Addition Of Plant Growth Regulators Research Articles

Solasodine accumulation in regenerated plants of Solanum torvum Sw

A nodal segment culture was developed in order to assess Solanum torvum Sw. regeneration and solasodine levels. The influence of auxins (indoleacetic acid, 1-Naphthaleneacetic acid) and benzyl adenine on S. torvum growth in micropropagation was investigated. A nodal segment culture was initiated with seeds germinated in MS basal medium added of GA3 and grown in different concentrations of IAA, IAA + BAP and NAA + BAP. Sixty-day-old plants from the in vitro culture were collected, frozen and lyophilized; then, the methyl orange method was used to quantify solasodine for the spectrophotometric assay. The best results regarding plant regeneration and solasodine accumulation were obtained by using the MS basal medium without addition of plant growth regulators; however, there was great production of calluses presenting friable bases. Based on these results, cell cultures can be initiated from such calluses with application of other auxins and cytokinins to enhance solasodine production, besides different elicitors, light intensities and sucrose concentrations.

Germination of mature seeds of Calanthe tricarinata Lindl., an endangered terrestrial orchid, by asymbiotic culture in vitro

The effects of culture conditions on the asymbiotic germination of mature seeds of Calanthe tricarinata Lindl., an endangered terrestrial cool-climate orchid, were examined. Specifically, conditions such as illumination, temperature, and the addition of plant growth regulators to the medium were studied. Mature seeds were harvested from plants that had been collected in Toyama Prefecture, Japan, and maintained at the Botanic Gardens of Toyama. Solidified “New Dogashima” medium was used as the basal medium, and it was supplemented with 6-benzyladenopurine (BA) or α-naphthalene acetic acid (NAA). White light at 40 µmol m−2 s−1, with a 16-h photoperiod, inhibited the germination of seeds by 53–80%, as compared to dark controls in genotypes examined. The optimal temperature for the germination of seeds in darkness was 20°C and the germination frequency reached 60%, whereas it was only 28% at 25°C. While both NAA and BA stimulated germination, BA was more effective than NAA. After storage for 18 mo at 5°C, seeds incubated on medium that contained 0.2 mg l−1 BA germinated at a frequency of 36%, which was twice that of seeds grown without any plant growth regulators. The frequency of subsequent germination decreased during storage of seeds at 5°C for approximately 2 yr, dropping from 61% to 13%. The protocorms obtained in this study were developed to plantlets readily after transferring to fresh 1/2 MS medium without any plant growth regulators. They were successfully acclimatized in green house after two to three subcultures in vitro. The significant role of a reproducible protocol for the germination of mature seeds is discussed in terms of the ex situ conservation of endangered orchid species.

Improved germination of somatic embryos and plant recovery of European chestnut

For the mass production of chestnut trees with selected, hybrid, or genetically engineered genotypes, one potentially desirable propagation strategy is based on somatic embryogenesis. Although methods exist for the initiation of embryogenic cultures of Castanea sativa from immature zygotic embryos or leaf explants, the embryos produced have had low rates of conversion into plantlets. This study explored the possible benefits for somatic embryos that have already undergone maturation and cold treatments, of (a) partial slow or fast desiccation, and (b) of the addition of plant growth regulators or glutamine to the germination medium. Germination response was evaluated in terms of both conversions to plantlets and through embryos developing only shoots (shoot germination) that could be rooted following the micropropagation protocols developed for chestnut. Two or 3 wk slow desiccation in sealed empty Petri dishes resulted in a slight reduction in water content that nevertheless increased total potential plant recovery, shoot length, and the number of leaves per plantlet. However, best results were achieved by 2 h fast drying in a laminar flow hood, which reduced embryo moisture content to 57–58% and enhanced the potential plant recovery and quality of regenerated plantlets. Plant yield was also promoted by addition of 0.44 μM benzyladenine and 200–438 mg/l of glutamine to the germination medium, and plantlet quality (as evidenced by root, shoot, and leaf growth) by the further addition of 0.49 μM indole-3-butyric acid.

