Amount Of Photosynthetic Pigments Research Articles

Selenium Enrichment of Broccoli (Brassica Oleracea Var. Italica) to Improve The Growth, Phenolic Compounds, Antioxidant Capacity and Glucosinolate Compounds.

Selenium is a micronutrient element that is beneficial for the growth and development of plants. It has antioxidant, anticancer, and antiviral properties that are essential for human and animal health. Low-consumption mineral elements such as selenium can be included in the diet from various sources. To investigate the growth and phytochemical attributes of a broccoli cultivar "Heracklion", an experiment with five levels of selenium concentration (0, 5, 10, 15, 20 mg/L sodium selenate) was carried out in a randomized complete block design with 3 replications in the field condition. With increasing the concentration of sodium selenate in the foliar application, the accumulation of sodium selenate in broccoli increased and the highest amount (1.47 mg/kg dry weight) was measured at 20 mg/L of sodium selenate. The highest amount of photosynthetic pigments in leaves was recorded at 15 mg/L of sodium selenate. In the case of glucosinolates, with increasing selenium concentration up to 20 mg/L concentration, glucoraphanin, 4-methoxy glucobrassicin, and aliphatic glucosinolates increased in leaves. It could be demonstrated that foliar application of selenium at 10 mg/L led to an improvement of secondary metabolites, especially glucoraphanin, both in leaves and florets, and could also have a positive effect on human nutrition.

Alteration of stress-physiological mechanisms in sRNA-treated sweet corn plants during MDMV infection.

Maize dwarf mosaic virus (MDMV) can significantly reduce the growth and development of susceptible varieties of sweet corn. The virus utilises the energy and reserve sources of plant cells to ensure its reproduction in the microspaces formed by cell membranes. Therefore, the severity of stress can be monitored by examining certain physiological changes, for example, changes in the degree of membrane damage caused by lipid peroxidation, as well as changes in the amount of photosynthetic pigments. The activation of antioxidant enzymes (e.g. ascorbate peroxidase, guaiacol peroxidase, glutathione reductase) and the accumulation of phenolic compounds with antioxidant properties can indirectly protect against the oxidative stress caused by the presence of the positive orientation, single-stranded RNA-virus. This study demonstrates the changes in these physiological processes in a sweet corn hybrid (Zea mays cv. saccharata var. Honey Koern.) susceptible to MDMV infection, and suggests that exogenous small RNA treatment can mitigate the damage caused by virus infection.

Salt-induced changes in morpho-physiological and biochemical properties in chickpea (Cicer arietinum L.) seedlings

Salinity is one of the most severe abiotic stresses for crop production. The present study was conducted to evaluate the effect of NaCl on growth and some biochemical parameters in chickpea (Cicer arietinum L.) seedlings. Chickpeas were grown hydroponically for 14 days and then treated with 0 mM and 200 mM NaCl. Plants were harvested for the experiment 7 days after salt treatment. Salinity showed marked changes in growth parameters (fresh and dry weight of roots and shoots) and the amount of photosynthetic pigments. The study revealed that the activity of photosystems (PS I and PS II) under salt stress is lower than that of plants growing under normal conditions. The spectral characteristics of the chloroplasts isolated from chickpea leaves were studied by the fluorescence method at liquid nitrogen temperature (77K). Under salt stress, the chloroplast fluorescence emission spectrum decreased in the parts of the spectrum characterizing the PSII (maxima at 686 nm and 695 nm) and PSI complexes (maxima at 735 nm). Keywords: Photosynthetic pigments, chloroplasts, photosystems, fluorescence, chickpea

Salicylic Acid Alleviates the Adverse of Salinity Stress in Fenugreek (Trigonella foenum-graecum)

