (Ads) 40 mg/L. Proliferated shoots were transferred to rooting media having different concentration of α-n-Naphthalene acetic (NAA) acid and Indole-3-butyric acid (IBA). Best rooting was observed with NAA 5.3 µM. The plantlets were successfully subjected to hardening media containing soil, soilrite and vermiculite (2:1:1 w/w) and then rooted plant transferred to pots and acclimatized, which showed 65% survival in the field with normal growth.
Key words: Stevia rebaudiana, adenine sulphate, in vitro.
TL;DR: A rapid in vitro protocorm development and mass multiplication protocol for Dactylorhiza hatagirea (D.Don) Soo that holds robust potential for large-scale propagation and metabolite production is described for the first time.
Abstract: Immature seeds were cultured on 10 different media for germination. Maximum germination was achieved on Lindeman orchid medium (37.12%) within 17 days of culturing. Protocorms with leaf primordia were cultured on BM-2 and 7 different modifications of Murashige and Skoog (MS) medium with various hormone combinations [0-3 mg/L indole butyric acid (IBA) and 0-3 mg/L kinetin (Kin)] for plantlet regeneration and mass multiplication. Maximum number of shoots (18.12 ± 0.3), highest shoot length (17.80 cm ± 2.16), maximum root number (8.25 ± 0.69), and highest root length (8.02 cm ± 1.45) were found on MS medium with 3 mg/L IBA and 1 mg/L Kin. Plantlets with 2-3 shoots were transferred to different potting mixtures for acclimatization to field conditions and further multiplication. One hundred percent survival was obtained in C-8 potting mixture consisting of cocopeat + vermiculite + perlite (1:1:1), which produced 75 shoots (25 plantlets) after 1 month of transplantation in the greenhouse. The current study describes for the first time a rapid in vitro protocorm development and mass multiplication protocol for Dactylorhiza hatagirea (D.Don) Soo that holds robust potential for large-scale propagation and metabolite production.
TL;DR: Ex vitro rooting was achieved best directly in soilrite when basal portion of the shoots were treated with 500 μM indole-3-butyric acid for 15 min which was the most effective in inducing roots, as 95 % of the microshoots produced roots.
Abstract: A rapid and efficient plant propagation system through shoot tip explants was established in Vitex trifolia L., a medicinally important plant belonging to the family Verbenaceae. Multiple shoots were induced directly on Murashige and Skoog (MS) medium consisting of different cytokinins, 6-benzyladenine (BA), kinetin (Kin) and 2-isopentenyl adenine (2-iP), BA at an optimal concentration of 5.0 μM was most effective in inducing multiple shoots where 90 % explants responded with an average shoot number (4.4±0.1) and shoot length (2.0±0.1 cm) after 6 weeks of culture. Inclusion of NAA in the culture medium along with the optimum concentration of BA promoted a higher rate of shoot multiplication and length of the shoot, where 19.2±0.3 well-grown healthy shoots with an average shoot length of 4.4±0.1 cm were obtained on completion of 12 weeks culture period. Ex vitro rooting was achieved best directly in soilrite when basal portion of the shoots were treated with 500 μM indole-3-butyric acid for 15 min which was the most effective in inducing roots, as 95 % of the microshoots produced roots. Plantlets went through a hardening phase in a controlled plant growth chamber, prior to ex-vitro transfer. Micropropagated plants grew well, attained maturity and flowered with 92 % survival rate. The results of this study provide the first report on in vitro plant regeneration of Vitex trifolia L. using shoot tip explants.