Genome-Wide Analysis of the UDP-Glycosyltransferase Family Reveals Its Roles in Coumarin Biosynthesis and Abiotic Stress in Melilotus albus

Coumarins, natural products abundant in Melilotus albus, confer features in response to abiotic stresses, and are mainly present as glycoconjugates. UGTs (UDP-glycosyltransferases) are responsible for glycosylation modification of coumarins. However, information regarding the relationship between coumarin biosynthesis and stress-responsive UGTs remains limited. Here, a total of 189 MaUGT genes were identified from the M. albus genome, which were distributed differentially among its eight chromosomes. According to the phylogenetic relationship, MaUGTs can be classified into 13 major groups. Sixteen MaUGT genes were differentially expressed between genotypes of Ma46 (low coumarin content) and Ma49 (high coumarin content), suggesting that these genes are likely involved in coumarin biosynthesis. About 73.55% and 66.67% of the MaUGT genes were differentially expressed under ABA or abiotic stress in the shoots and roots, respectively. Furthermore, the functions of MaUGT68 and MaUGT186, which were upregulated under stress and potentially involved in coumarin glycosylation, were characterized by heterologous expression in yeast and Escherichia coli. These results extend our knowledge of the UGT gene family along with MaUGT gene functions, and provide valuable findings for future studies on developmental regulation and comprehensive data on UGT genes in M. albus.

Nutrient status, hydrogen peroxide content and peroxidase activity of arbuscular mycorrhizal plants of Melilotus albus grown in diesel-contaminated substrate

Background: Petroleum hydrocarbons affect plant growth, but little is known about physiological responses of mycorrhizal plants facing diesel contamination. Objective: To evaluate the effects of arbuscular mycorrhizal fungi (AMF) on the nutritional status, peroxidase activity (POX), and hydrogen peroxide content (H2O2) in leaves of Melilotus albus planted under diesel-contaminated sand (7500 mg kg-1). Methods: A 2x2 factorial experiment was set in a completely randomized design, under greenhouse conditions for 35 days. Seedlings were pre-inoculated with AMF and transplanted to sand with or without diesel, including non-AMF plants. Results and conclusions: Diesel contamination impaired plant growth; AMF plants had similar growth than non-AMF plants at diesel-contamination, but low nutrient content. Protein content decreased due to diesel in non-AMF plants, but this content was low in AMF plants regardless diesel contamination. Diesel increased POX; whereas AMF plants with or without diesel had higher POX than non-AMF plants. The H2O2 content in AMF plants with or without diesel was low than non-AMF plants. Diesel contamination diminished AMF-colonization, but AMF dissipate more diesel hydrocarbons (>40%). Overall, AMF alleviated the toxic effects of diesel on plants.

Ensiling Reduces Seed Viability: Implications for Weed Management

Ensiling, a lactic acid fermentation process, is mainly used to preserve biomass. In addition, it has been shown to affect seed viability of some plant species. The extent to which this makes ensiling suitable as a weed control measure, however, has not yet been determined. Both the range of controllable species and the parameters of an ensiling process that safely kills seeds are still undefined. We aimed to determine the effect of varying substrate and ensiling conditions on the seed viability of 10 species selected to represent a wide range of different seed traits. Five different types of silages were made from maize or mixtures of wildflower and maize biomass and ensiled in lab-scale silos for 8 months. The pure maize silages were prepared under conditions either ideal or suboptimal for ensiling forage. Seeds of important weeds (Chenopodium album, Abutilon theophrasti) and of species from a wildflower mixture suitable for ensiling and biogas production (Cichorium intybus, Daucus carota, Echium vulgare, Malva alcea, Malva sylvestris, Melilotus albus, Melilotus officinalis) were tested. Seed viability was determined using a combination of tetrazolium and germination tests. Ensiling reduced seed viability across all 10 species significantly. Seed-killing efficacies of ensiling, however, differed widely among the species studied, largely related to whether the species could produce hard (physically dormant) seeds. Seeds from species without hardseededness were completely inactivated by ensiling, while the seed-killing efficacies for hardseeded species ranged from 5 to 60%. Variation in ensiled substrate and ensiling conditions had no consistent effect on seed survival. We concluded that ensiling has the potential to sustainably reduce seed viability of a wide range of species and therefore should be adopted as a component of integrated weed management in organic agriculture.