Aims: To discover the resistance of the Yemeni genotype of fenugreek to salt stress and the impact of salicylic acid on alleviating salt stress. Study Design: The experimental design adopted a completely randomized block design (RCBD), with pots filled with a 1:2 mixture of sand and soil serving as the experimental units. Place and Duration of Study: in a mini greenhouse covered with white polyethylene plastic sheet at Taiz University during the spring season 2021. The average temperature ranged from 32 ℃ during the day to 29 ℃ at night. chemical analyses were performed at the pharmaceutical laboratory in Al-Saeed University. Methodology: The fenugreek genotype was subjected to varying salinity levels (0, 50, 100, 150, and 200 mM) and the impact of salicylic acid (at concentrations of 0, 0.1, and 0.5 mg/l) in alleviating salt stress effects was examined at two time points: 15 and 30 days after 2 weeks of germination. Results: Increasing salinity significantly reduced shoot and root length and exhibited slight fluctuations influenced by salinity levels above 100 mM. Salicylic acid (SA) significantly reduced shoot length but had no effect on root length. Salinity had no appreciable effect on shoot dry matter (SDM%), while the application of SA significantly decreased it. Root dry matter percentage (RDM%) showed a notable and sharp increase with salinity. However, no appreciable changes in RDM% were observed in response to the SA application. In response to salinity, the ratio of SDM% to RDM% in treated plants decreased sharply, with the lowest ratio achieved when 0.1 SA was used for treatment. There were no significant modifications observed in the amounts of photosynthetic pigments in fenugreek leaves, including chl a, chl b and total chl. Nevertheless, using high concentration of Nacl led to a signifcantly reduced in the carotenoids and the chl. b. The protein content of fenugreek plants treated with salt was much higher than that of control plants. Also, protein levels increased with SA treatment across all NaCl concentration. Proline levels sharply increased with rising salinity, reaching a peak in approximately 22.28 ug/g DW. Application of 0.1 SA led to the highest proline level in comparison to other treatments, which was the highest level of Nacl in the second measurement time. Proline levels in plants treated with 200 Nacl and 0.1 SA were the highest, averaging roughly recorded 49.95 ug/g DW. APX significantly affected on fenugreek plants, the highest APX content was found in plants treated with 50 mM NaCl, the application of 0.1 SA produced the highest level of APX (0.373nm/g protein/minuet) in fenugreek. Catalase (CA) levels significantly decreased, but SA application did not affect CA levels. The data obtained may help in determining fenugreek cultivation areas and in managing breeding programs.

Changes in the amount of photosynthetic pigments in the native Artemisia diffusa in the semi-desert rangelands of Uzbekistan under the influence of different sheep grazing intensities and different seasons

Rangelands, as critical components of terrestrial ecosystems, play a pivotal role in supporting biodiversity and providing essential ecosystem services. The relationship between grazing activities and vegetation dynamics is a topic of ongoing research, with a focus on understanding how these interactions influence key physiological processes in dominant plant species. This study investigated the changes in photosynthetic pigments of rangeland Artemisia diffusa under varying sheep grazing intensities. Four different grazing intensities were imposed: initial, low, medium, and high. Sampling took place at regular intervals over the 2021-2022 year spring sezon to assess the temporal dynamics of photosynthetic pigments. The study focused on measuring changes in the concentration of key photosynthetic pigments, including chlorophyll-a, chlorophyll-b, and carotenoids, in selected Artemisia diffusa species over the grazing period. Our results showed a clear correlation between sheep grazing intensity and changes in photosynthetic pigment concentration. In general, Artemisia diffusa at initial and low intensities showed lower levels of chlorophyll a and b than those at moderate and high intensities. Carotenoid concentrations were also observed to change significantly and increase significantly at high sheep grazing intensities.

Seed priming with corona discharge plasma modified growth performance, improved metabolism, and elicited production of tropane alkaloids in Datura inoxia seedlings; plasma technology for application in plant in‐vitro cultures

AbstractThis study monitored the growth, biochemical, and developmental responses of Datura seedlings to the cold plasma. The effectiveness of different methods was explored to break seed dormancy. Germinating seeds were exposed to corona discharge plasma for different durations, including 0, 60, 120, 180, and 300 s. A procedure consisting of illumination with a red light (20 min), soaking in water (4°C for 48 h), and removing a part of Testa was the best method for breaking seed dormancy. The plasma treatments of 60, 120, and 180 s improved the plant growth performance, while this trait was declined in response to the plasma treatment of 300 s. The proline concentrations in both root and leaves displayed a linear significant upward trend in response to the plasma treatments. The plasma for 180 s was the most effective method to increase tropane alkaloids. With increasing the exposure time from 60 to 300 s, the leaf soluble phenols were linearly enhanced. The plasma application for 60, 120, and 180 s significantly augmented total protein concentration, while the exposure of seeds for 300 s significantly diminished it. The highest amounts of photosynthetic pigments (chlorophylls and carotenoids) were recorded in the seedlings treated with plasma for 120 and 180 s. The activities of enzymatic antioxidants (catalase and peroxidase) showed a similar upward trend to that of proline. The plasma priming also improved the phenylalanine ammonia‐lyase activity (a secondary metabolism index). Further investigations are needed to optimize plasma parameters and understand the involved mechanisms to maximize its benefits while minimizing potential risks.

