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Penthorum chinense (Penthoraceae) is a threatened South Korean medicinal plant used to treat alcohol-related diseases and prepare cosmetics in traditional Chinese medicine. Wetlands, the native habitat of this plant, have been decreasing owing to damage caused by landisation and urban development in recent years. In this study, we considered the effect of temperature and gibberellic acid treatment on P. chinense seed germination to improve conservation outcomes of the species. The optimum germination temperature was investigated using constant and alternating temperature treatments (60 conditions). In addition, gibberellic acid (GA3 ) treatment was performed to overcome physiological dormancy. We determined the germination (GP, %) and the number of days to reach 50% maximum germination (T50). The optimum temperature regime was 7°C / 23°C: GP was 95%, and T50 was 15 days. The GA3 treatment increased the GP of P. chinense seeds from 28 to 94% and decreased the T50 value from 14.6 to 6.3 days at concentrations above 40 mg L–1. After the GA3 treatment, the growth of radicles was delayed or inhibited. For the germination of P. chinense seeds, a diurnal temperature difference of ≥ 15°C is required.

Berberis koreana Palibin is an endemic plant native to Korea. In this study, we aimed to study the seed germination of this species using a water imbibition experiment, gibberellic acid (GA3) treatment (0, 10, 100, or 1000 mg·L−1), cold stratification (0, 2, 4, 8, or 12 weeks at 4 °C), move-along experiment, and phenology studies. In the water imbibition experiment, the weight of the seeds increased by more than 120% in 24 h. An analysis of the internal and external morphological characteristics of the seed revealed that the embryo was already fully grown from the fruit and did not grow thereafter. The final germination percentages for the cold stratification at 0, 2, 4, 8, and 12 weeks at 4 °C were 12 ± 3.65, 32 ± 9.09, 59 ± 1.00, 59 ± 9.59, and 71 ± 1.91%, respectively. In the move-along experiment and phenology studies, a longer low-temperature treatment period resulted in a higher germination percentage. However, the GA3 treatment had little effect on the seed germination. Our results indicate that B. koreana exhibits an intermediate physiological seed dormancy.

Berberis koreana Palibin is an endemic plant native to Korea. In this study, we aimed to study seed germination in this species using a water imbibition experiment, gibberellic acid (GA3) treat-ment (0, 10, 100, or 1000 mg·L−1), cold stratification (0, 2, 4, 8, or 12 weeks at 4 °C), a move-along experiment, and phenology studies. In the water imbibition experiment, the weight of the seeds increased by more than 120% in 24 h. Analysis of the internal and external morphological char-acteristics of the seed revealed that the embryo was already fully grown from the fruit and did not grow thereafter. The final germination percentages for cold stratification at 0, 2, 4, 8, and 12 weeks at 4 °C were 12, 32, 59, 59, and 71%, respectively. In the move-along experiment and phe-nology studies, a longer low-temperature treatment period resulted in a higher germination percentage. However, the GA3 treatment had little effect on seed germination. Our results indi-cate that B. koreana exhibits intermediate physiological seed dormancy.

During desiccation, the cytoplasm of orthodox seeds solidifies into an intracellular glass with highly restricted diffusion and molecular mobility. Temperature and water content govern seed ageing rates, while oxygen (O2) can promote deteriorative reactions. However, whether the cytoplasmic physical state affects involvement of O2 in seed ageing remains unresolved. We aged Pinus densiflora seeds by controlled deterioration (CD) at 45 °C and distinct relative humidity (RH), resulting in cells with a glassy (11% and 30% RH) or fluid (60% and 80% RH) cytoplasm. Hypoxic conditions (0.4% O2) during CD delayed seed deterioration, lipid peroxidation, and decline of antioxidants (glutathione, α-tocopherol, and γ-tocopherol), but only when the cytoplasm was glassy. In contrast, when the cytoplasm was fluid, seeds deteriorated at the same rate regardless of O2 availability, while being associated with limited lipid peroxidation, detoxification of lipid peroxide products, substantial loss of glutathione, and resumption of glutathione synthesis. Changes in metabolite profiles provided evidence of other O2-independent enzymatic reactions in a fluid cytoplasm, including aldo-keto reductase and glutamate decarboxylase activities. Biochemical profiles of seeds stored under seed bank conditions resembled those obtained after CD regimes that maintained a glassy cytoplasm. Overall, O2 contributed more to seed ageing when the cytoplasm was glassy, rather than fluid.

