Showing papers on "Kinetin published in 2004"
TL;DR: Two seaweed concentrates were made from the kelps Ecklonia maxima and Macrocystis pyrifera using a cell burst method and cytokinin- and auxin-like activities were measured using the soybean callus and mungbean bioassays, respectively.
Abstract: Two seaweed concentrates were made from the kelps Ecklonia maxima and Macrocystis pyrifera using a cell burst method. Cytokinin- and auxin-like activities were measured using the soybean callus and mungbean bioassays, respectively. Cytokinin-like activity was detected in both seaweed concentrates, being equivalent to approximately 50 μg L−1 kinetin. Auxin-like activity was also detected in both concentrates with the E. maxima derived concentrate having higher biological activity, equivalent to 10−5–10−4 M indole-butyric acid. Two replicates of each concentrate were stored at 54 °C for 14 days to accelerate the effects of storage. Both fresh and stored samples of the two seaweed concentrates were analysed for their endogenous cytokinin and auxin content. The samples were purified using a combined DEAE-Sephadex octadecylsilica column and immunoaffinity chromatography based on wide-range cytokinin and IAA specific monoclonal antibodies. These extracts were analysed by HPLC linked to a Micromass single quadrupole mass spectrophotometer. Eighteen and nineteen different cytokinins were detected, respectively, in the two concentrates, with trans-zeatin-O-glucoside being the main cytokinin present. Accelerated storage of the concentrates caused an increase in the total cytokinin concentration with a large increase in the aromatic meta-topolin. Indole-3-acetic acid was the main auxin in both seaweed concentrates. Indole conjugates, including amino acid conjugates, were also quantified. The total auxin concentration decreased with accelerated storage for both concentrates.
194 citations
TL;DR: Results show that, with this protocol, generation and multiplication of transgenic shoots can be achieved in about 5 months with transformation efficiencies as high as 50%.
Abstract: Direct regeneration from explants without an intervening callus phase has several advantages, including production of true type progenies. Axillary bud explants from 6-month-old sugarcane cultivars Co92061 and Co671 were co-cultivated with Agrobacterium strains LBA4404 and EHA105 that harboured a binary vector pGA492 carrying neomycin phosphotransferase II, phosphinothricin acetyltransferase (bar) and an intron containing beta-glucuronidase (gus-intron) genes in the T-DNA region. A comparison of kanamycin, geneticin and phosphinothricin (PPT) selection showed that PPT (5.0 mg l(-1)) was the most effective selection agent for axillary bud transformation. Repeated proliferation of shoots in the selection medium eliminated chimeric transformants. Transgenic plants were generated in three different steps: (1) production of putative primary transgenic shoots in Murashige-Skoog (MS) liquid medium with 3.0 mg l(-1) 6-benzyladenine (BA) and 5.0 mg l(-1) PPT, (2) production of secondary transgenic shoots from the primary transgenic shoots by growing them in MS liquid medium with 2.0 mg l(-1) BA, 1.0 mg l(-1) kinetin (Kin), 0.5 mg l(-1) alpha-napthaleneacetic acid (NAA) and 5.0 mg l(-1) PPT for 3 weeks, followed by five more cycles of shoot proliferation and selection under same conditions, and (3) rooting of transgenic shoots on half-strength MS liquid medium with 0.5 mg l(-1) NAA and 5.0 mg l(-1) PPT. About 90% of the regenerated shoots rooted and 80% of them survived during acclimatisation in greenhouse. Transformation was confirmed by a histochemical beta-glucuronidase (GUS) assay and PCR amplification of the bar gene. Southern blot analysis indicated integration of the bar gene in two genomic locations in the majority of transformants. Transformation efficiency was influenced by the co-cultivation period, addition of the phenolic compound acetosyringone and the Agrobacterium strain. A 3-day co-cultivation with 50 micro M acetosyringone considerably increased the transformation efficiency. Agrobacterium strain EHA105 was more effective, producing twice the number of transgenic shoots than strain LBA4404 in both Co92061 and Co671 cultivars. Depending on the variety, 50-60% of the transgenic plants sprayed with BASTA (60 g l(-1) glufosinate) grew without any herbicide damage under greenhouse conditions. These results show that, with this protocol, generation and multiplication of transgenic shoots can be achieved in about 5 months with transformation efficiencies as high as 50%.
185 citations
TL;DR: Results indicated that shoots established at 100% regardless of media type, however, shoot height, nodes per shoot, and leaf number were highest for explants established on MS medium compared to NN or B5.
144 citations
TL;DR: PCR and Southern blot analyses revealed that plants derived from hairy roots retained the Ri TL-DNA, and a significant difference in the frequency of adventitious shoot formation for each hairy-root line derived from a different cultivar.
