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Light provides the necessary energy for plant photosynthesis, which allows plants to produce organic matter and energy conversion, during plant growth and development. Light provides material energy to plants as the basis for cell division and differentiation, chlorophyll synthesis, tissue growth and stomatal movement, and light intensity, photoperiod, and light quality play important roles in these processes. There are several regulatory mechanisms involved in sugar metabolism in plants, and light, as one of the regulatory factors, affects cell wall composition, starch granules, sucrose synthesis, and vascular bundle formation. Similarly, sugar species and genes are affected in the context of light-regulated sugar metabolism. We searched the available databases and found that there are fewer relevant reviews. Therefore, this paper provides a summary of the effects of light on plant growth and development and sugar metabolism, further elaborates on the mechanisms of light effects on plants, and provides some new insights for a better understanding of how plant growth is regulated under different light conditions. [ABSTRACT FROM AUTHOR]

Introduction: Low-light-stress is a common meteorological disaster that can result in slender seedlings. The photoreceptors play a crucial role in perceiving and regulating plants' tolerance to low-light-stress. However, the low-lightstress tolerance of cucumber has not been effectively evaluated, and the functions of these photoreceptor genes in cucumber, particularly under lowlight-stress conditions, are not clear. Methods: Herein, we evaluated the growth characteristics of cucumber seedlings under various LED light treatment. The low-light-stress tolerant cucumber CR and intolerant cucumber CR were used as plant materials for gene expression analysis, and then the function of CsCRY1 was analyzed. Results: The results revealed that light treatment below 40 mmol m-2 s-1 can quickly and effectively induce low-light-stress response. Then, cucumber CR exhibited remarkable tolerance to low-light-stress was screened. Moreover, a total of 11 photoreceptor genes were identified and evaluated. Among them, the cryptochrome 1 (CRY1) had the highest expression level and was only induced in the low-light sensitive cucumber CS. The transcript CsaV3_3G047490.1 is predicted to encode a previously unknown CsCRY1 protein, which lacks 70 amino acids at its C-terminus due to alternative 5' splice sites within the final intron of the CsCRY1 gene. Discussion: CRY1 is a crucial photoreceptor that plays pivotal roles in regulating plants' tolerance to low-light stress. In this study, we discovered that alternative splicing of CsCRY1 generates multiple transcripts encoding distinct CsCRY1 protein variants, providing valuable insights for future exploration and utilization of CsCRY1 in cucumber. [ABSTRACT FROM AUTHOR]

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Ranunculus glacialis (L.) A. Löve & D. Löve is a rare species that is included in the Red Data Book of the Murmansk region. It belongs to a group of northern species that, under climate change conditions, will be exposed to a reduction of range and loss of genetic diversity. The objective of this study was to estimate the adaptive potential of this species in the Khibiny Mountains, which is the edge of the eastern limit of its range. Plants growing in natural conditions of the Khibiny Mountains and in the nurseries of the Polar-Alpine Botanical Garden-Institute (PABGI) were compared in terms of leaf mesostructure and pigment content. Under nursery conditions, at higher temperature than in the field, R. glacialis plants showed quantitative rearrangement of leaf mesostructure. Changes associated with increases in internal leaf volume and disturbance of ontogeny, changes in morphometric indicators of assimilating organs (mass and leaf area), reduced productivity and, consequently, reduced resistance to growing conditions were also found in the PABGI-cultivated plants. In this study, we show that this species has a low level of genetic diversity and a limited adaptive potential in the extreme eastern edge of its range in Russia (Kola Peninsula), as evidenced by numerous experiments on acclimatization of R. glacialis under nursery conditions in the Khibiny Mountains. [ABSTRACT FROM AUTHOR]

