The response to salt stress analysed by quantitative and qualitative analyses in three selected moss species was studied. Non-halophytic funaroid
and two halophytic mosses, funaroid
and pottioid
were ...exposed to salt stress under controlled in vitro conditions. The results clearly showed various phenolics to be present and included to some extent as a non-enzymatic component of oxidative, i.e., salt stress. The common pattern of responses characteristic of phenolic compounds was not present in these moss species, but in all three species the role of phenolics to stress tolerance was documented. The phenolic p-coumaric acid detected in all three species is assumed to be a common phenolic included in the antioxidative response and salt-stress tolerance. Although the stress response in each species also included other phenolics, the mechanisms were different, and also dependent on the stress intensity and duration.
The two accessions of the polytrichaceous moss species Polytrichum formosum, namely German and Serbian genotypes, were subjected to salt stress, aiming to study the species’ developmental and ...physiological features. Various concentrations of sodium chloride were applied to an axenic in vitro culture of the two moss genotypes, and the growth parameters as well as physiological feature changes were followed. As inferred by the morpho-developmental parameters and survival index, the Serbian genotype showed higher resistance to salt stress as compared to the German one. However, both moss genotypes survived the highest applied concentration (500 mM). As expected, short exposures to salt were rather easily overcome. No clear patterns in sugar content and changes were observed during the stress, but they are surely included in salt stress response and tolerance in P. formosum. Longer stress increased total chlorophyll content in both genotypes. In short-term applied salt stress, the Serbian genotype had a higher total chlorophyll concentration to control unstressed plants, while the German genotype decreased the total amount of chlorophyll. Similarly, carotenoids were shown to be significantly higher in the Serbian genotype, both in unstressed and treated plants, compared to the German one. The contents of tocopherols were higher in the Serbian genotype in controlled unstressed and subsequently short- and long-stressed plantlets compared to the German accession. In general, we can assume that P. formosum is unexpectedly tolerant to salt stress and that there are differences within various accessions of overall European populations, as referred by two randomly selected genotypes, which is most probably a consequence of different genetic structure.
The new extinction risk assessments of hornwort and liverwort species of
Serbia have been completed. Based on the available data, 40% of Serbian
liverwort flora is under threat (status 2024). ...Additionally, 11% of Serbian
liverwort flora is considered to be Data Deficient (DD) 11% Near Threatened
(NT). These findings clearly indicate the urgent need for field
investigation and species biology research in order to define the major
threats and adequate conservation measures.
The biological features of the recently described peculiar and rare pottioid moss species
have been studied. A conservation physiology approach through in vitro axenic establishment and ...laboratory-controlled tests was applied to learn more about its development, physiology, and ecology. Additionally, ex situ collection for this species was established, and a micropropagation methodology was developed. The results obtained clearly document its reaction to salt stress in contrast to its sibling bryo-halophyte species
. The reaction to exogenously applied plant growth regulators, auxin and cytokinin, can be used in the different moss propagation phases of this species or for target structure production and development. Inference to the poorly known ecology of this species should also help in recent species records, and thus improve knowledge about its distribution and conservation.
In vivo measurements of the optical properties of plant leaves, by spectrophotometric methods, could potentially provide very useful information for the assessment of the plant's health. This paper ...describes a novel experimental set-up that enables continuous measurements of the optical reflection and transmission coefficients of broad-leaved plants. The optical spectral characteristics of leaves, in the broad wavelength range, are often a discussed topic in the scientific literature. Nevertheless, to the best of our knowledge, the real-time spectral analyses of the leaf haven't been reported so far. Monitoring the evolution of the plant activity in real-time has resulted in the graph of the spectral Circadian rhythm as a function of time. The set-up was tested on Phaseolus vulgaris and the results of the measurements are presented and discussed.