Abstract: Hypocotyl explants of Catharanthus roseus produced hairy roots when cultured on Murashige and Skoog (MS) basal medium after infection by Agrobacterium rhizogenes. Explants gave rise to adventitious shoots at a frequency of up to 80% when cultured on MS medium supplemented with 31.1 μM 6-benzyladenine and 5.4 μM α-naphthaleneacetic acid. There was a significant difference in the frequency of adventitious shoot formation for each hairy-root line derived from a different cultivar. Plants derived from hairy roots exhibited prolific rooting and had shortened internodes. Approximately half of the plants had wrinkled leaves and an abundant root mass with extensive lateral branching, but otherwise appeared morphologically normal. Plants with hairy roots that were derived from the cultivar Cooler Apricot developed flowers with petals that were white in the proximal region, whereas the wild-type flower petals are red. PCR and Southern blot analyses revealed that plants derived from hairy roots retained the Ri TL-DNA.
103 citations
TL;DR: Investigation of cell growth dynamics, intracellular levels of proteins, starch and polyamines in suspension cultures of Pinus taeda established in plant growth regulator-free medium and in medium supplemented with 2 μM 2,4-dichlorophenoxyacetic acid and 0.5 μM Kinetin finds highest putrescine levels occurred in cultures growing in BM0 medium and this was associated with the low cellular growth.
Abstract: Somatic embryogenesis is the most important in vitro culture system for conifer propagation. However, Pinus taeda has been considered recalcitrant to somatic embryogenesis in commercial scale-up. The study of biochemical and physiological aspects of cell growth could lead to a better understanding of somatic embryogenesis in this species. In the present work, we investigated the cell growth dynamics, intracellular levels of proteins, starch and polyamines in suspension cultures of Pinus taeda established in plant growth regulator-free medium (BM0) and in medium supplemented with 2 μM 2,4-dichlorophenoxyacetic acid, 0.5 μM 6-benzylaminopurine and 0.5 μM Kinetin (BM2). Cell cultures growing in BM0 medium showed an increase in the sedimented cell volume from 3.77 to 17.73 ml after 24 days of culture. Those cultured in BM2 medium showed an increase in the sedimented cell volume from 4.23 to 25.17 ml after 20 days of culture. Intracellular proteins levels increased during the exponential growth phase and starch levels decreased until the exponential phase, followed by a synthesis up to the stationary phase, in both BM0 and BM2 media. Highest putrescine levels occurred in cultures growing in BM0 medium and this was associated with the low cellular growth.
102 citations
TL;DR: Using this efficient regeneration system, plantlets were regenerated from seven elite maize inbred lines and provided a solid basis for genetic transformation of maize.
Abstract: An efficient maize regeneration system was developed using mature embryos. Embryos were removed from surface-sterilized mature seeds and sliced into halves. They were used as explants to initiate callus on induction medium supplemented with 4.0 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). The induction frequency of primary calli was over 90% for all inbred lines tested. The primary calli were then transferred onto subculture medium supplemented with 2.0 mg l(-1) 2,4-D. Following two biweekly subcultures, embryogenic calli were formed. Inclusion of a low concentration (0.2 mg l(-1)) of 6-benzylaminopurine (BA) in the subculture medium significantly promoted the formation of embryogenic callus. The addition of silver nitrate (10 mg l(-1)) also supported an increased frequency of embryogenesis. The embryogenic callus readily formed plantlets on regeneration medium supplemented with 0.5 mg l(-1) BA. The regenerated plantlets were transferred to half-strength Murashige and Skoog medium supplemented with 0.6 mg l(-1) indole-3-butyric acid to develop healthy roots. The regenerated plantlets were successful on transfer to soil and set seed. Using this system, plantlets were regenerated from seven elite maize inbred lines. The frequency of forming green shoots ranged from 19.8% to 32.4%. This efficient regeneration system provides a solid basis for genetic transformation of maize.
101 citations
TL;DR: High frequency of root induction was obtained due to pulse treatment with a NAA and IBA combination (1:1) at the concentration of 100 mg l−1 for 60 min.
Abstract: The effect of liquid pulse treatment of growth regulators on in vitro propagation of banana (Musa spp. AAA) was studied. Optimal shoot proliferation rates were achieved due to the pulse treatment of 6-benzylaminopurine (BA) and kinetin combination (1:1) at the concentration of 50 mg l −1 for 60 min. Similarly high frequency of root induction was obtained due to pulse treatment with a NAA and IBA combination (1:1) at the concentration of 100 mg l −1 for 60 min.
92 citations
TL;DR: Bamboo somatic embryos and in vitro regenerants and potted plants flowered, but no seeds were produced and the effects of sucrose and thidiazuron (TDZ) on callus proliferation were studied.