Today, in microclonal propagation of plants, there is a demand for effective and low-toxic rhizogenesis stimulators of plant explants. The use of such compounds significantly increases the efficiency of microclonal reproduction. The modern direction in the design of effective non-toxic substances is molecular modeling based on known natural and synthetic compounds. An important place as synthons for development is occupied by nitrogen-containing heterocycles, in particular quinoline. Results and discussion. Among the derivatives of 3-((6-R-quinolin-4-yl)thio) propanoic acid, the most toxic compounds were those that did not have alkoxy substituents in the 6th position of the quinoline cycle and no methyl radical in the 2nd position. Sodium salts are more toxic than the corresponding acids. This is due to the increase in water solubility of ionized compounds. Derivatives of 3-((6-R-quinolin-4-yl)thio)propanoic acid (sodium salt of 3-((quinolin-4-yl)thio)propanoic acid (QРА-5) showed the greatest toxic effect on the model of the study of progressive sperm motility) and 3-((quinolin-4-yl)thio)propanoic acid (QРА-1), which would reduce this indicator by 25-30 % compared to intact. The toxicity assessment of the investigated compounds made it possible to determine a number of factors and factors of the structure of molecules, which affected the level of toxic action of 3-((6-R-quinolin-4-yl)thio) propanoic acid derivatives and directions for creating nontoxic growth stimulants in this series of 4-thioderivatives of quinoline. Conclusions. The investigated compounds showed a high stimulating effect on rhizogenesis in vitro in explants of pink rose (Rosa damascena Mill.) variety Lada. The selection of leader compounds for further testing of potential stimulators of rhizogenesis for microclonal propagation of ornamental plants was carried out. The obtained results are of high practical importance for obtaining and further introduction of new effective, low-toxic, less expensive substances for plant reproduction, in the conditions of microclonal production. [ABSTRACT FROM AUTHOR]

In recent years, the demand for effective and low-toxic stimulators of rhizogenesis, which are used in microclonal propagation of plants, has been increasing in Ukraine. One of the promising directions in the search for effective compounds is molecular modeling based on known natural and synthetic compounds. The development of new highly effective and low-toxic biologically active compounds is largely based on derivatives of nitrogen-containing heterocycles, and quinoline occupies a significant place among them. Modern methods of chemometric analysis make it possible to find certain regularitiesin the "chemical structure – biological activity" and to select the most promising compounds for experimental research. The values of lipophilicity log P for neutral forms and the value of the distribution coefficient log D at pH = 7 were obtained by quantum chemical calculation. The values of log P and log D of the studied compounds are in the most favourable interval for overcoming the biological membranes of the cells of the root system, depending on the pH of the environment. According to Lipinski’s "rule of five", all studied compounds can show high biological activity. The toxicity of compounds of 2-((6-R-quinolin-4-yl)thio)acetic acid derivatives was evaluated by computer programs and experimentally. Among the derivatives of 2-((6-R-quinolin-4-yl)thio)acetic acid, the most toxic compounds were those that did not have alkoxy substituents in the 6th position of the quinoline ring. Sodium salts are more toxic than the corresponding acids. This is due to an increase in the bioavailability of ionized compounds. Derivatives of 2-((6-R-quinolin-4-yl)thio)acetic acid (sodium salt of 2- ((quinolin-4-yl)thio)acetic acid (QAC-5) showed the greatest toxic effect on the model of the study of progressive sperm motility) and 2-((quinolin-4-yl)thio)acetic acid (QAC-1), which will reduce this indicator by 15–20% compared to intact. The toxicity assessment of the studied compounds made it possible to determine a number of factors of the structure of molecules which affect the level of toxic action of 2-((6-R-quinolin-4-yl)thio)acetic acid derivatives and the directions of creation of non-toxic growth stimulants in this series. The impact on rhizogenesis during microclonal reproduction in vitro in explants Paulownia clone 112 and further adaptation of microplants in vivo hybrid molecules of quinoline and acetic acid, which are analogues of known growth stimulants, was studied. A number of factors influencing the level of influence on rhizogenesis of the action of derivatives of 2-((6-R-quinolin-4- yl)thio)acetic acid and directions of creation of highly active substances in this series was defined. The studied compounds showed a high stimulating effect on rhizogenesis in vitro in Paulownia explants. It was established that the sodium salt of 2-((quinolin-4- yl)thio)acetic acid was the greatest stimulator of rhizogenesis compared to the corresponding original acid. Thepresence of alkoxy groups in the 6th position and methyl in the 2nd position of the quinoline ring of 2-((6-R-quinolin-4-yl)thio)acetic acid reduced the activity of the compounds. The selection of new effective, low-toxic, less expensive substances was carried out for further testing as potential stimulators of rhizogenesis for microclonal propagation of plants. [ABSTRACT FROM AUTHOR]