In recent years, the rapid development of genetically modified (GM) technology has raised concerns about the safety of GM crops and foods for human health and the ecological environment. Gene flow from GM crops to other crops, especially in the Brassicaceae family, might pose a threat to the environment due to their weediness. Hence, finding reliable, quick, and low-cost methods to detect and monitor the presence of GM crops and crop products is important. In this study, we used visible near-infrared (Vis-NIR) spectroscopy for the effective discrimination of GM and non-GM Brassica napus, B. rapa, and F1 hybrids (B. rapa X GM B. napus). Initially, Vis-NIR spectra were collected from the plants, and the spectra were preprocessed. A combination of different preprocessing methods (four methods) and various modeling approaches (eight methods) was used for effective discrimination. Among the different combinations, the Savitzky-Golay and Support Vector Machine combination was found to be an optimal model in the discrimination of GM, non-GM, and hybrid plants with the highest accuracy rate (100%). The use of a Convolutional Neural Network with Normalization resulted in 98.9%. The same higher accuracy was found in the use of Gradient Boosted Trees and Fast Large Margin approaches. Later, phenolic acid concentration among the different plants was assessed using GC-MS analysis. Partial least squares regression analysis of Vis-NIR spectra and biochemical characteristics showed significant correlations in their respective changes. The results showed that handheld Vis-NIR spectroscopy combined with chemometric analyses could be used for the effective discrimination of GM and non-GM B. napus, B. rapa, and F1 hybrids. Biochemical composition analysis can also be combined with the Vis-NIR spectra for efficient discrimination.

This study was conducted to elucidate the germination characteristics and dormancy types in Maianthemum dilatatum (A. W. Wood) A. Nelson and J. F. Macbr. M. dilatatum seeds were collected from the Nari Basin on Ulleungdo Island, South Korea and used in a water imbibition test; the seed weight increased by approximately 20% within 48 h. The embryo-to-seed ratio at the time of seed dispersal was 0.57 ± 0.03. When the seeds were incubated under light and dark conditions, they germinated under dark conditions, and the germination rate was higher at 25 °C than at 20 °C. However, the final germination rates under dark conditions were 27.4 ± 3.6 and 47.1 ± 7.6%, respectively. Under 4, 8, 12, and 16 weeks of cold stratification treatment, the highest germination rate of 83.6 ± 3.6% was observed at 25 °C at 12 weeks of cold stratification treatment, the germination start date was decreased by more than 10 d, and the mean germination time (MGT) was shortened from 50 d to 39 d. However, the germination rate, germination start date, and MGT did not differ significantly among the gibberellic acid hormone treatments. Therefore, it was evident that M. dilatatum demonstrated physiological dormancy (PD) that can broken by cold stratification treatment and dark conditions.

Penthorum chinense Pursh is a plant belonging to the Crassulaceae family and is a representative perennial herb that grows nationwide in watersides and wetlands. This study was conducted to enhance the competitiveness of wild plant seeds and contribute to the conservation of species diversity through the evaluation of antioxidant and antidiabetic activities of P. chinense seed extracts based on extraction solvents. The total phenolics content was 19.83 mg GAE/g seeds in the 75% ethanol extract, whereas the flavonoid content was the highest (10.89 mg QE/g seeds) in the 75% methanol extract. Total phenolicss content was higher in the organic solvent extract than in the water extract. The DPPH radical scavenging activity was the highest (IC50 27.60 μg/mL) in the 75% methanol extract, and the ABTS radical scavenging activity was the highest (IC50 53.54 μg/mL) in the 75% methanol extract. Total antioxidant capacity was the highest (30.87 μmol AAE/g) in the 75% ethanol extract. The α-glucosidase-inhibitory activity was the highest (IC50 46.47 μg/mL) in the 75% ethanol extract. From the results of this study, it was confirmed that P. chinense seed extracts, which possess high phenolics content, exhibit antioxidant and antidiabetic effects, and could be used as an effective health functional food material and natural medicine.