Abstract: Current research on somatic embryogenesis of bamboo uses reproductive tissue as explants. However, it was hard to obtain the explant. Shoots of a local accession (3–4 m high) were used for multiple shoot production. In order to obtain embryogenic callus, nodal and internodal tissues from in vitro plantlets were placed on Murashige and Skoog (MS) medium supplemented with 9.2 μM kinetin (KN), 13.6 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1% (v/v) coconut milk, and 6% (w/v) sucrose. We studied the effects of sucrose and thidiazuron (TDZ) on callus proliferation. Optimal additives to the MS medium for embryogenic callus proliferation were 0.046 μM TDZ, 13.6 μM 2,4-D and 3% (w/v) sucrose. TDZ also promoted the germination of bamboo somatic embryos. The germination rate of the somatic embryos exceeded 80% on MS-based medium supplemented with 0.455μM TDZ. Naphthaleneacetic acid (NAA) reduced germination. Well-developed plantlets were successfully transferred to soil. There was no albino mutant in subsequent culture. In vitro regenerants and potted plants flowered, but no seeds were produced.
91 citations
TL;DR: Seed germination decreased with the increase in salinity, and more than 10% of the seeds germinated at 900 mmol/L NaCl, while ethephon almost completely reverted the effect of salinity.
Abstract: Ceratoides lanata (Pursh) J.T. Howell is a shrub with numerous annual branchlets from the family Chenopodiaceae and is widely distributed in brackish water playas of northern Utah. Seeds had no dormancy, and about 90% of the seeds germinated in nonsaline control. Seed germination decreased with the increase in salinity, and more than 10% of the seeds germinated at 900 mmol/L NaCl. Almost all seeds germinated in less than 24 h, and no additional seed germinated after this time. Gibberellic acid had no effect in alleviating salinity effects; however, kinetin and fusicoccin substantially alleviated the effect of salinity on germination, while ethephon almost completely reverted the effect of salinity.Key words: Ceratoides lanata, gibberellic acid, ethephon, fusicoccin, halophytes, kinetin.
90 citations
TL;DR: High frequency plant regeneration from mature seed derived embryogenic calli of two recalcitrant indica rice cultivars H KR-46 and HKR-126 after partial desiccation treatment is reported.
Abstract: An efficient and reproducible protocol is required to achieve high frequency transformation from transformed calli. We report here high frequency plant regeneration from mature seed derived embryogenic calli of two recalcitrant indica rice cultivars HKR-46 and HKR-126 after partial desiccation treatment. Embryogenic and nodular callus was initiated on MS basal medium supplemented with 2.5 mg l -1 2,4-D, 500 mg l -1 proline, 500 mg l -1 casein hydrolysate, 30 g l -1 sucrose and 2.5 g l -1 gelrite. Several media with different combinations of growth regulators were tried. Maximum shoot regeneration frequency (63%) was observed in partially desiccated calli for 48 h in cv. HKR 46 and 82.1 per cent in cv. HKR-126 on the MS modified medium supplemented with 2 mg l -1 kinetin + 0.5 mg l -1 NAA + 30 gl -1 sucrose + 6 g l -1 gelrite followed by in the medium supplemented with 1 mgl -1 2ip + 30 g l -1 sucrose + 6 g l -1 gelrite (61% in cv. HKR-46 and 79.2 % in cv. HKR-126). Highly significant regeneration differences were observed in partially desiccated calli (48 h) in comparison to non-dehydrated (0 h desiccation) calli. Shoot regeneration frequency increased from 1.2 to 5.6 fold after 48 h of desiccation in both the cultivars on different regeneration media. Shoot regeneration frequency declined at 72 h desiccation treatment as compared to 48 h treatment. Well-developed plantlets were hardened and transferred to the green house. Key words: Plant regeneration; indica rice; mature embryo; partial desiccation. African Journal of Biotechnology Vol.3(5) 2004: 256-259
81 citations
TL;DR: A protocol has been developed for in vitro plant regeneration from cotyledonary nodes of Pterocarpus marsupium Roxb and about 52% of plantlets were successfully acclimatized and established in pots.
Abstract: A protocol has been developed for in vitro plant regeneration from cotyledonary nodes of Pterocarpus marsupium Roxb. Multiple shoots were induced from cotyledonary nodes derived from 20-d-old axenic seedlings grown on Murashige and Skoog (MS) medium containing 2.22–13.32 μM benzyladenine (BA) or 2.32–13.93 μM kinetin alone or in combination with 0.26 μM α-naphthaleneacetic acid (NAA). The highest frequency for shoot regeneration (85%) and maximum number of shoots per explant (9.5) were obtained on the medium supplemented with 4.44 μM BA and 0.26 μM NAA after 15 wk of culture. A proliferating shoot culture was established by repeatedly subculturing the original cotyledonary nodal explant on fresh medium after each harvest of the newly formed shoots. Nearly 30% of the shoots formed roots after being transferred to half-strength MS medium containing 9.84 μM indole-3-butyric acid (IBA) after 25 d of culture. Fifty percent of shoots were also directly rooted as microtuttings on a peat moss, soil, and compost mixture (1∶1∶1). About 52% of plantlets were successfully acclimatized and established in pots.
TL;DR: With the protocol described here, the authors have obtained hundreds of regenerating plantlets from 10 recalcitrant cultivars, which is important for the application of tissue culture to cotton breeding and biotechnology.
