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A stable QTL qSalt-A04-1 for salt tolerance in the cotton seed germination stage, and two candidate genes, GhGASA1 and GhADC2, that play negative roles by modulating the GA and PA signalling pathways, respectively, were identified. The successful transition of a seed into a seedling is a prerequisite for plant propagation and crop yield. Germination is a vulnerable stage in a plant’s life cycle that is strongly affected by environmental conditions, such as salinity. In this study, we identified a novel quantitative trait locus (QTL) qRGR-A04-1 associated with the relative germination rate (RGR) after salt stress treatment based on a high-density genetic map under phytotron and field conditions, with LOD values that ranged from 6.65 to 16.83 and 6.11–12.63% phenotypic variations in all five environmental tests. Two candidate genes with significantly differential expression between the two parents were finally identified through RNA-seq and qRT-PCR analyses. Further functional analyses showed that GhGASA1- and GhADC2-overexpression lines were more sensitive to salt stress than wild-type Arabidopsis based on the regulation of the transcript levels of gibberellic acid (GA)- and polyamine (PA)- related genes in GA and PA biosynthesis and the reduction in the accumulation of GA and PA, respectively, under salt stress. Virus-induced gene silencing analysis showed that TRV:GASA1 and TRV:ADC2 were more tolerant to salt stress than TRV:00 based on the increased expression of GA synthesis genes and decreased H2O2 content, respectively. Taken together, our results suggested that QTL qRGR-A04-1 and its two harboured genes, GhGASA1 and GhADC2, are promising candidates for salt tolerance improvement in cotton.

Background Low growth temperatures and the special light qualities of midnight sun in northern Scandinavia, have both been shown to improve eating quality of swede root bulbs. To study the combined effect of these factors on root development and sensory-related compounds, plants were grown in phytotron under different 24 h supplemental light-emitting diode (LED) light colours, at constant 15 °C, or reduced end-of-season temperature at 9 °C. Results Far-red LED (740 nm) light induced longer leaves and produced more roundly shaped bulbs, than the other light quality treatments. At constant 15 °C, supplemental light of far-red LED also produced a stronger purple crown skin colour than the other LED treatments. This difference between light quality treatments disappeared at 9 °C, as all bulb crowns developed a purple colour. There were no significant effects of LED-supplements on sugar concentrations, while the reduced temperature on average did increase concentrations of d-fructose and d-glucose. Total glucosinolate concentrations were not different among treatments, although the most abundant glucosinolate, progoitrin, on average was present in highest concentration under LEDs containing far-red light, and in lower concentration at 9 °C compared to 15 °C. Conclusion The light quality of 24 h photoperiods in combination with temperature appears primarily important for growth and morphological traits in swede root bulbs. Influence of light quality and low temperature on appearance and sensory-related compounds may be utilized in marketing of root vegetables with special quality related to growth conditions of high latitude origin. © 2020 Society of Chemical Industry.

This paper presents the results of experimental study on the possibility of improving consumer properties of lettuce (Lactuca sativa – var. Dubachuk MC) grown under the conditions of closed system in ISR-0.1 phytotron by applying foliar treatment of different concentrations of 1-ethoxysilatran - a new silicon based preparation belonging to Silatrans group. The trail demonstrated no effect of the preparation when applied in a concentration of 5.10-4 ml/l in ES1 treatment. However, the effectiveness starts upon using higher concentrations. The best yield components were obtained as a result of foliar treatments of ES3 and ES4 with concentrations of 5.10-3 and 10-2 ml/l respectively. Applying foliar treatment in vegetative phase resulted in complex effect of activation of physiological processes in plants, stimulating the photosynthetic activity and accumulation of photosynthetic pigments by recording a 22.7% increase in chlorophyll-a and 18.6% in carotenoids content in fresh leaves. Nitrate accumulation recorded 792.3 mg/100g in ES4 which is 2.7 times higher than the control. Also, an increase in dry matter content by 12.2%, pigments by 16.3%, total antioxidants capacity, a 40% increase in ascorbic acid content were recorded. While only slight increase in total phenolic content was observed in higher concentrations. These overall considerable influences in metabolic activities lead to a better productivity in case of production mass. Further studies should be concerning the effect of 1-ethoxysilatran on other leafy vegetables and prolonging the storage of them.

Summary Lignin is a major component of cell wall biomass and decisively affects biomass utilisation. Engineering of lignin biosynthesis is extensively studied, while lignin modification often causes growth defects.We developed a strategy for cell‐type‐specific modification of lignin to achieve improvements in cell wall property without growth penalty. We targeted a lignin‐related transcription factor, LTF1, for modification of lignin biosynthesis. LTF1 can be engineered to a nonphosphorylation form which is introduced into Populus under the control of either a vessel‐specific or fibre‐specific promoter.The transgenics with lignin suppression in vessels showed severe dwarfism and thin‐walled vessels, while the transgenics with lignin suppression in fibres displayed vigorous growth with normal vessels under phytotron, glasshouse and field conditions. In‐depth lignin structural analyses revealed that such cell‐type‐specific downregulation of lignin biosynthesis led to the alteration of overall lignin composition in xylem tissues reflecting the population of distinctive lignin polymers produced in vessel and fibre cells.This study demonstrates that fibre‐specific suppression of lignin biosynthesis resulted in the improvement of wood biomass quality and saccharification efficiency and presents an effective strategy to precisely regulate lignin biosynthesis with desired growth performance.

Background Catechins are crucial in determining the flavour and health benefits of tea, but it remains unclear that how the light intensity regulates catechins biosynthesis. Therefore, we cultivated tea plants in a phytotron to elucidate the response mechanism of catechins biosynthesis to light intensity changes. Results In the 250 μmol·m− 2·s− 1 treatment, the contents of epigallocatechin, epigallocatechin gallate and total catechins were increased by 98.94, 14.5 and 13.0% respectively, compared with those in the 550 μmol·m− 2·s− 1 treatment. Meanwhile, the photosynthetic capacity was enhanced in the 250 μmol·m− 2·s− 1 treatment, including the electron transport rate, net photosynthetic rate, transpiration rate and expression of related genes (such as CspsbA, CspsbB, CspsbC, CspsbD, CsPsbR and CsGLK1). In contrast, the extremely low or high light intensity decreased the catechins accumulation and photosynthetic capacity of the tea plants. The comprehensive analysis revealed that the response of catechins biosynthesis to the light intensity was mediated by the photosynthetic capacity of the tea plants. Appropriately high light upregulated the expression of genes related to photosynthetic capacity to improve the net photosynthetic rate (Pn), transpiration rate (Tr), and electron transfer rate (ETR), which enhanced the contents of substrates for non-esterified catechins biosynthesis (such as EGC). Meanwhile, these photosynthetic capacity-related genes and gallic acid (GA) biosynthesis-related genes (CsaroB, CsaroDE1, CsaroDE2 and CsaroDE3) co-regulated the response of GA accumulation to light intensity. Eventually, the epigallocatechin gallate content was enhanced by the increased contents of its precursors (EGC and GA) and the upregulation of the CsSCPL gene. Conclusions In this study, the catechin content and photosynthetic capacity of tea plants increased under appropriately high light intensities (250 μmol·m− 2·s− 1 and 350 μmol·m− 2·s− 1) but decreased under extremely low or high light intensities (150 μmol·m− 2·s− 1 or 550 μmol·m− 2·s− 1). We found that the control of catechin accumulation by light intensity in tea plants is mediated by the plant photosynthetic capacity. The research provided useful information for improving catechins content and its light-intensity regulation mechanism in tea plant.