The role of photosynthetic pigments in the leaf of maize inbred lines in improving photosynthetic efficiency

Methods of absorption and Raman spectroscopy were applied in this study to analyze functions and amounts of photosynthetic pigments in the leaf of maize inbred lines (M1-3-3Sdms, ZPPL186, and ZPPL225). Absorption spectroscopy was used to determine the dynamics of biosynthesis of chlorophyll a, chlorophyll b, and carotenoids. Raman spectroscopy was used to present the dynamics of biosynthesis of carotenoids and other compounds in terms of origin and kinetic form of the formation of spectra with all spectral bands. Organic molecules and compounds causing the formation of certain spectral bands in the Raman spectrum (carotenoids, phosphates, glycogen, amid III, and others) were determined. Conformational and functional changes of photosynthetic pigments in the leaves of the maize inbred lines, which occur due to changes in the ratio (quotient), were analyzed. The ratios (quotients) obtained indicate different contributions of valence oscillations of their chemical bonds, which inevitably alter the conformation of molecules and compounds. The results presented for the overall study point to minor biogenic differences among the maize inbred lines under study.

Photosynthesis, chlorophyll content and water potential of a mistletoe-host pair in a semi-arid savanna

Mistletoes can have detrimental effects on host trees. Mistletoe-infected trees may suffer from reduced growth and loss of vigor thereby contributing to low productivity of host trees. However, hosts may tolerate low levels of infection. This study aimed to determine photosynthetic rate, chlorophyll content and transpiration rate of a mistletoe-host pair (Viscum rotundifolium-Boscia albitrunca) and the water potential of two mistletoe host pairs (V. rotundifolium-B. albitrunca and Tapinanthus oleifolius-Senegalia mellifera) in a semi-arid savanna at Windhoek, Namibia. Photosynthetic rates were measured using a LI-6400XT photosynthesis system, while photosynthetic pigments were extracted in acetone and quantified spectrophotometrically. Plant water potential was measured using a Scholander pressure chamber. Results revealed greater photosynthetic rates and amounts of photosynthetic pigments in B. albitrunca than in V. rotundifolium while transpiration rates showed opposite trends to photosynthetic rates. Non-host B. albitrunca trees recorded significantly higher photosynthetic rates than the hosts, which suggests a parasite-induced reduction of photosynthetic rate in host plants. Water potential was greater in host trees than in mistletoes. These findings show negative effects of mistletoes on host trees, which may ultimately affect their reproduction and survival. Further research may be required to determine effects of parasite density on host trees.

Seed Treatment with Electromagnetic Field Induces Different Effects on Emergence, Growth and Profiles of Biochemical Compounds in Seven Half-Sib Families of Silver Birch.

In the context of climate change, strategies aimed at enhancing trees' resistance to biotic and abiotic stress are particularly relevant. We applied an electromagnetic field (EMF) seed treatment to observe changes in the establishment and content of biochemical compounds in silver birch seedlings induced by a short (1 min) seed exposure to a physical stressor. The impact of EMF treatment was evaluated on seedling emergence and growth of one-year-old and two-year-old seedlings from seven half-sib families of silver birch. The effects on numerous biochemical parameters in seedling leaves, such as total phenolic content (TPC), total flavonoid content (TFC), amounts of photosynthetic pigments, total soluble sugars (TSS), level of lipid peroxidation level, antioxidant activity and activity of antioxidant enzymes, were compared using spectrophotometric methods. The results indicated that, in one-year-old seedlings, two of seven (60th and 73rd) half-sib families exhibited a positive response to seed treatment with EMFs in nearly all analyzed parameters. For example, in the 60th family, seed treatment with EMFs increased the percentage of emergence by 3 times, one-year-old seedling height by 71%, leaf TPC by 47%, antioxidant activity by 2 times and amount of chlorophyll a by 4.6 times. Meanwhile, the other two (86th and 179th) families exhibited a more obvious positive response to EMF in two-year-old seedlings as compared to one-year-old seedling controls. The results revealed that short-term EMF treatment of silver birch seeds can potentially be used to improve seedling emergence and growth and increase the content of secondary metabolites, antioxidant capacity and photosynthetic pigments. Understanding of the impact of EMFs as well as the influence of genetic differences on tree responses can be significant for practical applications in forestry. Genetic selection of plant genotypes that exhibit positive response trends can open the way to improve the quality of forest stands.

