The Gymnocalycium genus includes numerous highly valued species in the ornamental plant market and their propagation is usually carried out using traditional methods. However, there is a lack of ...information regarding the efficiency of micropropagation through in vitro tissue culture techniques on these species. So, with the objective of establishing an efficient micropropagation protocol that allows for optimizing the plant obtaining processes, the morphogenic potential of Gymnocalycium cv. Fancy has been studied in this work. For this purpose, plants of two different sizes (medium and large) were used as the starting material, from which three types of explants were obtained (apex, central discs and bases). The effect of three plant growth regulators (6-Benzylaminopurine, BAP; Kinetin, KIN; and Thidiazuron, TDZ) at three different concentrations each were studied, and the number of generated shoots, the frequency of appearance of callogenesis and rhizogenesis by explant and condition were assessed. An efficient protocol based on the use of KIN at 4 µM and central discs as a starting explant was developed. Moreover, the obtained sprouts rooted successfully (especially using BAP at 2 µM), and their subsequent acclimatization was very effective. Furthermore, emergence of a new morphotype is presented, that has not previously been described.
Increasing shoot branch numbers of Chrysanthemum morifolium Ramat cv. Hangbaiju (Hangbaiju) is crucial for producing high flower yields. Pot experiments were designed to evaluate the effects of ...foliar application of 6-benzylaminopurine (6-BA) combined with prohexadione-Ca (Pro-Ca) on the yield and quality of Hangbaiju flowers. Foliar application of 6-BA combined with Pro-Ca typically increased leaf chlorophyll content and decreased leaf soluble sugar and soluble protein contents throughout the floral organ growth phase. At the bud formation phenophase stage (August), the contents of gibberellin (GA), indole-3-acetic acid (IAA), and zeatin (ZA) decreased (except for GA content in the 10 mg Lsup.−1 6-BA combined with 100 mg Lsup.−1 Pro-Ca treatment), but abscisic acid (ABA) content increased. The yield of Hangbaiju flowers was found higher in plants treated with foliar application of 6-BA combined with Pro-Ca. Higher yields were found in the 6-BAsub.5 + Casub.100 and 6-BAsub.10 + Casub.100 treatments than in the 6-BAsub.5 + Casub.50 and 6-BAsub.10 + Casub.50 treatments, and the highest yield was observed in the 6-Basub.5 + Casub.100 treatment both in 2019 and 2020. Nutritional indices such as soluble sugar, soluble protein, total amino acid, and water extract increased, and medicinal indices such as flavonoid, total phenolics, chlorogenic acid, cynaroside, and 3,5-dicaffeoyl quinic acid slightly decreased after foliar application of 6-BA combined with Pro-Ca; however, they were all higher than the standards recorded in the Chinese Pharmacopeia. Overall, foliar application of 6-BA combined with Pro-Ca could increase the yield and nutritional quality of Hangbaiju flowers, enhancing its tea quality.
Solid phase extraction of Am in ionic liquid Gujar, R. B; Ansari, S. A; Mohapatra, P. K ...
Journal of radioanalytical and nuclear chemistry,
08/2016, Volume:
309, Issue:
2
Journal Article
Peer reviewed
Solvent extraction of Am(III) and Cm(III) with several diglycolamide ligands in an ionic liquid, C.sub.4mimTf.sub.2N was investigated from nitric acid medium. Based on the encouraging extraction ...behaviour with N,N,N',N'-tetraethyldiglycolamide (TEDGA), extraction chromatographic studies were carried out using a resin material made from Chromosorb-W impregnated with a solution of TEDGA in C.sub.4mimTf.sub.2N. The kinetics of metal ion uptake and sorption isotherms were also investigated. The maximum sorption capacity of the resin was estimated to be 20.05 ± 0.73 mg/g.
