Ethylene and cytokinin interaction in the morphogenesis of Pelargonium × hortorum L.H. Bailey in vitro

Pelargonium × hortorum ‘Grand Prix’ which is susceptible to leaf yellowing and ‘Bergpalais’ which is not susceptible to leaf yellowing were chosen for the experiments. Ethylene production and action as well as the associated morphological response of Pelargonium shoots grown in the presence of a precursor of ethylene biosynthesis 1-aminocyclopropane-1-carboxylic acid (ACC), ethylene inhibitors: α-aminooxyacetic acid (AOA) and silver nitrate (AgNO₃) and different cytokinins: (meta-topolin) (mT) or 6-benzylaminopurine (BAP) were studied. It was found that ‘Grand Prix’ was more sensitive to ethylene than ‘Bergpalais’ and it showed the leaf yellowing in response to 0.1 mg l^?1 ACC. Moreover, it was noted that ACC added separately or together with cytokinin influenced Pelargonium morphogenesis. Depending on the concentration of ACC (0.1–2.0 mg l^?1), it either stimulated or inhibited shoot and root formation as well as the growth of shoots and leaf blades. ACC-induced leaf yellowing in ‘Grand Prix’ was effectively inhibited by mT. In contrast, BAP did not enhance shoot quality. Simultaneously, the presence of mT in the medium resulted in up to a twofold increase in the ethylene production by ‘Grand Prix’ shoots throughout the culture period compared with the shoots growing on the BAP-medium. The inhibitor of ethylene action (AgNO₃) added with cytokinin prevented the yellowing of Pelargonium shoots, but simultaneously influenced the formation of mature shoots with limited long-term multiplication potential. The shoots of P. × hortorum ‘Grand Prix’ treated with AgNO₃ and mT emitted two- and sevenfold more ethylene after 11th and 21st day of culture compared with those treated with AgNO₃ and BAP. It is suggested that mT inhibits the early senescence of Pelargonium in vitro by decreasing its sensitivity to ethylene.     

Cytological investigations of the effect of colchicine on meiosis in Lilium hybrid cv. “Black Beauty” microsporocytes

Using colchicine, two methods have been successfully applied for the induction of tetraploid meiocytes at premeiotic mitosis in the near achiasmate diploid hybrid cultivar Black Beauty of Lilium. The experiments were aimed at understanding whether the achiasmate condition is attributable to insufficient homology for effective pairing or to some genie defect in order to interpret the data obtained from molecular studies. Cytological observations demonstrate a strong correlation between the induction of tetraploidy and subsequent chiasma formation. The chiasma frequency per cell in untreated diploid control meiocytes ranged from 0 to 8 (mean 2.25), while in colchicine treated undoubled cells sampled 14±2 days after the start of treatment it ranged from 0 to 2 (mean 0.148). By comparison, the chiasma frequency per cell in colchicine-doubled tetraploid cells ranged from 29 to 51 (mean 42.24), such cells showing complete or near complete bivalent pairing. These results, similar to those reported previously for other higher plant species, demonstrate that the achiasmatic condition in Black Beauty is not due to a genie defect. The methods developed have made possible hitherto inaccessible biochemical analyses of meiocytes that had been treated with colchicine or other chemicals at premeiotic stages.     

The purification of cellulase and exo-laminaranase and their role in the formation ofPythium sp. “protoplasts”

A cellulase and a laminaranase have been purified from a Streptomyces lytic enzyme complex. Lipase and protease were separated from glucanases. A combination of the purified glucanases produced protoplasts fromPythium sp. PRL 2142. Lipase was shown to act as an adjuvant in this process.National Research Council of Canada Postdoctorate Fellow 1965–67.     

The Effect of Rye Chromosomes on the Characteristic Features of Androgenesis in Wheat–Rye Substitution Lines Triticum aestivumL. (cv. Saratovskaya 29)/Secale cerealeL. (cv.Onokhoiskaya) and Triticale

The characteristic features of androgenesis in six wheat–rye substitution lines Triticum aestivumL. (cv. Saratovskaya 29)/Secale cerealeL. (cv. Onokhoiskaya) and triticale (2n= 56) using anther culture at different concentrations of 2,4-D in the growth medium were studied. Under variable cultivation conditions, the significant effect of genotypic diversity on the variability of such androgenesis parameters as the frequency of productive anthers, the frequency of embryoid formation, and the frequency of total regenerated plantlets, was shown. It was demonstrated that chromosomes 1R, 3R, and 7R stimulated the formation of androgenous embryoids, while chromosome 5R produced an opposite effect. In triticale and substitution lines, the regeneration ability of androgenous embryoids induced by elevated 2.4-D concentrations was inhibited. Chromosome 1R of the Onokhoiskaya cultivar was suggested to contain genes suppressing regeneration of green plantlets, while chromosome 3R, conversely, stimulated their formation. Chromosomes 1R, 2R, 3R, and 7R of the Onokhoiskaya cultivar did not inhibit the spontaneous formation of androgenous hexaploids in the substitution lines.     