Effectiveness of a complex microbial preparation for oats and spring barley growing

Today, one of the main challenges for agriculture is to increase grain production and its profitability while reducing the use of chemicals. Addressing this issue is a key to meeting the human need for quality and affordable food. One of the ways to improve the efficiency of grain industry is to use effective microbial-based biological products. They will help to reduce the chemical burden on the environment and produce high quality crops. The aim of this study was to evaluate the effectiveness of treatment and the growing season of spring oats and barley with a complex microbial preparation based on promising strains of Azotobacter vinelandii 7 AI, Azotobacter chroococcum 8 AI and Bacillus megaterium 39 AI isolated by us earlier. Field trials were carried out on the experimental fields of the Skvyra Experimental Station of Organic Production of the Institute of Agroecology and Nature Management of the National Academy of Agrarian Sciences of Ukraine (Ukraine, Kyiv region, Skvyra) in 2022. For the treatment of plants during the growing season, strains of microorganisms and their compositions were used in critical phases of crop development. After 6–7 days, the effect of these compositions on some plant growth parameters was studied. To confirm the hypothesis about the effect of treatment with promising microorganisms on the ability of plants to increase the amount of photosynthetic pigments, a quantitative analysis of plants for their content was performed. The positive effect of plant treatment was found not only on the quantity of the harvest, but also on its quality. The results of the research indicate the effectiveness of the use of a complex microbial preparation based on the proposed strains of microorganisms for such cereals as oats and spring barley. Treatment with a biopreparation based on effective, environmentally friendly and agronomically useful strains of microorganisms improves both growth and photosynthetic processes, which in turn activates their development and enhances the productivity of these crops, while significantly improving the quality of grain.

Response of seed yield and biochemical traits of Eruca sativa Mill. to drought stress in a collection study

Drought tolerance is a complex trait in plants that involves different biochemical mechanisms. During two years of study (2019–2020), the responses of 64 arugula genotypes to drought stress were evaluated in a randomized complete block design with three replications under field conditions. Several metabolic traits were evaluated, i.e. relative water content, photosynthetic pigments (chlorophyll and carotenoids), proline, malondialdehyde, enzymatic antioxidants (catalase, ascorbate peroxidase, and peroxidase), total phenolic and flavonoid contents and seed yield. On average, the drought stress significantly increased the proline content (24%), catalase (42%), peroxidase (60%) and malondialdehyde activities (116%) over the two years of study. As a result of the drought stress, the seed yield (18%), relative water content (19.5%) and amount of photosynthetic pigments (chlorophyll and carotenoids) dropped significantly. However, the total phenolic and flavonoid contents showed no significant changes. Under drought stress, the highest seed yields were seen in the G50, G57, G54, G55 and G60 genotypes, while the lowest value was observed in the G16 genotype (94 g plant−1). According to the findings, when compared to the drought-sensitive genotypes, the drought-tolerant arugula genotypes were marked with higher levels of proline accumulation and antioxidant enzyme activity. Correlation analysis indicated the positive effects of peroxidase, catalase and proline on seed yield under drought conditions. These traits can be considered for the selection of drought-tolerant genotypes in breeding programs.