To test the effects of elevated CO2 and soil N deficiency on N resorption efficiency (NRE) from senescing leaves in two non-N2-fixing deciduous broadleaved tree species, Japanese oak (Quercus mongolica var. grosseserrata Blume) and Painted maple (Acer mono Maxim. var. glabrum (Lév. Et Van’t.) Hara), potted seedlings were grown in a natural daylight phytotron with either ambient or elevated CO2 conditions (36 Pa and 72 Pa CO2) and with two levels of N (52.5 and 5.25 mg N pot−1 week−1 for high N and low N, respectively). We examined the N content (Nmass) of mature and senescent leaves, as well as photosynthesis and the growth of plants, and calculated both the mass-based NRE (NREmass) and leaf area-based NRE (NREarea). In both species, the Nmass of mature leaves decreased with high CO2 and low N, whereas the leaf mass per area (LMA) increased under elevated CO2, regardless of N treatments. In Q. mongolica, both the maximum rate of carboxylation (Vcmax) and the maximum electron transport rate (Jmax) were reduced by elevated CO2 and low N, but Vcmax exhibited an interactive effect of N and CO2 treatments. However, in A. mono, both the Vcmax and Jmax decreased under elevated CO2, regardless of N treatments. The partitioning of N for the photosynthetic function within leaves was also significantly decreased by elevated CO2 in both species and increased under low N in A. mono. The Nmass of senesced leaves decreased under low N in both species and exhibited an increase (Q. mongolica) or no effect (A. mono) by elevated CO2. The NREarea of Q. mongolica was affected by CO2 and N treatments, with a decrease under elevated CO2 compared to ambient CO2 and under low N compared to high N. The NREarea of A. mono was also affected by CO2 and N treatments and decreased under elevated CO2, however, unlike in the case of Q. mongolica, it increased under low N. We speculate that these interspecific differences in the responses of leaf N allocation, indicated by the photosynthetic (Vcmax and Jmax) and morphological (LMA) responses to elevated CO2, may have affected the NRE during defoliation under high CO2 and soil N-deficient conditions.

This study investigates potential influence of urban trees on black carbon (BC) removal by Norway spruce and silver birch along with the BC formation, mass concentration in air, and source apportionment. The main sources of BC in urban areas are transport, household and industry. BC concentrations monitored in urban background station in Vilnius (Lithuania) showed that biomass burning was a significant contributor to BC emissions even during warm period of the year. Therefore, BC emission levels were determined for the most common biomass fuels (mixed wood pellets, oak, ash, birch and spruce firewood) and two types of agro-biomass (triticale and rapeseed straw pellets) burned in modern and old heating systems. The highest emissions were obtained for biomass fuels especially birch firewood. BC aerosol particles produced by the condensation mechanism during the combustion processes were found in all samples taken from the leaf surface. The short-term effect of BC exposure on photosynthetic pigments (chlorophyll a and b; and carotenoids) in the foliage of one-year-old Norway spruce and silver birch seedlings was evaluated by the experiment carried out in the phytotron greenhouse. The seedlings showed different short-term responses to BC exposure. All treatments applied in the phytotron greenhouse resulted in lower chlorophyll content in spruce foliage compared to natural conditions but not differed for birch seedlings. However, the exposure of BC particles on the spruce and birch seedlings in the phytotron increased the content of photosynthetic pigments compared to the control seedlings in the phytotron. Overall, urban trees can help improve air quality by reducing BC levels through dry deposition on tree foliage, and needle-like trees are more efficient than broad-leaved trees in capturing BC. Nevertheless, a further study could assess the longer-term effects of BC particles on tree biochemical and chemical reactions.

Air pollutants are emitted from various anthropogenic sources into the atmosphere. Especially, ozone (O3) has become a critical problem since the average O3 concentration is increasing every year by about 0.5–2% across the world. O3 in the air affects plant growth because it mainly passes through the stomata of leaves into plants. This experiment was designed to identify the physiological, morphological, and biochemical responses of plants to O3. For the purposes of this study, eggplant (Solanum melongena L.), which is one of the most well-known crops produced in the world, was used. Eggplants were continuously subjected to 110 nmol mol−1 for 25 days using the phytotron. Following O3 treatment, the growth and biomass of the eggplant were reduced, and the photosynthetic rates were lower than those of the controls. In contrast, water use efficiency increased progressively on the leaves of the eggplant. Initial visible injures were observed at 15 days after O3 treatment. Stomatal density was reduced in response to the O3 treatment. With regard to biochemical responses, malondialdehyde content and relative ion leakage were higher than those of the control. Superoxide and hydrogen peroxide accumulation was observed on the leaf surface after 25 days of O3 treatment. These observations indicate that treatment with 110 nmol mol−1 O3 had negative effects on the physiological, morphological, and biochemical activities of eggplant. Further studies investigating the damage caused by exposure to different concentrations of O3 and for different periods of time are required.

One of major problems of sub-tropical papaya (Carica papaya L.) cultivation is its susceptibility to low temperature. Here, we report the effect of five low temperature regimes on five C. papaya genotypes and one distant relative cold tolerant species Vasconcellea cundinamarcensis, under complete controlled conditions of National Phytotron Facility. The level of low temperature stress perceived by the seedling plants (8-week-old) was quantified by the quantum efficiency of photosystem II (PSII) by measuring the chlorophyll fluorescence (Fv/Fm). The cold tolerant V. cundinamarcensis reflected the most stable Fv/Fm values irrespective of temperature regimes as compared to the other C. papaya genotypes. Induction of cold treatment increased the membrane lipid peroxidation leading to higher malondialdehyde (MDA) content, which could have reduced the membrane stability index (MSI) of the papaya genotypes, which was most pronounced in the genotype Red Lady with 35.71% reduction at 20/10 °C day/night temperature regimes as compared to control. The results suggested a genotype-specific increase in leaf proline content, while the total chlorophyll content and relative water content (RWC) decreased under low temperature regimes as compared to the control. Our results showed that chlorophyll fluorescence, membrane lipid peroxidation and MSI can be used to determine the extent of damage and screening the potential genotypes for cold stress in cultivated species C. papaya.

Withania coagulans is one of the most important medicinal species of the Solanaceae which has pharmacological properties for future research in drug development. Photosynthesis and morphological parameters in response to drought of this species have not been investigated as yet, though the issue is of interest. The factorial combination of four water deficit stress (20% (un-stressed control), 30%, 40% and 50% of FC depletion) and four landraces of W. coagulans (Fanuj, Khash, Saravan and Sarbaz) were laid out in a randomized complete design in a phytotron over the course of 180 days. The first, second, third and fourth samplings were performed every 45 day after imposing the treatments (DAT). The results demonstrated that increase in the water deficit stress levels, decreased minimal fluorescence (F0), leaf greenness, photosynthesis rate, plant height, leaf area, dry weight and quantum yield of PSII photochemistry )ФPSII(in all landraces and maximum photochemical efficiency of PSII (Fv/Fm) in Fanuj, but increased non-photochemical quenching)NPQ(and Fv/Fm in Saravan and Sarbaz landraces. The W. coagulans landraces such as Fanuj with the highest vector loadings of ФPSII at 135 and 180 DAT and Fv/Fm at 45 DAT and Sarbaz with the highest vector loading of F0 at 45 DAT were found suitable for unstressed and severe stress conditions, respectively. Among the chlorophyll fluorescence and morphological parameters, total dry weight had the significant positive correlations with plant height, leaf area and F0 at 45 DAT. Thus, this study indicated chlorophyll florescence should be measured at different phases and future studies should focus on the sensitivity of these parameters to detect potential times among subjects of different stresses. These parameters are easy, cheap, efficient and reliable physiological characteristics which can be used to guide the breeding of new resistant genotypes. According to results, W. coagulans can be called "Xerophytes Camel".

summary Effects of short-term ozone exposure of mature trees were compared with those of seedlings. Both 25-yr-old Douglas firs [Pseudotsuga menziesii (Mirb.) Franco] and 3-yr-old Douglas fir seedlings were exposed to 0, 200 and 400 μgm−1ozone for about 1.5 wk and then labelled with 14CO2 to study the effect on net photosynthesis, translocation and partitioning of assimilates. In the seedling experiment, two identical growth cabinets with separated shoot and root compartments were used for ozone fumigation and 14C-labelling. Seedlings were harvested and HC contents in the needles (subdivided into starch, ethanol-soluble and residue fractions), branches, roots, root/soil respiration and soil residue were determined, together with the total starch content of the needles. Ozone increased the retention of 14C-photosynthates in the needles. Translocation of carbon to the branches and roots seemed to be inhibited by the highest ozone treatment. The increased 14C-retention was mainly recovered in the residue fraction of the needles. Total starch content of the needles decreased in the highest ozone treatment. In the experiment with mature trees, terminal shoots were fumigated with ozone and labelled with 14C using three small branch chambers. Carbon distribution was studied after harvest of the branches. Total 14C contents in the needle fractions and the branches were determined, together with the total starch content of the needles. Ozone was found to inhibit net 14CO2 assimilation as well as translocation of 14C-labelled assimilates from exposed needles to the branch. No effects of ozone were found on the partitioning of 14C among the starch, ethanol-soluble, and residue fractions of the needles, although amounts in the ethanol-soluble fraction tended to increase after exposure to ozone. The results indicate that mature and juvenile Douglas firs respond in a similar way to short-term ozone exposure with regard to carbon translocation. If this similarity also applies to other species, then results from phytotron experiments on ozone and translocation of carbon might gain importance with respect to extrapolation to forest ecosystems.