The same population of the polytrichaceous moss Polytrichum formosum was
studied over four different periods of the year, analysing its carbohydrate
and polyphenolic content and dynamics related to ...environmental seasonal
changes. A total of 18 different types of sugars (including mono-, di-, tri-
and tetra-saccharides) and four sugar alcohols were determined. Chlorogenic
acid was the most represented among the 10 detected phenolic compounds. As
inferred by the sugar content, sucrose, fructose and glucose were the most
dominant sugars, but it is worth mentioning the abundance of trehalose and
turanose at least during one of the observed seasons. The presence of four
trisaccharides and one tetrasaccharide within P. formosum should be
highlighted, as well as the first reports of turanose, isomaltotriose,
panose and rhamnose within this species. The quantitative changes over the
year clearly demonstrate carbohydrate dynamics in relation to seasonal
climatic variation. Sugars are shown to be significant constitutive
molecules within P. formosum, but also physiologically active compounds,
i.e. signalling and energy storage and supplier molecules. We assume that
phenolics have moss-supportive effects during oxidative stress and biotic
interaction.
An introduction to the conservation physiology of bryophytes is given. The insights into the problems, solutions and examples of the physiological approach to conservation within bryophyte ...representatives are discussed. The significance of experimental treatments of bryophytes is highlighted. The documentation of bryophyte functional traits and eco-physiological mechanisms in the conservation background for protection purposes is highlighted by the selected examples. The introduction of bryophytes into a new scientific field is resumed and some insights from specific case studies are presented.
There is limited evidence on bryophyte-tracheophyte allelopathic interactions. Even less is known about such relationships among commercially important plants and mosses. With the aim of screening ...such interactions, various extract concentrations of nine different mosses were tested on the seed germination and seedlings, i.e., hypocotyl elongation and total chlorophyll content of lettuce and radish. The allelopathic effects are documented to be pairwise (moss-vegetable) and species-specific. Based on the results, the extracts of Leucodon sciuroides and Dicranum polysetum are not harmful to lettuce and radish. Lower extract concentrations of Leucodon sciuroides and Ctenidium molluscum have a positive effect on lettuce development, while those of Thuidium delicatulum, Ctenidium molluscum, and Dicranum polysetum showed to be effective on radish. Further, negative effects were noticed when applying higher extract concentration of Abietinella abietina, Isothecium alopecuroides, Dicranum polysetum, and Racomitrium elongatum to lettuce and Isothecium alopecuroides to radish. The dataset presented in this study offers numerous possibilities for further target pest/vegetable type applications since some of the moss extracts are shown to be positive, negative, or indifferent to the tested features in lettuce and radish.
The rare moss species Hennediella heimii (Pottiaceae) was established in in
vitro culture. Various treatments were tested to achieve axenical cultures.
The most effective sterilising procedure was ...NaDCC treatment of sporophytes,
keeping the spore viability and giving high disposal of xenic cohabiting
organisms. The effects of plant growth regulators were studied regarding new
shoot formation, i.e. bud formation on the protonemal filaments and
protonemal patch size. Low concentrations of cytokinin and medium
concentrations of auxin are shown to increase protonemal patch size and
shoot production. Multiplication of H. heimii was observed to occur
spontaneously on BCD medium type, but to achieve better and rapid biomass
production and development it is suggested to grow it on a BCD medium
enriched with auxin and cytokinin combined.
Mosses are proven bioindicators of living environments. It is known that mosses accumulate pollutants from precipitates and, to some lesser extent, from the substrate. In this study, the effects of ...cesium (Cs) on the physiological traits of acrocarp polytrichaceous Catherine's moss (
Hedw.) were studied under controlled, in vitro conditions. Cesium can be found in the environment in a stable form (
Cs) and as a radioactive isotope (
Cs and
Cs). Belonging to the same group of elements, Cs and potassium (K) share various similarities, due to which Cs can interfere with this essential element and thus possibly alter the plant's metabolism. Results have shown that Cs affects the measured physiological characteristics of
, although the changes to antioxidative enzyme activities were not drastic following Cs treatments. Therefore, the activities of antioxidative enzymes at lower pH values are more the consequence of pH effects on enzymatic conformation than simply the harmful effects of Cs. Moreover, Cs did not affect the survival of plants grown on the solid substrate nor plants grown in conditions of light and heavy rain simulation using Cs with variable pH, indicating that Cs is not harmful in this form for the studied species
.