Hungarian sainfoin and its ecological value for agriculture

В последние годы в Пермском крае прекратилось известкование кислых почв, недостаточно вносятся минеральные и органические удобрения. Всё это постепенно привело к снижению плодородия почв. Избежать или снизить влияние негативных явлений можно за счёт использования многолетних трав. Перспективной фитомелиоративной культурой является эспарцет песчаный (Onobrychis arenaria (Kit.) Ser.), который ранее в Пермском крае не возделывался, но встречается в естественных фитоценозах ряда районов края. Целью настоящей работы является поиск и обобщение научной информации по морфо-биологическим особенностям и агроэкологической роли эспарцета песчаного в земледелии. В статье приведён литературный обзор биологических особенностей этой культуры: азотфиксации, накопления пожнивно-корневых остатков, формирования корневой системы эспарцета песчаного в различных регионах его возделывания. Для сравнения приведены экспериментальные данные ряда исследователей, полученные в Пермском крае при изучении клевера лугового (Trifolium pratense L.), люцерны изменчивой (Medicago×varia Mart.), донника белого (Melilotus albus Medik.). Эспарцет песчаный за счёт корневых выделений способен усваивать из глубоких горизонтов почвы труднодоступные для других культур кальциевые и фосфорные соединения и обогащать ими верхний горизонт почвы, то есть он может выступать в роли биологического мелиоранта. На опытном поле Пермского НИИСХ эспарцет песчаный изучался с 2011 по 2019 год и зарекомендовал себя как перспективная кормовая культура. Изучение его особенностей с целью разработки технологий возделывания и использования целесообразно продолжить и расширить. Over the last years, liming of acidic soils stopped in the Perm Territory; mineral and organic fertilizers are not applied sufficiently. All this gradually led to a decrease in soil fertility. It is possible to avoid or reduce the influence of negative factors by planting perennial grasses. Hungarian sainfoin (Onobrychis arenaria (Kit.) Ser.) is a promising phytomeliorative crop for the Perm Territory. It was not previously cultivated there, but it is found in natural ecosystems in a number of locations. The investigation aimed at reviewing morphology, biology and ecological value of Hungarian sainfoin. The article deals with its biological features: nitrogen fixation, accumulation of crop residues as well as root system formation in various regions. To compare sainfoin with other crops in the Perm Territory, the article provides the experimental data on red clover (Trifolium pratense L.), alfalfa (Medicago×varia Mart.), and white melilot (Melilotus albus Medik.). Due to root secretions, Hungarian sainfoin is able to assimilate calcium and phosphorus from deep soil that are unavailable for other crops. So, the crop can enrich the upper soil layers with these elements, being a biological ameliorant. Studied during 2011–2019 on the trial field of the Perm Research Institute of Agriculture, Hungarian sainfoin was shown to be a promising forage crop. Its further investigation as well as development of efficient cultural practices is of high value.

Comparative assessment of the amino acids content of some legumes species in Southern Ukraine