Potato production is highly affected by viral diseases such as potato virus X (PVX) and potato virus Y (PVY) which can be overcome by establishing a reproducible meristem culture protocol for the production of virus-free potato plants. This study was conducted during 2017 and 2018 on two potato cultivars "Spunta" and "Alaska Red" in Palestine. The tubers were subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of virus infection. The infected tubers for both cultivars were incubated, and after sprouting, meristems-tips were isolated and cultured on Murashige and Skoog (MS) medium. After four weeks, developed shoots were cultured on MS media supplemented with different rates of three hormonal combinations (0.54 µM NAA; 0.54 µM NAA + 1.0 µM TDZ; 0.54 µM NAA + 2.2 µM BA; 0.54 µM NAA + 2.3 µM Kinetin; 0.54 µM NAA + 1.0 µM TDZ+ 2.2 µM BA + 2.3 µM Kinetin). The results showed that maximum shoot multiplication was observed when NAA at 0.54 µM was combined with 1 µM TDZ (2.85 and 2.55 shoots) in both "Spunta" and "Alaska Red" cultivars, respectively. Higher shoot length and leaf number were obtained when NAA was combined with either BA (2.2 µM) or Kinetin (2.3 µM) in both cultivars. In vitro multiplied shoots were rooted and acclimatized successfully. Neither t PVY nor PVX viruses were detected by RT-PCR on the RNA extracts from the tested in vitro grown samples. [ABSTRACT FROM AUTHOR]

When growing potato regenerants in vitro fluorescent or sodium lamps are most often used as light sources. This is due to significant energy consumption and limited spectral capabilities of these light sources. Therefore, research was aimed to study the growth and development of meristem potato plants in vitro using LEDs of different technical design as light sources and to find out lights that can contribute to the most efficient plant growth and development. The research was conducted during April and May 2021, at the Laboratory of Biotechnology of Agricultural Plants of the Samara Scientific Research Agriculture Institute named after N.M. Tulajkov, Branch of the SamSC RAS, Bezenchuk vill., Russia, using meristem potato var. Rosara, Arosa and Riviera. The explants were cultivated on a Murashige-Skoog growing medium for 30 days using various LED artificial illumination sources with a 16-hour light period, an air temperature of 22- 24 °C, and a relative air humidity of 70-75%. After 10, 20 and 30 days of cultivation, the plant length and the number of internodes were measured. A positive effect on plants of LED lights was revealed during in vitro propagation. The most developed regenerants with a high number of internodes were obtained using LED lamps UnielA60 10W, UnielA60 16W, T8-phyto, and Era FITO. On average for three studied varieties after 30 days of cultivation, regenerants with the maximum length were those, which were grown under illumination with T8-phyto and Era FITO lamps that mean variants with the highest level of photosynthetic photon flux of 21.8 μmol/s and 32.4 μmol/s and a wavelength of 450-650 nm. It was shown that the lighting conditions had the greatest impact on potato growth in the period from 10th to 30th days of cultivation. Different variety reactions to changes in light regime were detected. [ABSTRACT FROM AUTHOR]

We investigated the influence of different conditions (light composition and plant growth regulators (PGRs) in culture media) on the morphophysiological parameters of Stevia rebaudiana Bertoni in vitro and in vivo. Both PGRs and the light spectra applied were found to significantly affect plant morphogenesis. During the micropropagation stage of S. rebaudiana, optimal growth, with a multiplication coefficient of 15, was obtained in an MS culture medium containing 2,4-epibrassinolide (Epin) and indole-3-acetic acid (IAA) at concentrations of 0.1 and 0.5 mg L-1, respectively. During the rooting stage, we found that the addition of 0.5 mg L-1 hydroxycinnamic acid (Zircon) to the MS medium led to an optimal root formation frequency of 85% and resulted in the formation of strong plants with well-developed leaf blades. Cultivation on media containing 0.1 mg L-1 Epin and 0.5 mg L-1 IAA and receiving coherent light irradiation on a weekly basis resulted in a 100% increase in the multiplication coefficient, better adventitious shoot growth, and a 33% increase in the number of leaves. S. rebaudiana microshoots, cultured on MS media containing 1.0 mg L-1 6-benzylaminopurine (BAP) and 0.5 mg L-1 IAA with red monochrome light treatments, increased the multiplication coefficient by 30% compared with controls (white light, media without PGRs). [ABSTRACT FROM AUTHOR]