Phenetic phytoindication and biotesting of soils in recreation zones of Tver city

Исследованы фенофонды ценопопуляций подорожника большого (Plantago major L.) и сныти обыкновенной (Aegopodium podagraria L.) в рекреационных зонах г. Твери с разным уровнем загрязнения почв тяжелыми металлами (ТМ). Параллельно проведено биотестирование почв модельных биотопов по параметрам развития семян тест-растений - горчицы белой (Sinapis alba L.), кресс-салата (Lepidium sativum L.), сорго черного (Sorghum nigrum L.) в соответствии с ГОСТ Р ИСО 18763-2019. По мере возрастания суммарной токсической нагрузки на биотопы среднее число фенов у сныти и подорожника снижается. Однако доля редких фенов у сныти возрастает, а у подорожника уменьшается. Общие показатели фенетического разнообразия (среднее число и доля редких фенов) у сныти коррелируют с суммарной токсической нагрузкой на почвы в большей степени, чем у подорожника. Параметры развития семян разных видов тест-растений неоднозначно отражают фитотоксичность почв. В большей степени с суммарным содержанием ТМ в почве коррелируют показатели всхожести семян и размеры корней проростков у горчицы. Данные по фитоиндикации биотопов на основе фенетических показателей ценопопуляций сныти и, в меньшей степени подорожника, в целом согласуются с результатами биотестирования почв. The phenofonds of Plantago major L. and Aegopodium podagraria L. cenopopulations in recreation zones of Tver with different levels of soil contamination with heavy metals (HM) were studied. In parallel, biotesting of soils of model biotopes was carried out according to the parameters of test plants seeds development - Sinapis alba L., Lepidium sativum L., Sorghum nigrum L. in accordance with ISO 18763:2016. With an increase in the total toxic load on biotopes, the average number of phenes in P. major and A. podagraria decreases. However, the share of rare phenes increases in A. podagraria, and decreases in P. major. The general indicators of phenetic diversity (average number and proportion of rare phenes) in A. podagraria correlate with the total toxic load on soils to a greater extent than in P. major. The development parameters of seeds of different species of test plants ambiguously reflect the phytotoxicity of soils. To a greater extent, the indicators of seed germination and the seedlings root size in S. alba correlate with the total content of HM in the soil. The data on the phytoindication of biotopes based on the phenetic indices of the cenopopulations of A. podagraria and, to a lesser extent, P. major, are generally consistent with the results of soil biotesting.

What's past is past, mostly: Brassicaceae host plants mask the feedback from the previous year's soil history on bacterial communities, except when the Brassicaceae hosts experience drought

Previous soil history and the current plant hosts are two plant-soil feedbacks that operate at different time-scales to influence the structure soil bacterial communities. In this study, we used a MiSeq metabarcoding strategy to describe the impact of five Brassicaceae host plant species, and three different soil histories, on the structure of their bacterial root and rhizosphere communities at full flower. We found that the Brassicaceae host plants were consistently significant in structuring the bacterial communities. Four host plants (Sinapis alba, Brassica napus, B. juncea, B. carinata) formed nearly the same bacterial communities, regardless of soil history. Camelina sativa host plants structured phylogenetically distinct bacterial communities compared to the other hosts, particularly in their roots. Soil history established the previous year was only a significant factor for bacterial community structure when the feedback of the Brassicaceae host plants was weakened, potentially due to limited soil moisture during a dry year. Understanding how plant-soil feedbacks operate at different time-scales and are involved in how microbial communities are structured is a pre-requisite for employing microbiome technologies in improving agricultural systems.

