Showing papers on "Zeatin published in 2019"

Yeasts producing zeatin.

Abstract: The present paper describes the first screening study of the ability of natural yeast strains to synthesize in culture the plant-related cytokine hormone zeatin, which was carried out using HPLC-MS/MS. A collection of 76 wild strains of 36 yeast species (23 genera) isolated from a variety of natural substrates was tested for the production of zeatin using HPLC-MS/MS. Zeatin was detected in more than a half (55%) of studied strains and was more frequently observed among basidiomycetous than ascomycetous species. The amount of zeatin accumulated during the experiment varied among species and strains. Highest zeatin values were recorded for basidiomycete Sporobolomyces roseus and ascomycete Taphrina sp. that produced up to 8,850.0 ng and 5,166.4 ng of zeatin per g of dry biomass, respectively. On average, the ability to produce zeatin was more pronounced among species isolated from the arctic-alpine zone than among strains from tropical and temperate climates. Our study also demonstrated that epiphytic strains and pigmented yeast species, typically for phyllosphere, are able to more often produce a plant hormone zeatin than other yeasts.

The effect of selected growth regulators and culture media on regeneration of Daphne mezereum L. ‘Alba’

Abstract: Tissue cultures are the only effective way to proliferate this valuable species (Daphne mezereum). These researches may help in solving the problem of reproduction of other woody plants. Daphne mezereum L. commonly known as February daphne or mezereon is a decorative shrub from the family Thymelaeaceae. It is a valuable nursery plant due to its high ornamental values, but its propagation by traditional methods is ineffective, therefore, little profitable. Micropropagation may be a good alternative way to produce this ornamental shrub. The experiment aimed to examine the effect of cytokinins (meta-Topolin, benzyladenine, and zeatin) and other growth regulators (gibberellic acid GA3 and auxin 1-naphthalene acetic acid NAA) added to the Murashige and Skoog (MS) and Woody Plant Medium (WPM) nutrients on regeneration of explants of D. mezereum ‘Alba’. In the all treatments containing plant growth regulators (PGR), 100% regeneration of explants has been observed. The highest number of shoots, after 6 weeks of culture, was produced on MS medium with 1 mg·L−1 BA and 0.1 mg·L−1 NAA. The longest shoots were produced on MS medium with 0.1 mg·L−1 of gibberellic acid (GA3) and 1 mg·L−1 of meta-Topolin (mT). Generally, the type and concentration of plant growth regulators had an essential effect on regeneration and growth of shoots of Daphne mezereum ‘Alba’ in the in vitro culture.

Hydrogen cyanamide induces grape bud endodormancy release through carbohydrate metabolism and plant hormone signaling

Abstract: Grape buds exhibit non-uniform, or delayed, break in early spring in subtropical regions because the accumulation of chilling is insufficient. Hydrogen cyanamide (H2CN2, HC) can partially replace chilling to effectively promote bud sprouting and is used widely in warm winter areas. However, the exact underlying mechanism of grape bud release from endodormancy induced by HC remains elusive. In this study, the transcriptome of grape winter buds under in vitro conditions following HC and water treatment (control) was analyzed using RNA-seq technology. A total of 6772 differentially expressed genes (DEGs) were identified. Furthermore, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that starch and sucrose metabolism and plant hormone signaling transduction were most enriched out of the 50 total pathways. HC treatment induced the upregulated expression of sucrose synthase (SUS), sucrose phosphate synthase (SPS), α-amylase (AM), and β-amylase (BM) and downregulated expression of sucrose invertase (INV), hexokinase (HK), fructokinase (FK), soluble starch synthase (SS), and granule-bound starch synthase (GBSS). Hence, the starch concentration in the HC-treated group was significantly lower than that in control, whereas soluble sugar content in the HC-treated group increased quickly and was higher than that in control between 0 and 8 d. The concentration of indoleacetic acid (IAA) and zeatin (ZT) increased, whereas that of abscisic acid (ABA) and gibberellin (GA) decreased in HC treated group, which coincided with the expression level of genes involved in above hormone signals. The content of hydrogen peroxide (H2O2) and enzyme activity of superoxide dismutase (SOD) and peroxidase (POD) were increased in grape buds with HC treatment, whereas catalase (CAT) activity was decreased. HC treatment increased the expression of POD, SOD, primary amine oxidase (PAO), polyamine oxidase (PAOX), and glutathione peroxidase (GSH-Px). Based on these results, it is possible to propose a mechanistic model that underlies the regulation of endodormancy release in grapevine buds by exogenous HC application.