Bupleurum latissimum Nakai is a rare endemic species native to Ulleung-do in South Korea. This study aimed to report on the rhizosphere soil microbial diversity of B. latissimum . Proteobacteria , Actinobacteria , and Verrucomicrobia were identified in relative abundances of 27.77%, 21.70%, and 15.27%, respectively.

The occurrence of exotic weeds and their influx into farmlands due to climate change poses many problems. Therefore, it is necessary to generate a prediction model for the occurrence pattern of these exotic weeds based on scientific evidence and devise prevention measures. The photosynthetic apparatus is known as the most temperaturesensitive component of a plant cell and its initial response to temperature stress is to inhibit the activation of photosystem II. This study investigated the potential of OJIP transients in assessing temperature stress in exotic weeds. The four exotic weeds currently flowing into Korean farmlands include Amaranthus spinosus, Conyza bonariensis, Crassocephalum crepidioides, and Amaranthus viridis. These weeds were treated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C and the OJIP curves and JIP parameters were measured and analyzed. The results showed that heat and chilling stress affected the photosystem II (PSII) electron transport of A. spinosus, whereas C. crepidioides and A. viridis were more affected by high-temperature stress than by low-temperature stress. Lastly, C. bonariensis showed resistance to both high and low-temperature stress. The results of this study suggest that OJIP transients and JIP parameters can be used to analyze damage to the photosynthetic apparatus by temperature stress and that they can serve as sensitive indicators for the occurrence pattern of exotic weeds.

The rapid advancement of genetically modified (GM) technology over the years has raised concerns about the safety of GM crops and foods for human health and the environment. Gene flow from GM crops may be a threat to the environment. Therefore, it is critical to develop reliable, rapid, and low-cost technologies for detecting and monitoring the presence of GM crops and crop products. Here, we used visible near-infrared (Vis-NIR) spectroscopy to distinguish between GM and non-GM Brassica napus, B. juncea, and F1 hybrids (B. juncea X GM B. napus). The Vis-NIR spectra were preprocessed with different preprocessing methods, namely normalization, standard normal variate, and Savitzky–Golay. Both raw and preprocessed spectra were used in combination with eight different chemometric methods for the effective discrimination of GM and non-GM plants. The standard normal variate and support vector machine combination was determined to be the most accurate model in the discrimination of GM, non-GM, and hybrid plants among the many combinations (99.4%). The use of deep learning in combination with Savitzky–Golay resulted in 99.1% classification accuracy. According to the findings, it is concluded that handheld Vis-NIR spectroscopy combined with chemometric analyses could be used to distinguish between GM and non-GM B. napus, B. juncea, and F1 hybrids.

In this study, we determined the germination response in the seeds of the rare plant Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee to different temperatures. P. pusanensis seeds were collected from the Baekdudaegan National Arboretum, South Korea, in November 2019, and dried. Dry seeds were placed at constant and alternating temperatures (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) to determine their germination percentage (GP). The seeds were exposed to 59 temperature combinations ranging from 5 °C to 43 °C using a thermal gradient plate. The photoperiod was set at 12:12 h (light:dark) and germination assays were performed five times a week. Subsequently, the seed GP and the number of days required to reach 50% of the germination (T50) were determined. The highest final GP was 94.38%, with a T50 value of 9.26 d at 15 °C. However, the mean germination time was 12.5 d at 15 °C, and linear regression using 1/T50 revealed that the base temperature ranged from 2.69 °C to 4.68 °C. These results for P. pusanensis seeds stored in a seed bank provide useful data for the native plants horticulture industry and can also be utilized for storage management.