For sugar beet (Beta vulgaris) breeding, producing homozygous lines through haploid and doubled haploid techniques are preferred over conventional and time-consuming methods. Doubled haploid sugar ...beet production necessitates inducing ovules to develop into haploid plants, referred to as gynogenesis. The protocol involves an interaction between cold pretreatment of six genotypes of sugar beet inflorescences at 4 °C for 1 week or more and 6-benzylaminopurine (BAP) concentrations (1 or 2 mg L.sup.-1) to increase the response rate of haploid embryo induction. Compared with freshly cultured ovules (6.49%), cold pretreatment for 1 week almost doubled the mean of haploid plantlet induction rate (11.3%), whereas pretreatment for more than 1 week was not as effective as the control. Addition of 2 mg L.sup.-1 BAP to the culture medium nearly doubled the induction rate of the cultured ovules (10.75%), followed by 1 mg L.sup.-1 BAP (7.78%) in comparison with hormone-free medium (5.69%). The highest gynogenesis rate (37.8%) was achieved when ovules were cultured on medium containing 2 mg L.sup.-1 BAP following 1-week cold pretreatment. This combination approximately tripled the mean total haploid embryo induction rate of all the genotypes to 16.3% in comparison with the control (5.74%). However, the addition of BAP resulted in vitrification proportionately. As a result, 2 mg L.sup.-1 BAP decreased the normal plantlet emergence (NPE) to one-third (7.59%) while 1 mg L.sup.-1 BAP had a moderate effect (NPE: 18.98%) in comparison with hormone-free treatment (NPE: 24.35%). The results indicate that the combination of cold pretreatment and BAP is very effective in inducing haploid plants from recalcitrant genotypes of sugar beet, but BAP can have both advantages and disadvantages.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cytokinins (CKs) are thought to play important roles in fruit development, especially cell division. However, the mechanisms and regulation of CK activity have not been well investigated. This study ...analysed CK concentrations and expression of genes involved in CK metabolism in developing tomato (Solanum lycopersicum) ovaries. The concentrations of CK ribosides and isopentenyladenine and the transcript levels of the CK biosynthetic genes SlIPT3, SlIPT4, SlLOG6, and SlLOG8 were high at anthesis and decreased immediately afterward. In contrast, trans-zeatin concentration and the transcript levels of the CK biosynthetic genes SlIPT1, SlIPT2, SlCYP735A1, SlCYP735A2, and SlLOG2 increased after anthesis. The expression of type-A response regulator genes was high in tomato ovaries from pre-anthesis to early post-anthesis stages. These results suggest that the CK signal transduction pathway is active in the cell division phase of fruit development. This study also investigated the effect of CK application on fruit set and development. Application of a synthetic CK, N-(2-chloro-pyridin-4-yl)-N’-phenylurea (CPPU), to unpollinated tomato ovaries induced parthenocarpic fruit development. The CPPU-induced parthenocarpic fruits were smaller than pollinated fruits, because of reduction of pericarp cell size rather than reduced cell number. Thus, CPPU-induced parthenocarpy was attributable to the promotion of cell division, not cell expansion. Overall, the results provide evidence that CKs are involved in cell division during development of tomato fruit.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The metabolism of cytokinins (CKs) and auxins in vascular plants is relatively well understood, but data concerning their metabolic pathways in non-vascular plants are still rather rare. With the aim ...of filling this gap, 20 representatives of taxonomically major lineages of cyanobacteria and algae from Cyanophyceae, Xanthophyceae, Eustigmatophyceae, Porphyridiophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae, Zygnematophyceae and Klebsormidiophyceae were analysed for endogenous profiles of CKs and auxins and some of them were used for studies of the metabolic fate of exogenously applied radiolabelled CK,
Htrans-zeatin (transZ) and auxin (
Hindole-3-acetic acid (IAA)), and the dynamics of endogenous CK and auxin pools during algal growth and cell division.
Quantification of phytohormone levels was performed by high-performance or ultrahigh-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS, UHPLC-MS/MS). The dynamics of exogenously applied
HtransZ and
HIAA in cell cultures were monitored by HPLC with on-line radioactivity detection.
The comprehensive screen of selected cyanobacteria and algae for endogenous CKs revealed a predominance of bioactive and phosphate CK forms while O- and N-glucosides evidently did not contribute greatly to the total CK pool. The abundance of cis-zeatin-type CKs and occurrence of CK 2-methylthio derivatives pointed to the tRNA pathway as a substantial source of CKs. The importance of the tRNA biosynthetic pathway was proved by the detection of tRNA-bound CKs during the course of Scenedesmus obliquus growth. Among auxins, free IAA and its oxidation catabolite 2-oxindole-3-acetic acid represented the prevailing endogenous forms. After treatment with
HIAA, IAA-aspartate and indole-3-acetyl-1-glucosyl ester were detected as major auxin metabolites. Moreover, different dynamics of endogenous CKs and auxin profiles during S. obliquus culture clearly demonstrated diverse roles of both phytohormones in algal growth and cell division.