Effect of cytokinins and sucrose concentration on the efficiency of micropropagation of ‘Zes006’ Actinidia chinensis var. chinensis, a red-fleshed kiwifruit cultivar

Abstract: The effect of N6(3-hydroxybenzyl)adenine (meta-Topolin—mT) was compared with that of N6-benzylaminopurine (BAP) and zeatin at the proliferation stage of micropropagation of red-fleshed Actinidia chinensis var. chinensis ‘Zes006’ in two separate experiments. Shoot number, shoot weight, leaf number and leaf area were significantly higher in mT-supplemented media compared with BAP or zeatin. When transferred to rooting media, plantlets that were propagated in mT-supplemented media readily produced roots, enabling easy acclimation to the greenhouse, whereas none of the plantlets propagated in BAP- or zeatin-supplemented media produced roots. Using 12 pairs of Simple Sequence Repeat primers designed for A. chinensis var. chinensis, a very low rate of somaclonal variation was detected at some loci in plantlets produced in zeatin- (1.04%), BAP- (0.4%) as well as in mT- (0.2%) supplemented media. Overall, mT in equimolar concentrations was the better cytokinin for tissue culture of ‘Zes006’ kiwifruit and may well be applicable to many other kiwifruit genotypes. Supplementation of media with meta-Topolin for in vitro propagation of the red-fleshed kiwifruit cultivar ‘Zes006’ enhanced better shoot proliferation, giving healthy plantlets that were easier to acclimatize to the greenhouse environment compared with media supplemented with 6-benzylaminopurine or zeatin. It also induced a lower rate of somaclonal variation, as detected by SSR markers.

Identification of plant hormones and candidate hub genes regulating flag leaf senescence in wheat response to water deficit stress at the grain-filling stage.

Abstract: In order to clarify the transcriptional regulatory network and physiological mechanisms governing leaf senescence response to drought stress in wheat, experiments were performed using two wheat varieties with contrasting drought tolerance: Fu287 (F287, a drought-sensitive genotype) and Shannong20 (SN20, a drought-resistant genotype). The latter has higher SPAD values, salicylic acid (SA), jasmonic acid (JA), zeatin (Z), zeatin riboside (ZR), and gibberellin (GA 3) content as well as higher expression levels of Cu/Zn-SOD, Mn-SOD, Fe-SOD,POD,CAT, and APX under various water deficit conditions. Conjoint analysis of physiological and biochemical indicators and transcriptome data by weighted gene co-expression network analysis (WGCNA) in the present study provides a useful genomic and molecular resource for studying drought adaptation in wheat. The flag leaf senescence process was changed by altering the concentration of phytohormones. SA, JA, abscisic acid (ABA), Z, ZR, and GA 3 coordinate with each other to control leaf senescence and plant adaptation under drought stress. Further, the leaf senescence process was divided into two phases: the persistence phase and the rapid loss phase. Shorter Chltotal (duration of the flag leaf being photosynthetically active), shorter Chlper (persistence phase), reduced M (inflection point cumulative temperature when senescence rate is the maximum), decreased r max (the maximum senescence rate), larger r 0 (the initial senescence rate), and increased r aver (the average senescence rate) were slightly associated with low grain mass. We speculated that extending the period of the persistence phase by cultivation or chemical control measures could further increase the drought survivability and productivity of wheat.

Identification and quantification of some phytohormones in seaweeds using UPLC-MS/MS

Abstract: The aim of this work was to identify main plant growth regulators (PGRs), such as, indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA), zeatin, kinetin and 6-benzyl amino...

GhNAC83 inhibits corm dormancy release by regulating ABA signaling and cytokinin biosynthesis in Gladiolus hybridus

Abstract: Corm dormancy is an important trait for breeding in many bulb flowers, including the most cultivated Gladiolus hybridus. Gladiolus corms are modified underground stems that function as storage organs and remain dormant to survive adverse environmental conditions. Unlike seed dormancy, not much is known about corm dormancy. Here, we characterize the mechanism of corm dormancy release (CDR) in Gladiolus. We identified an important ABA (abscisic acid) signaling regulator, GhPP2C1 (protein phosphatase 2C1), by transcriptome analysis of CDR. GhPP2C1 expression increased during CDR, and silencing of GhPP2C1 expression in dormant cormels delayed CDR. Furthermore, we show that GhPP2C1 expression is directly regulated by GhNAC83, which was identified by yeast one-hybrid library screening. In planta assays show that GhNAC83 is a negative regulator of GhPP2C1, and silencing of GhNAC83 promoted CDR. As expected, silencing of GhNAC83 decreased the ABA level, but also dramatically increased cytokinin (CK; zeatin) content in cormels. Binding assays demonstrate that GhNAC83 associates with the GhIPT (ISOPENTENYLTRANSFERASE) promoter and negatively regulates zeatin biosynthesis. Taken together, our results reveal that GhNAC83 promotes ABA signaling and synthesis, and inhibits CK biosynthesis pathways, thereby inhibiting CDR. These findings demonstrate that GhNAC83 regulates the ABA and CK pathways, and therefore controls corm dormancy.

