The prevalence of hexavalent chromium Cr(VI) and microplastics (MPs) is ubiquitous and is considered a threat to aquatic biota. MPs can act as a vector for waterborne metals; however, the combined ...effects of Cr(VI) and MPs on aquatic organisms are largely unknown. In this study, aquatic model animals, such as rotifers (Brachionus calyciflorus and B. plicatilis), water fleas (Daphnia magna), amphipods (Hyalella azteca), polychaetes (Perinereis aibuhitensis), and zebrafish (Danio rerio) were exposed to environmental concentrations (1, 10, and 100 particles L−1) of 1 μm polystyrene MPs alone, Cr(VI) alone, or Cr(VI) combined with MPs. Following exposure, the potential effects were measured by analyzing basic life endpoints (e.g., survival rate and growth). A significant response to MPs alone was not observed in all animals. However, MPs combined with Cr(VI) concentration-dependently increased Cr(VI) toxicity in two rotifer species. The survival rate of water fleas was significantly reduced upon exposure to Cr(VI) + MPs (100 particles L−1) compared with exposure to Cr(VI) alone, and significantly decreased the number of offspring. Although there was no significant effect on the body length of the amphipod, concentration-dependent decreases in their survival rates were observed. In contrast, no significant change was found in the survival rate of polychaetes; however, their burrowing ability was inhibited by Cr(VI) + MPs (100 particles L−1). Further, larval mortality was increased in response to Cr(VI) + MPs (100 particles L−1) in zebrafish. Taken together, the findings suggest that MPs can exacerbate Cr(VI) toxicity, even at environmental levels.
Here, we sequenced and annotated the complete mitochondrial genome for the terebellid polychaete, Neoamphitrite affinis (Malmgren 1866). The complete mitogenome of N. affinis is 15,823 bp, with 33.4% ...A, 18.2% C, 11.5% G, and 37.0% T. The circular N. affinis mitochondrial genome comprises 13 protein-coding genes (PCGs), 23 transfer RNA (tRNA) genes including 2 methionine tRNA genes, 2 ribosomal RNA (rRNA) genes, and a non-coding region. Phylogenomic analysis based on 26 in-group taxa belonging to the two main clades, Sedentaria and Errantia, is congruent with published phylogenetic relationship for annelids, which N. affinis was grouped with Pista cristata (Terebellida; Terebellidae). This mitogenome resource will be useful for future phylogenetic studies of families belonging to Sedentaria.
In this study, we report the complete mitogenome sequence of the polychaete, Melinna cristata (Sars, 1851). The circular M. cristata mitochondrial genome is 15,696 bp in length and has an AT content ...of 66%. As in other polychaetes, the genome has 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a non-coding region. Gene composition and their order in the M. cristata mitochondrion are identical to the Terebelliformia mitogenomes. A maximum-likelihood gene tree based on the M. cristata mitogenome combined with previously published Sedentaria and Errantia mitogenomes revealed that M. cristata forms a clade with two Terebelliformia species.
Here, we present the first whole mitogenome sequence of the marine polychaete, Nereis zonata, isolated from the Beaufort Sea. The mitochondrial genome of N. zonata is 15,757 bp in length and consists ...of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a non-coding region that is typical of polychaetes. GC content of the N. zonata mitogenome is 37.2%. A maximum-likelihood gene tree based on the N. zonata mitogenome combined with previously published annelid mitogenome data revealed that N. zonata is clustered with Cheilonereis cyclurus, which form a sister group to Nereis sp.
To increase the mitogenome data available for robust phylogeny, we sequenced the complete mitochondrial DNA of the scale worm Eunoe nodosa (Sars, 1861) in the family Polynoidae of the order ...Phyllodocida. The complete mitogenome has 15,366 bp and has 28.9% A, 13.2% C, 19.0% G, and 38.8% T. Using MITOS and tRNAscan-SE, we identified the 13 typical protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a non-coding region. Phylogenomic analysis based on 27 in-group taxa belonging to five families of the subclass Errantia show congruence with the published phylogenetic relationship within the Polynoidae, in which E. nodosa lies in the clade of shallow water species.