Our data suggest the existence and functioning of a complex network of metabolic pathways and activity control of CKs and auxins in cyanobacteria and algae that apparently differ from those in vascular plants.
Full text
Available for:
BFBNIB, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Strigolactones (SLs), a group of terpenoid lactones derived from carotenoids, are plant hormones that control numerous aspects of plant development. Although the framework of SL signaling that the ...repressor DWARF 53 (D53) could be SL-dependently degraded via the SL receptor D14 and F-box protein D3 has been established, the downstream response genes to SLs remain to be elucidated. Here we show that the cytokinin (CK) content is dramatically increased in shoot bases of the rice SL signaling mutant d53. By examining transcript levels of all the CK metabolism-related genes after treatment with SL analog GR24, we identified CYTOKININ OXIDASE/DEHYDROGENASE 9 (OsCKX9) as a primary response gene significantly up-regulated within 1 h of treatment in the wild type but not in d53. We also found that OsCKX9 functions as a cytosolic and nuclear dual-localized CK catabolic enzyme, and that the overexpression of OsCKX9 suppresses the browning of d53 calli. Both the CRISPR/Cas9-generated OsCKX9 mutants and OsCKX9-overexpressing transgenic plants showed significant increases in tiller number and decreases in plant height and panicle size, suggesting that the homeostasis of OsCKX9 plays a critical role in regulating rice shoot architecture. Moreover, we identified the CK-inducible rice type-A response regulator OsRR5 as the secondary SL-responsive gene, whose expression is significantly repressed after 4 h of GR24 treatment in the wild type but not in osckx9. These findings reveal a comprehensive plant hormone cross-talk in which SL can induce the expression of OsCKX9 to down-regulate CK content, which in turn triggers the response of downstream genes.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Nitrogen is the mineral nutrient that often limits plant growth and development. In response to changes in nitrogen supply, plants display elaborate responses at both physiological and morphological ...levels to adjust their growth and development. Because higher plants consist of multiple organs with different functions and nutritional requirements, they rely on local and long-distance signalling pathways to coordinate the responses at the whole-plant level. Phytohormones have been considered as signalling substances of such pathways. Amongst phytohormones, abscisic acid, auxin, and cytokinins have been closely linked to nitrogen signalling. Recent evidence has provided some insights into how nitrogen and the phytohormone signals are integrated to bring about changes in physiology and morphology. In this review, the evidence is summarized, mostly focusing on examples related to nitrogen acquisition.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Cytokinins are a major class of plant hormones that are involved in various aspects of plant development, ranging from organ formation and apical dominance to leaf senescence. Cytokinin and auxin ...have long been known to interact antagonistically, and more recent studies have shown that cytokinins also interact with other plant hormones to regulate plant development. A growing body of research has begun to elucidate the molecular and genetic underpinnings of this extensive crosstalk. The rich interconnections between the synthesis, perception and transport networks of these plant hormones provide a wide range of opportunities for them to modulate, amplify or buffer one another. Here, we review this exciting and rapidly growing area of cytokinin research.
Rapeseed (Brassica napus L.) is a globally important oilseed crop with various uses, including the consumption of its succulent stems as a seasonal vegetable, but its uniaxial branching habit limits ...the stem yield. Therefore, developing a multi-stem rapeseed variety has become increasingly crucial. In this study, a natural mutant of the wild type (ZY511, Zhongyou511) with stable inheritance of the multi-stem trait (ms) was obtained, and it showed abnormal shoot apical meristem (SAM) development and an increased main stem number compared to the WT. Histological and scanning electron microscopy analyses revealed multiple SAMs in the ms mutant, whereas only a single SAM was found in the WT. Transcriptome analyses showed significant alterations in the expression of genes involved in cytokinin (CK) biosynthesis and metabolism pathways in the ms mutant. These findings provide insight into the mechanism of multi-main-stem formation in Brassica napus L. and lay a theoretical foundation for breeding multi-main-stem rapeseed vegetable varieties.
PDF