In vitro tuberisation of Gloriosa superba L. on basal medium

A suitable protocol for in vitro tuber production using non-dormant tubers of Gloriosa superba L. on Murashige and Skoog (MS) medium without addition of plant growth regulators is reported in the present study. Among the different basal media tested MS medium was found to be suitable for induction and development of secondary tubers; one in vitro tuber per explant was obtained after 6 weeks and 3 tubers per explant after 12 weeks of culture. These tubers produced healthy green shoots that rooted on basal medium. Best rooting was noted in half strength (half organics and inorganics) MS medium with one-fifth nitrates.

Effect of plant growth regulators on growth and biosynthesis of phenolic compounds in genetically transformed hairy roots ofPanax ginseng C. A. Meyer

In this study, morphological alterations, biomass growth, and secondary metabolite production of genetically transformed hairy roots ofPanax ginseng C. A. Meyer, were evaluated after administration of plant growth regulators. The addition of benzylamino purine and kinetin to the culture media increased biomass formation and phenolic compound biosynthesis in the hairy roots. α-Naphthaleneacetic acid and indole-3-butyric acid inhibited hairy root growth, however, low concentrations of indole-3-acetic acid slightly increased hairy root growth. Low concentrations of 2,4-Dichlorophenoxyacetic acid profoundly inhibited growth of hairy roots. The addition of plant growth regulators, such as auxin, did not increase total phenolic compounds in hairy roots that did not contain gibberellic acid and cytokinins. Callus formation was induced in cultures suspended in liquid medium amended with benzylamino purine and kinetin. Hairy roots regenerated from these calluses exhibited an active growth pattern with extensive lateral branching in non-amended medium, similar to the growth pattern of the original hairy roots.

Growth and gender in the gametophyte of Blechnum spicant L

The growth and gender in the gametophyte of Blechnum spicant L. were strongly affected by its origin, spore or mature homogenized gametophytes, and also by the addition of plant growth regulators to the culture medium. Spore-derived gametophytes cultured in Murashige and Skoog liquid medium were females and heart-shaped, whereas those derived from mature homogenized gametophytes were shorter and male or asexual (1:3) because of the release of antheridiogen to the culture medium. In the latter, maleness was especially increased by the addition of BA. This cytokinin is a strong inductor of maleness in homogenized cultures; however, even though BA influenced sexual organ formation in spore-derived gametophytes, it does not change the␣female sexual pattern that these gametophytes have. Separate male and female populations of gametophytes were obtained in this work.

Involvement of Plant Hormones and Plant Growth Regulators on in vitro Somatic Embryogenesis

In spite of the importance attained by somatic embryogenesis and of the many studies that have been conducted on this developmental process, there are still many aspects that are not fully understood. Among those features, the involvement of plant hormones and plant growth regulators on deTermining the conversion of somatic onto embryogenic tissues, and on allowing progression and maturation of somatic embryos, are far away from being completely comprehended. Part of these difficulties relies on the frequent appearance of contradictory results when studying the effect of a particular stimulus over a specific stage in somatic embryogenesis. Recent progress achieved on understanding the interaction between exogenously added plant growth regulators over the concentration of endogenous hormones, together with the involvement of sensitivity of the tissues to particular hormone groups, might help clarifying the occurrence of divergent patterns in somatic embryogenesis, and in tissue culture in general. The aspects described above, emphasizing on the effect of the concentration of plant hormones and of the addition of plant growth regulators during the different phases of somatic embryogenesis, will be reviewed in this paper. Citations will be limited to review articles as much as possible and to individual articles only in those cases in which very specific or recent information is presented.

Acmella radicans var. radicans: In vitro culture establishment and alkamide content

Acmella radicans var. radicans propagation was established in vitro. This plant belongs to the Asteraceae from which some species are known for their insecticide, fungicide and antibacterial activity. The complete Murashige and Skoog (MS) medium was the best in assisting seed germination. In order to obtain shoots in vitro, a complete MS medium and half-strength MS medium were assayed with explants from leaves, nodes, and internodes. The best medium for shoot production was the half-strength MS medium with no addition of plant growth regulators, and the highest shoot propagation was from single-node explants. Regeneration of roots on shoot explants in the medium was obtained without the addition of growth regulators. Of the plantlets that were acclimated, 90% of them were obtained from rooted shoots with completely expanded leaves. The alkamide content was evaluated for each tissue and the higher concentration was observed in flower heads. The main alkamides present in the leaves and the flower heads were N-(2-phenylethyl)-2Z,4E-octadienamide and 3-phenyl-N-(2-phenylethyl)-2-propenamide. This study describes the methodology for the establishment and propagation of Acmella radicans in vitro and the evaluation of different tissue alkamide contents in vitro and in the field.