Several studies have recommended the incorporation of environmental fluctuations in indoor experiments if closer-to-natural results in plant experiments are desired. Previous authors have suggested that if these fluctuations are not applied in synchrony, a stress effect could be present since plants have evolved to cope with synchronic environmental fluctuations. This study aimed to identify the effect of disparity in fluctuations of two important environmental variables, light quantity and temperature, on the growth of seven plant species from different functional plant types. A full-factorial combination of light and temperature under fixed or variable conditions was applied in phytotrons, and plant performance under these conditions was compared with a previous field trial. In all phytotron treatments, the average light and temperature conditions were the same as in the initial field trial. Productivity, leaf gas exchange, chlorophyll fluorescence, pigmentation, and other leaf traits were recorded in all species at the end of the experiments. Most plant trait responses were highly dependent on species and treatment, but some general trends were observed. Light fluctuations were mainly responsible for increases in specific leaf area (SLA) and chlorophyll a concentration, as well as for reductions in total dry weight and chlorophyll a/b ratio, independent if in combination with fluctuation or fixed temperatures. When fixed light conditions were combined with variable temperatures, the plants showed on average lower Fv/Fm values, Amax, and CO2 yield, while under variable light conditions and fixed temperatures, Fv/Fm increased compared with fully fixed or variable conditions. Although significant differences of plant traits between the field trial and all phytotron treatments were present (likely due to differences in other parameters that were not controlled in the phytotrons), our results still suggest that a synchronous variation of environmental factors lead to a more natural-like plant growth than if these factors are fixed or vary asynchronously.

Growth and competitive infection behaviors of two sets of Bradyrhizobium spp. strains were examined at different temperatures to explain strain-specific soybean nodulation under local climate conditions. Each set consisted of three strains—B. japonicum Hh 16-9 (Bj11-1), B. japonicum Hh 16-25 (Bj11-2), and B. elkanii Hk 16-7 (BeL7), and B. japonicum Kh 16-43 (Bj10J-2), B. japonicum Kh 16-64 (Bj10J-4), and B. elkanii Kh 16-7 (BeL7)—which were isolated from the soybean nodules cultivated in Fukagawa and Miyazaki soils, respectively. The growth of each strain was evaluated in YM liquid medium at 15, 20, 25, 30, and 35 °C with shaking at 125 rpm for one week while measuring their OD660 daily. In the competitive infection experiment, each set of the strains was inoculated in sterilized vermiculite followed by sowing surface-sterilized soybean seeds, and they were cultivated at 20/18 °C and 30/28 °C in a 16/8 h (day/night) cycle in a phytotron for three weeks, then nodule compositions were determined based on the partial 16S-23R rRNA internal transcribes spacer (ITS) gene sequence of the isolates from the nodules. The optimum growth temperatures were at 15–20 °C for all B. japonicum strains, while they were at 25–35 °C for all B. elkanii strains. In the competitive experiment with the Fukagawa strains, Bj11-1 and BeL7 dominated in the nodules at the low and high temperatures, respectively. In the Miyazaki strains, BjS10J-2 and BeL7 dominated at the low and high temperatures, respectively. It can be assumed that temperature of soil affects rhizobia growth in rhizospheres and could be a reason for the different competitive properties of B. japonicum and B. elkanii strains at different temperatures. In addition, competitive infection was suggested between the B. japonicum strains.

Soil salinization adversely affects agricultural productivity. Mitigating the adverse effects of salinity represents a current major challenge for agricultural researchers worldwide. The effects of exogenously applied glycine betaine (GB) and salicylic acid (SA) on mitigating sodium toxicity and improving the growth of cotton seedlings subjected to salt stress remain unclear. The treatments in a phytotron included a control (CK, exogenously untreated, non-saline), two NaCl conditions (0 and 150 mM), four exogenous GB concentrations (0, 2.5, 5.0, and 7.5 mM), and four exogenous SA concentrations (0, 1.0, 1.5, and 2.0 mM). The shoot and roots exposed to 150 mM NaCl without supplementation had significantly higher Na+ and reduced K+, Ca2+, and Mg2+ contents, along with lowered biomass, compared with those of CK. Under NaCl stress, exogenous GB and SA at all concentrations substantially inversed these trends by improving ion uptake regulation and biomass accumulation compared with NaCl stress alone. Supplementation with 5.0 mM GB and with 1.0 mM SA under NaCl stress were the most effective conditions for mitigating Na+ toxicity and enhancing biomass accumulation. NaCl stress had a negative effect on plant growth parameters, including plant height, leaf area, leaf water potential, and total nitrogen (N) in the shoot and roots, which were improved by supplementation with 5.0 mM GB or 1.0 mM SA. Supplementation with 5.0 mM exogenous GB was more effective in controlling the percentage loss of conductivity (PLC) under NaCl stress.

Journal of chromatography / A 1652, 462379 (2021). doi:10.1016/j.chroma.2021.462379, Published by Science Direct, New York, NY [u.a.]

Extreme heat-stress events have become more frequent due to climate change often with devastating effects on rice production. Accumulation and translocation of nitrogen (N) in rice organs is an important process that determines rice yield and quality. To assess the effects of short-term heat stress during booting stage on the accumulation and remobilization of N in rice plant organs, a pot-experiment in phytotron chambers was conducted using two cultivars (Nanjing 41 and Wuyunjing 24) at mean temperatures of 27 °C, 31 °C, 35 °C and 39 °C for 2, 4 and 6 days at booting stage. The results showed that high temperatures of 35 °C and 39 °C for 4 and 6 days significantly increased N concentration in leaves, stems, panicles and grains. Severe heat stress strongly reduced N translocation from leaves and stems into grains, resulting in an increased N distribution in stems and leaves. Moreover, N translocation efficiency of the vegetative parts decreased with increasing heat degree-days (HDD), and when HDD > 21.5 °C d, N translocation efficiency was negative, indicating re-accumulation of N in vegetative organs under severe heat stress. N concentration in leaves was positively associated with photosynthetic rate. Dry matter partitioning index of leaves and stems was positively correlated with their N concentration, whereas grain dry matter partitioning index was negatively correlated with grain N concentration. Heat stress reduced the ratio of grain number to leaf area, thereby reducing the proportion of sink to source. These results suggested that the low N translocation efficiency under heat stress could be due to a decrease in sink capacity. Our findings demonstrate that projected climate warming is likely to induce a significant reduction in N accumulation in rice grains by inhibiting the translocation of N from vegetative organs to grains.

The paper presents the results of influence the light of different wavelengths and pulsed electric fields on the content of carotenoids. Seeds germination was carried out in a climatic chamber with phytotron system. The experiment was carried out under seven growing conditions differing in light-emitting diode (LED) wavelengths and using pulsed electric fields (PEFs) with different strength applied before sowing. Cultivation of the sprouts was carried out for seven days at relative humidity 80% and 20 &plusmn, 1 &deg, C. Different light wavelengths were used during cultivation: white light (380&ndash, 780 nm), UVA (340 nm), blue (440 nm), and red (630 nm). In addition, the pulsed electric field (PEF) with three values of strength equal to 1, 2.5 and 5 kV/cm, respectively, was applied to three series of sprouts before sowing. Sprouts treated with the PEF were grown under white light (380&ndash, 780 nm). The light exposure time for all experimental series of sprouts was 12 / 12 h (12 h light, 12 h dark for seven days). Lutein is the dominant carotenoid in germinating red clover seeds, the content of which varies from 743 mg/kg in sprouts grown in red light, 862 mg/kg in sprouts grown in UVA, to 888 mg/kg in sprouts grown in blue light. Blue light in the cultivation of red clover sprouts had the most beneficial effect on the increase of carotenoids content and amounted to 42% in &beta, carotene, 19% in lutein, and 14% in zeaxanthin. It confirms that modelling the content of carotenoids is possible using UVA and blue light (440 nm) during seed cultivation. An increase in the content of &beta, carotene and lutein in red clover sprouts was obtained in comparison to the test with white light without PEF pre-treatment, respectively by 8.5% and 6%. At the same time a 3.3% decrease in the content of zeaxanthin was observed. Therefore, it can be concluded that PEF pre-treatment may increase mainly the content of &beta, carotene.

