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Oxidative stress has been recognized as a critical pathogenetic mechanism for the initiation and the progression of hepatic injury in a variety of liver disorders. Antioxidants, including many natural compounds or extracts, have been used to cope with liver disorders. The present study was designed to investigate the hepatoprotective effects of cassia seed ethanol extract (CSE) in carbon tetrachloride (CCl4)-induced liver injury in mice. The animals were pre-treated with different doses of CSE (0.5, 1.0, 2.0 g/kg body weight) or distilled water for 5 days, then were injected intraperitoneally with CCl4 (0.1% in corn oil, v/v, 20 ml/kg body weight), and sacrificed at 16 hours after CCl4 exposure. The serum aminotransferase activities, histopathological changes, hepatic and mitochondrial antioxidant indexes, and cytochrome P450 2E1 (CYP2E1) activities were examined. Consistent with previous studies, acute CCl4 administration caused great lesion to the liver, shown by the elevation of the serum aminotransferase activities, mitochondria membrane permeability transition (MPT), and the ballooning degeneration of hepatocytes. However, these adverse effects were all significantly inhibited by CSE pretreatment. CCl4-induced decrease of the CYP2E1 activity was dose-dependently inhibited by CSE pretreatment. Furthermore, CSE dramatically decreased the hepatic and mitochondrial malondialdehyde (MDA) levels, increased the hepatic and mitochondrial glutathione (GSH) levels, and restored the activities of superoxide dismutase (SOD), glutathione reductase (GR), and glutathione S-transferase (GST). These results suggested that CSE could protect mice against CCl4-induced liver injury via enhancement of the antioxidant capacity.
The effect of auxin, GA and BAP on potato shoot growth and tuberization was investigated under in vitro condition. The shoot length of potato explants increased with the increasing of concentrations (0.5 - 10 mgdm⁻³) of IAA treatment especially with the addition of GA3 (0.5 mgdm⁻³), but was inhibited by BAP (5 mgdm⁻³). The root number and root fresh weight of potato explants increased with the increasing of IAA levels either in the presence of GA3 (treatment IAA+GA) or not (IAA alone). However, no root was observed in the treatment IAA+BAP, inttead there were brown swolten calli formed around the basal cut surface of the explants. The addition of GA3 remarkably increased the fresh weight and diameter of calli. Micro tubers were formed in the treatments of IAA + BAP and IAA + GA + BAP but not observed in the treatments of IAA alone or IAA + GA. IAA of higher concentrations (2.5 - 10 mgdm⁻³) was helpful to form sessile tubers. With the increastng of IAA levels, the fresh weight and diameter of micro tubers increased progressively. At 10 mg/L IAA, the fresh weight and diameter of microtubers in the treatment of IAA + GA + BAP were 409.6 % and 184.4 % of that in the treatment of IAA + BAP respectively, indicating the interaction effect of GA and IAA in potato microtuberization.
This study investigated the neuronal protective effect of monosialotetrahexosylganglioside (GM1) on the hypoxia-ischemia white matter damage (WMD) in neonatal rats. Brain hypoxia-ischemia was induced by bilateral carotid artery occlusion in 4-day-old neonatal rats. Bilateral carotid artery occlusion (BCAO) was performed in rats in WMD and GM1 groups, while in sham group; the rat bilateral carotid arteries were merely exposed without occlusion. Immunohistochemical staining was used to determine the expression of myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), and P-amyloid precursor protein (P-APP). In addition, suspension test, slope test, and open-field test were carried out on day 26 after BCAO to determine the neurobehavioral function. The percentage of MBP-positive cells was decreased while P-APP-and GFAP- positive cells were increased in WMD group. After treated with GM1, the percentage of MBP-positive cells increased significantly than WMD rats at post-operation 72 h and day 7. GFAP-positive cells and P-APP-positive cells decreased significantly in WMD group at post-operation 72 h, day 7 and 26. The suspension test, slope test, and open-field test showed that neurobehavioral function was improved in ganglioside GM1 group compared with WMD group. Taken together, our findings suggested that ganglioside GM1 treatment reduces hypoxia-ischemia induced impairment of the neurobehavioral function in WMD in neonatal rats.