Development of plant regeneration and Agrobacterium tumefaciens -mediated transformation methodology for Physalis pruinosa

Abstract: Physalis pruinosa, also known as groundcherry, produces a small, yellow, highly nutritious edible fruit that is enveloped by a papery husk. In order for the potential of large-scale production of P. pruinosa fruit to be realized, undesirable characteristics, such as an unmanageable, sprawling growth habit and extensive fruit drop, need to be improved by exploiting approaches available through plant breeding, genetic engineering, and gene editing. In this study, we established plant regeneration and Agrobacterium tumefaciens-mediated methods to allow application of genetic engineering and gene editing of P. pruinosa. Cotyledon and hypocotyl explants from 7 to 8-day-old in vitro-grown seedlings were assessed for plant regeneration. Explants were cultured for 2 weeks on a Murashige and Skoog salts-based medium that contained 2 mg/L zeatin followed by transfer to medium containing 1 mg/L zeatin. Only hypocotyl explants regenerated shoots. Hypocotyl explants were infected with Agrobacterium tumefaciens strain AGL1 containing the pJL33 binary vector that has the green fluorescent protein reporter and neomycin phosphotransferase II (nptII) selectable marker genes. After cocultivation, explants were cultured on selective plant regeneration medium that contained 50, 100, 200, 250, and 300 mg/L kanamycin to determine the most effective level for efficient recovery of transgenic lines. Based on PCR analysis for the presence of the nptII gene, medium containing 200 mg/L kanamycin resulted in the highest transformation efficiency at 24%. This study sets the foundation for future genetic engineering and gene editing approaches for improvement of P. pruinosa. Methodology for regeneration and transformation of Physalis pruinosa is a key component for the genetic improvement of this underutilized fruit crop for future agricultural production.

Unravelling the Metabolic and Hormonal Machinery During Key Steps of Somatic Embryogenesis: A Case Study in Coffee.

Abstract: Somatic embryogenesis (SE) is one of the most promising processes for large-scale dissemination of elite varieties. However, for many plant species, optimizing SE protocols still relies on a trial-and-error approach. Using coffee as a model plant, we report here the first global analysis of metabolome and hormone dynamics aiming to unravel mechanisms regulating cell fate and totipotency. Sampling from leaf explant dedifferentiation until embryo development covered 15 key stages. An in-depth statistical analysis performed on 104 metabolites revealed that massive re-configuration of metabolic pathways induced SE. During initial dedifferentiation, a sharp decrease in phenolic compounds and caffeine levels was also observed while auxins, cytokinins and ethylene levels were at their highest. Totipotency reached its highest expression during the callus stages when a shut-off in hormonal and metabolic pathways related to sugar and energetic substance hydrolysis was evidenced. Abscisic acid, leucine, maltotriose, myo-inositol, proline, tricarboxylic acid cycle metabolites and zeatin appeared as key metabolic markers of the embryogenic capacity. Combining metabolomics with multiphoton microscopy led to the identification of chlorogenic acids as markers of embryo redifferentiation. The present analysis shows that metabolite fingerprints are signatures of cell fate and represent a starting point for optimizing SE protocols in a rational way.

Protoplast isolation and culture from Kalanchoë species: optimization of plant growth regulator concentration for efficient callus production