Fertility management techniques being promoted in sub-Saharan Africa (SSA) seek to grow indigenous vegetables economically and sustainably. This study was conducted in a phytotron chamber and compared yield, soil carbon (C) speciation and greenhouse gas (nitrous oxide (N2O) and carbon dioxide (CO2)) emissions from SSA soils of two ecoregions, the dry savanna (lna, Republic of Benin) and rainforest (Ife, Nigeria) cultivated with local amaranth (Amaranthus cruentus) under manure (5 t/ha) and/or urea (80 kg N/ha) fertilization. Vegetable yield ranged from 4331 kg/ha to 7900 kg/ha in the rainforest, RF, soils and 3165 kg/ha to 4821 kg/ha in the dry savanna, DS, soils. Yield in the urea treatment was slightly higher compared to the manure, and manure+urea treatment, but the difference was not statistically significant. Cumulative CO2 emissions over 21 days ranged from 497.06 to 579.47 g CO2-C/kg soil/day in the RF, and 322.96 to 624.97 g CO2-C/kg soil/day in the DS, while cumulative N2O emissions ranged from 60.53 to 220.86 mg N2O-N/kg soil/day in the RF, and 24.78 to 99.08 mg N2O-N/kg soil/day in the DS. In the RF samples, when compared to the use of urea alone, the combined use of manure and urea reduced N2O emissions but led to an increase in the DS samples. ATR-FTIR analysis showed that the combined use of manure and manure+urea increased the rate of microbial decomposition in the soils of the DS, but no such effect was observed in soils of the RF. We conclude that combining manure and urea fertilization has different effects on soils of the two ecoregions, and that RF farmers can reduce agricultural N2O emissions without compromising soil productivity and yield potential.

Isoprene emissions from six tropical trees were evaluated by “Ping-Pong” method that iteratively optimized the temperature (CT) and light (CL) parameters of the Guenther model, G-93. Six tropical trees; Bauhinia variegate (camel's foot tree), Calophyllum inophyllum (ball tree), Garcinia subelliptica (fukugi tree), Syzygium cumini (black plum), Syzygium samarangense (wax jambu), and Mangifera indica (mango; red and yellow fruit) were exposed to LED light in a phytotron. Saplings of Populus nigra were similarly treated under the same experimental conditions for reference. The irradiance protocol consisted of 26 steps and two cycles of increase and decrease in light intensity. Plants were exposed to a wide variation in light intensity (200–1500 μmol/m2/s), which resulted in leaf temperature variation of 29–40 °C. Predictions of isoprene emission by the optimized G-93 well captured the light and temperature dependent increase and decrease of isoprene emission rate in all tropical trees assessed. Comparatively, G-93 with default parameters showed lower efficacy in predicting emission rates during the ascending phase in the initial round, and at the peak phase in the second round of the irradiation scheme. G-93 with default parameters overestimated emissions at the initial ascending phase and underestimated at the second peak phase. Calculated Q10 values for isoprene emission from tropical trees were much higher than that of the temperate plant P. nigra under same observational conditions. These results strongly imply that isoprene emission behavior of tropical plants deviate from that of temperate plant.

Seedlings of Pterocarpus indicus were grown in both well-watered and drought stress conditions in phytotron. Seedlings grown under well-watered and drought stress conditions were exposed to either combined or without ozone of 200 ppb for one month. First, the physiological responses to elevated ozone levels indicated a decreased biomass. The seedlings grown in arid soil and exposed to ozone showed less biomass than those grown in arid soil but not exposed to ozone. Moreover, all the seedlings except the well-watered and unexposed ones showed a significantly lower photosynthetic rate (PN) over time. However, with the accumulation of ozone injuries, the antioxidant enzyme activities increased overall. In the study results, when exposed to ozone, the well-watered seedlings exhibited more antioxidative enzyme activity than did the seedlings grown in arid soil. Generally, P. indicus in arid soil suffered less damage from elevated ozone than did the well-watered plants.

Pre-sowing seed treatment by various energy methods is used as an effective way of stimulating the seed material. (Research purpose) The authors have studied the effect of a low-frequency electromagnetic field on the seed properties of sunflower (Helianthus), soybean (Glycine max) and maize (Zea mays L.) seeds. (Materials and methods) Parameters of the electromagnetic field: induction of 16 mT, pulse repetition rate of 16 Hertz I; exposure time of 15 and 20 minutes. The experiment has been conducted in two stages. The first stage is the determination of the germination and germination energy of irradiated and non-irradiated seeds, as well as the biometric characteristics of seedlings: the mass of stems and leaves, the length and mass of the root system. The second stage is the phenological observations of the growth and development of plants according to the phases of their development in the VIM climatic chamber. (Results and discussion) It has been shown that the sowing qualities of maize seeds after 15 min of irradiation are higher than the control ones. It has been determined that germination energy has increased by 10 percent as compared to the control sample, germination by 8 percent, seedling weight by 6.4 percent, weight of stems and leaves by 16, root system by 3.4 and stem height by 30 percent. It has been found that there is no influence of low-frequency electromagnetic radiation on the germination of soybeans both in the laboratory and in the climate chamber. It has been found that at the end of the growing season, the mass of plants irradiated for 20 minutes has turned out to be greater than the control values by 20%, the root mass by 25%, and the root length by 16%. The authors have determined that the treatment of sunflower seeds (Helianthus) with a low-frequency electromagnetic field has no stimulating effect on germination energy and germination capacity, but contributes to an increase in the mass of plants when they are grown in a phytotron. It has been calculated that a 15-minute irradiation of sunflower seeds before sowing resulted in an increase in the mass of plants by 34.9%; the mass of the root system – by 22%; length of roots – by 3.65%; the head (anthodium) diameter – by 5.3% and their weights – by 25.3 %. (Conclusions) The response of plants to the energy impact depends on the type of crop. It has been determined that low-frequency magnetic radiation without changing the sowing properties of seeds can positively influence the growth and development of plants.

Ammonium sulfate (AS) particles of submicron size are a major component of inorganic aerosol, and are regarded as a long-range transboundary air pollutant in Asia. However, only a few studies have focused on the effects of submicron AS particles on plants. In the present study, we investigated the amount of submicron AS particles deposited on the leaf surface of komatsuna plants (Brassica rapa L. var. perviridis), and their effects on nocturnal leaf (gnight) and cuticular (gcut) conductance. The plants were grown for 23 days after sowing in a naturally lit phytotron at air temperature of 25.0 ± 1.0 °C/18.0 ± 1.0 °C (6:00–18:00/18:00–6:00) and relative air humidity of 70 ± 5%, and were artificially exposed to submicron AS particles at the 21st day after sowing. The exposure to submicron AS particles resulted in average daily atmospheric concentration of SO42− in PM2.5 inside the phytotron of 16.5 μg m−3. After the end of exposure, the plants were kept under light or dark conditions for 48 h in the phytotron. The amount of SO42− deposited on the leaf surface reduced over time, but did not significantly differ between the plants kept under light and dark conditions at 0, 6, 12, 18, 30, and 48 h after the end of exposure. An exposure to submicron AS particles with average daily atmospheric concentration of SO42− in PM2.5 inside the phytotron of 24.7 μg m−3 did not significantly affect the gcut of the plants. At 1.5 and 5 h after the end of exposure, the gnight was significantly higher in the submicron AS particle-exposed plants than in the non-exposed control plants. These results indicate that submicron AS particles deposited on the leaf surface enhance the nocturnal water consumption of komatsuna plants.

It is very significant to study the impact of deficit irrigation on crop growth and water use under the future scenarios with elevated CO2 concentrations and reduced water availability. This study investigated the growth and yield differences of maize grown in a phytotron in response to elevated CO2 concentrations under different irrigation treatments. Two irrigation treatments were carried out: regular irrigation (RI) and deficit irrigation (DI), in which the irrigation amounts were respectively 100 and 70% of evapotranspiration (ET), with four CO2 concentrations (400, 550, 700, and 900 μmol mol−1). Thus eight treatments, i.e. RI400, RI550, RI700, RI900, DI400, DI550, DI700, and DI900 were included in this study. Results show that, the relative reductions of stomatal conductance (gs) and transpiration rate (Tr) in response to elevated CO2 concentrations were higher under DI than RI, thus causing leaf temperature (Tleaf) rose higher under DI due to the transpiration cooling effect. As photosynthetic rate (Pn) and its physiological process were positively correlated with Tleaf, the relative increases of Pn and the resulting maximum leaf area index (LAImax), total dry matter weight (TDW), and grain yield (GY) react to elevated CO2 concentrations were higher under DI than RI, as well as the leaf water use efficiency (WUEL) and water productivity (WP). The DI900 treatment in which the irrigation amount was reduced by 30% only decreased the TDW and GY by 7 and 5% when compared with RI900. The variation of GY was consistent with the variation of kernels per ear (KPE), but was not directly related to hundred-grain weight (HGW). The above results show that when atmospheric CO2 concentrations rise in the future, deficit irrigation would be an effective way of saving water and would not only have a mitigating effect on water crises, but would also contribute to improving WP, which is more important in terms of actual production.