EFFECT OF VARIOUS CARBON SOURCES ON THE GROWTH PROPERTIES AND MORPHOLOGY OF $SPIRULINA~PLATENSIS$

Cyanobacteria generate biomass under photoautotrophic conditions during photosynthesis. Cultivation of cyanobacteria under photoheterotrophic conditions using various organic carbon sources can increase yield of biomass. In the current study, the effect of organic carbon sources on the growth properties and morphology of cyanobacteria Spirulina platensis, as well as the production of the photosynthetic pigments: chlorophyll a, carotenoids, and phycocyanin were investigated. Carbon sources, such as glucose, fructose and succinate, caused not only an increase in the cyanobacterial growth rate, but also morphological changes in S. platensis trichomes. An increase in the amounts of photosynthetic pigments was also observed. Thus, glucose, fructose, and succinate are more efficient substrates for photoheterotrophic cultivation of these cyanobacteria.

Exogenous application of spermidine and methyl jasmonate can mitigate salt stress in fenugreek (Trigonella foenum-graecum L.)

Fenugreek (Trigonella foenum-graecum L.) has long been cultivated as both culinary and medicinal plant. The objective of this study was to investigate the effect of plant growth regulators such as spermidine (Spd) and methyl jasmonate (MeJA) on morpho-physiological and biochemical properties of fenugreek under saline conditions. A replicated greenhouse experiment in completely randomized block design was conducted with two levels of salinity (0.5 dS/m as control and 6 dS/m), three levels of spermidine (0, 1, 2 mM) and methyl jasmonate (0, 100, 200 µM), respectively. The results showed that salinity elevation reduced the leaf relative water content, leaf water potential, canopy-air temperature difference, photochemistry efficiency of photosystem II, and water-use efficiency of fenugreek. In contrast, salinity increased leaf thickness,greenness index, canopy temperature, leaf Na+, ash contents, malondialdehyde, other aldehydes, and electrolyte leakage. Moreover, Salinity stress reduced the amount of photosynthetic pigments, chlorophyll a/b ratio, total soluble protein, K+, maximum fluorescence, and K+/Na+ ratio in leaves. Elevation of water salinity, however, resulted in an increase in the activity of antioxidant enzymes (except superoxide dismutase), proline, and minimum fluorescence. When fenugreek was treated with 1 mM spermidine and/or 100 µM methyl jasmonate, the adverse effects of salinity stress were significantly mitigated, while the effects of these plant growth regulators on mitigating salinity stress were less pronounced at higher concentrations (2 mM spermidine and/or 200 µM methyl jasmonate). The current study suggests the application of 1 mM spermidine and/or 100 µM methyl jasmonate during the vegetative growth stage mitigating the adverse effects of salinity with an associated improvement in plant growth under moderate salinity (about 6 dS/m) when used for irrigation.

Changes of photosynthetic pigments of Artemisia diffusa under the influence of grazing stress of livestock grazing in Karnabchul semi-desert, Uzbekistan

On the transformed natural rangelands of Karnabchul desert, the natural Artemisia diffusa studied four different grazing intensities the change in the amount of photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids). It was found that the amount of A. diffusa pigments also increased with increasing stress levels in livestock grazing. In general, different grazing intensities had a different impact on the morphological and physiological traits of plants, especially their photosynthetic pigments.

Amelioration of the adverse effects of thiram by 24- epibrassinolide in tomato (Solanum lycopersicum Mill.)

This study investigated thiram fungicide-induced-stress effects in tomato plants and the possible protective role of 24-epibrassinolide (24-EBL) in response to thiram (tetramethyl thiuram disulfide) toxicity. Tomato seedlings pretreated with 0, 10-11, 10-9 and 10-7 M 24-EBL were treated with 6.6 mM thiram. Tomato leaves harvested 5 and 11 days after thiram treatment (DAT) were used for analysis. Thiram application caused oxidative stress by increased hydrogen peroxide and malondialdehyde levels, whereas the chlorophyll a, b and carotenoid amounts and total protein content decreased. In addition, the activities of antioxidant enzymes such as catalase, ascorbate peroxidase and glutathione reductase decreased in the thiram-treated tomato plants on DAT 5 and 11 while pesticide detoxification enzymes (peroxidase and glutathione- S-transferase) activities increased. The thiram-induced oxidative stress was alleviated after pretreatments with different concentrations of 24-EBL. The hydrogen peroxide and malondialdehyde levels decreased and the amounts of photosynthetic pigments and total protein content increased after 24-EBL pretreatments. In addition, the activities of antioxidant enzymes and pesticide detoxification enzymes further increased as the concentration of 24-EBL decreased in tomato under thiram stress, and the most effective concentration was determined as 10-11 M 24-EBL. The results suggested that 24-EBL could effectively alleviate thiram-induced phytotoxicity in tomato plants.