The data on the composition and amount of amino acids have been analyzed in the raw materials of five legume species. All of them grow in Southern Ukrainian flora (Securigera varia (L.) Lassen, Vicia cracca L., Lupinus luteus L., Melilotus officinalis (L.) Pall., Melilotus albus Medic.) and may be used as a source of amino acids, especially essential, whose resource has to be replenished from the outside. Aim. We have studied and compared the amino acid profile of some species of the Ukrainian South Legumes, and used the multidimensional statistical cluster analysis to construction of histograms based on the amino acids content and composition of such plants as: Securigera varia (L.) Lassen, Vicia cracca L., Lupinus luteus L., Melilotus officinalis (L.) Pall., Melilotus albus Medic. Materials and methods. The raw materials were harvested at the South of Ukraine and were investigated by gas-liquid chromatography. The amino acid analyzer has been used after hydrochloric acid hydrolysis at elevated temperature. Results. 19 amino acids have been identified, of which nine are essential or partially interchangeable. The non-polar amino acid proline is in the lead in terms of quantity among the essential amino acids. Its amount was 6932 mg/100 g and the ability to accumulate it was noted in Melilotus officinalis (2276 mg/100 g). The smallest proline amount was found in Lupinus luteus (388 mg/100 g). The sulfur-containing non-polar amino acid methionine is in the smallest amount in the selected plants (506 mg/100 g). Our attention was drawn to the absence of the polar amino acid glutamine among the non-essential amino acids in some plants. Securigera varia, Vicia cracca, and Melilotus officinalis did not contain glutamine. In this subgroup, the polar aspartic acid was found in the highest amount (6824 mg/100 g) with the highest content in Vicia cracca and the lowest – in Melilotus albus (2660 mg/100 g and 385 mg/100 g, respectively). Conclusions. The analysis of the presence and number of amino acids was the basis for our multidimensional statistical cluster analysis and histograms of the presentation of the amino acid profile of the studied plant members of the family Fabaceae L. In constructing the dendrogram, three clusters were identified, and representatives of one genus (Melilotus L.) were attributed to different clusters which is significant for further chemosystematic studies.

Genome-Wide Identification and Development of LTR Retrotransposon-Based Molecular Markers for the Melilotus Genus

Melilotus is an important genus of legumes with industrial and medicinal value, partly due to the production of coumarin. To explore the genetic diversity and population structure of Melilotus, 40 accessions were analyzed using long terminal repeat (LTR) retrotransposon-based markers. A total of 585,894,349 bp of LTR retrotransposon sequences, accounting for 55.28% of the Melilotus genome, were identified using bioinformatics tools. A total of 181,040 LTR retrotransposons were identified and classified as Gypsy, Copia, or another type. A total of 350 pairs of primers were designed for assessing polymorphisms in 15 Melilotus albus accessions. Overall, 47 polymorphic primer pairs were screened for their availability and transferability in 18 Melilotus species. All the primer pairs were transferable, and 292 alleles were detected at 47 LTR retrotransposon loci. The average polymorphism information content (PIC) value was 0.66, which indicated that these markers were highly informative. Based on unweighted pair group method with arithmetic mean (UPGMA) dendrogram cluster analysis, the 18 Melilotus species were classified into three clusters. This study provides important data for future breeding programs and for implementing genetic improvements in the Melilotus genus.

Effect of Seed Coating and PEG-Induced Drought on the Germination Capacity of Five Clover Crops

The effect of coating the seed of clover crops by water absorbing seed process (WASP) technology pelletization on its germination capacity was studied in conditions of diverse drought intensities simulated by different concentrations of polyethylenglycol (PEG) 8000 solution. Drought resistance was monitored in the seed of five fodder clover species: Anthyllis vulneraria L., Medicago lupulina L., Trifolium repens L., Melilotus albus Medik. and Onobrychis viciifolia Scop. In the seed of given plant species, germination capacity was determined along with the share of dead and hard seeds. Although the coating significantly (p < 0.05) affected the drought resistance of seeds, the germination capacity increased only in conditions of milder drought (simulation with PEG: 0.1–0.3 mol). With the increasing intensity of drought induced by higher PEG concentrations (0.4–0.7 mol) the number of germinable seeds demonstrably decreased and the number of dead seeds increased in the coated seed as compared with the uncoated seed. The coated seed can be appropriate for use in M. lupulina, M. albus and T. repens, while the uncoated seed can be used in A. vulneraria and O. viciifolia.