PENGEMBANGAN BIBIT UNGGUL PORANG (Amarphopallus oncophilus) MELALUI TEKNIK KULTUR IN VITRO UNTUK MENDUKUNG KETAHANAN PANGAN NASIONAL

<p>Porang (Amarphophallus. oncophyllus) is a type of plant tubers that have the potential and prospects for development in Indonesia. In addition to readily available, plants are also capable of producing carbohydrates and high harvest index. The last few years a very large porang needs. Porang plant propagation is vegetative and generative in which to make the seeds are ready to harvest takes between 4-6 months. This study aims to determine kinds of the appropriate medium for growing plants porang network and determine the concentration of each medium, so we get a superior porang plants. Research using factorial completely randomized design. The first factor is a growth regulator BAP concentration: 0 mg / l, 0.5 mg / l, 1.0 mg / l, 1.5 mg / l and 2.0 mg / l, while the second factor is the concentration of IBA 0 mg / l, 0.5 mg / l and 1.0 mg / l, in order to obtain 15 treatments and each treatment made 15 replications. Data were collected for the pengkalusan, contamination callus, callus mortality rate, number of buds, leaf buds height, number of leaves and root. The results showed that the addition of plant growth regulators (hormones) BAP in MS medium effect on the number of shoots, buds and the high number of young leaves. The addition of hormone IBA in MS medium pengkalusan affect the process and the number of roots. The addition of hormone BAP and IBA on MS medium did not significantly affect mortality contamination callus and callus. The interaction between BAP and IBA hormone given on MS medium did not significantly affect the pengkalusan, contamination callus, callus mortality rate, number of buds, leaf buds height, number of leaves and root</p> <p> </p>

Roscovitine, a novel cyclin-dependent kinase inhibitor, characterizes restriction point and G2/M transition in tobacco BY-2 cell suspension.

Although the developmental programs of plants and animals differ, key regulatory components of their cell cycle have been conserved. Particular attention has been paid to the role of the complexes between highly conserved cyclin and cyclin-dependent kinases in regulating progression through the cell cycle. The recent demonstration that roscovitine is a potent and selective inhibitor of the animal cyclin-dependent kinases cdc2 (CDK1), CDK2 and CDK5 prompted an investigation into its effects on progression through the plant cell cycle. Roscovitine induced arrests both in late G1 and late G2 phase in BY-2 tobacco cell suspensions. Both block were fully reversible when roscovitine was used at concentrations similar to those used in the animal system. Stationary-phase cells subcultured in the presence of roscovitine were arrested at a 2C DNA content. This arrest was more efficient without exogenous addition of plant growth regulator. Roscovitine induced a block in G1 earlier than that induced by aphidicolin. S-phase synchronized cells treated with roscovitine were arrested at a 4C DNA content at the G2/ M transition. The expression analysis of a mitotic cyclin (NTCYC1) indicated that the roscovitine-induced G2 block probably occurs in late G2. Finally, cells in metaphase were insensitive to roscovitine. The purified CDK/cyclin kinase activities of late G1 and early M arrested cells were inhibited in vitro by roscovitine. The implications of these experimental observations for the requirement for CDK activity during progression through the plant cell cycle are discussed.

Relationship between endogenous auxin and cytokinin levels and morphogenic responses inActinidia deliciosa tissue cultures

Thein vitro culture ofActinidia deliciosa petioles results in a decline of cytokinin content and an increase of auxin levels. The addition of plant growth regulators (PGRs) to the medium lead to recovery of the initial auxin content, and callus induction occurs at the basal end of the explants. Endogenous auxin/cytokinin ratio was higher at this side than in the apical one, due to unequal distribution of endogenous PGRs in the cultured petioles. Some of the induced calluses showed shoot formation when they were transferred to proliferation medium. Most important differences found in hormonal content between organogenic and non-organogenic callus concerned benzyladenine levels. In this paper the relationships between explant behaviour and their hormonal content is discussed.