Abstract: A high yield of isolated protoplasts and efficient regeneration protocols are prerequisites for successful development of somatic hybrids. In the present study, protoplast isolation and regeneration were evaluated in 12 Kalanchoe accessions belonging to nine species. The highest protoplast yield was obtained from K. blossfeldiana ‘Charming Red Meadow’ with 10.78 ± 0.51 × 105 protoplasts per gram fresh weight. We observed significant differences of protoplast yield while there was no distinct difference in viability among the accessions. Seven accessions reached the microcolony stage and four developed microcalli in medium supplemented with 1.0 mg/l 1-naphthaleneacetic acid (NAA), 0.5 mg/l 6-benzylaminopurine (BAP) and 0.5 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D). Using five selected accessions we optimized the PGR (plant growth regulators) concentrations using combinations of NAA, BAP and 2,4-D. K. blossfeldiana cultivars ‘Charming Red Meadow’ and ‘Paris’ produced significantly different numbers of calli depending on the PGR concentrations. For plant regeneration, the medium was supplemented with 1 mg/l NAA and 2 mg/l BAP or 2 mg/l zeatin. Shoots were regenerated on medium supplemented with NAA and BAP for K. blossfeldiana ‘Charming Red Meadow’ and K. blossfeldiana ‘Paris’. The plants successfully developed roots on the medium supplemented with IAA. The medium containing zeatin induced root formation directly from callus in K. blossfeldiana ‘Charming Red Meadow’. Our findings have the potential to facilitate the use of Kalanchoe species in somatic hybridization breeding programs. The study revealed a strong genotype-dependent efficiency of colony and microcallus formation. Plants were regenerated from two Kalanchoe blossfeldiana cultivars on medium supplemented with NAA and BAP.

Adsorption of Trans-Zeatin on Laser-Ablated Gold Nanoparticles for Transport into Plant Cells and Growth Stimulation

Abstract: Gold nanoparticles can serve as nanovectors for trans-zeatin, a natural cytokinin used in plant culture to stimulate growth and bud formation. Here, we have used Raman scattering, X-ray photoelectr...

Effect of additives on enhanced in-vitro shoot multiplication and their functional group identification of Chlorophytum borivilianum Sant. Et Fernand

Abstract: The present study was commenced with the aim to optimize the proficient in vitro regeneration protocol and phytochemical constituents and their functional groups identification through FT-IR spectrum analysis. As per of our knowledge, very few or no reports are available on the effects of additives on the nodal explant of C. borivilianum. Surface sterilized explants viz. nodal segments were inoculated on MS basal medium supplemented with 19 different concentrations of cytokinins (BAP, Kinetin and zeatin). BAP at a concentration of 2 mg ml−1 was found superior out of three cytokinins for shoot induction. This study confirmed that the inclusion of additives (Adenine sulphate, casein hydrolysate and putrescine) had a promoting effect on multiple shoot induction and shoot proliferation. Best response was achieved on MS medium supplemented with 2.0 mg l−1 BAP + 1.0 mg l−1 NAA + 20.0 mg l−1 AdSO4 from nodal explant on 45th day of culture. For in vitro rooting, the semi solid rooting medium with IBA (2.0 mg l−1) + putrescine (50.0 mg l−1) was found to be best with 90% maximum field survival rate. The proposed protocol can be used for the conservation of germplasm and propagation of these endangered plant species. FT-IR spectroscopic analysis revealed the presence of alcohols, phenols, alkanes, alpha and beta-unsaturated aldehydes, ketones, aromatic amines, alkyl halides, aliphatic amines, ether linkage and alkenes might be responsible for the various medicinal properties of test plant.

Establishment of callus-cultures of the Argentinean mistletoe, Ligaria cuneifolia (R. et P.) Tiegh (Loranthaceae) and screening of their polyphenolic content

Abstract: Ligaria cuneifolia (R. et P.) Tiegh (Loranthaceae), known as liga, muerdago criollo, or Argentinean mistletoe, is a hemiparasitic plant with a broad distribution in central and northern Argentina. Pharmacological studies showed that L. cuneifolia extracts have hypolipemic, antioxidant, antibacterial, and immunomodulatory effects. We have established callus cultures from embryo and haustoria fragments. The highest frequency of callus formation from embryos (85%) was obtained on White medium with 4% (w/v) sucrose and 2.5 µM 1-naphtalene acetic acid and 9.2 µM kinetin as plant growth regulators (PGRs). From haustoria, the best result (35%) was obtained on Gamborg medium with 3% (w/v) sucrose and 0.45 µM 2,4-dichlorephenoxyacetic acid and 0.47 µM zeatin as PGRs. Thin layer chromatography showed that callus methanolic extract (2.5% w/v) had a lower content of flavonoids and proanthocyanins as compared to the wild plant (5% w/v for leaves, stems, and flowers), but a higher content of hydroxycinnamic acids. High performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) showed the presence of quercetin glycosides and phenolic acids in the methanolic extracts both from the parent plant and the callus obtained from embryo. Callus cultures were established from embryo and haustorium explants of Ligaria cuneifolia. Leaves, stems, and meristems were recalcitrant to in vitro culture. Callus tissues contained quercetin glycosides and phenolic acids.

