Potato (Solanum tuberosum) mutant (ST) lacking one isoform of manganese-stabilizing protein (MSPI) of photosystem II exhibited besides spontaneous tuberization also growth changes with strongly impaired root system development. Previous studies revealed marked changes in carbohydrate levels and allocation within ST plant body. To verify causal relationship between changed carbohydrate balance and root growth restriction we engaged dark grown sucrose-supplied root organ-cultures of ST plants to exclude/confirm shoot effects. Unexpectedly, in ST root cultures we observed large alterations in growth and architecture as well as saccharide status similar to those found in the intact plant roots. The gene expression analysis, however, proved PsbO1 transcript (coding MSPI protein) neither in ST nor in WT root-organ cultures. Therefore, the results point to indirect effects of PsbO1 allele absence connected possibly with some epigenetic modulations.
- MeSH
- Alleles MeSH
- Photosynthesis genetics radiation effects MeSH
- Photosystem II Protein Complex genetics metabolism MeSH
- Plant Tubers genetics growth & development MeSH
- Plant Roots growth & development metabolism MeSH
- Cells, Cultured MeSH
- Manganese metabolism MeSH
- Carbohydrate Metabolism genetics MeSH
- Mutation MeSH
- Mutant Proteins chemistry genetics metabolism MeSH
- Protein Isoforms genetics metabolism MeSH
- Gene Expression Regulation, Plant genetics physiology MeSH
- Plant Proteins genetics metabolism MeSH
- Sucrose metabolism MeSH
- Solanum tuberosum genetics growth & development MeSH
- Publication type
- Journal Article MeSH
The possibility of Miscanthus×giganteus cultivation as an energy crop on the different types of mining rocks was studied. It was revealed that a loess-like loam and red-brown clay with the added black soil were the most suitable for plant growing. The yield of dry above-ground biomass ranged from 4.3 to 6.8 t DM ha-1 after the first year of cultivation and from 8.9 to 9.7 t DM ha-1 after the second year while using these substrates. The application of amendments stimulated the growth and development of plants and increased productivity from 50 to 140%. M.×giganteus showed sufficient tolerance and good enough growth on the geochemically active dark-gray schist clay with yield from 2 to 3 t DM ha-1 after the first year of cultivation already. For plants grown on the different strata of dark-gray schist clay, the thermal decomposition of the biomass took place in four stages in the temperature range from 30 to 640 °C. The samples grown on stratum 0-20 cm showed the highest reactivity with a peak 30.6%/min at 290 °C. There were differences in the concentrations of determined heavy metals: iron, zinc, copper, and lead in the plant tissues depending on the layer depth of dark-gray schist clay from 0 to 20 cm to 40-60 cm. The relatively limited content of heavy metals in the above-ground biomass was due to the preferential accumulation in the roots.
- MeSH
- Adaptation, Biological * MeSH
- Biomass MeSH
- Mining * MeSH
- Plant Roots chemistry growth & development MeSH
- Soil Pollutants analysis MeSH
- Poaceae chemistry growth & development MeSH
- Soil chemistry MeSH
- Metals, Heavy analysis MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Ukraine MeSH
In germinating seeds under unfavorable environmental conditions, the mobilization of stores in the cotyledons is delayed, which may result in a different modulation of carbohydrates balance and a decrease in seedling vigor. Tall fescue (Festuca arundinacea Schreb.) caryopses grown at 4°C in the dark for an extended period in complete absence of nutrients, showed an unexpected ability to survive. Seedlings grown at 4°C for 210 days were morphologically identical to seedlings grown at 23°C for 21 days. After 400 days, seedlings grown at 4°C were able to differentiate plastids to chloroplast in just few days once transferred to the light and 23°C. Tall fescue exposed to prolonged period at 4°C showed marked anatomical changes: cell wall thickening, undifferentiated plastids, more root hairs and less xylem lignification. Physiological modifications were also observed, in particular related to sugar content, GA and ABA levels and amylolytic enzymes pattern. The phytohormones profiles exhibited at 4 and 23°C were comparable when normalized to the respective physiological states. Both the onset and the completion of germination were linked to GA and ABA levels, as well as to the ratio between these two hormones. All plants showed a sharp decline in carbohydrate content, with a consequent onset of gradual sugar starvation. This explained the slowed then full arrest in growth under both treatment regimes. The analysis of amylolytic activity showed that Ca2+ played a central role in the stabilization of several isoforms. Overall, convergence of starvation and hormone signals meet in crosstalk to regulate germination, growth and development in tall fescue.
- MeSH
- alpha-Amylases metabolism MeSH
- Cell Wall metabolism physiology MeSH
- Time Factors MeSH
- Festuca metabolism physiology MeSH
- Adaptation, Physiological physiology radiation effects MeSH
- Stress, Physiological physiology MeSH
- Gibberellins metabolism MeSH
- Plant Roots metabolism physiology MeSH
- Cotyledon metabolism physiology MeSH
- Abscisic Acid metabolism MeSH
- Lignin metabolism MeSH
- Cold Temperature MeSH
- Plant Proteins metabolism MeSH
- Carbohydrates analysis MeSH
- Seedlings physiology MeSH
- Light MeSH
- Darkness MeSH
- Calcium metabolism MeSH
- Publication type
- Journal Article MeSH
Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.
- MeSH
- Acyltransferases genetics metabolism MeSH
- Arabidopsis genetics growth & development metabolism radiation effects MeSH
- Cytokinins metabolism pharmacology MeSH
- Phenotype MeSH
- Membrane Lipids biosynthesis MeSH
- Meristem drug effects genetics growth & development radiation effects MeSH
- Morphogenesis * drug effects radiation effects MeSH
- Mutation MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- Gene Expression Regulation, Plant drug effects radiation effects MeSH
- Seedlings drug effects genetics growth & development radiation effects MeSH
- Darkness MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The collet (root-hypocotyl junction) region is an important plant transition zone between soil and atmospheric environments. Despite its crucial importance for plant development, little is known about how this transition zone is specified. Here we document the involvement of the exocyst complex in this process. The exocyst, an octameric tethering complex, participates in secretion and membrane recycling and is central to numerous cellular and developmental processes, such as growth of root hairs, cell expansion, recycling of PIN auxin efflux carriers and many others. We show that dark-grown Arabidopsis mutants deficient in exocyst subunits can form a hair-bearing ectopic collet-like structure above the true collet, morphologically resembling the true collet but also retaining some characteristics of the hypocotyl. The penetrance of this phenotypic defect is significantly influenced by cultivation temperature and carbon source, and is related to a defect in auxin regulation. These observations provide new insights into the regulation of collet region formation and developmental plasticity of the hypocotyl.