This article presents comparative data regarding the effect of foliar application of silicon dioxide and organosilicon compounds on soilless-grown Oak leaf lettuce (Lactuca sativa var. crispa). Data were derived from dry and fresh samples. Total nitrogen, total antioxidants capacity, total phenolic content, ascorbic acid, total pigments concentrations and growth parameters varied in response to the concentrations of the used preparations (silicon dioxide and organosilicon compounds). Capillary zone electrophoresis, spectrophotometry and coulometric analyzer were the principal involved methods. Data of total phenolic content, antioxidants capacity and ascorbic acid concentrations can provide physiological health benefits as functional foods along with an insight to plant stress physiology. Chlorophyll a and b concentrations, nitrogen content, dry matter content, plant height and fresh weights contribute to the understanding of physiological and biometric plants growth parameters.

To elucidate changes in the defensive traits of tree seedlings under global environmental changes, we evaluated foliar defensive traits of the seedlings of successional trees, such as beech, oak, and magnolia grown in a natural-light phytotron. Potted seedlings were grown under the combination of two CO2 concentrations (360 vs. 720 ppm) and two nitrogen (N) treatments (4 vs. 15 kg N ha−1 yr−1) for two growing seasons using quantitative chemical analyses and anatomical method. We hypothesized that the effects of CO2 and N depend on the successional type, with late successional species providing greater defense of their leaves against herbivores, as this species exhibits determinate growth. Beech, a late successional species, responded the most to both elevated CO2 concentration (eCO2) and high N treatment. eCO2 and low N supply enhanced the defensive traits, such as the high leaf mass per area (LMA), high carbon to N ratio (C/N ratio), and increase in the concentrations of total phenolic and condensed tannin in agreement with the carbon–nutrient balance (CNB) hypothesis. High N supply decreased the C/N ratio due to the high N uptake in beech leaves. Oak, a mid–late successional species, exhibited different responses from beech: eCO2 enhanced the LMA, C/N ratio, and concentration of total phenolics of oak leaves, but only condensed tannin increased under high N supply. Magnolia did not respond to all treatments. No interactive effects were observed between CO2 and N supply in all species, except for the concentration of total phenolics in oak. Although the amounts of phenolic compounds in beech and oak varied under eCO2 and high N treatments, the distribution of these compounds did not change. Our results indicate that the changes in the defensive traits of forest tree species under eCO2 with N loading are related to the successional type.

Climate change scenarios project an increase in the frequency of heat stress events, making it critical to quantify adverse heat stress effects on wheat production. Biomass growth determines much of grain yield in winter wheat, but it is substantially reduced under heat stress during the reproductive phase. In this study, leaf photosynthesis, biomass production, and leaf area index (LAI) dynamics were measured under various heat stress treatments in a 4-year phytotron experiment with two winter wheat cultivars. Heat stress at anthesis and during grain filling accelerated the measured degradation of leaf chlorophyll (SPAD) and resulted in a lower leaf photosynthesis rate with decreased final biomass growth. The observed relationships between leaf photosynthesis, LAI, and high temperatures were integrated into the WheatGrow model. In this study, we introduced a new cultivar parameter into the model to simulate cultivar difference in the sensitivity of biomass growth to heat stress. The new heat stress routines in the WheatGrow model significantly improved the simulated growth dynamics and the root mean square error (RMSE) with an independent validation data set for LAI and final aboveground biomass by 40% and 57% under heat stress treatments, respectively. This improvement in the crop model WheatGrow enables more reliable studies on climate change impacts and reduces uncertainties in simulations, particularly the impacts of extreme temperature events on crop growth and yields.

The behaviour of Myrothecium roridum, artificially inoculated on cultivated rocket (Eruca sativa), has been evaluated under eight different temperature and CO2 concentration combinations (from 14-18 °C to 26-30 °C and with 400-450 or 800-850 ppm of CO2). The pathogen isolate used for this study was inoculated on rocket and disease severity increased with high temperatures for both CO2 levels. Verrucarin A and roridin E mycotoxins were produced under all the tested temperatures at high CO2 conditions. The maximum level of verrucarin A was found at 14-18 °C and 800-850 ppm of CO2, and the maximum roridin E production was detected at 26-30 °C with 800-850 ppm of CO2. The results obtained in this study show that both the CO2 concentration and the temperature influence disease severity and mycotoxin production in different ways. An increase in temperature, which is favourable for attacks of the pathogen, could induce the spread of M. roridum in temperate regions, and this pathogen could take on even greater importance in the future, considering its ability to produce mycotoxins.

Climate change has brought more low temperature events and posed an increasing risk to the global wheat production. In order to evaluate the effects of low temperature at jointing and booting stages on wheat grain yield and its components, two years of environment-controlled phytotron experiments were carried out with two wheat cultivars under different low temperature levels and durations. Low temperature level and its interaction with low temperature duration had negative effects on the observed grain yield in two cultivars. Moreover, wheat yield was more sensitive to low temperature at booting than at jointing stages. Compared with the control treatment (T min /T max /T mean of 6 °C/16 °C/11 °C, T1), 4.6%–56.4% and 3.1%–44.6% decreases of grain yield per plant (YPP) were observed under low temperature at jointing in Yangmai16 (spring wheat) and Xumai30 (semi-winter wheat), and 13.9%–85.2% and 3.2%–85.9% decreases under low temperature at booting in Yangmai16 and Xumai30, respectively. The spike number per plant (SNPP) and grain number per spike (GNPS) were more sensitive to low temperature at jointing and booting stages than 1000-grain weight (TGW). Furthermore, significant negative linear relationships were observed between the accumulated cold degree days (ACDD) and YPP, SNPP, GNPS and TGW in both cultivars. The contribution of GNPS to the variation of YPP was greater than SNPP and TGW at the mild low temperature level (T min /T max /T mean of −2 °C/8 °C/3 °C, T3) in both cultivars. However, at the extreme low temperature level (T min /T max /T mean of −6 °C/4 °C/−1 °C, T5), the major variation of YPP was caused by SNPP of Yangmai16 and GNPS of Xumai30. In general, the decreased YPP under low temperature condition was mainly from the decreased grain number per plant (GNPP = SNPP × GNPS) in both cultivars and treatment stages, thus maintaining a high GNPP is very important for compensating the yield losses caused by low temperature at jointing and booting stages.

Background: Vegetable growers in Arctic areas must increasingly rely on market strategies based on regional origin and product quality. Swede roots (rutabaga) were grown in a phytotron to investigate the effect of high latitude light conditions on sensory quality and some health and sensory-related compounds. Experimental treatments included modifications of 24 h natural day length (69° 39' N) by moving plants at daily intervals to dark chambers with either no light, fluorescent growth light and/or low intensity photoperiod extension.; Results: Shortening the photosynthetic light period to 12 h produced smaller roots than 15.7 h and 18 h, with highest scores for bitter and sulfur taste, and lowest scores for sweetness, acidic taste and fibrousness. The photoperiod in combination with the photosynthetic light period also had an influence on glucosinolate (GLS) contents, with lowest concentrations in 24 h natural light and highest in 12 h natural light. Concentrations of vitamin C, glucose, fructose and sucrose were not significantly influenced by any of the treatments.; Conclusion: High latitude light conditions, with long photosynthetic light periods and 24 h photoperiod, can enhance sweet/less bitter taste and reduce GLS contents in swede roots, compared to growth under short day conditions. This influence of light conditions on eating quality may benefit marketing of regional products from high latitudes. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

To counter the threat of drought, which is expected to increase in the future, we analyzed the combined effects of elevated carbon dioxide (CO2) concentration and drought on the photosynthetic apparatus and morphological traits in seedlings of yellow poplar (Liriodendron tulipifera). The plants were grown for four months in a phytotron under different CO2 concentrations [ambient CO2, 430 ppm, AC) and elevated CO2, 640 ppm, EC] and water treatment [field capacity, FC and 50% of field capacity, FC50]. FC50 was sufficient for inducing a reduction in the photosynthetic rate of L. tulipifera. However, under FC50 combined with EC, we observed an increase in photosynthetic rate with increased photopigment content, photochemistry efficiency, and light harvesting ability. Further, decreased specific leaf area and increased wax coverage in EC suggested that EC contributed to protect chloroplasts and reduce water loss. In conclusion, functional improvements of the photosynthetic apparatus with changes in morphological traits were observed under FC50 combined with EC and EC ameliorated the adverse effect of FC50 on the seedlings of L. tulipifera.