“Arabidobrassica”: Chromosomal recombination and morphogenesis in asymmetric intergeneric hybrid cells

A somatic hybrid cell line, cloned from an individual protoplast-fusion product between Arabidopsis thaliana and Brassica campestris, gave rise to formation of numerous plants differing drastically in morphology. Analysis of these various regenerants, all of which originated from one and the same heterokaryon derived from the fusion of two cells, shows the unspecific elimination of chromosomes of both parental species during the callus growth phase. Whereas the parental cells have so far not been sucessfully regenerated into plants, several of their different asymmetric hybrids are capable of morphogenesis. Furthermore, chromosomal analysis indicates extensive recombination. Most of the plants are predoinantly morphologically regular. Abnormalities are mostly limited to the flowers which tend to undergo phyllody. The results demonstrate that remote somatic hybridization may have applications although true amphidiploids may not be obtainable. The transfer of small units of genetic material between distantly related species by protoplast fusion seems to be a more realistic approach than the combination of complete, highly diverse genomes.     

Detachment-accelerated ripening and senescence of strawberry (Fragaria × ananassa Duch. cv. Akihime) fruit and the regulation role of multiple phytohormones

To study the detachment stress on the ripeness of strawberry fruit, physiological characteristics of strawberry fruit on and off plant during ripeness and senescence processes were investigated. The results indicated that the ripeness of strawberry fruit upon detachment was accelerated, in terms of firmness, soluble solid content and especially color development. The color of fruit off plant changed rapidly from white to full red in 1–2 days. The respiratory rate in fruit off plant was strengthened, higher than that on plant. Abscisic acid level and ethylene production in fruit off plant were also higher than those on plant and auxin degradation was exacerbated by detachment. Expression levels of FaMYB1, FabHLH3 and FaTTG1 were generally reduced with phenotypes of redder color and more anthocyanin accumulation in fruit off plant. Results also suggested that the detachment initially stimulated ethylene and abscisic acid production and auxin degradation, which modulated ripening-related gene expression and at last enhanced fruit pigmentation.     

The effect of cytokinins on shoot proliferation,biochemical changes and genetic stability of Rhododendron ‘Kazimierz Odnowiciel’ in the in vitro cultures

Plant Cell, Tissue and Organ Culture (PCTOC) - Shoot proliferation is a very important micropropagation phase, decisive for economic efficiency of this method for a given taxon. To obtain a high...     

The gene pool of the Belgorod oblast population: II. “Family name portraits” in groups of districts with different degrees of subdivision and the role of migrations in their formation

The frequencies and spectra of surnames have been analyzed in groups of raions (districts) of the Belgorod oblast (region) with different degrees of population subdivision. The “family name portraits” of districts with low (0.00003 < < f*_r < 0.00022, \(\overline {f_r^ * } \) = 0.00015) and moderate (0.00023 < f*_r < 0.00042, \(\overline {f_r^ * } \) = 0.00029) inbreeding levels are similar both to each other and to the “family name portrait” of the Belgorod oblast as a whole. Districts with high subdivision levels (0.00043 < f*_r < 0.00125, \(\overline {f_r^ * } \) = 0.00072) had very distinctive surname spectra and the highest surname frequencies. Intense immigration to the Belgorod oblast significantly affects its population genetic structure, decreasing the population subdivision.     

The effect of colchicine on meiosis in Lilium speciosum cv. “Rosemede”

Chromosome pairing and chiasma frequency were studied in meiocytes at diakinesis of Lilium speciosum cv. Rosemede fixed up to 21 days after the start of either continuous or 3 day pulse colchicine treatment. The two treatments gave similar results. In pulse treated pollen mother cells (PMCs) the mean chiasma frequency per cell fell from 26.4 in controls to 8.5 after fourteen days while the mean number of univalents per cell increased from 0.05 to 17.58. There was a negative correlation between mean chiasma frequency per bivalent and per PMC in colchicine treated buds; univalents were preferentially induced in bivalents with one chiasma, and preferentially excluded in bivalents with 4 chiasmata. Some chiasmata were redistributed to surviving bivalents despite the concurrent reduction in chiasma frequency per meiocyte. — Colchicine sensitivity began in premeiotic interphase and extended to mid or late zygotene in PMCs; ongoing synapsis was unaffected. However, susceptibility to univalency was asynchronous between bivalents occurring at zygotene in short chromosomes but at late premeiotic interphase in the longest chromosomes. The number of chiasmata per bivalent could be altered by colchicine without inducing univalents, but the ultimate effect was to reduce the number of chiasmata per bivalent (or per chromosome arm) directly to zero. The major factors determining the order and extent of reduced pairing and chiasma number were total chromosome length and arm length. Pairing and chiasma formation in embryo sac mother cells were less sensitive to colchicine than in PMCs, but their behavior was otherwise similar.     