Plantlet regeneration from primary callus cultures of Lilium brownii F.E.Br. ex Miellez var. giganteum G. Y. Li & Z. H. Chen, a rare bulbous germplasm

Abstract: Lilium brownii F.E.Br. ex Miellez var. giganteum G. Y. Li & Z. H. Chen, an endangered valuable genetic resource, was used to establish and optimize a callus propagation system and to investigate the effects of internal and external phytohormones for the purpose of germplasm conservation. Of the combinations and concentrations of auxins and cytokinins examined, Murashige and Skoog (MS) medium supplemented with 8 g L−1 agar, 30 g L−1 sucrose, 0.45 μM 2,4-dichlorophenoxyacetic acid, 2.69 to 5.37 μM α-naphthaleneacetic acid, and 0.44 μM 6-benzyladenine, 0.45 μM thidiazuron, and 0.28 μM zeatin riboside generated the best results, effectively promoting callus proliferation. Four callus types could be discriminated, of which type A (yellowish, granular) and type B (yellow, medium-granular) were dry, friable, and grew well. Periodic acid-Schiff staining revealed small and regular cells, with numerous starch granules surrounding each nucleus. In culture, callus clumps produced an average of 14.33 shoots under “MS + 7-d-dark–light” treatment with 100% regeneration frequency. Bulblets formed within 60 d after shoot transfer to bulblet formation medium. Type A and B callus was likely to be embryogenic, according to morphology, cytology, and high shoot regenerating capacity. Examination of endogenous phytohormone levels showed that the abscisic acid to indole-3-acetic acid (ABA/IAA) ratio gradually increased with increasing diameter of callus clumps treated with all exogenous phytohormones, except zeatin riboside, leading to the hypothesis that callus induction competence was closely associated with endogenous ABA/IAA ratio. This first report should assist further genetic studies of this rare Lilium and other bulbous plants.

Hormonal Profiling Reveals a Hormonal Cross-Talk During Fruit Decay in Sweet Cherries

Abstract: Although fruit decay in sweet cherries has been studied in some detail, information is still scarce about the possible role of phytohormones during postharvest Here, we examined whether or not changes in endogenous contents of phytohormones occur during fruit decay of sweet cherries stored at room temperature We evaluated (i) the endogenous variations in the contents of phytohormones, including abscisic acid, gibberellins, cytokinins, auxin, jasmonic acid, salicylic acid and melatonin, by UHPLC–ESI–MS/MS during fruit decay at room temperature, and (ii) to what extent these changes in phytohormone contents were associated with alterations in water contents, soluble sugars and acidity Endogenous contents of abscisic acid, cytokinins and gibberellins decreased in parallel with fruit decay, thus suggesting a protective role against over-ripening for these compounds Among cytokinins and gibberellins, free cytokinin bases (zeatin and 2-isopentenyl adenine, rather than their ribosides), and gibberellin 3, changed in parallel with fruit decay It is concluded that abscisic acid, free cytokinin bases and gibberellin 3 may prevent fruit decay during storage of sweet cherries at room temperature

Effects of Exogenous Cytokinins on Spore Germination and Gametophyte Morphogenesis of Dryopteris filix-mas (L.) Schott in vitro Culture

Abstract: The impact of exogenous cytokinins (kinetin, zeatin, 6-benzylaminopurine, and N6-2-isopentenyladenine) on the pattern of Dryopteris filix-mas (L.) Schott spore germination, gametophyte growth and morphology in vitro have been studied. It was found that all studied cytokinins significantly retarded spore germination, inhibited gametophyte growth, caused deformations and decrease in the thallus size, and suppressed the development of reproductive structures and sporophyte growth at the concentration of 10–5 М. The reduction of the hormone concentration to 10–8 М stimulated the gametophyte development, induced cell divisions, particularly in the apical zone, due to which some of thalli were deformed, promoted the production of rhizoids, affected the formation of antheridia and archegonia, and slowed the sporophyte development.

Multiplicación in vitro de Macleania rupestris (Kunth) A.C. Sm. (Ericaceae)

Abstract: Macleania rupestris (Kunth) A.C. Smith ( Ericaceae ) is a plant native to the Andes, which produces edible fruits with great food and commercial potential. M. rupestris plants have been in vitro established from seeds of ripe fruits and to increase their number it is necessary to define the conditions of their multiplication. The objective of the investigation was to determine the effect of zeatin and kinetin to in vitro multiply M. rupestris plants. As a basal culture medium, Woody Plant (WP) was used. Treatments included the CIRGEBB culture medium (WP + 0.5 mg l -1 zeatin), A (WP + 0.5 mg l -1 kinetin), B (WP + 1.0 mg l -1 kinetin) and WP as control. The variables evaluated were explant height (cm), number of shoots and number of leaves, at 60 and 120 days of culture. The use of zeatin and kinetin in the WP culture medium allow in vitro multiplication of M. rupestris . However, the addition of zeatin favors the development of plants with phenotypic characteristics suitable for micropropagation. Based on the results, it is proposed to use the culture medium A (WP + 0.5 mg l -1 kinetin).