Bioavailability, Accumulation and Distribution of Toxic Metals (As, Cd, Ni and Pb) and Their Impact on Sinapis alba Plant Nutrient Metabolism

This study presents the behavior of white mustard seedlings Sinapis alba grown for three months in laboratory polluted soil containing As, Cd, Ni and Pb. Four different experiments were performed in which As was combined with the other three toxic metals in different combinations (As, AsCd, AsCdNi, AsCdNiPb), keeping the same concentrations of As and Cd in all tests and following the national soil quality regulations. The effects of these metals were monitored by the analytical control of metal concentrations in soil and plants, bioavailability tests of mobile metal fractions using three different extracting solutions (DTPA + TEA + CaCl2-DTPA, DTPA + CaCl2-CAT, and CH3COONH4 + EDTA-EDTA) and calculation of bioaccumulation and translocation factors. Additionally, micro, and macro-nutrients both in soil and plant (root, stem, leaves, flowers and seeds) were analyzed in order to evaluate the impact of toxic metals on plant nutrient metabolism. Metals were significantly and differently accumulated in the plant tissues, especially under AsCdNi and AsCdNiPb treatments. Significant differences (p < 0.05) in the concentration of both As and Cd were highlighted. Translocation could be influenced by the presence of other toxic metals, such as Cd, but also of essential metals, through the competition and antagonism processes existing in plant tissues. Significantly, more Cd and Ni levels were detected in leaves and flowers. Cd was also detected in seeds above the WHO limit, but the results are not statistically significant (p > 0.05). The extraction of metallic nutrients (Zn, Cu, Mn, Ni, Mg, K, Fe, Ca, Cr) in the plant was not influenced by the presence of toxic metal combinations, on the contrary, their translocation was more efficient in the aerial parts of the plants. No phytotoxic effects were recorded during the exposure period. The most efficient methods of metal extraction from soil were for As-CAT; Cd-all methods; Pb and Ni-DTPA. The Pearson correlations (r) between applied extraction methods and metal detection in plants showed positive correlations for all toxic metals as follows: As-CAT > DTPA > EDTA, Cd-DTPA > CAT > EDTA, Ni-EDTA = DTPA > CAT, Pb-EDTA = DTPA = CAT). The results revealed that Sinapis alba has a good ability to accumulate the most bioavailable metals Cd and Ni, to stabilize As at the root level and to block Pb in soil.

Tritium Incorporation From Tritium Water as an Index of Metabolism

<p>Part A The metabolism of mustard (Sinapis alba) seeds wet at sub-germination temperatures has been studied using tritium incorporation as an index of metabolism. The theory and scope of the method are discussed. The enzymic reactions known in 1964 are surveyed one by one, suggesting which will, or will not, incorporate tritium from THO into specified metabolites, or cannot be confidently predicted either way. Improvements have been made in the chromatography procedure. At 0°, many of the normal germination chemical reactions proceed, but about one tenth as fast as at 24°. Amino-acids are being metabolised within 2 h of wetting the seeds, and malic and citric acids within 4 h. Within 24 h lipids and fructose are undergoing reactions. An unidentified compound “M”, not reported in normal germination, is being metabolised within 48 h. Another aberration from normal is the absence of detectable succinate metabolism. Labelling of the solid residue (insoluble in ethanol and in water) always occurs, shown to be largely non-metabolic. To explain the non-germination of seeds at temperatures near 0°, it is hypothesized that the Krebs cycle is qualitatively altered, perhaps by “wasting away” of glutamate to 4-aminobutyrate instead of its routing into the Krebs cycle as alpha-oxoglutarate. Part B A method has been developed for studying the metabolism of dry seeds, spores and pollen by exposure to THO vapour. Dry Pinus radiata pollen labels many compounds. A few have been identified and are common metabolites. It may be that the metabolism of dry pollen is not qualitatively different from its germination reactions. Dry mustard seeds and spores of the fungus Pithomyces chartarum give, in contrast to pollen, patterns of incorporation very different from those in early germination.</p>