DETERMINATION OF THE BOTANICAL ORIGIN OF HONEY AND THE BONITET OF HONEY-BEARING VEGETATION BY POLLEN ANALYSIS

Разработка систем качества потребляемых населением продуктов из меда невозможна без оценки флористического богатства региона. Цель настоящего исследования – установление ботанического происхождения меда по пыльцевому анализу, а также бонитета медоносной растительности юга Западной Сибири. Объектом исследования были 92 образца меда сбора 2019 года, полученные с пасек, расположенных в разных почвенно-климатических зонах региона. Для анализа из образца массой 200 г стеклянной палочкой мед наносили на предметное стекло в количестве одной естественной капли, закрывали покровным стеклом и под микроскопом при увеличении 400 исследовали морфологическое строение пыльцевых зерен. После идентификации пыльцевых зерен при увеличении 100 подсчитывали количество зерен каждого найденного морфологического типа. Затем вычисляли среднее арифметическое значение результатов пяти параллельных исследований в 5 каплях, определяли сумму средних арифметических значений общего количества подсчитанных пыльцевых зерен каждого идентифицированного типа и вычисляли частоту встречаемости. Ботаническое происхождение меда определяли исходя из процентного количества пыльцевых зерен в меде: при количестве пыльцевых зерен одного морфологического типа, превышающем 45%, образец считали монофлерным, от 44 до 15% – составной частью смешанного меда (полифлерным), от 14 до 0% – фиксировали присутствие, но не принимали в расчет. Установлено, что при получении монофлерных медов медоносные пчелы предпочитают растения: дягиль сибирский (Archangellica decurens Idb.), дудник лесной (Angelica silvestris L.), донник желтый, (Melilotus officinalis L.), донник белый, (Melilotus albus Medic.), рапс (Brássica nápus L.), синяк обыкновенный (Echium vulgare L.). По наличию пыльцевых зерен в образцах меда установлено, что 82,02% видов медоносных растений являются дикорастущими, 17,08% введены в культуру и используются для получения продуктов питания, кормов, как припасечные растения. Выявлена связь почвенно-климатических зон с видовым приоритетом пыльцевых зерен растений в образцах меда. Для всего региона это дикорастущие виды – дягиль сибирский и дудник лесной, с которых получено максимальное количество монофлерных медов – 42,42%. The development of quality systems for honey products consumed by the population is impossible without an assessment of the floral wealth of the region. The purpose of this study is to establish the botanical origin of honey by pollen analysis, as well as the bonitet of honey-bearing vegetation in the south of Western Siberia. The object of the study was 92 samples of honey collected in 2019, obtained from apiaries located in different soil and climatic zones of the region. For the analysis, honey in the amount of one natural drop was applied with a glass stick to a slide, covered with a cover glass. The morphological structure of pollen grains was examined under a microscope at a magnification of 400. After identification of pollen grains at an increase of 100, the number of grains of each morphological type found was counted. Then the arithmetic mean of the results of five parallel determinations in 5 drops was calculated, the sum of the arithmetic mean values of the total number of counted pollen grains of each identified type was determined, and the frequency of occurrence was calculated. The botanical origin of honey was determined based on the percentage of pollen grains present: when the number of pollen grains of the same morphological type exceeds 45%, the sample was considered monoflower, from 44 to 15% – a component of mixed honey (polyflower), from 14 to 0% – the presence was recorded, but not taken into account. It was found that when obtaining monofleral honey, honey bees prefer plants: siberian angelica (Archangellica decurens Idb.), wood angelica (Angelica silvestris L.), yellow melilotus (Melilotus officinalis L.), white melilotus (Melilotus albus Medic.), rapeseed (Brássica nápus L.), common bruise (Echium vulgare L.). Based on the presence of pollen grains in honey samples, it was found that 82,02% of honey plant species are wild, 17,08% are introduced into culture and are used for food, feed, and as supply plants. The connection of soil-climatic zones with the specific priority of pollen grains of plants in honey is revealed. For the entire region, these are wild species – siberian angelica and forest angelica, from which the maximum amount of monoflower honey is obtained – 42,42%.