Influence of N, K, and Seaweed Extract Fertilization on Biomass, Photosynthetic Pigments, and Essential Oil of Thymus vulgaris: Optimization Study by Response Surface Methodology

Nutrient management has a decisive impact on the biomass and essential oil yield of medicinal plants. This study aimed to determine the optimal levels of nitrogen, potassium, and seaweed extract fertilizers to maximize the yield and quality of thyme using the response surface methodology (RSM). The experiment was laid out as a Box-Behnken design with three replications and three experimental factors, including nitrogen (urea) (0, 200, and 400 kg ha−1), and foliar application of potassium (Flourish Sulfopotash) (0, 6, and 12 kg ha−1) and seaweed extract (0, 3, and 6 L ha−1). The generated models were statistically significant for all measured traits except for γ-terpinene and p-cymene. While the influence of N on the amount of photosynthetic pigments followed a quadratic trend, the response of total chlorophyll and carotenoids to increasing potassium was linear. The response of biomass yield to N and seaweed was quadratic and linear, respectively. Potassium application had no significant influence on biomass. Essential oil yield reached its peak value (12 kg ha−1) when N and seaweed were applied at their intermediate levels and with the maximum application rate of potassium. Thymol was identified as the highest essential oil component (46.1%), followed by γ-terpinene (19.2%), p-cymene (14.1%), and carvacrol (5.6%). The optimization results suggested that the application of 162 kg ha−1 urea, 12 kg ha−1 Flourish Sulfopotash, and 4 L ha−1 seaweed extract was sufficient to produce the maximum dry matter (1247 kg ha−1), and more than 11 kg ha−1 of essential oil, with a concentration of 1%. Through optimization, the amounts of thymol and carvacrol were estimated to be as much as 44.2% and 6.2%, respectively. The results of the study suggested that resource optimization through RSM can be used as an efficient method to manage the consumption of fertilizers in thyme production.

Effect of Various Growth Medium on the Physiology and De Novo Lipogenesis of a Freshwater Microalga Scenedesmus rotundus-MG910488 under Autotrophic Condition

The microalga Scenedesmus rotundus, isolated from Jabalpur, Madhya Pradesh, India was designated as Scenedesmus rotundus-MG910488 after morphological and molecular identification. In this study, the effects of various autotrophic growth media on the physiology and lipid accumulation of this microalga were investigated. The cell density, amount of photosynthetic pigments, the productivity of biomass and lipid content and the cell morphology of the microalga were shown to be significantly affected by the variation in growth media. The highest biomass of 754.56 ± 14.80 mg L−1 with biomass productivity of 37.73 ± 0.74 mg L−1 day−1 was achieved when this microalgae was cultivated in the Zarrouk’s medium, whereas the highest lipid content of 33.30 ± 1.21% was observed in the BG-11 medium. The results confirm that the BG-11 is a cost-effective and efficient growth medium for this microalga. It also shows that the ingredients of the growth medium and its concentration influence the growth and synthesis of biomolecules produced by microalga. The biodiesel produced from obtained lipids was qualitatively estimated by Gas Chromatography-Mass Spectroscopy (GC-MS), Nuclear Magnetic Resonance (1H, 13C NMR) and Fourier Transform-Infrared Spectroscopy (FT-IR), which indicate the presence of oleic acid methyl ester, linoleic acid methyl ester and palmitic acid methyl ester as the leading fatty acid methyl esters (FAME) in the samples, which make this strain an ideal feedstock for biodiesel production.