In this study, a marine mysid, Neomysis awatschensis, was exposed to 1 × 103–5 × 105 particles mL−1 of polystyrene microbeads (1 and 10 μm). Exposure to microplastics (MPs) resulted in ingestion and ...egestion in feces. MPs exposure during the early stage resulted in mortality and oxidative stress, while more mature stages were increasingly tolerant to MPs. Feeding rates were inhibited by MPs, and age-specific oxidative stress was observed. Growth parameters were significantly affected by MPs with lower 20–hydroxyecdysone (20E) concentrations and longer intermolt durations. The number of hatched juveniles from females that were exposed to MPs was significantly lower than the control treatment, but no significant differences were observed between survival rates of newly hatched juveniles in the different treatments. Our results suggest that the detrimental effects of prolonged exposure to MPs could be age- and size-specific and harmful for the maintenance of mysid populations.
•Adverse effects of MPs on mysid life cycle and its multi-generation were investigated.•Juvenile mysids are sensitive to MPs due to gut blockage and limited capacity of antioxidant defense system.•Consistent exposure to MPs inhibits mysid growth by modulation of ecdysone and molting process.•Consistent exposure to MPs significantly inhibits mysid fecundity.
색채선별기 이용한 남부평야지 조기재배 해담쌀의 품질향상 이종희(Jong-Hee Lee); 이지윤(Ji-Yoon Lee); 이소명(Somyeong Lee) ...
Korean journal of crop science,
06/2020, Letnik:
65, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A photoelectric grain color sorter is commonly used in postharvest technology to detect and separate grains considered to be of good quality from those of poor quality based on color. In this study, ...the milled rice of Haedamssal cultivated under early transplanting conditions was evaluated using the color sorting device. Rice was classified according to standard grades of 64% for grade A, 18% for grade B, and 17.2% for grade C. By head rice ratio analysis, the milled rice of Haedamssal was recorded a grade A of 72.9%, representing a 24.5% improvement compared to the 48.4% of original grains. However, the grades B and C of Haedamssal rice were lower than those of original rice. In addition, grade A whiteness of Haedamssal rice was 45.3, which was lower than that of original grains. The color affinity redness was significantly lower in Haedamssal rice than in the screening control. No significant difference was found in the amylose and protein contents of rice before and after selection by the grain color sorter. In contrast, grain viscosity analysis revealed an increase in peak and final viscosities, while the consistence viscosity increased in low grade levels. Our results suggest that the photoelectric grain color sorter could improve the head rice ratio and palatability of early transplanted Hadamssal rice. 본 연구에서 남부 평야지 조기재배 조건에서 생산된 쌀을 색채선별기를 이용한 쌀의 외관특성 향상과 밥맛의 향상을 위해 품질관련 특성을 분석하였다. 해담쌀 백미를 색채선별기에 2회 통과하여 등급별로 분류한 결과, A급은 64.8%, B급 18.0%, C급 17.2%이였다. 분류등급별 쌀을 백미완전미율을 분석한 결과, A급은 72.9%로 색채선별전 쌀 48.4%보다 약 25.4%정도 향상되었다. B등급과 C등급은 원료곡보다 완전미율이 낮았다. 쌀의 백도는 A등급이 45.3으로 색채선별전의 원곡보다 1.7정도 낮아졌다. 색상색차계 적색도 a값은 색채선별전 대비구에 비해 유의하게 낮았다. 아밀로스 함량과 단백질 함량은 색채선별 전후 유의한 차이가 없었으나, 쌀의 호화특성은 정상립으로 분류된 A등급은 최고점도와 최종점도가 각각 266.1RVU와 215.9 RVU로 색채선별전보다 높았고, 밥의 윤기치에서도 68.8로 색채 선별전보다 증가하였다. 이 결과로 볼 때 평야지 조기재배 조건에서 생산된 쌀을 색채선별기를 이용한 쌀의 외관특성을 분류함으로써 완전미율과 밥맛이 향상될 수 있을 것으로 기대된다.
A broad-spectrum fungicide, dichlofluanid is widely used in antifouling paints and agricultural pesticides. In this study, the acute and chronic effects of sublethal concentrations, namely, no ...observable effect concentration (NOEC) and 50% lethal concentration (LC50) of dichlofluanid (1/10 NOEC, NOEC, 1/10 LC50, and LC50) were evaluated on the marine mysid, Neomysis awatschensis. Acute toxicity test (96 h) showed higher sensitivity to dichlofluanid in juvenile mysids (LC50 3.1 μg L−1) than adults (LC50 24.5 μg L−1), with lower survival rate and reduction in food consumption. Exposure with dichlofluanid considerably induced oxidative imbalance, as NOEC (0.006 μg L−1 for juveniles and 0.074 μg L−1 for adults) and 1/10 LC50 values increased intracellular concentrations of malondialdehyde and glutathione, and the enzymatic activities of catalase and superoxide dismutase, whereas exposure to LC50 value decreased the values of oxidative parameters. Enzymatic activity of acetylcholinesterase decreased considerably when exposed to LC50 value. In the case of chronic effects, exposure to NOEC for 4 weeks markedly decreased the juvenile survival rate, while adults showed tolerance. Multigenerational monitoring in response to NOEC showed a significant growth retardation with an increase in intermolt duration as well as a decrease in the number of newborn mysids from females of the third generation. Consistent exposure to environmentally relevant sublethal concentrations of dichlofluanid would be detrimental to mysid individuals and the survival of the mysid population.