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

Platycosides, saponins contained in balloon flower, which have been used as food health supplements for respiratory diseases, have diverse pharmacological effects. Platycosides exhibit better pharmacological activity by hydrolyzing their own sugars. However, to date, there have been no studies on the production of deglucosylated platycodin D suitable for food applications. In this study, Pluszyme 2000P, which was derived from Aspergillus niger, a food-grade microorganism, was used to completely convert platycoside E into deglucosylated platycodin D. For an efficient and economical production of deglucosylated platycodin D, the productivity was improved approximately 2.4 times by application of high hydrostatic pressure and the discarded balloon flower leaf was used as a substrate. As a result, deglucosylated platycodin D was produced with the highest concentration (3.49 mg/mL) and productivity (581.7 mg/L/h) reported so far. Our results contribute to functional saponin production and the related food industries., Platycoside; Pluszyme 2000P; Food additive; Aspergillus niger; Balloon flower; Medicinal herb.

This study investigated the kind of seed dormancy and seed germination of Gentiana&nbsp, triflora var. japonica (Kusn.) H. Hara for developing a seed propagation method. The seeds were collected in October 2020 from plants at Mt. Sobaeksan, Korea. In a water imbibition experiment, seed weights increased by &gt, 101.9% of their initial masses over 12 h. Effects of incubation temperature (5, 15, 20, 25, 15/6, or 25/15 °C), cold stratification period (5 °C, 0, 4, 8, or 12 weeks), and gibberellic acid (GA3, 0, 10, 100, or 1000 mg∙L−1) and potassium nitrate treatment (KNO3, 0, 1000, 2000, or 4000 mg∙L−1) on seed germination were investigated to characterize seed dormancy. These seeds exhibited underdeveloped embryos during seed dispersal. The seeds failed to reach the final germination of 15.0% after treatment at 5, 15, 20, 25, 15/6, or 25/15 °C. After cold stratification for 8 weeks, the germination increased dramatically by &gt, 90.0% compared to that at 0 weeks. After the GA3 treatment, the germination reached &gt, 80.0% within 5 days. The final germination was 90.0% in the 100 mg∙L−1 GA3 treatment group. However, the KNO3 treatment had no effect on seed germination. Therefore, the G. triflora var. japonica seeds exhibited non-deep simple morphophysiological dormancy.

This study investigated the kind of seed dormancy and seed germination of Gentiana triflora var. japonica (Kusn.) H. Hara for developing a seed propagation method. The seeds were collected in October 2020 from plants at Mt. Sobaeksan, Korea. In a water imbibition experiment, seed weights increased by >101.9% of their initial masses over 12 h. Effects of incubation temperature (5, 15, 20, 25, 15/6, or 25/15 °C), cold stratification period (5 °C; 0, 4, 8, or 12 weeks), and gibberellic acid (GA3; 0, 10, 100, or 1000 mg∙L−1) and potassium nitrate treatment (KNO3; 0, 1000, 2000, or 4000 mg∙L−1) on seed germination were investigated to characterize seed dormancy. These seeds exhibited underdeveloped embryos during seed dispersal. The seeds failed to reach the final germination of 15.0% after treatment at 5, 15, 20, 25, 15/6, or 25/15 °C. After cold stratification for 8 weeks, the germination increased dramatically by >90.0% compared to that at 0 weeks. After the GA3 treatment, the germination reached >80.0% within 5 days. The final germination was 90.0% in the 100 mg∙L−1 GA3 treatment group. However, the KNO3 treatment had no effect on seed germination. Therefore, the G. triflora var. japonica seeds exhibited non-deep simple morphophysiological dormancy.

Platycosides, saponins contained in balloon flower, which have been used as food health supplements for respiratory diseases, have diverse pharmacological effects. Platycosides exhibit better pharmacological activity by hydrolyzing their own sugars. However, to date, there have been no studies on the production of deglucosylated platycodin D suitable for food applications. In this study, Pluszyme 2000P, which was derived from Aspergillus niger, a food-grade microorganism, was used to completely convert platycoside E into deglucosylated platycodin D. For an efficient and economical production of deglucosylated platycodin D, the productivity was improved by application of high hydrostatic pressure and the discarded balloon flower leaf was used as a substrate. As a result, deglucosylated platycodin D was produced with the highest concentration and productivity reported so far. Our results contribute to functional saponin production and the related food industries.