Secondary embryogenesis from thin cell layers of Brassica napus ssp. oleifera

summaryThin cell layers approximately 1 × 8 mm in size were excised from secondary embryoids of Brassica napus ssp. oieifera cv. Primor. Further secondary embryogenesis was observed in about 35% of the thin cell layers cultured on a medium without the addition of plant growth regulators. In one experiment using 168 thin cell layers, the explants showing embryogenesis produced an average of 23 embryoids per explant. Secondary embryogenesis was found to be inhibited with the addition of high concentrations of auxin or cytokinin to the culture medium. Callus, root, shoot, and leafy structures were obtained depending on the type and concentration of auxin and cytokinin used. The embryoids from thin cell layers were capable of producing further secondary embryoids.

Tissue-specific and stress-enhancing expression of the TR promoter for mannopine synthase in transgenic medicinal plants

Transgenic tobacco (Nicotiana tabacum L.), licorice (Glycyrrhiza uralensis Fisher) and foxglove (Digitalis purpurea L.) were obtained with binary vector systems based on a disarmed Agrobacterium tumefaciens and on a virulent A. rhizogenes. The chimeric neomycin phosphotransferase II (NPT-II) gene (kan) and the ß-glucuronidase (GUS) gene (uidA) were under the control of the TR1' and 2' promoters, respectively, on a binary vector, pGSGluc1. Tissue-specific expression of the chimeric TR2' -uidA gene was studied using regenerants of N. tabacum from transformed callus and hairy roots, and also using the transformed roots of G. uralensis and D. purpurea. In all these transformed tissues, the phloem and surrounding tissues were stained with 5-bromo-4-chloro-3-indolyl-ß-d-glucuronide, showing the specific expression of uidA. The enzymatic assays of NPT-II and GUS indicated that the expression of both TR1' -kan and TR2'- uidA were coordinately enhanced by wounding and by the addition of plant growth regulators. These results indicate that the gene expression by the dual TR promoters is regulated in the several plant species studied in a tissue-specific manner and enhanced by physiological stresses.

Modulation by abscisic acid and S-2-aminoethyl-L-cysteine of α-amylase mRNA in barley aleurone cells

The changes in the levels of α-amylase mRNA is barley aleurone layers in response to addition of plant growth regulators have been studied using a cloned α-amylase cDNA as the hybridization probe. An increase in gibberellic acid (GA) concentration in the incubation medium from 10(-9) M to 10(-6) M results in a progressive increase in α-amylase mRNA concentration in the aleurone cells. Detectable levels of α-amylase mRNA appear in the aleurone cells as early as 1 h after addition of GA. The concentration of this mRNA increases for several hours and then declines rapidly. Abscisic acid (ABA) and the amino acid analog S-2-aminoethyl-L-cysteine (AEC) suppress the GA-mediated induction of α-amylase. These compounds appear to affect the level of α-amylase mRNA in aleurone cells as measured byin vitro translation assays and by analysis of RNA blots with α-amylase cDNA probes. It is concluded that the regulation of α-amylase gene expression by ABA is at the level of transcription. Further, a protein factor appears to be required in addition to GA for transcription of α-amylase genes.

Growth of excised meristem-tips of kumara, Ipomoea batatas (Linn.) Poir in axenic culture

Summary Same factors affecting the growth of excised kumara, Ipomoea batatas (Linn.) Poir, meristem-tips into plantlets, were studied. Root initiation and subsequent development into plantlets were influenced by the length of the shoot apex excised, the clone of kumara used and (the addition of plant growth regulators to the culture medium. Shoot apices longer than 1.6 mm rooted better than shorter apices. 1-naphthylacetic acid (1 mg/l) added to a high salt nutrient medium during early stages of culture, stimulated root initiation in two out of three clones of kumara tested and accelerated development in all three clones. Gibberellic acid (10 mg/l) stimulated root initiation in all three clones, but development was slower than with 1-naphthylacetic acid.