The motivation behind the papers “Availability of life-cycle assessment studies in (different countries)”

The International Journal of Life Cycle Assessment -     

The effect of genetically enriched (E)-β-ocimene and the role of floral scent in the attraction of the predatory mite Phytoseiulus persimilis to spider mite-induced volatile blends of torenia

Plants under herbivore attack emit mixtures of volatiles (herbivore-induced plant volatiles, HIPVs) that can attract predators of the herbivores. Although the composition of HIPVs should be critical for the attraction, most studies of transgenic plant-emitted volatiles have simply addressed the effect of trans-volatiles without embedding in other endogenous plant volatiles. We investigated the abilities of transgenic wishbone flower plants (Torenia hybrida and Torenia fournieri) infested with spider mites, emitting a trans-volatile ((E)-β-ocimene) in the presence or absence of endogenous volatiles (natural HIPVs and/or floral volatiles), to attract predatory mites (Phytoseiulus persimilis). In both olfactory- and glasshouse-based assays, P. persimilis females were attracted to natural HIPVs from infested wildtype (wt) plants of T. hybrida but not to those of T. fournieri. The trans-volatile enhanced the ability to attract P. persimilis only when added to an active HIPV blend from the infested transgenic T. hybrida plants, in comparison with the attraction by infested wt plants. Intriguingly, floral volatiles abolished the enhanced attractive ability of T. hybrida transformants, although floral volatiles themselves did not elicit any attraction or avoidance behavior. Predator responses to trans-volatiles were found to depend on various background volatiles (e.g. natural HIPVs and floral volatiles) endogenously emitted by the transgenic plants.     

The role of β-sheets in the structure and assembly of keratins

X-ray diffraction, infrared and electron microscope studies of avian and reptilian keratins, and of stretched wool and hair, have played a central role in the development of models for the β-conformation in proteins. Both α- and β-keratins contain sequences that are predicted to adopt a β-conformation and these are believed to play an important part in the assembly of the filaments and in determining their mechanical properties. Interactions between the small β-sheets in keratins provide a simple mechanism through which shape and chemical complementarity can mediate the assembly of molecules into highly specific structures. Interacting β-sheets in crystalline proteins are often related to one another by diad symmetry and the data available on feather keratin suggest that the filament is assembled from dimers in which the β-sheets are related by a perpendicular diad. The most detailed model currently available is for feather and reptilian keratin but the presence of related β-structural forms in mammalian keratins is also noted.     

Differences in the floral anthocyanin content of violet–blue flowers of Vinca minor L. and V. major L. (Apocynaceae)

Two novel delphinidin 3-(tri or di)-glycoside-7-glycosides were isolated from the violet–blue flowers of Vinca minor L. and V. major L. (Family: Apocynaceae), and determined to be delphinidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-(2^G-xylosylrobinobioside)-7-rhamnoside] as major floral anthocyanin of V. minor and delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-robinobioside-7-rhamnoside] as major floral anthocyanin of V. major by chemical and spectroscopic methods. In addition, chlorogenic acid and kaempferol 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= kaempferol 3-robinobioside-7-rhamnoside (robinin)] were identified in these flowers. In this paper, the relation between the structure of floral anthocyanins and classification of Vinca species was discussed.     

The role of glutamine synthetase in the regulation of nitrogenase activity (“switch off” effect) in Rhodospirillum rubrum

We have studied the changes in the activities of both nitrogenase (switch off) and glutamine synthetase in Rhodospirillum rubrum upon addition of ammonium ions or glutamine to nitrogen fixing cultures. Both activities decrease drastically and return in a parallel manner when added ammonia is metabolized. The decrease in glutamine synthetase activity does not seem to be primarily due to adenylylation of the enzyme. Addition of glutamine to cells starved for nitrogen results in inactivation of glutamine synthetase but nitrogenase is only partially switched off.Abbreviations CeMe₃NBr Cetyltrimethylammonium bromide - Hepes N-2-hydroxyethyl-piperazine-N-2 sulfonic acid - MSO methionine-D,L-sulfoximine - Tea-Dmg triethanol amine-3,3-dimethylglutaric acid     