Characterization and T-DNA insertion sites identification of a multiple-branches mutant br in Betula platyphylla × Betula pendula.

Abstract: Plant architecture, which is mostly determined by shoot branching, plays an important role in plant growth and development. Thus, it is essential to explore the regulatory molecular mechanism of branching patterns based on the economic and ecological importance. In our previous work, a multiple-branches birch mutant br was identified from 19 CINNAMOYL-COENZYME A REDUCTASE 1 (CCR1)-overexpressed transgenic lines, and the expression patterns of differentially expressed genes in br were analyzed. In this study, we further explored some other characteristics of br, including plant architecture, wood properties, photosynthetic characteristics, and IAA and Zeatin contents. Meanwhile, the T-DNA insertion sites caused by the insertion of exogenous BpCCR1 in br were identified to explain the causes of the mutation phenotypes. The mutant br exhibited slower growth, more abundant and weaker branches, and lower wood basic density and lignin content than BpCCR1 transgenic line (OE2) and wild type (WT). Compared to WT and OE2, br had high stomatal conductance (Gs), transpiration rate (Tr), but a low non-photochemical quenching coefficient (NPQ) and chlorophyll content. In addition, br displayed an equal IAA and Zeatin content ratio of main branches’ apical buds to lateral branches’ apical buds and high ratio of Zeatin to IAA content. Two T-DNA insertion sites caused by the insertion of exogenous BpCCR1 in br genome were found. On one site, chromosome 2 (Chr2), no known gene was detected on the flanking sequence. The other site was on Chr5, with an insertion of 388 bp T-DNA sequence, resulting in deletion of 107 bp 5′ untranslated region (UTR) and 264 bp coding sequence (CDS) on CORONATINE INSENSITIVE 1 (BpCOII). In comparison with OE2 and WT, BpCOI1 was down-regulated in br, and the sensitivity of br to Methyl Jasmonate (MeJA) was abnormal. Plant architecture, wood properties, photosynthetic characteristics, and IAA and Zeatin contents in main and lateral branches’ apical buds changed in br over the study’s time period. One T-DNA insertion was identified on the first exon of BpCOI1, which resulted in the reduction of BpCOI1 expression and abnormal perception to MeJA in br. These mutation phenotypes might be associated with a partial loss of BpCOI1 in birch.

Plant growth regulator and application method thereof

Abstract: The invention belongs to the technical field of pesticides, and particularly relates to a plant growth regulator and an application method thereof. Effective components of the plant growth regulator comprise alternaria tenuissima activated protein and any one selected from diethyl aminoethyl hexanoate, zeatin and compound sodium nitrophenolate. According to the plant growth regulator, and wettablepowder, water dispersible granule, suspension and water aqua thereof, the alternaria tenuissima activated protein and any one selected from diethyl aminoethyl hexanoate, zeatin and compound sodium nitrophenolate are mixed with each other to be used as the effective components, and the action mechanisms are different; after compounding, a synergistic effect is achieved under a defined usage concentration and usage method according to various crops such as rice, corns, wheat, peanuts, cotton, vegetables, tobaccos, fruit trees, gardens, flowers and the like, and the yield and the income are increased; an obvious weight-increasing effect is achieved for fruits of the fruit trees, and the chlorophyll content of plants is effectively improved; and moreover greenness preservation and an anti-aging effect are achieved, the sugar content is improved, growth of the crops is promoted, and quality of the fruits is effectively improved.

High speed regeneration via somatic embryogenesis in elite Indian banana cv. Somrani monthan (ABB)