We aimed to evaluate the effects of light spectral components on the phenolic compounds in young and mature green and red perilla leaves seeking to raise plants with increased antioxidant and nutritional value. Plants were cultivated in phytotron (21/17°C) under experimental light emitting diode (LED) based lighting (18 h, 300 µmol m-2 s-1) the whole 30 days growth cycle (long-term exposure) or transferred from high pressure sodium lighting to experimental LED lighting for the last 3 days of experiment (short-term exposure). Experimental lighting spectra consisted of sole red 638 or 665 nm LED light (300 µmol m-2 s-1) or the combination of red 665 nm with 50 µmol m-2 s-1 of blue 455, yellow 595, green 520 nm or 15 µmol m-2 s-1 of UV-A 385 nm light (total PPFD of 300 µmol m-2 s-1 maintained). Sole red light promoted accumulation of phenolic compounds in young red and green perilla leaves both after short-term and long-term exposure, when supplemental blue light had significant effect only in mature leaves. In young green perilla leaves higher contents of phenolic compounds were determined after short-term UV-A exposure. The higher contents of phenolic compounds under different light spectra exposure correlates with higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity after long-term exposure in green perilla and both after long and short-term exposure in red perilla leaves.

[object Object]The work continues serial studies on short-term effects of medium-wave ultraviolet radiation (UV-B) at 12.5 kJ/m2 on plants. Special attention is paid to the rapid response of the antioxidant system. Free and conjugated forms of putrescine polyamines (putrescine, spermine, and spermidine), as well as those of cadaverine, are recognized to be constituents of the antioxidant system. These compounds were analyzed in plants 24 h after UV-B irradiation. Thellungiella salsuginea (Pallas) O.E.Schulz, Salvia officinalis L, Plantago major L., and Geum urbanum L. grown in aquatic culture under phytotron conditions were examined. The results support the hypothesis that putrescine plays the chief role in the plant defense response against medium-wave ultraviolet irradiation. Three of four plants manifested an increase in the content of this polyamine in leaves. It is the change that determines the enhanced total level of free polyamines. We failed to reveal a general tendency in dynamics of levels of conjugated forms of spermine, spermidine, and cadaverine; only conjugates of putrescine demonstrated a distinct increase. This study allows a conclusion that contributions of particular polyamines to the protective response primarily depend on the species to which the investigated plant belongs. It is likely that conjugated polyamines can be reserved as a pool necessary for rapid recovery of free polyamine levels.

Ex-situ cultivation of biological soil crusts (biocrusts) is a promising technology to produce materials that can induce the recovery of biocrusts in the field for the purposes of preventing soil erosion and improving hydrological function in degraded ecosystems. However, the ability of artificially cultivated biocrusts to survive under adverse field conditions, including drought and heat stresses, is still relatively unknown. Mosses can bolster biocrust resistance to the stresses (e.g., drought and heat) and the resistance may be introduced prior to field cultivation. In this study, we subjected the well-developed artificial moss biocrusts (dominant species of Didymodon vinealis (Brid.) Zand.) that we cultivated in the phytotron to a dehydration-rehydration experiment and also a heat stress experiment and measured the activities of protective enzymes (including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT)) and the contents of osmoregulatory substances (including soluble proteins and soluble sugars) and malondialdehyde (MDA, an indicator of oxidative stress) in the stem and leaf fragments of mosses. The results showed that, during the dehydration process, the activities of protective enzymes and the contents of osmoregulatory substances and MDA gradually increased with increasing duration of drought stress (over 13 days). During the rehydration process, values of these parameters decreased rapidly after 1 d of rehydration. The values then showed a gradual decrease for 5 days, approaching to the control levels. Under heat stress (45°C), the activities of protective enzymes and the content of soluble proteins increased rapidly within 2 h of heat exposure and then decreased gradually with increasing duration of heat exposure. In contrast, the contents of soluble sugars and MDA always increased gradually with increasing duration of heat exposure. This study indicates that artificial moss biocrusts possess a strong drought resistance and this resistance can be enhanced after a gradual dehydration treatment. This study also indicates that artificial moss biocrusts can only resist short-term heat stress (not long-term heat stress). These findings suggest that short-term heat stress or prolonged drought stress could be used to elevate the resistance of artificial moss biocrusts to adverse conditions prior to field reintroduction.

Mangrove is one of the dominant plants in tropical and sub-tropical estuarine ecosystems. The understanding of growth and nitrogen (N) assimilation rates of mangrove at different water salinities can be beneficial for evaluating the response of mangroves to increased anthropogenic N loading into these systems. We investigated the effect of salinity on growth and N assimilation of Kandelia candel (L) Druce under the phytotron conditions at alternating temperatures of 25 °C (day) and 20 °C (night) with 16-h light at ∼300 μmol photons m−2 s−1. The experiment included four salinity treatments (0, 8.8, 17.5 and 35 psu) and two N sources (NO3− and NH4+). With increasing salinity, mangrove shoot and root biomass decreased, but its hypocotyl biomass increased. Thus, the total biomass yield of mangrove remained unchanged in different salinity treatments. Nevertheless, N assimilation rate measured by the 15N stable isotope technique was significantly reduced from about 2.2 mg N g−1 biomass hr−1 under control conditions (0 psu) to 0.9 mg N g−1 biomass hr−1 under 35 psu. Mangrove favored nitrate than ammonium at low salinity (0 psu), but preferred NH4+ to NO3− at higher salinity (17.5 and 35 psu).

The multifunctional use of macrophytes including production of biofuels, reduction of post-industrial waste, animal feed, phytoremediation and bioindication of toxicity, are developing directions that support the energy industry, including RES. The ash from Sorghum contains large amounts of macroelements, including phosphorus, nitrogen, potassium, calcium, as well as many micronutrients. The aim of the research was to determine the possibility of using ash from Sorghum as a media supplement for the cultivation of aquatic macrophytes. Plant cultivation was carried out in a phytotron room at 24 °C, 40 W light on a liquid medium supplemented with various concentrations of ash coming from the Sorghum combustion and control series. For all experimental series, Lemna minor L. plant growth analysis was performed by counting the number of fronds, determination of chlorophyll index, gas exchange (net photosynthesis, transpiration, stomatal conductivity of the cells and intercellular CO2 concentration), chlorophyll fluorescence, fresh and dry mass of plants as well as of important physical and chemical parameters of the medium i.e. COD, PO43− phosphates, NO3− nitrates. The energy value for L. minor L. biomass was determined. The experiments showed high sensitivity of plants grown on a medium supplemented with different concentrations of Sorghum ash compared to the control series, and depending on the concentration, the plant biomass increased proportionally. The medium supplemented with ashes was characterized by high physico-chemical parameters. The above studies indicate the possibility of using waste ashes and their management in supplementation of breeding media for macrophytes Lemnaceae, which constitute a new source of energy biomass.