Constraints and release at different scales – The role of adaptation in biological invasions

Attempts to find a consensus on traits promoting the invasiveness of exotic species have agreed on the idiosyncrasy of successful invasions. Despite considerable efforts to integrate aspects of context-dependency into theories of invasions, none of them has provided an evolutionary perspective taking consistently into account the direction of environmental changes in terms of ‘constraint’ vs. ‘release’. Applying the filter theory of species sorting, I consider different filters at different scales explaining evolutionary changes during invasions. Within this hierarchical approach, the focus is on the factorial filters climate, abiotic environment and biotic environment, distinguishing trophic interactions and plant-plant interactions. This review summarizes the evidence of adaptive shifts from native to exotic ranges, thereby differentiating the direction of shifts with regard to either constrained or released situations. Following this systematic approach, the present paper identifies further trade-offs within hierarchical levels complementing already existing hypotheses such as those for biotic interactions. In particular, the role of climatic changes should more explicitly be linked with evolutionary responses during invasions. Studying exotic species successfully invading several regions with different environmental conditions will be a promising starting point to enlarge the understanding of context-dependency of invasions.     

The response of different genotypes of Fragaria × ananassa and their seedling progenies to in vitro micropropagation and the effects of varying the concentration of 6-benzylaminopurine in the proliferation medium

Two experiments are reported. In the first, six different strawberry genotypes were each grown in vitro on media containing five different concentrations of 6-benzylaminopurine (BAP) ranging from 0.5 M to 8.0 M. Responses of the genotypes to different BAP levels varied and the optimum levels for maximum proliferation were between 1 M and 8 M. In the second experiment the six genotypes were split into two groups of three and all crosses between the two groups were made. Seedlings from the nine progenies were then grown on media with the same five levels of BAP. Of the 12% of seedlings that did not proliferate, most were on media with the two lowest BAP levels (0.5 and 1.0 M). Seedlings from crosses involving the cv. Bogota proliferated least, while the three progenies with the breeding line ES652 as a parent had the highest mean proliferation rates. One cross, Bogota × Providence, had a particularly low mean proliferation rate. It was concluded that to optimize proliferation rate the medium must be tailored to the genotype. The best medium could not be reliably predicted from knowledge of the pedigree of a genotype.     

The role of food in the population dynamics of Orchesella cincta (Linné) (Collembola)

Summary The feeding activity of the collembolan species Orchesella cincta (Linné) was studied in the laboratory and in the field. In the laboratory it was shown that at any one time only about 50–60% of the animals were feeding; the remainder were occupied with molting activities. Most of the time similar values were obtained in the field but during winter and during dry summer periods high percentages of empty guts could be demonstrated, indicating an absence or inaccessability of food. When favorable weather returned, a high feeding activity was again observed. Laboratory experiments and field observations indicate that temporary starvation periods are followed by synchronization of the molting and reproductive rhythms and an apparent increase in longevity. These phenomena are important for the restoration of the population after unfavorable periods but reduce the stabilizing force of food scarcity.     

Culture-independent analysis of an endophytic core microbiome in two species of wheat: Triticum aestivum L. (cv. ‘Hondia’) and the first report of microbiota in Triticum spelta L. (cv. ‘Rokosz’)

The main goal of the study was to determine the structure of endophytic bacteria inhabiting different parts (endosperm, germ, roots, coleoptiles, and leaves) of two wheat species, Triticum aestivum L. (cv. ‘Hondia’) and Triticum spelta L. (cv. ‘Rokosz’), in order to provide new knowledge about the stability and/or changeability of the core microbiome in different plant organs. The endophytic core microbiome is associated with plants throughout their whole life cycle; however, plant organs can determine the actual endophytic community. Therefore, next generation sequencing with MiSeq Illumina technology was applied to identify the endophytic microbiome of T. aestivum and T. spelta. Bioinformatic analyses were performed with the use of the DADA2(1.8) package and R software (3.5.1).It was demonstrated that wheat, which is an important crop plant, was associated with beneficial endophytic bacteria inside the endosperms, germs, roots, leaves, and coleoptiles. Importantly, for the first time, biodiversity was recognized in the coleoptiles of the investigated wheat species. Flavobacterium, Pseudomonas and Janthinobacterium were shown to be common genera for both tested wheat cultivars. Among them, Pseudomonas was found to be the only endophytic genus accompanying both wheat species from the endosperm stage to the development of the leaf. Paenibacillus was recognized as a core genus for the ‘Hondia’ cv., whereas Pedobacter and Duganella constituted the core microbiome in the ‘Rokosz’ cv. In addition, the first insight into the unique and yet unrecognized endophytic microbiome of T. spelta is presented.