Abstract: An efficient and rapid regeneration system is indispensable for germplasm conservation and valuable trait incorporation through genetic engineering. The present study was aimed to investigate regeneration potential of Musa sp. cv. Somrani monthan (ABB) via somatic embryogenesis. Meristematic shoot tips were used as explant and cultured on MS medium supplemented with 6-BAP (50 and 100 µM) and IAA (1 µM) for scalp (cauliflower like compact buds) induction. The highest percentage (~ 60%) of homogenous differentiation of shoot tip explants into scalp was observed in MS medium supplemented with 100 µM of 6-BAP and 1 µM of IAA after 6 months of culture. The scalps were sub-cultured on MS medium supplemented with different compositions of 2, 4-D (1, 2, 3, 4, 5 and 10 µM) and zeatin (1 and 2 µM) for embryogenic calli induction. The highest frequency (97%) of embryogenic calli induction was recorded in MS medium supplemented with 5 µM 2, 4-D and 1 µM zeatin after 6 weeks of culture. The histological and morphological studies suggest that, callus possessed high competence for embryogenesis and could be induced to form somatic embryos. Embryogenic cell suspension (ECS) was successfully established by culturing these embryonic calli in liquid medium. About 70% of the mature somatic embryos germinated and converted to plantlets with a regeneration capacity of 8.5 × 103. After the gradual acclimatization and hardening, the plants were transferred to nursery with 82% of survival rate. Here we report a successful regeneration system for an elite Indian Musa cv. Somrani monthan via somatic embryogenesis. The embryogenic callus and ECS are ideal explants for mass clonal propagation, germplasm conservation and genetic transformation for future research.

Effect of some immunomodulators and zeatin on susceptibility of wheat to powdery mildew

Abstract: The effects of zeatin, salicylic acid, and plant oligoadenylates on susceptibility of wheat seedlings to powdery mildew and the shape of dose-response curves for immunomodulation were studied. Salicylic acid and zeatin produced complex dose-responses with upregulation or downregulation of plant susceptibility. Under different experimental conditions, the dose-response curve for zeatin varied in shape from a curve with a maximum to a curve with a minimum of susceptibility to powdery mildew. More complicated curves with a resistance region framed with regions of increased susceptibility were also found. Plant oligoadenylates inhibited the development of powdery mildew at optimal concentrations. The increasing concentrations of salicylic acid and plant oligoadenylates, when combined with zeatin, led to a gradual change in the shape of the zeatin concentration curve. Treatment with salicylic acid and plant oligoadenylates in these experiments may simulate plant responses under biotic and abiotic stresses. Thus, exogenous zeatin was applied to model changes in the phytohormone metabolism. The complex multiphase nature of dose-response is proposed to cause a kind of random-number generator that produces variability in the physiological and immunological status of plants in natural conditions. Variation in susceptibility of individual plants may be crucial for the survival of infected plants and the stabilization of plant?pathogen interactions.

Quantitative trait loci analysis of hormone levels in Arabidopsis roots.

Abstract: Quantitative trait loci (QTL) analyses for five groups of hormones, including cytokinins in Arabidopsis roots were performed using recombinant inbred lines (Ler×Cvi). Significant QTLs were detected for cytokinins, jasmonic acid and salicylic acid. Separate analysis of two sub-populations, viz., vegetative and flowering plants revealed that many of the QTLs were development-specific. Using near-isogenic lines, several significant QTLs were confirmed; three co-localized QTL regions were responsible for determining several cytokinin metabolites. Using a knock-out plant, a functional role of zeatin N-glucosyltransferase gene (UGT76C2) underlying a large-effect QTL for levels of tZ-N-glucosides and tZRMP was evaluated in the metabolism of cytokinins. Pleotropic effects of this gene were found for cytokinin levels in both roots and leaves, but significant changes of morphological traits were observed only in roots. Hormone QTL analysis reveals development-specific and organ-dependent aspects of the regulation of plant hormone content and metabolism.

MICROPROPAGATION of Olea europaea L. cv. Barnea, THROUGH NODAL SEGMENT OF ADVENTITIOUS SHOOT AND ASSESSMENT OF ITS GENETIC FIDELITY THROUGH MOLECULAR MARKERS

Abstract: Olea europaea is an economically important tree species native to Mediterranean region. The present study is focused on developing the regeneration protocol and production of true-to-type plants of Olea europaea L. cv Barnea. Nodes from adventitious shoots were surface sterilized and inoculated in different tissue culture media such as Woody Plant Media (WPM), Murashige and Skoog media (MS), Rugini Olive media (OM), Schenk and Hildebrandt media (SH) and Multiplication media (Combination of half strength MS and half strength Rugini OM) in which culture establishment was best obtained in multiplication media supplemented with 1mg/l zeatin. The explants treated with fungicide in addition to other surface sterilants resulted in reduced in-vitro explant contamination. Different treatment was given to induce shoot proliferation and the highest shoot number 4.2±0.4 was obtained in multiplication media enriched with 2.0 mg/l zeatin and silver nitrate at 2.0 mg/l. The effect of sub-culturing on shoot proliferation was also studied. The in-vitro derived shoots were assessed for genetic fidelity using different molecular markers Random Amplification of Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR). Monomorphic bands were obtained between the mother DNA and in-vitro derived progenies which indicated that there is genetic stability in the in-vitro regenerated plants. The protocol developed shows the highest multiplication rate and confirms genetic uniformity by assessing through RAPD and ISSR markers. In this study, for the first time we described a successful in-vitro regeneration protocol for uniform plant production of Olea europaea L. cv. Barnea.

