Plant growth regulators
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elektronický časopis
The endogenous auxin and cytokinin contents of in vitro regenerated Tulbaghia simmleri maintained on applied plant growth regulators in Murashige and Skoog (MS) medium were investigated using UHPLC-MS analysis. The highest number of shoots (27.6 per leaf) were produced in MS medium supplemented with 2.5 μM thidiazuron. A higher number of these shoots were rooted with 10 μM 6-(2-hydroxy-3-methylbenzylamino) purine (PI-55, cytokinin antagonist). Production of somatic embryos (SEs: 16.4-4.6, globular to cotyledonary stages) improved significantly with liquid MS medium containing 2.5 μM picloram, 2.5 μM phloroglucinol (PG) and 1.5 μM gibberellic acid or 1.5 μM PI-55 and 1.0 μM trans-zeatin. SEs (torpedo and cotyledonary stages) germinated (100%) in plant growth regulator free MS medium. The plantlets were acclimatized and all survived in the greenhouse. Higher levels of endogenous auxin, 2-oxindole-3-acetic acid (oxIAA, 371.52 pmol/g DW) and indole-3-acetylaspartate (IAAsp, 141.56 pmol/g DW) were detected in shoots from PG treatments. The roots of garden-grown mother plants possessed the highest level of indole-3-acetic acid (IAA, 630.54 pmol/g DW) and oxIAA (515.26 pmol/g DW). Cytokinins [CKs: trans-zeatin-O-glucoside (tZOG), cis-zeatin (cZ) and N6-isopentenyladenosine-5'-monophosphate (iPRMP)] levels were relatively high in shoots and roots of plantlets in vitro. However, PI-55 treatments influenced the development of plantlets promoting a higher biosynthesis level of iPRMP (418.06 pmol/g DW in root) and cZRMP (904.61 pmol/g DW in roots and 1427.83 pmol/g DW in shoots). The presented protocols offer organogenesis and somatic organogenesis systems for rapid plant regeneration of T. simmleri. In addition, the importance of exogenous and endogenous hormonal effects on in vitro plant growth and development as well as endogenous hormone metabolism signalling and transport related to the physiological processes of CK metabolism and transport are illustrated for in vitro development of T. simmleri.
Cytokinins are naturally occurring substances that act as plant growth regulators promoting plant growth and development, including shoot initiation and branching, and also affecting apical dominance and leaf senescence. Aromatic cytokinin 6-benzylaminopurine (BAP) has been widely used in micropropagation systems and biotechnology. However, its 9-glucoside (BAP9G) accumulates in explants, causing root inhibition and growth heterogenity. To overcome BAP disadvantages, a series of ring-substituted 2'-deoxy-9-(β)-d-ribofuranosylpurine derivatives was prepared and examined in different classical cytokinin bioassays. Amaranthus, senescence and tobacco callus bioassays were employed to provide details of cytokinin activity of 2'-deoxy-9-(β)-d-ribosides compared to their respective free bases and ribosides. The prepared derivatives were also tested for their recognition by cytokinin receptors of Arabidopsis thaliana AHK3 and CRE1/AHK4. The ability of aromatic N6-substituted adenine-2'-deoxy-9-(β)-d-ribosides to promote plant growth and delay senescence was increased considerably and, in contrast to BAP, no loss of cytokinin activity at higher concentrations was observed. The presence of a 2'-deoxyribosyl moiety at the N9-position led to an increase in cytokinin activities in comparison to the free bases and ribosides. The antioxidant capacity, cytotoxicity and effect on the MHV-68 gammaherpesvirus strain were also examined.
- MeSH
- antioxidancia chemická syntéza chemie farmakologie MeSH
- Arabidopsis účinky léků metabolismus MeSH
- Cercopithecus aethiops MeSH
- molekulární struktura MeSH
- purinové nukleosidy chemická syntéza chemie farmakologie MeSH
- regulátory růstu rostlin chemická syntéza chemie farmakologie MeSH
- Vero buňky MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The impact of plant growth regulators (PGRs) "Stimpo" and "Regoplant" on Miscanthus x giganteus (Mxg) biomass parameters was investigated when the plant was grown in military soils with different properties from Dolyna, Ukraine and Hradcany, Czech Republic. The results showed that PGRs positively influenced the biomass parameters when the plant was grown in soil in Dolyna with good agricultural characteristics, the influence of "Regoplant" was higher and the best results were obtained with combined treatment: application to rhizomes before planting and spraying on the biomass during vegetation. Using of PGRs did not improve the biomass parameters when the plant was grown in poor soil in Hradcany. In parallel the peculiarities of the metals uptake process were studied for the following metals: chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), strontium (Sr) and lead (Pb). The uptake behavior of the monitored elements differed based on the soil quality. According to the bioconcentration factor uptake of the abiogenic elements, Cr and Pb, was dominant in the plant roots in both soils, whereas Ni was not detected in any plant tissues. The behavior of biogenic elements (Mn, Cu, Zn) and their analogs (Sr) was different. Those elements were more intensively taken up in shoot tissues in low-nutrient sandy Hradcany soils, while they were mainly taken up in plant roots in fertile Dolyna soils. The unusual behavior of biogenic elements in the low-nutrient soils may be explained by the effect of stress. However, more research is needed focused mainly on soil properties and nutrient availability in order to confirm or disprove this hypothesis and to explore the cause of the stress. The summarized results here show that soil properties influenced Mxg biomass parameters, affected the uptake behavior of metals significantly and tested PGRs cannot be utilized universally in the production of Mxg in the poor military soils.
- MeSH
- bioakumulace MeSH
- biomasa * MeSH
- látky znečišťující půdu metabolismus MeSH
- lipnicovité růst a vývoj metabolismus fyziologie MeSH
- ozbrojené síly MeSH
- půda chemie MeSH
- regulátory růstu rostlin metabolismus MeSH
- těžké kovy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Ukrajina MeSH
sv.
- MeSH
- rostliny MeSH
- růstové látky MeSH
- vývoj rostlin MeSH
- Publikační typ
- periodika MeSH
- Konspekt
- Biologické vědy
- NLK Obory
- biologie
Cytokinins (CKs) are well-established as important phytohormonal regulators of plant growth and development. An increasing number of studies have also revealed the function of these hormones in plant responses to biotic and abiotic stresses. While the function of certain CK classes, including trans-zeatin and isopentenyladenine-type CKs, have been studied in detail, the role of cis-zeatin-type CKs (cZs) in plant development and in mediating environmental interactions is less well defined. Here we provide a comprehensive summary of the current knowledge about abundance, metabolism and activities of cZs in plants. We outline the history of their analysis and the metabolic routes comprising cZ biosynthesis and degradation. Further we provide an overview of changes in the pools of cZs during plant development and environmental interactions. We summarize studies that investigate the role of cZs in regulating plant development and defence responses to pathogen and herbivore attack and highlight their potential role as 'novel' stress-response markers. Since the functional roles of cZs remain largely based on correlative data and genetic manipulations of their biosynthesis, inactivation and degradation are few, we suggest experimental approaches using transgenic plants altered in cZ levels to further uncover their roles in plant growth and environmental interactions and their potential for crop improvement.