Abstract: A new protocol has been developed for the highly efficient somatic embryogenesis and plant regeneration of 10 recalcitrant Chinese cotton cultivars. Calluses and embryogenic calluses were induced on MSB1 medium containing the optimal combination of indolebutyric acid (IBA; 2.46 μM) and kinetin (KT; 2.32 μM). Up to 86.7% of embryogenic calluses differentiated into globular somatic embryos 2 mo. after culture on MSB2 medium containing double KNO3 and free of growth regultors. Up to 38.3% of the somatic embryos were converted into complete plants in 8 wk on MSB3 medium with l-asparagine (Asn)/l-glutamine (Gln) (7.6/13.6 mM). The plants were successfully transferred to soil and grew to maturity. With the protocol described here, we have obtained hundreds of regenerating plantlets from 10 recalcitrant cultivars, which is important for the application of tissue culture to cotton breeding and biotechnology.
Journal Article•
TL;DR: This method could be useful for regenerating large number of plants as well as provide a target tissue for genetic transformation studies after induction of direct embryogenesis from inflorescence segments in Indian sugarcane.
Abstract: A protocol for direct somatic embryogenesis without an intervening callus phase was developed for sugarcane (Saccharum spp. hybrids) using immature inflorescence segments. Murashige and Skoog (MS) medium supplemented with0.5 mg/l naphthaleneacetic acid, 2.5 mg/I kinetin, 100 mg/l L-glutamine and 4% sucrose showed high frequency of somatic embryo development (54.09 ′ 2.7%), with an average 7.72 ′ 0.89 plants per explant. Embryo development was seen all over the cultured explants within four weeks of culture and the embryos germinated within a week upon transfer to basal MS medium without any growth regulators and all the plants grew normally in the greenhouse. This is a report on the induction of direct embryogenesis from inflorescence segments in Indian sugarcane. This method could be useful for regenerating large number of plants as well as provide a target tissue for genetic transformation studies.
TL;DR: Callus developed on NAA and Kn-supplemented medium favored induction and maturation of embryos earlier compared to that on 2,4-D and Kn, andEmbryo-derived plantlets established in field conditions displayed morphological characters identical to those of the parent plant.
Abstract: High-frequency somatic embryogenesis and plant regeneration was achieved on callus derived from leaf (petiole and lamina) and internode explants of Centella asiatica L. Growth regulators significantly influenced the frequency of somatic embryogenesis and plant regeneration. Calluses developed on Murashige and Skoog (MS) medium fortified with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D) or 5.37 μM α-naphthaleneacetic acid (NAA), both with 2.32 μM kinetin (Kn), were superior for somatic embryogenesis. Callus developed on NAA and Kn-supplemented medium favored induction and maturation of embryos earlier compared to that on 2,4-D and Kn. Embryogenic callus transferred from NAA and Kn-supplemented medium to suspension cultures of half-strength MS medium with NAA (2.69 μM) and Kn (1.16 μM) developed a mean of 204.3 somatic embryos per 100 mg of callus. Embryogenic callus transferred from 2,4-D and Kn subsequently to suspension cultures of half-strength MS medium with 2,4-D (0.45 μM) and Kn (1.16 μM) developed a mean of 303.1 embryos per 100 mg of callus. Eighty-eight percent of the embryos underwent maturation and conversion to plantlets upon transfer to half-strength MS semisolid medium having 0.054 μM NAA with either 0.044 μM BA or 0.046 μM Kn. Embryo-derived plantlets established in field conditions displayed morphological characters identical to those of the parent plant.
Journal Article•
TL;DR: The mixed doses of GA3 with IAA and kinetin revealed early flowering alongwith nonsignificant increase in the number of flower buds, however, the dose of IAA+kinetin promoted late flowering with noticeable increase in number of floral buds.
Abstract: The effect of growth hormones on the morphology of shoot of lentil was examined. The hormones viz., 1.5 mM (500 mg L -1 ) GA3, 2.85 mM (500 mg L -1 ) IAA and 0.14 mM (30 mg L -1 ) kinetin were applied individually as well as in combination i.e., 1.5 mM GA3 + 2.85 mM IAA, 1.5 mM GA3 + 0.14 mM kinetin, 2.85 mM IAA + 0.14 mM kinetin and 1.5 mM GA3 + 2.85 mM IAA + 0.14 mM kinetin. GA3 showed a marked elongation in the length of shoot and increase in the number of internodes and compound leaves. Application of IAA showed a decrease in length of shoot and number of internodes. The increase in the diameter, area and number of leaves was also observed. IAA induced branching with lush green colour of leaves. Kinetin showed inhibition in length and in the number of internodes. Inhibition was associated with a significant expansion in diameter and an increase in area of leaves as well as their number. The combined dose of GA3+IAA, GA3+kinetin and GA3+IAA+kinetin showed a significant increase in length and number of internodes as well as in the number of compound leaves. The colour of leaves was green and no branching was induced. However, the diameter of main stem showed inhibition. The dose of IAA+kinetin showed a decrease in length and number of internodes. However, expansion in the main stem diameter and increase in the number and area of leaves was also observed. The colour of leaves was lush green with more branches as compared to control. In GA3 treated plants, early flowering with higher number of floral buds was recorded. Applied IAA caused late flowering and increased the number of floral buds, while kinetin showed no significant delay in flowering but number of floral buds was more as compared to control. The mixed doses of GA3 with IAA and kinetin revealed early flowering alongwith nonsignificant increase in the number of flower buds. However, the dose of IAA+kinetin promoted late flowering with noticeable increase in number of floral buds.