Morphological and biochemical changes during somatic embryogenesis in mahogany, Swietenia macrophylla (Meliaceae)

Abstract: Intensive exploitation of mahogany wood (Swietenia macrophylla, Meliaceae) has resulted in the loss of natural populations. Somatic embryogenesis offers an alternative to clonal propagation and conservation of mahogany. This study describes biochemical (carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators content) and histological characteristics of the somatic embryogenesis process in mahogany. Calli were obtained by culturing cotyledons of seeds from immature fruits for six weeks on semi-solid MS medium supplemented with 1.0 mgL-1 of kinetin and 4.0 mgL-1 of 2, 4-D. Primary callus was cultured on half strength semi-solid MS medium supplemented with 1.0 mgl-1 6-BA (6-benzylaminopurine) and embryogenic structures were obtained. Embryo development from globular-shaped somatic embryos to the cotyledonary stage was confirmed by histology and scanning electron microscopy. Shoot initiation was observed after somatic embryos were transferred to germination and maturation medium. Endogenous concentrations of carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators were determined in embryogenic (EC) and non-embryogenic (NEC) calli of mahogany. Embryogenic cultures contained significantly higher concentrations of IAA (indoleacetic acid), ABA (abscisic acid), and GAs (Gibberellins 1+3+20), whereas non-embryogenic calli contained more total phenols, flavonoids and resistant starch. Fructose and glucose were not present at detectable levels in EC or NEC, whereas soluble starch and sucrose were only detectable in EC. Concentrations of total proteins, Z/ZR (Zeatin/zeatin riboside) and iP/iPA (N6-(Δ2-isopentenyl) adenine and N6-(Δ2-isopentenyl) adenosine) were similar in EC and NEC.

Effect of Nitrogen-Fixing Cyanobacteria on the Growth of Wheat Crop

Abstract: Isolation and purification of cyanobacteria from kafr El-Sheikh soil samples revealed that, two isolates (Anabaena cylindrica and Nostoc clacicola) were acquired as bacterial free cyanobacteria and nitrogen fixed. These cynobacteria isolates were produced auxin (Indole-3-acetic acid), gibberellins (Gibberellic acid) and cytokinin (Zeatin). Therefore, when inoculation with Anabaena cylindrica, Nostoc clacicola and their mixture were significantly increased the plant height, number of spikes/m2, 1000-grain weight, grain yield, straw yield protein content% on wheat crop and total counts of cyanobacteria in soil.

Augmenting a competent in vitro organogenesis etiquette from leaf base of country mallow, Abutilon indicum L. sweet: An ethno-botanically valuable medicinal plant

Abstract: An easy, efficient and highly reproducible regeneration system was established through organogenesis from leaf base mediated callus of an ethnobotanical hairy shrub Abutilon indicum L. sweet, which is documented to possess pharmaceutically important phytochemicals. Among various explants, leaf bases produced significant callus induction (89%) with 140 mg fresh weight on Murashige and Skoog (MS) medium supplemented with 11.31 μM 2, 4-Dichlorophenoxyacetic acid (2, 4-D). Combinations of 2, 4-D and kinetin (KIN) increased the biomass (191 mg) of embryogenic calli. Regeneration medium with a combination of 8.88 μM of 6-amino benzyl purine (BAP) and 8.06 μM of naphthalene acetic acid in MS basal media significantly influenced the initiation of shoot primordium with 91% of regeneration. Proficiently regenerated shoot apical meristems (SAMs) produced higher frequency of multiple shoot induction on 4.10 μM of zeatin. The fully regenerated mature shootlets produced high root biomass (791.67 ± 48.05 mg) on half - strength MS with 4.54 μM indole-3-butyric acid (IBA) with an excellent mat root system for efficient acclimatization. In vitro established plantlets were successfully acclimatized under ex vitro conditions with high frequency. Presence of homologous DNA banding pattern with Single Primer Amplification Reaction markers confirmed the genetic similarity. FTIR and GC-MS spectrum showed similar metabolic profiles between wild and in vitro regenerated plantlets. Thus the protocol is reliable for in vitro regeneration through leaf base derived callus which could pave a way to the large scale production of secondary metabolite through biotechnological approaches.