At high O2 tensions, as encountered prehistorically, Chlamydomonas reinhardtii elevated levels of NPQ-related proteins and LHCSR3 had an important function in protecting PSI., Non-photochemical quenching (NPQ) helps dissipate surplus light energy, preventing formation of reactive oxygen species (ROS). In Chlamydomonas reinhardtii, the thylakoid membrane protein LHCSR3 is involved in pH-dependent (qE-type) NPQ, lacking in the npq4 mutant. Preventing PSII repair revealed that npq4 lost PSII activity faster than the wild type (WT) in elevated O2, while no difference between strains was observed in O2-depleted conditions. Low Fv/Fm values remained 1.5 h after moving cells out of high light, and this qH-type quenching was independent of LHCSR3 and not accompanied by losses of maximum PSII activity. Culturing cells in historic O2 atmospheres (30–35%) increased the qE of cells, due to increased LHCSR1 and PsbS levels, and LHCSR3 in the WT, showing that atmospheric O2 tensions regulate qE capacity. Colony growth of npq4 was severely restricted at elevated O2, and npq4 accumulated more reactive electrophile species (RES) than the WT, which could damage PSI. Levels of PsaA (PSI) were lower in npq4 grown at 35% O2, while PsbA (PSII) levels remained stable. We conclude that even at high O2 concentrations, the PSII repair cycle is sufficient to maintain net levels of PSII. However, LHCSR3 has an important function in protecting PSI against O2-mediated damage, such as via RES.

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.

The present study was conducted to examine the response of Pterocarpus indicus to elevated ozone by comparing the effects between well-watered and soil drought treatments. The ozone concentration was 200 ppb and the exposure was conducted for a month with well-watered and soil drought treatments in chamber environmental conditions. Elevated ozone-induced visible injuries to P. indicus varied among the well-watered environmental conditions, with the appearance of light green chlorosis in the SWO seedlings over time. However, in the SDO seedlings, no difference was visible between drought and drought with ozone treatment. Shriveled leaves were evident because of the water deficiency. Moreover, elevated ozone induced leaf stomata injury and a harsh abaxial surface, whereas drought stress induced less injured stomata because of stomata closing. In addition, the palisade tissues exhibited smaller chloroplasts, damaged thylakoid, increased plastoglobuli, decreased starch grain and thinner cell walls on the upper leaf surface. Thus, the SDO seedlings were less influenced by elevated ozone stress than SWO seedlings due to the reduced ozone absorption which caused by stomata closing to prevent water loss.

The main purpose of this study was to evaluate the antioxidant and neuroprotective activities in the aerial parts of seven Eragrostis species (Poaceae) and to find antioxidant or neuroprotective compounds from the most active species. The total phenolic content (TPC), total flavonoid content (TFC), 1,1-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH RSA), total antioxidant capacity (TAC), and neuroprotective activity against amyloid beta peptide induced toxicity in PC12 cells were measured in the methanol extracts of the aerial parts of E. ferruginea, E. cilianensis, E. minor, E. multicaulis, E. pilosa, E. japonica, and E. curvula collected from June to August 2013. All species showed antioxidant or neuroprotective activities and, among them, E. japonica was the most active species to isolate antioxidant or neuroprotective compounds, because it was found to show both the highest TPC (10.63 ± 0.31 mg/g) and TFC (2.83 ± 0.06 mg/g) values, as well as TAC (11.34 ± 0.80 mg/g) and DPPH RSA (47.07 ± 2.81 µg/mL), with the second-highest neuroprotective value (23.0 µg/mL). Three known compounds were isolated from E. japonica by the bioassay guided approach and these were identified as isoorientin, isovitexin, and caffeic acid that have antioxidant and neuroprotective activities.