Chilling stress has a strong negative impact on the growth and development of winter wheat (Triticum aestivum L.). To investigate the recovery of physiological function and yield formation by plant growth regulators following chilling stress, we performed low-temperature phytotron experiments at the booting stage, and sprayed 6-benzylamino adenine (6-BA), salicylic acid (SA), brassinolide (BR) and abscisic acid (ABA) after chilling stress. Plant growth regulators significantly enhanced SPAD value and net photosynthetic rate (Pn) in flag leaves following chilling stress (p

Introduction Blackcurrant (Ribes nigrum L.) is an excellent example of a “super fruit” with potential health benefits. Both genotype and cultivation environment are known to affect the chemical composition of blackcurrant, especially ascorbic acid and various phenolic compounds. Environmental conditions, like temperature, solar radiation and precipitation can also have significant impact on fruit chemical composition. The relevance of the study is further accentuated by the predicted and ongoing changes in global climate. Objectives The aim of the present study was to provide new knowledge and a deeper understanding of the effects of post flowering environmental conditions, namely temperature and day length, on fruit quality and chemical composition of blackcurrant using an untargeted high performance liquid chromatography–photo diode array–mass spectrometry (HPLC–PDA–MS) metabolomics approach. Methods A phytotron experiment with cultivation of single-stemmed potted plants of blackcurrant cv. Narve Viking was conducted using constant temperatures of 12, 18 or 24 °C and three different photoperiods (short day, short day with night interruption, and natural summer daylight conditions). Plants were also grown under ambient outdoor conditions. Ripe berries were analysed using an untargeted HPLC–PDA–MS metabolomics approach to detect the presence and concentration of molecules as affected by controlled climatic factors. Results The untargeted metabolomics dataset contained a total of 7274 deconvolved retention time-m/z pairs across both electrospray ionisation (ESI) positive and negative polarities, from which 549 metabolites were identified or minimally annotated based upon accurate mass MS. Conventional principal component analysis (PCA) in combination with the Friedman significance test were applied to first identify which metabolites responded to temperature in a linear fashion. Multi-block hierarchical PCA in combination with the Friedman significance test was secondly applied to identify metabolites that were responsive to different day length conditions. Temperature had significant effect on a total of 365 metabolites representing a diverse range of chemical classes. It was observed that ripening of the blackcurrant berries under ambient conditions, compared to controlled conditions, resulted in an increased accumulation of 34 annotated metabolites, mainly anthocyanins and flavonoids. 18 metabolites were found to be regulated differentially under the different daylength conditions. Moreover, based upon the most abundant anthocyanins, a comparison between targeted and untargeted analyses, revealed a close convergence of the two analytical methods. Therefore, the study not just illustrates the value of non-targeted metabolomics approaches with respect to the huge diversity and numbers of significantly changed metabolites detected (and which would be missed by conventional targeted analyses), but also shows the validity of the non-targeted approach with respect to its precision compared to targeted analyses. Conclusions Blackcurrant maturation under controlled ambient conditions revealed a number of insightful relationships between environment and chemical composition of the fruit. A prominent reduction of the most abundant anthocyanins under the highest temperature treatments indicated that blackcurrant berries in general may accumulate lower total anthocyanins in years with extreme hot summer conditions. HPLC–PDA–MS metabolomics is an excellent method for broad analysis of chemical composition of berries rich in phenolic compounds. Moreover, the experiment in controlled phytotron conditions provided additional knowledge concerning plant interactions with the environment. Electronic supplementary material The online version of this article (10.1007/s11306-018-1462-5) contains supplementary material, which is available to authorized users.

Extremely high temperature decreases grain yield and grain quality in rice (Oryza sativa L.). To investigate the effects of short-term post-anthesis high-temperature stress on accumulation of grain protein and protein compositions in rice, 2-year experiments were carried out in phytotron with two different cultivars, Nanjing 41 (NJ41, heat-sensitive) and Wuxiangjing 14 (WJ14, heat-tolerant), under different conditions of high-temperature levels and durations during anthesis and grain-filling stages. The results showed that grain protein content and its components (albumin, globulin, and glutelin) increased with rising temperature levels and durations, while prolamin content decreased. The contents of total protein, storage protein, albumin, globulin, and prolamin in NJ41 were more sensitive to different temperature levels than those in WJ14. Moreover, the contents of albumin and prolamin in NJ41 changed greater under temperature durations than those in WJ14. The effects of high-temperature stress on accumulation of grain protein and composition were more sensitive to high-temperature levels and durations during anthesis stage than those during grain-filling stage. The results could help us further understand the physiochemical processes governing rice yield and quality under high-temperature conditions during rice anthesis and grain-filling stages.

BACKGROUND Marked effects of the climatic environment on fruit chemical composition have often been demonstrated in field experiments. However, complex covariations of several climatic factors in the natural environment complicate the interpretation of such experiments and the identification of the causal factors. This can be better achieved in a phytotron where the various climatic factors can be varied systematically. Therefore, we grew four black currant cultivars of contrasting origin in a phytotron under controlled post-flowering temperature and photoperiod conditions and analysed the berries for their ascorbic acid, sugar and organic acid contents. RESULTS The analyses revealed significant effects of genotype on all investigated compounds. Particularly large cultivar differences were observed in the concentrations of l-ascorbic acid (AA) and sucrose. The concentrations of both AA and dehydroascorbic acid (DHAA), as well as the concentrations of all major sugars, decreased consistently with an increasing temperature over the temperature range 12–24 °C. Fructose and glucose were the predominant sugars with concentrations several fold higher than that for sucrose. AA was the main contributor to the total ascorbate pool in black currant berries. The AA/DHAA ratio varied from 5.6 to 10.3 among the studied cultivars. The concentration of citric acid, which was the predominant organic acid in black currant berries, increased with an increasing temperature, whereas the opposite trend was observed for malic and shikimic acid. Quninic acid was always present at relatively low concentrations. By contrast, photoperiod had no significant effect on berry content of any of the investigated compounds. CONCLUSION It is concluded that the post-flowering temperature has marked effects on the concentration of important chemical compounds responsible for taste and nutritional value of black currant berries, whereas photoperiod has no such effect in the studied cultivars. © 2016 Society of Chemical Industry

The effects of postflowering temperature and daylength on the concentration of individual phenolic compounds were studied in black currant (Ribes nigrum L.) berries under controlled phytotron conditions. The four cultivars studied varied greatly in their concentrations of individual phenolic compounds and temperature stability for accumulation. The concentrations of a wide range of identified phenolic compounds were strongly influenced by temperature over the 12-24 °C range, often with opposite temperature gradient patterns for compounds within the same subclass. Accumulation of anthocyanins and flavonols increased under natural long day conditions, which provided an increased daily light integral, while under identical light energy conditions, photoperiod had little or no effect on the concentration of phenolic compounds. Furthermore, with the exception of members of the hydroxycinnamic acid subclass, the concentration of most phenolic compounds was higher in berries ripened outdoors than in the phytotron, apparently due to screening of UV-B radiation by the glass cover.

Low temperature greatly affects wheat production, while low-temperature pretreatments may enhance plant tolerance to subsequent low-temperature stress. However, the knowledge on grain yield formation responses to multiple low-temperature stresses under natural conditions is still limited. Here, two years of environment-controlled phytotron experiments were carried out with two wheat cultivars under different low-temperature levels, periods and frequencies, and the temperature regimes in this study were designed to be similar to the daily variation in natural temperature. Spring frost (canopy temperature fall below 0 °C or Stevenson screen air temperatures below 2 °C) had negative effects on grain yield and yield components for both cultivars. Moreover, wheat yield was more sensitive to low temperatures at booting than at jointing. The reduction in grain yield under low-temperature conditions was mainly attributed to the decreased spike number per plant (SNPP) and grain number per spike (GNPS). Furthermore, grains in the apical spikelets were the most sensitive to spring frost, followed by those in the basal and central spikelets. Compared to the non-low-temperature-pretreated plants, the low-temperature-pretreated plants did not have an increased grain yield, except at T4 (Tmin/Tmax/Tmean, −6 °C/4 °C/−1 °C). Grain yield under T4 probably increased because severe low temperatures killed parts of the tillers, which resulted in carbon and nitrogen relocation to the roots, young tillers and axillary buds. As a result, the young and new tillers in the axillary buds grew rapidly and eventually formed spikes.

There was studied impact of the bitter almond seeds preliminary steeping on the development of plants at the first stages of development in conditions of saline waters irrigation in the greenhouse experiment ambient in phytotron. It was established that steeping the seeds in excessive salt solution results in enhanced plants tolerance to the soil salinization and saline waters irrigation. This is evidenced by the obtained regularities of influence on the development of plants of biochemical character (content of proline, chlorophyll and carotinoids, total carbon); chemical (content of basic chemical elements); morphological (rate of the plants height and stalk diameter growth, leaf-area duration). The introduction of developed technology into nursery science will permit to improve the tolerance of seedlings to salinization of soils and irrigation waters.