TL;DR: Pepper was characterized by a strong asynchrony of pollen development within a single anther, and associations were found among the percentage of early-binucleate pollen, the frequency of embryogenic multinucleates pollen, and the yield of pollen embryos.
Abstract: Anthers of Capsicum annuum L. were cultured on Murashige and Skoog (MS) medium containing 0.1 mg l−1 NAA and 0.1 mg l−1 kinetin. Inoculated anthers were subjected to 31 °C and development of microspores in anthers of varying stages was observed cytologically using 4′-6-diamidino-2-phenylindol-2HCl (DAPI). Pepper was characterized by a strong asynchrony of pollen development within a single anther. Percentage of pollen at different stages changed with the culture period, and the proportion of dead pollen increased drastically from day 2 after culture. Microspores that were cultured at the late-uninucleate stage followed one of two developmental pathways. In the more common route, the first sporophytic division was asymmetric and produced what appeared to be a typical bicellular pollen. Embryogenic pollen was formed by repeated divisions of the vegetative nucleus. In the second pathway, which occurred in fewer microspores, the first division was symmetric and both nuclei divided repeatedly to form embryogenic pollen. In early-bicellular pollen, sporophytic pollen was produced through division of the vegetative nucleus. In mid-bicellular pollen, the generative nucleus may undergo division to produce two or more sperm-like nuclei. However, division of the generative nucleus alone to form the embryo was never observed. The anther stage optimal for embryo production contained a large proportion (>75%) of early-binucleate pollen. Associations were found among the percentage of early-binucleate pollen, the frequency of embryogenic multinucleate pollen, and the yield of pollen embryos.
TL;DR: The increase in the levels of antioxidant enzyme activities, for example superoxide dismutase and peroxidase, indicated the presence of excess oxygen uptake and the stressed condition of the plant tissues that arose from haemoglobin supplementation, appeared to accelerate somatic embryogenesis in cotton.
Abstract: Somatic embryogenesis in cotton (Gossypium hirsutum L.) is accelerated when the plant regeneration medium is supplemented with haemoglobin (erythrogen). In cotton SVPR 2 lines, a higher frequency of embryoid formation was observed when the medium contained 400 mg/l haemoglobin. Fresh weight of the callus, rate of embryoid induction, number of embryoids formed and the percentage of plant regeneration from somatic embryos were increased. Among the two different cultivars tested, MCU 11 showed no response to the presence of haemoglobin when compared to SVPR 2, and embryogenic callus formation was completely absent in the former. Medium containing MS salts, 100 mg/l myo-inositol , 0.3 mg/l thiamine-HCL, 0.3 mg/l Picloram (PIC), 0.1 mg/l kinetin and 400 mg/l haemoglobin effected a better response with respect to embryogenic callus induction. After 8 weeks of culture, a high frequency of embryoid induction was observed on medium containing MS basal salts, 100 mg/l myo-inositol, 0.3 mg/l PIC , 0.1 mg/l isopentenyl adenine, 1.0 g/l NH4NO3 and 400 mg/l haemoglobin. Plant regeneration was observed in 75.8% of the mature somatic embryos, and whole plant regeneration was achieved within 6–7 months of culture. The regenerated plantlets were fertile and similar to in vivo-grown, seed-derived plants except that they were phenotypically smaller. A positive influence of haemoglobin was observed at concentrations up to 400 mg/l at all stages of somatic embryogenesis. The increase in the levels of antioxidant enzyme activities, for example superoxide dismutase and peroxidase, indicated the presence of excess oxygen uptake and the stressed condition of the plant tissues that arose from haemoglobin supplementation. This increased oxygen uptake and haemoglobin-mediated stress appeared to accelerate somatic embryogenesis in cotton.
TL;DR: Kinetin was found superior to benzyl amino purine and N 6 (γ,γ-dimethylallyamino)purine (2iP) for explant establishment and multiplication and Woody Plant Medium was found to be the best.