Wheat mature seeds have large, lenticular A-type starch granules, and small, spherical B-type and irregular C-type starch granules. During endosperm development, large amyloplasts came from proplastid, divided and increased in number through binary fission from 4 to 12 days after flowering (DAF). Large starch granules formed and developed in the large amyloplast. One large amyloplast had only one large starch granule. Small amyloplasts came from the protrusion of large amyloplast envelope, divided and increased in number through envelope protrusion after 12 DAF. B-type starch granules formed and developed in small amyloplast from 12 to 18 DAF, C-type starch granules formed and developed in small amyloplast after 18 DAF. Many B- and C-type starch granules might form and develop in one small amyloplast. The amyloplast envelopes were asynchronously degraded and starch granules released into cell matrix when amyloplasts were full of starch granules. Apparent amylose contents of large starch granules were higher than that of small starch granules, and increased with endosperm development. The swelling powers and crystallinity of large starch granule were lower than that of small starch granules, and decreased with endosperm development. Small starch granules displayed broader gelatinization temperature ranges than did large starch granules.
Forest soil respiration (SR) has become a vital issue in global change ecology because of its critical role in global warming processes. However, SR remains the least understood component of the terrestrial carbon cycle because of its high spatial-temporal variability, inaccessibility of the soil substrate, and the high cost of measurement equipment. This study investigated the spatial and temporal variations of SR in six temperate and subtropical forest sites in eastern China. Seasonal variations of SR, the relationship between SR and soil temperature (ST) and volumetric water content (SW) were analyzed. Mean monthly SR varied seasonally and peaked in summer. SR varied temporally with ST (R² = 0.43∼0.79) in different sites and varied spatially with latitude (R² = 0.68). The responses of SR to the changes of SW varied across different sites and forest types. Their relationships were simulated by piecewise functions in the north three sites. The modules of ST and SW showed that ST is the dominant environmental factor in regulating seasonal dynamics of SR. This study is the first to examine the temporal and spatial variations of SR using a consistent method in situ in temperate and subtropical forests in eastern China. The results provide a scientific basis for accurately assessing future soil CO₂ efflux as a result of climate changes, and aid predictions of the changes of forest SR.
In vitro microtuberization provides an adequate experimental model for the physiological and metabolic studies of tuberization and the preliminary screenings of potential potato genotypes. The effects of saline stress at 0-80 mmol concentration on in vitro tuberization of two potato cultivars were investigated in this study. With an increase in the salt concentration, the microtuberization of potato was either delayed by 5-10 days (20 and 40 mmol NaCl) or inhibited completely (80 mmol NaCl) in addition to the reduction in microtuber yields. The two potato genotypes studied showed different trends in total soluble sugars, sucrose and starch contents of microtubers under NaCl stress, while glucose and fructose levels remained unchanged. The vitamin C content in microtubers of two potato genotypes was reduced by salt stress. Salinity applied from 20 to 60 mmol progrestively increased proline and malondialdehyde (MDA) levels in microtubers of both the potato cultivars. In genotype Zihuabai, NaCl at a low concentration (20 mmol) led to a signifi cant increase in peroxidase (POD) and polyphenoloxiadase (PPO) activities, while in Jingshi-2, the PPO activity decreased progressively with an increase in NaCl concentrations. Genotype Zihuabai exhibited higher tolerance to salt stress than Jingshi-2 under in vitro conditions. These results could be used for preliminary selections of salt tolerance in potato breeding programmes.
Experiments were conducted to study the influence of sowing seasons and drying methods on the seed vigour of two spring soybean (Glycine max (L.) Merr.) cultivars. Two cultivars, ‘Huachun18’ and ‘Huachun 14’, were sown in three seasons viz., spring, summer and autumn and the harvested seeds were dried using three different methods. The results showed that soybean sown in spring had a higher number of branches per plant, pods per branch and seed weight, and consequently resulted in higher seed yields than that of soybean sown in autumn or summer seasons. Seeds sown in the autumn season had the lowest values of electrical conductivity during seed imbibitions, higher peroxidase (POD) activity in germinated seedlings and lower contamination by the seed-borne fungi on the MS medium, which indirectly improved the seed vigour, which was followed by summer sown seeds. Seeds sown during the spring season resulted in poor seed vigour. In addition, the effect of drying methods on the seed vigour was also clarified. Seeds that hung for four days before threshing and then air-dried had the poorest seed vigour which was determined by germination, electrical conductivity, POD activity and seed borne fungal growth. There was no difference in seed vigour between other methods, i.e. seeds threshed directly at harvest and then air-dried on a bamboo sifter or concrete floor. These results indicated that autumn sowing soybean and the drying method in which seeds were threshed directly at harvest and then air-dried on a bamboo sifter resulted in higher seed vigour.
Propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy) benzylamino)benzoate (ZJ0273) is a new herbicide which inhibits acetolactate synthase (ALS). The ZJ0273 is considered as safe for the environment and exhibits a satisfactory effect on weed control in the rapeseed field. ALS is the key enzyme of reactions in the biosynthesis of total amino acids (TAAs) especially branched-chain amino acids (BCAAs). This study reports the effect of ZJ0273 on BCAAs and TAAs in rapeseed leaves using near-infrared spectroscopy (NIRS) techniques. A decrease in TAAs and BCAAs contents was observed as the herbicide dosages were increased along with leaf senescence. The wavelengths 2,416 and 1,340 nm were selected to develop the NIRS model for detecting BCAAs and TAAs, and correlation coefficients of model’s prediction set were 0.9823, 0.9764, 0.9831, and 0.9968 for valine, isoleucine, leucine, and TAAs, respectively. The results indicated that 100 mg/L ZJ0273 was a safe dosage for oilseed rape as it did not show a significant effect on the contents of amino acids compared to other higher dosages (500 and 1,000 mg/L).
Increased ultraviolet radiations intruding on the earth pose a serious threat to the unadapted plants. Due to the ecological and economic significance of mat rush (Juncus effusus L.), an in vitro experiment was conducted to unveil the toxic effects of ultraviolet radiation (UV-C) on its physiology and ultrastructure. The basal culm segments of plant were used for in vitro treatments of UV-C with different exposure times (15, 30 and 45 min). The treated segments were first transferred to 1/2 strength MS media and then shifted to soil-perlite mixture for further growth. With increasing exposure time to UV-C, there was significant reduction in plant growth and biomass, and increased activities of antioxidant enzymes. Physiological and ultrastructural alterations were observed in the shoots of UV-treated plants. These plants exhibited significant reduction in chlorophyll contents and noticeable modifications at the ultra-cellular levels. Cell and chloroplast size reduced greatly, and there was appearance of higher amounts of plastoglobuli in chloroplasts resulting in disruption of thylakoid integrity. The functional and ultrastructural alterations in the stressed plants suggest a potential hazard of UV-C radiation on this aquatic flora and thus the ecosystem. The study further explores that UV-C radiations trigger these modifications mainly by damaging the chloroplast.
The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonate (MVA), which is the first committed step in MVA pathway for isoprenoid biosynthesis in plants. In this study, a full-length cDNA encodingHMGRwas isolated from Salvia miltiorrhiza by rapid amplification of cDNA ends (RACE) for the first time, which was designated as SmHMGR (Gen-Bank Accession No.EU680958). The full-length cDNA of SmHMGR was 2,115 bp containing a 1,695 bp open reading frame (ORF) encoding a polypeptide of 565 amino acids. Bioinformatic analyzes revealed that the deduced SmHMGR had extensive homology with other plant HMGRs contained two transmembrane domains and a catalytic domain. Molecular modeling showed thatSmHMGRis a newHMGR with a spatial structure similar to other plant HMGRs. Phylogenetic tree analysis indicated that SmHMGR belongs to the plant HMGR super-family and has the closest relationship with HMGR from Picrorhiza kurrooa. Expression pattern analysis implied that SmHMGR expressed highest in root, followed by stem and leaf. The expression of SmHMGR could be up-regulated by salicylic acid (SA) and methyl jasmonate (MeJA), suggesting that SmHMGR was elicitorresponsive. This work will be helpful to understand more about the role of HMGR involved in the tanshinones biosynthesis at the molecular level.
This study evaluates the role of exogenous foliar application of 5-aminolevulinic acid (ALA) on water relations, gas exchange, chlorophyll fluorescence, and the activities and gene expression patterns of antioxidant enzymes in leaves of oilseed rape under drought stress and recovery conditions. Seedlings at four-leaf stage were imposed to well-watered condition (80 % of water-holding capacity) or drought stress (40 % of water-holding capacity) and subsequently foliar sprayed with water or ALA (30 mg l-1). Drought suppressed the accumulation of plant biomass and decreased chlorophyll content and leaf water status (relative water content and water potential). The actual quantum yield of photosystem II and electron transport rates were hampered in parallel to net photosynthetic rate. However, drought stress induced the accumulation of malondialdehyde (MDA) and hydrogen peroxide, enhanced the activities of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and superoxide dismutase and up-regulated the expression of APX and GR. After rehydration for 4 days, the growth of drought-treated seedlings was restored to normal level for most of the physiological parameters. Foliar application of ALA maintained relatively higher leaf water status and enhanced chlorophyll content, net photosynthetic rate, actual quantum yield of photosystem II, photochemical quenching, non-photochemical quenching and electron transport rates in stressed leaves. Exogenous ALA also alleviated the accumulation of MDA and hydrogen peroxide, increased the activities of antioxidant enzymes and enhanced the expression of CAT and POD in drought-treated plants. These results indicate that ALA may effectively protect rapeseed seedlings from damage induced by drought stress.
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