In constructed wetlands (CWs) with forced aeration and vertical flow, plants can suffer from iron (Fe) deficiency due to Fe immobilization in the gravel substrate as a consequence of the oxic condition. The common reed (Phragmites australis) is the most commonly used plant species in CWs and frequently displays Fe-deficiency symptoms particularly in new-established systems. The aim of this study was therefore to study the Fe-nutrition of P. australis in order to gain knowledge on how Fe-deficiency in P. australis can be alleviated. For this purpose, we grew two genetically distinct phylogeographic groups of P. australis hydroponically with seven different Fe concentrations (0, 0.1, 0.2, 0.5, 1.0, 5.0 and 20.0 mg Fe-EDDHA ([iron (3+) ethylenediamine di (o-hydroxyphenylacetic) acid]) L−1) in a phytotron. Both groups responded strongly to the increasing Fe supply. The belowground biomass allocation ratio, light-saturated photosynthesis rates, chlorophyll content and leaf Fe tissue concentration all significantly increased with increasing Fe availability. Phragmites australis in the 0 mg Fe-EDDHA L−1 treatment suffered strongly from Fe deficiency, and plants in the high 20.0 mg Fe-EDDHA L−1 treatment also had reduced growth and Fe toxicity symptoms. The ‘critical deficiency concentration’ of Fe in leaves of juvenile P. australis was 40–50 mg kg−1 DM, and the ‘critical toxicity concentration’ of Fe in leaves of juvenile P. australis were approximately 150 mg kg−1 DM. Overall the two genetically distinct P. australis groups differed in their ecophysiological traits, and the two groups also responded differently to the different Fe-supply rates which may be the result of adaptations obtained in their native growth habitats. We suggest that the Fe-deficiency in CW systems with unsaturated vertical flow and/or forced aeration can be alleviated by application of a foliar spray containing chelated iron. However, the application rate and frequency should be further studied.

Most of plant development, physiological and metabolic processes are regulated by not only soluble sugars such as glucose and sucrose, but also by other signal molecules, such as phytohormones. The investigation of flowering induction, considering the influence of vernalisation duration and photoperiod on morphogenesis stages and accumulation metabolites in the two Festulolium cultivars ’Vėtra’ and ’Punia’ was carried out at the phytotron complex of the Plant Physiology Laboratory, Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in 2011-2012. The data revealed impact of vernalisation and photoperiod on accumulation of both types of assessed metabolies, i.e. phytohormones and saccharides, and thus confirmed their substantial role. 90 short-day vernalisation induced the highest total phytohormone content in ‘Vėtra’, when plant achieved tillering stage and was going for intensive growth when growth regulators will be important in the metabolic regulation. The highest phytohormone content was recorded after long –day 130+20 day vernalization at VII and IV organogenesis stages of ‘Vėtra’ and ʽPuniaʼ respectively. Saccharides content significantly depended on photoperiod and temperature during vernalisation and was different in ’Vėtra’ and ’Punia’. Keywords: Festulolium, phytohormones, saccharides Article DOI: http://doi.org/10.15544/RD.2017.003

Wheat (Triticum aestivum L.) known as bread wheat (hexaploid), is an important cereal for millions around the world. Excessive salts in soil affect growth, development and productivity of crop plants and have been major constraints to agriculture. Plants, being sessile in nature, have developed mechanisms to cope with high salt concentrations in soil. To understand salt-tolerance in crop plant and its improvement, Total Phenolic Content (TPC), Lipid Peroxidation (LP), total Antioxidant activity (AO) and high affinity potassium transporters (HKTs) in shoot and root regions of contrasting wheat genotype WH 542 (salt-susceptible) and KRL 210 (salt-tolerant) were studied on seed priming with two different biotic elicitors-Salicylic Acid (SA) and Methyl Jasmonate (MJ). Primed seeds were sown in pots under controlled conditions in phytotron and were exposed to 150 mM NaCl stress after 14 days of germination. Expression pattern of HKT genes in the root and shoot of the primed and unprimed as well as stressed and unstressed seedlings were also studied using semi-quantitative and quantitative analysis. Higher levels of TPC, LP and AO activity were observed in the contrasting wheat genotypes under salt stressed condition. Both HKT1 and HKT3 genes were involved in regulating ion homeostasis. Up and down regulation of expression of HKT genes in shoot and root, respectively, provide resistance against salt uptake. Biotic elicitors (SA and MJ) were found to mitigate the effect of salt-stress by affecting expression of HKT genes as well their biochemical-processes. MJ showed better response than that of SA, and can be utilized to improve defense responses of crop plant against salt stress. The regulation of gene expressions and signaling cascades that regulate Na+ transporters remain to be elucidated and these studies will help in understanding the mechanism of ion homeostasis during salt stress to improve crop yield.

The uranium removal capacity of radish sprouts (Raphanus sativus L.) in groundwater was calculated on the basis of the amount of uranium accumulated in the radish sprouts rather than the concentration in solution, of which process was very limited in previous studies. Continuous rhizofiltration clean-up system was designed to investigate the feasibility of radish sprouts, applying for uranium contaminated groundwater (U concentration: 110 μg/L) taken at Bugogdong, Busan. Six acrylic boxes (10 cm × 30 cm × 10 cm) were connected in a direct series for the continuous rhizofiltration system and 200 g of radish sprouts cultivars was placed in each box. The groundwater was flushed through the system for 48 hours at the constant rate of 5 mL/min. The rhizofiltration system was operated in the phytotron, of which conditions were at 25℃ temperature, 70% of relative humidity, 4,000 Lux illumination (16 hours/day) and 600 mg/L of CO2 concentration. While 14.4 L of contaminated groundwater was treated, the uranium removal efficiency of the radish sprouts (1,200 g in wet weight) was 77.2% and their removal capacities ranged at 152.1 μg/g-239.7 μg/g (the average: 210.8 μg/g), suggesting that the radish sprouts belong to the group of hyper-accumulation species. After the experiment, the sum of U amounts accumulated in radish sprouts and remained in groundwater was 1,472.2 μg and the uranium recovery ratio of this rhizofiltration experiment was 92.9%. From the results, it was investigated that the radish sprouts can remove large amounts of uranium from contaminated groundwater in a short time (few days) because the fast growth rate and the high U accumulation adsorption capacity.

The influence of weak permanent horizontal magnetic field (PMF, field strength ∼400 A/m) on lipid peroxidation was studied with 5-day-old radish (Raphanus sativus L. var. radicula D.C.) seedlings grown in a phytotron at 18–20℃ under illuminance of 1–6 klx and in darkness. Seedlings raised at geomagnetic field (GMF) were used as the reference (control) sample. Under the action of PMF, the largest content of a terminal lipid peroxidation product, MDA was observed in seedlings grown at illuminance of 2–3 klx. No clear dependence of MDA accumulation on light intensity during seedling growth was observed. The action of PMF altered the proportion between light and dark reactions of lipid peroxidation; lipid peroxidation decreased in the magnetic field. During seed germination under the action of PMF, the content of MDA was found to decrease: the largest decrease was observed in 5-day-old seedlings at illuminance of 1 klx. The permanent magnetic field acted as a correcting factor by affecting the MDA content.

The influence of 3 temperatures: 4°, 13°, and 22°C and of 3 humidities 50% r.h., 77% r.h. and 95% r.h. on the effectiveness of two defolians KJ and Mg(ClO3)2•6H2O was investigated in a phytotron. By changing day and night temperature and humidity the weather conditions encountered in nurseries in autumn were simulated. The influence of environment on defoliation depended markedly on the species of plant and on the defoliant. In several cases defoliation started earliest at 13° but over a longer period of time the temperature 4° stimulated markedly leaf shedding.

This study was undertaken by simulating the effects of increasing the temperature and CO2 values on the incidence and severity of F. equiseti on wild rocket (Diplotaxis tenuifolia) and radish (Raphanus sativus), under phytotron conditions. Two sets of 3 trials were carried out in which eight different temperature and CO2 combinations were tested:1) 400–450 ppm CO2, 18–22 °C; 2) 800–850 ppm CO2, 18–22 °C; 3) 400–450 ppm CO2, 22–26 °C, 4) 800–850 ppm CO2, 22–26 °C, 5) 400–450 ppm CO2, 26–30 °C; 6) 800–850 ppm CO2, 26–30 °C; 7) 400–450 ppm CO2, 14–18 °C; 8) 800–850 ppm CO2, 14–18 °C. The temperature and CO2 levels were significant factors of influence on disease incidence (DI) and severity (DS) in all the trials, and their combination significantly influenced the DI and DS of F. equiseti leaf spot on both hosts. Disease incidence and severity increased on wild rocket at 850 ppm of CO2, in comparison to 450 ppm, in each tested temperature range. The highest CO2 value on radish, for all the tested temperature regimes, caused an increase in DI and DS, which resulted statistically significant at the highest tested temperature range. The results obtained in this study add more concern to the possible negative effects of the spread of F. equiseti on vegetables in Italy as well as in other areas suffering from increased temperatures as a consequence of climate changes.