Abstract: Various factors such as browning, season, media type and plant growth regulators influence the micropropagation of female trees of Myrica esculenta . These factors have successfully been addressed after addition of some media additives, collection of the explant at right season, standardizing the media type and use of plant growth regulators at varying concentrations. Polyvinylpyrollidone (PVP - 0.5%) was found effective for successful partial removal of phenolic compounds and obtaining maximum percent survival of explants. The explant collection season played an important role in reducing phenol induced browning and winter season was found best for explant establishment. The maximum number of shoots (4-5/explant) was obtained in Woody Plant Medium (WPM) supplemented with 10µM kinetin and 0.1µM naphthalene acetic acid (NAA). Of all the media types tried, Woody Plant Medium was found to be the best. Kinetin was found superior to benzyl amino purine and N 6 (γ,γ-dimethylallyamino)purine (2iP) for explant establishment and multiplication. NAA induced rooting to 45.8% of explants in 1/2 strength Woody Plant Medium. However, ex vitro survival percentage was low. Key Words: Browning, in vitro, plant regeneration, tissue culture, woody plant medium. African Journal of Biotechnology Vo l.3(10) 2004: 534-540
TL;DR: Effects of 28-homobrassinolide and kinetin and especially HBR increased the activities of nitrate reductase and carbonic anhydrase, chlorophyll and total protein contents and net photosynthetic rate in the leaves and pod number and seed yield, at harvest.
Abstract: Effects of 28-homobrassinolide (HBR) and kinetin (KIN) on photosynthesis, nitrogen metabolism, and the seed yield were studied. The leaves of 25-d-old plants of Vigna radiata (L.) Wilczek were sprayed with 0.01, 1.0 or 100 μM aqueous solution of KIN, or 0.0001, 0.01 or 1.0 μM that of HBR. KIN and especially HBR increased the activities of nitrate reductase and carbonic anhydrase, chlorophyll and total protein contents and net photosynthetic rate in the leaves, and pod number and seed yield, at harvest.
TL;DR: In vitro shoot culture of four Solidago species, S.virgaurea L., S.canadensis L. and S.graminifolia (L.) Salisb. were established from aseptically germinated seedlings as discussed by the authors.
Abstract: In vitro shoot culture of four Solidago species, S.virgaurea L., S.canadensis L., S.gigantea Ait. and S.graminifolia (L.) Salisb. were established from aseptically germinated seedlings. Proliferated axillary shoots were multiplied rapidly on Murashige and Skoog's medium, supplemented with 9.3 µm kinetin and 11.4 µm indole-3-acetic acid. Rooted plantlets were transferred to the soil, then grown in the field. Aerial parts were collected from clonal-propagated Solidago species during the flowering stage. The essential oils, obtained from air-dried plant material by hydrodistillation, were studied by GC and GC–MS. Slight differences were found in the yield and composition of essential oils between the micropropagated plants and wild plants growing in natural sites. Copyright © 2003 John Wiley & Sons, Ltd.
TL;DR: It is indicated that auxins and cytokinin have a regulatory role in the growth and morphogenesis in G. tenuistipitata and G. perplexa, and diversity of responses presented by both species is related to specific developmental systems.
Abstract: SUMMARY
The effects of auxins and cytokinin on callus formation, growth and regeneration of Gracilaria tenuistipitata Chang et Xia and G. perplexa Byrne et Zuccarello (Gracilariales, Rhodophyta) are reported. Plant growth regulators (PGR) in concentrations ranging from 0.1 to 100.0 μmol of indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid (2,4-D), and kinetin (K) were added to the ASP 12-NTA solid medium (0.7% agar), and apical and intercalary segments (5 mm long) were inoculated as initial explants. K stimulated growth rates of intercalary segments of G. tenuistipitata in a linear relation, and 2,4-D (1.0 μmol) and K (10.0 μmol) stimulated growth rates of apical and intercalary segments of G. perplexa, respectively. The simultaneous formation of apical, basal, and intermediate calluses is reported for the first time in axenic tissue cultures of red algae. With intercalary segments of G. tenuistipitata, basal callus induction rates were higher than those of apical and intermediate calluses in the majority of treatments, and auxins had stimulatory effects on the formation of all callus types. In apical segments of G. perplexa, intermediate callus formation was stimulated only by treatment with 1.0 μmol of K, while apical callus formation was stimulated by indole-3-acetic acid (1.0–10.0 μmol), 2,4-D (10.0–100.0 μmol), or K (0.1 μmol). Intercalary segments of G. perplexa developed only intermediate calluses, and the majority of treatments with PGR stimulated higher rates than those presented by apical segments. Potential for regeneration (development of adventitious plantlets originated from callus cells) was higher in apical calluses than in basal and intermediate calluses developed in intercalary segments of G. tenuistipitata. Moreover, auxins and cytokinin were essential to the induction of regeneration in intermediate calluses, while specific concentrations stimulated regeneration from basal and apical calluses. Plant regeneration in G. perplexa was observed only after transferring calluses from solid to liquid medium, and the majority of treatments with PGR had stimulatory effects. Regenerating plants of G. perplexa developed tetrasporangia, and released tetraspores giving rise to adult gametophytes. Our results indicate that auxins and cytokinin have a regulatory role in the growth and morphogenesis in G. tenuistipitata and G. perplexa, and diversity of responses presented by both species is related to specific developmental systems.