The equilibrium moisture contents (EMC) in seeds of four Echinochloa (E. crus-galli var. crus-galli, E. crus-galli var, echinata, E. crus-galli var. praticola, E. esculenta) were measured at 20oC with equilibration over a series of lithium chloride solutions with relative humidities ranging from 0.11 to 0.8 to determine sorption isotherms and safe storage relative humidity. Standard seed sorption isotherm models i.e. modified Henderson, modified Chung-Pfost, modified Halsey, modified Oswin and Guggenheim-Anderson-deBoer (GAB) equations were adopted to evaluate the goodness of fit to sorption isotherms. This study indicated that EMC of seeds was significantly different in four Echinochloa species at various relative humidity. The modified Oswin equations for E. crus-galli var. crou-galli, E. crus-galli var, echinata, E. esculenta and GAB equation for E. crus-galli var. praticola were adequate models for the EMC data. Seeds of four Echinochloa species have monolayer moisture contents when stored at RH < 0.1. These results show that seed moisture isotherm model should be selected according to genetic variation.

The effects of chronic gamma ray irradiation on Brachypodium distachyon were investigated to lignocellulose composition and enzymatic hydrolysis. Four-week-old plants of B. distachyon were exposed to gamma-ray irradiation at doses of 50, 100, 150, 200, 250, and 300 Gy. Gamma-ray irradiation negatively influenced biomass related morphology including plant height and cell size; however, it increased tiller number and internode diameter. SEM image analysis showed that the cell size of 300-Gy gamma irradiated plants was 45 % lower than that of the control. Destroyed regions on the cell wall surface were observed according to the dose of radiation. Cell wall yield, lignin content, and neutral sugar content were decreased in a dose-dependent manner. Glucose yield via enzymatic hydrolysis was positively correlated with radiation dose. In addition, 250-Gy and 300-Gy irradiated plants showed significantly better saccharification efficiency than non-irradiated controls. Initial glucose yields from 250-Gy- and 300-Gy-irradiated plants were 121.5 and 139.4 % of yields from non-irradiated controls, and final yields were 184.7 and 213.7 % of control yields, respectively. Reverse-transcription polymerase chain reaction (RT-PCR) analysis of lignin pathway-related genes showed increase of F5H, COMT, and CAD expression in 250-Gy- and 300-Gy-irradiated Brachypodium plants. Chemical composition analysis further verified that chronic gamma ray irradiation degraded lignocellulose as a pretreatment.

International audience; The production of reactive oxygen species (ROS) is an unavoidable part of photosynthesis. Stress that accompanies high light levels and low CO2 availability putatively includes enhanced ROS production in the so-called Mehler reaction. Such conditions are thought to encourage O2 to become an electron acceptor at photosystem I, producing the ROS superoxide anion radical (O2·-) and hydrogen peroxide (H2 O2 ). In contrast, here it is shown in Chlamydomonas reinhardtii that CO2 depletion under high light levels lowered cellular H2 O2 production, and that elevated CO2 levels increased H2 O2 production. Using various photosynthetic and mitochondrial mutants of C. reinhardtii, the chloroplast was identified as the main source of elevated H2 O2 production under high CO2 availability. High light levels under low CO2 availability induced photoprotective mechanisms called non-photochemical quenching, or NPQ, including state transitions (qT) and high energy state quenching (qE). The qE-deficient mutant npq4 produced more H2 O2 than wild-type cells under high light levels, although less so under high CO2 availability, whereas it demonstrated equal or greater enzymatic H2 O2 -degrading capacity. The qT-deficient mutant stt7-9 produced the same H2 O2 as wild-type cells under high CO2 availability. Physiological levels of H2 O2 were able to hinder qT and the induction of state 2, providing an explanation for why under high light levels and high CO2 availability wild-type cells behaved like stt7-9 cells stuck in state 1.

Photosynthetic organisms have to tolerate rapid changes in light intensity, which is facilitated by non-photochemical quenching (NPQ) and involves modification of energy transfer from light-harvesting complexes (LHC) to the photosystem reaction centres. NPQ includes dissipating excess light energy to heat (qE) and the reversible coupling of LHCII to photosystems (state transitions/qT), which are considered separate NPQ mechanisms. In the model alga Chlamydomonas reinhardtii the LHCSR3 protein has a well characterised role in qE. Here, it is shown in the npq4 mutant, deficient in LHCSR3, that energy coupling to photosystem II (PSII) more akin to qT is also disrupted, but no major differences in LHC phosphorylation or LHC compositions were found in comparison to wild-type cells. The qT of wild-type cells possessed two kinetically distinguishable phases, with LHCSR3 participating in the more rapid (2O2, which accelerated qE induction, revealing a way that may help C. reinhardtii tolerate a sudden increase in light intensity. Overall, a clear mechanistic overlap between qE and qT is shown.