Tritium Incorporation From Tritium Water as an Index of Metabolism

<p>Part A The metabolism of mustard (Sinapis alba) seeds wet at sub-germination temperatures has been studied using tritium incorporation as an index of metabolism. The theory and scope of the method are discussed. The enzymic reactions known in 1964 are surveyed one by one, suggesting which will, or will not, incorporate tritium from THO into specified metabolites, or cannot be confidently predicted either way. Improvements have been made in the chromatography procedure. At 0°, many of the normal germination chemical reactions proceed, but about one tenth as fast as at 24°. Amino-acids are being metabolised within 2 h of wetting the seeds, and malic and citric acids within 4 h. Within 24 h lipids and fructose are undergoing reactions. An unidentified compound “M”, not reported in normal germination, is being metabolised within 48 h. Another aberration from normal is the absence of detectable succinate metabolism. Labelling of the solid residue (insoluble in ethanol and in water) always occurs, shown to be largely non-metabolic. To explain the non-germination of seeds at temperatures near 0°, it is hypothesized that the Krebs cycle is qualitatively altered, perhaps by “wasting away” of glutamate to 4-aminobutyrate instead of its routing into the Krebs cycle as alpha-oxoglutarate. Part B A method has been developed for studying the metabolism of dry seeds, spores and pollen by exposure to THO vapour. Dry Pinus radiata pollen labels many compounds. A few have been identified and are common metabolites. It may be that the metabolism of dry pollen is not qualitatively different from its germination reactions. Dry mustard seeds and spores of the fungus Pithomyces chartarum give, in contrast to pollen, patterns of incorporation very different from those in early germination.</p>

Ecotoxicological Tests of Metal-Contaminated soils

The raw steel production plays a key role in the economic development of Slovakia. Unfortunately, the technology of steel production, agricultural and industrial activities contribute to contamination of the soil in the region Eastern Slovakia. The purpose of this study was to investigate the effect of heavy metals in urban soils from the Košice area, using bioassays on earthworms and phytotoxicity. An earthworm avoidance test has potential advantages for use in evaluation of hazardous soils sites and proved as a quick approach to determining the presence of contaminants. The earthworm (Dendrobaena veneta) takes up and retains metals from soil containing of heavy metals. Assessment of soil phytotoxicity was based on germination and seedling growth of the terrestrial plant (mustard Sinapis alba). The level of Cr, Co, Cd and Hg were assessed in 8 industrial soils (4 agricultural areas and 4 grass-plot areas) from the area U.S. Steel Košice. The highest levels contaminations of chromium (278mg/kg), cobalt (39mg/kg), cadmium (21mg/kg) and mercury (0.80mg/kg) were determined for the grass-plot soils (main gate of the U. S. Steel-plant). Phytotoxkit results for the agricultural soils from around Košice showed that, the potential toxicity values are lowly, represented by a lower percentage of inhibition in germination range between 5 and 33 % and the average percentage of growth inhibition was 12-39 % for Sinapis alba. The results for the grass-plot areas soils from around Košice showed the percentage of inhibition in germination range between 13 and 47 % and the average percentage of growth inhibition was 19-49 % for Sinapis alba. Low mortality effects were recorded in the tests with Dendronaena veneta. The distribution of the worms found in the double control was within the range 10–100 % for all areas of the agricultural soils and grass-plot soils, for after 48h. The significant (P<0.05) avoidance by Dendronaena veneta were 100% in soils of areas Gomboš and from main gate of the U. S. Steel-plant, Košice. The above results reflect that not only may the worms be able to detect metals, but in fact they may also change their behavioural response over time.

Microcystin-LR, a Cyanobacterial Toxin, Induces DNA Strand Breaks Correlated with Changes in Specific Nuclease and Protease Activities in White Mustard (Sinapis alba) Seedlings

There is increasing evidence for the induction of programmed cell death (PCD) in vascular plants by the cyanobacterial toxin microcystin-LR (MC-LR). Our aim was to detect the occurrence of PCD-related DNA strand breaks and their possible connections to specific nuclease and protease activities. DNA breaks were studied by the deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method in the photoperiodically grown dicot model of white mustard (Sinapis alba). In-gel nuclease and protease activity assays showed changes in the activities of specific isoenzymes during treatments with MC-LR. Strand breaks occurred both in the developing root epidermis and cortex. Several isoenzyme activities were related to these breaks, for example: an increase in the activity of neutral 80–75 kDa, acidic high MW (100–120 kDa) and, most importantly, an increase in the activity of neutral 26–20 kDa nucleases, all of them having single-stranded DNA cleaving (SSP nuclease) activities. Increases in the activities of alkaline proteases in the 61–41 kDa range were also detected and proved to be in relation with MC-LR-induced PCD. This is one of the first pieces of evidence on the correlation of PCD-related DNA strand breaks with specific hydrolase activities in a model dicot treated with a cyanobacterial toxin known to have environmental importance.