TL;DR: The regular strength of WPM in combination with 0.5 mgl−1 kinetin was the best condition for shoot proliferation of Ficus carica ‘Roxo de Valinhos’ plants, and the addition of activated charcoal in the medium completely inhibited shoot proliferation.
Abstract: An in vitro protocol for Ficus carica cv. ‘Roxo de Valinhos’ was optimized. Nodal explants containing two buds were excised from field-grown mature plants, and transferred to different proliferation media consisting of combinations of distinct concentrations of activated charcoal with benzyladenine (BA), kinetin with gibberellic acid (GA3), and WPM (woody plant medium) with kinetin. The regular strength of WPM in combination with 0.5 mgl−1 kinetin was the best condition for shoot proliferation of Ficus carica ‘Roxo de Valinhos’ plants. The addition of activated charcoal in the medium completely inhibited shoot proliferation. The inclusion of BA in the medium induced excessive callus formation as well as small and vitrified shoots, while GA3 induced excessive elongation associated with vitrification, chlorosis, and tip-burned shoots.
TL;DR: No morphological differences were observed between plants derived from somatic embryos and control plants, and no differences in ploidy were detected between the somatic embryo-derived plants and the mother plants.
Abstract: Somatic embryogenesis from mature elm (Ulmus minor Mill.) in vitro-cloned material is possible. Embryogenic callus was obtained from leaves inoculated on two different MS-based media—one supplemented with 2.3 μM 2,4-dichlorophenoxyacetic acid (I2) and the other supplemented with 1.1 μM kinetin (I6). However, only leaves cultured on medium I6 produced somatic embryos, at the globular stage, when embryogenic callus was maintained in induction media. When embryogenic callus from medium I6 was transferred to basal medium, somatic embryos with green cotyledons were obtained. An average of 35.9% of these embryos converted easily into normal plants in conversion medium with 1% sucrose. Acclimatisation reached 39.7%, and this was not significantly different from a control group consisting of plants propagated by axillary buds. No morphological differences were observed between plants derived from somatic embryos and control plants. Also, no differences in ploidy were detected between the somatic embryo-derived plants and the mother plants.
TL;DR: In vitro shoot regeneration from leaf discs of Passiflora edulis f.
Abstract: A protocol for in vitro shoot regeneration from leaf discs of Passiflora edulis f. flavicarpa is described. The effect of explant source on morphogenesis was studied by comparing the response of explants collected from young plants, in vitro plantlets, and reinvigorated adult plants. Highest de novo shoot production was observed in explants from 2-month-old plants cultured in Murashige and Skoog medium supplemented with sucrose 30 g l−1, 4.44 µM benzyladenine, and 2.32 µM kinetin. Regenerated shoots rooted spontaneously in growth regulator-free medium and were successfully acclimatized to greenhouse conditions. Influence of the age and physiological state on shoot regeneration and gradual loss of morphogenic capacity is discussed.
TL;DR: Embryogenic culture was initiated from mature zygotic embryos of Panax ginseng and showed a slight improvement in the root meristem organization of torpedo-stage embryos (embryos were more compact and their cells exhibited a lower degree of vacuolation).
Abstract: Embryogenic culture was initiated from mature zygotic embryos of Panax ginseng. Multiple somatic embryos formed and proliferated on Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2.26 microM) and kinetin (0.046 microM). Mature as well as immature somatic embryos grew into plantlets lacking roots on the same media. Histomorphological analysis of somatic embryos treated with abscisic acid (ABA) and polyethylene glycol (PEG 4000) showed a slight improvement in the root meristem organization of torpedo-stage embryos (embryos were more compact and their cells exhibited a lower degree of vacuolation). Shoot regeneration of non-treated somatic embryos was 31% while that for somatic embryos treated with PEG 4000 and ABA was 70%. Moreover, 75% of plants regenerated from PEG- and ABA-treated embryos formed roots while plants from non-treated embryos did not form roots.
TL;DR: On mice with leukaemia P388, this product has no effect on the tumour growth, and it appears to be toxic at the dose of 25 mg/kg, and Kinetin riboside was shown to have a cytotoxic effect on plant tumour cells (crown-gall).
TL;DR: A highly efficient three-step protocol for in vitro propagation of Ensete ventricosum (enset) was developed that consisted of initiation, bud proliferation, and shoot elongation and rooting stages and the plantlets were acclimatized with 100% success.
Abstract: A highly efficient three-step protocol for in vitro propagation of Ensete ventricosum (enset) was developed that consisted of initiation, bud proliferation, and shoot elongation and rooting stages. At the initiation stage, it was crucial to use shoot tips (5–8 mm) with subtending corm tissues as explants to obtain growth. The addition of 0.5–1% (w/v) activated charcoal to the medium was essential to prevent phenol exudation which otherwise leads to the loss of cultures. During the bud proliferation stage, modified MS macronutrients and micronutrients together with a combination of cytokinins (1.6 μM naphthaleneacetic acid, 4.4 μM 6-benzylaminopurine, 23.2 μM kinetin, 22.6 μM N6 2-isopentyladenine) was used. This novel composition of macronutrients was based on the analysis of leaf nutrient content of glasshouse-grown enset sprouts. Multiple bud formation on the enlarged corm tissue was induced only when the meristem region was wounded before transfer to the bud proliferation medium. Up to 75 healthy shoots per explant were produced, whereas unwounded explants produced, only one to two shoots per explant. A third stage with a low concentration of cytokinin enabled shoot elongation as well as root development. The plantlets were acclimatized with 100% success and they showed no apparent phenotypical deviation.