Integrated physiological, transcriptomic and metabolomic analysis of the response of Trifolium pratense L. to Pb toxicity

Lead (Pb) interferes with plant gene expression, alters metabolite contents and affects plant growth. However, the molecular mechanism underlying the plant response to Pb is not completely understood. In the present study, Trifolium pratense L. was exposed to Pb concentrations of 0 (Pb0), 500 (Pb500), 1000 (Pb1000), 2000 (Pb2000) and 3000 (Pb3000) mg/kg in soils. Pb stress affected the ability of T. pratense to accumulate and transport Pb, increased the activity of peroxidase (POD) and the contents of malondialdehyde (MDA) and proline, decreased the amount of photosynthetic pigments and soluble proteins, and led to changes in growth and biomass. Transcriptomic and metabolomic analyses showed that Pb mainly affected eight pathways, and LHC, flavonoids, organic acids, amino acids and carbohydrates were upregulated or downregulated. Moreover, Pb500 induced the upregulation of serA, promoted the synthesis of citric acid, maintained photosynthetic pigment levels, and ultimately promoted an increase in stem length. Pb3000 induced the upregulation of ARF, GH3 and SAUR genes, but the saccharide contents and stem length decreased in response to Pb stress. We used a variety of methods to provide a molecular perspective on the mechanism underlying the response of T. pratense to Pb stress.

THE COMPARISON OF PHOTOSYNTHESIS PARAMEATERS OF DIFFERENT WHEAT (TRITICUM AESTIVUM L.) VARIETIES

Field experiments were carried out at the Experimental Station of Vytautas Magnus University Agriculture Academy in Lithuania (54° 53' 3.26", 23° 50' 33.25") during 2017-2018. Six winter wheat varieties were studied in the experiment: 'Skagen' (control), 'Julius', 'Edvins', 'Artist', 'Aron' and 'Evina', which were sown on September 15. Preceding crop – winter rape. Seed rate – 4.5 million ha-1. The aspects of the dynamics of photosynthesis pigments in winter wheat leaves depending on variety is analysed in the article. Physiological activity of the plant, the growth and development are the most important moments decisive the accumulation of these pigments in the plant. Thus, the general condition of the plant might be described by the composition and content of photosynthesis pigments chlorophyll a, b and carotenoids. Spectrophotometric Wettstein method and “Genesys” 6 spectrophotometer were used for determination of the content of photosynthesis pigments (chlorophyll a, b and carotenoids) in green leaf mass in 96 % ethyl alcohol extract. The accumulated amounts of photosynthetic pigments (chlorophylls a, b and carotenoids) in different varieties of winter wheat leaves differed. Winter wheat variety 'Aron' accumulated the highest contents of photosynthetic pigments during the tillering and stem elongation stages, meanwhile during the heading – anthesis and early milky maturity stages winter wheat varieties 'Artist' and 'Skagen' demonstrated the best results. The LAI of different varieties of winter wheat differed in the field experiment. Significantly higher LAI was defined for winter wheat variety Artist (0.9) after the resumption of vegetation (BBCH 24–27) and for 'Skagen' (4.0) at the end of vegetation (BBCH 70–73). The highest LAI of winter wheat is determined during the heading - anthesis stage (varieties 'Aron', 'Edvins', 'Skagen'). During the growing season, the lowest LAI was observed for winter wheat variety 'Evina'.

IMPACT OF OIL CONTAMINATION AND HUMATES ON THE GROWTH OF POACEAE

The article examines the impact of oil contamination and humates (Humifield Forte and Fulvital Plus) on the growth characteristics of Poaceae, such as corn (Zea mays L.) of Dostatok 300 MV hybrid, spring barley of the Karat variety and spring wheat of the Diana variety. Oil contamination has proved to inhibit plant growth and affect a decrease in the amount of photosynthetic pigments in the leaves, which can be explained by oil toxicity and the acquired hydrophobicity of soil. Soaking seeds in humate solution proved the effectiveness of their use for corn (Zea mays L.) of Dostatok 300 MV hybrid and spring barley of the Karat variety: the plants developed well and accumulated biomass actively. The use of humates for spring wheat of the Diana variety did not produce the desired effect: growth characteristics were lower, and the studied plants were weaker. An increase in the number of photosynthetic pigments, especially carotenoids, in the leaves of Poaceae plants indicates the feasibility of using humates to increase the stress resistance of plants in the early stages of growth and development in conditions of oil contamination of soil. A stimulating effect of the combination of oil contamination and Fulvital Plus on the growth of Poaceae was proved. Fulvital Plus is a growth stimulator and deficiency corrector of plant nutrition elements. The results obtained from the research prove the effectiveness of using humates for plants and can be used to increase the stress resistance and yield capacity of Poaceae in man-made conditions and to develop phytoremediation technologies for restoring oil-contaminated areas.