This study was conducted in order to investigate the distribution pattern of weeds on upland crop field in northern Gyeonggi-do. The weeds were summarized as 201 taxa including 42 families, 129 genera, 178 species, 1 subspecies, 21 varieties and 1 form. One hundred and thirty one species were classified to annual plants, accounting for 65.1% and 70 species were classified to perennials, accounting for the rest of 34.9%. Compositae was dominant family (21%), followed by Gramineae (12%), Polygonaceae (7%) and Brassicaceae (5%). Among the weeds appearing in the fields of northern Gyeonggi-do, the invasive weeds were classified to 62 species in18 families. The most dominant weed species in the fields were Portulaca oleracea, followed by Echinochloa crus-galli, Amaranthus lividus. Detrended correspondence analysis for investigation of occurrence pattern of weeds by crops revealed the occurrence pattern of weed species in adlay field were different from those in other crop fields. This information could be useful for establishment of weed control methods in northern Gyeonggi-do.

This study was conducted to examine the change of flora and plant species diversity between 2005 and 2010 in Yangjaecheon (stream) which was divided among three different types of vegetation management method; ecological vegetation management (weeding vines and invasive plants; EVM), plant cultivation (PC) and uncared for vegetation (UC). There were total 478 taxa, composed by 429 spontaneous taxa and 49 cultivated taxa in 2005 and total 424 taxa composed by 318 spontaneous taxa and 106 cultivated taxa in 2010. In spontaneous plants, 201 taxa were distributed over total area, 197 taxa were distributed in only EVM area, 10 taxa in only PC area and 59 taxa in only UC area. Also, the most dominant family (AsteraceaePoaceae) and number of rare taxa (reduced) and wide distributed taxa (increased) was changed from 2005 to 2010. The rate of perennial taxa was found to be increased in only EVM area. In conclusion, EVM is thought to be a more efficient method for plant species diversity of restored stream.

Disagreement among the various publications providing lists of Korean endemic plants makes confusion inevitable. We summarized the six previous reports providing comprehensive lists of endemic plants in Korea: 407 taxa in Lee (1982), 570 taxa in Paik (1994), 759 taxa in Kim (2004), 328 taxa in Korea National Arboretum (2005), 515 taxa in the Ministry of Environment (2005) and 289 taxa in Flora of Korea Editorial Committee (2007). The total number of endemic plants described in the previous reports was 970 taxa, including 89 families, 302 genera, 496 species, 3 subspecies, 218 varieties, and 253 formae. Endemic plants listed four times or more were collected to compare the data in terms of scientific names and synonyms (339 taxa in 59 families and 155 genera). If the varieties and formae were excluded, the resulting number of endemic plants was 252 taxa for the 339 purported taxa analyzed. Seven of the 155 genera analyzed were Korean endemic genera. Among the 339 taxa, the same scientific names were used in the original publications for 256 taxa (76%), while different scientific names were used for 83 taxa (24%). The four largest families were Compositae (42 taxa, 12.4%), Ranunculaceae (19 taxa, 5.6%), Rosaceae (19 taxa, 5.6%), and Scrophulariaceae (19 taxa, 5.6%). Saussurea (Compositae) had the highest number of taxa within one genus (17 taxa; 5% of total endemic taxa).

► Seven flavonol glycosides were isolated from Sicyos angulatus. ► All flavonols were identified as 3,7-O-glycosides of quercetin and kaempferol. ► These flavonoids were first time isolated from the genus Sicyos. ► These flavonoids showed differences with other genera of same tribe the Sicyeae. ► Four of the seven flavonoids have various biological activities.