01 Jan 2004
TL;DR: In this paper, an efficient protocol for rapid multiplication of the herbal spice Mentha piperita L. through axillary bud multiplication and ex vitro rooting was established using Murashige and Skoog (MS) medium.
Abstract: Efficient protocol for rapid multiplication of the herbal spice Mentha piperita L. through axillary bud multiplication and ex vitro rooting was established using Murashige and Skoog (MS) medium. Media prepared with tap water and commercial sugar, and those prepared with double distilled water and tissue culture grade sucrose did not show significant difference in the in vitro induction of shoots/node, and roots/shoot. MS medium fortified with 4.44 μM N-benzyladenine (BA) and 2.32 μM kinetin (Kn) was the best for proliferation of shoots; induced a mean of 4.1 shoots/node explant. The shoots attained a height of more than 4.5 cm bearing more than 5 nodes within 40 days. Excision and culture of in vitro derived node segments on medium with 3.33 μM BA and 2.32 μM Kn facilitated enhanced axillary bud proliferation. Shoots developed were rooted best on half-strength MS medium with 0.49 μM indole-3-butyric acid (IBA); induced a mean of 10.3 roots. In vitro rooted shoots exhibited 100% survival in field conditions. Dipping of the basal end of shoots harvested from multiplication medium in 0.49 μM IBA solution for 10 days induced a mean of 8 roots and its transfer to small pots facilitated survival of 95% rooted shoots. Ex vitro rooting by direct transfer of the shoots from multiplication medium to small pots showed 72% survival. Commercial sugar and tap water and ex vitro rooting make the protocol economic.
TL;DR: Several plant growth regulators BA, TDZ, 2,4- and Kn were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf and internode explants of Paulownia elongata to show morphologically identical to the donor material and developed normally in the greenhouse.
Abstract: Several plant growth regulators BA, TDZ, 2,4- and Kn were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf and internode explants of Paulownia elongata Calli were produced when leaf explants were cultured on Murashige and Skoog (MS) medium containing 3 % sucrose, 04 % phytagel, 4 mg l-1 TDZ and 01 mg l-1 Kn after 3 weeks and the initiation rate was 541% After subculturing on the same medium, embryos at various developmental stages (globular, heart and torpedo shaped) were transferred for maturation onto MS medium supplemented with 3 % sucrose, 04 % phytagel, 01 mg l-1 TDZ, 1 mg l-1 Kn and 2 mM glutamine An average of 507 somatic embryos were obtained from 100 mg of embryogenic callus after 4 weeks at high frequency (647 %) Afterward, mature somatic embryos were isolated and cultured on hormone-free MS medium for germination (80 %) and development into plantlets Plantlets were transferred to pots with a mixture of peat and perlite in a 3:1 ratio and showed a survival rate of 70–80 % Plantlets regenerated by this procedure were morphologically identical to the donor material and developed normally in the greenhouse
Journal Article•
TL;DR: The proline level showed a positive correlation with the degree of tolerance to water stress, which suggests that proline accumulation accompanies survival and growth in drought environment.
Abstract: Cell cultures of sunflower (Helianthus annus L. cv. Myak) were established from callus tissues inoculated in MS liquid medium supplemented with 1.0 mg/L NAA (naphthalene acetic acid), 0.1 mg/L KN (kinetin). PEG 6000 was added to the medium to induce water deficit. Water stress tolerant callus line was isolated by plating the cell suspension on agar-solidified medium containing the same solute potential of PEG (polyethylene glycol). This selected line grew better than the nonselected one on various levels of water deficit induced by PEG. Moreover, the selected line accumulated more K, Na and N but less Ca and P than the non-selected line. The proline level showed a positive correlation with the degree of tolerance to water stress, which suggests that proline accumulation accompanies survival and growth in drought environment. With the exception of polysaccharides, the sugar contents of both callus lines significantly increased with increasing PEG concentration. Protein profile of both selected and non-selected callus lines shows the presence of four major and three minor polypeptide bands. No qualitative differences have been obtained between both callus lines in presence or absence of water stress. No de novo proteins have been produced under PEG-induced water stress conditions. DNA banding pattern indicated the occurrence of four de novo DNA fragments in the non-selected callus line exposed to -0.8 and -1.0 MPa osmotic stress. Exposing selected callus line to water stress was accompanied by the induction of a unique DNA fragment of an approximate size of 571 bp. The better performance of selected line under water stress may be attributed to its greater osmotic adjustment in relation to non-selected line.