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•Dichlofluanid toxicity, for the first time, was evaluated on mysid crustaceans at a multigenerational level.•Dichlofluanid induced oxidative stress with age-specific decrease in survival and food consumption.•Dichlofluanid reduced the antioxidant defense ability and cholinergic response of mysid.•Higher concentrations directly affected mysid growth, molting, and fecundity.•Even sublethal concentrations significantly modulated mysid population when they were exposed consistently.
Coexistence of metals and microplastics (MPs) in aquatic environments represents a growing concern; however, little is known regarding the risks associated with their combined effects. Here, the ...effects of five metals (As, Cd, Cu, Pb, and Zn), alone or combined with MPs for various premixing durations (30 and 60 days), on the juvenile and adult stages of the marine mysid Neomysis awatschensis were evaluated. The toxicity (50% lethal concentration for 96 h) and bioconcentration of metals premixed with MPs were measured, and their effects on the antioxidant defense and cholinergic systems were examined. Metal toxicity increased with increasing premixing period with MPs, and juveniles were more sensitive to exposure to metals premixed with MPs than adults. Metal bioconcentration in the mysid body increased following co-exposure with MPs. Metals premixed with MPs significantly increased intracellular malondialdehyde content at both stages but decreased glutathione content in juveniles. At both stages, catalase and superoxide dismutase activity was suppressed following co-exposure to metals and MPs, except under the Cu treatment. Moreover, co-exposure inhibited acetylcholinesterase activity at both stages, suggesting cholinergic impairment. Taken together, metals and MPs produce synergistic detrimental effects on marine mysids in a stage-specific manner. Further studies are warranted to elucidate the role of MPs as a vector for contaminants and stimulator of toxicity in aquatic organisms.
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•Metals premixed with MPs increased acute toxicity and bioconcentration in a marine mysid.•Metals premixed with MPs induced oxidative stress and modulated the antioxidant defense system.•Metals premixed with MPs induced cholinergic impairment.•Stage-specific sensitivity to metals premixed with MPs was observed.
To determine the effect of copper pyrithione (CuPT) and zinc pyrithione (ZnPT), a set of acute (96 h–LC50) and chronic endpoints was studied in the marine mysid, Neomysis awatschensis. Based on the ...1/10 NOECs and NOEC values calculated from 96 h–toxicity test, survival and growth, intermolt duration, feeding, and the number of newborn juveniles were measured by evaluating enzymatic activity of detoxification parameter glutathione S–transferase (GST) and cholinergic biomarker acetylcholinesterase (AChE) in the marine mysid exposed to 96 h–NOECs of CuPT and ZnPT for four weeks across three generations. Dose–dependent decreases in survival rate monitored for four weeks were observed with age–specific sensitivity in response to the 96 h–NOECs of both antifoulants. Higher growth retardation was observed with an increase in intermolt duration and inhibition of the feeding rate in CuPT–exposed mysid compared to ZnPT–exposed mysid across generations. The numbers of newborn juveniles significantly decreased at the third generation by exposure to the 96 h–NOECs of both antifoulants. GST activity was significantly inhibited in response to 96 h–NOECs of both antifoulants, whereas AChE activity was only reduced by the 96 h–NOECs of CuPT at the third generation. These results indicate that CuPT has a higher toxicity than ZnPT and even sublethal levels of CuPT and ZnPT would have detrimental effects on the maintenance of the mysid population. Finally, consistent exposure to environmentally relevant concentrations of CuPT and ZnPT can induce intergenerational toxicity in mysid.
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•Mysids, non-target animals can be exposed to biofoulants during life cycle across generation.•Chronic exposure to sub-lethal concentrations of CuPT and ZnPT altered physiological and biochemical parameters.•Significant growth retardation observed at the third generation upon NOEC values of both biofoulants.•Sub-lethal concentrations of both biofoulants inhibited reproduction and GST activity.•CuPT specifically reduced molting activity, feeding rate, and acetylcholinesterase activity across generation.
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