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1.
The dynamics of microtubules is regulated mainly by microtubule-associated proteins (MAPs) and plays an important role in plant development and response to environmental signals. End-binding protein 1 (EB1) is a MAP specially binding to the microtubule plus end. Blast search of tomato genome showed two EB1 genes, which were named as SlEB1a (Solyc03g116370) and SlEB1b (Solyc02g092950) in this study. Transgenic tomato plants over-expressing SlEB1a or RNA interfering both SlEB1a and SlEB1b were constructed, and their sensitivity to microtubule depolymerization drug propyzamide and salt stress were analyzed. In this study, we determined the role of tomato EB1 (SlEB1) in the response to salt stress. Compared to the wild-type control plants, OE plants were more sensitive to 1 μmol/L propyzamide, whereas RNAi plants were more tolerant to 1 μmol/L propyzamide; in contrast, OE plants were more tolerant to 100 mmol/L NaCl, whereas RNAi plants were more sensitive to 100 mmol/L NaCl. Thus, SlEB1 might positively regulate salt stress response by negatively regulating the dynamics of tomato cortical microtubules. This study forms a basis for how cortical microtubule dynamics plays a role in plant response to salt stress. © 2018 Science Press. All rights reserved.  相似文献   

2.
Polygonum viviparum, which reproduces sexually and asexually, is widely distributed in the Qinghai-Tibet Plateau, and its reproduction strategies are very sensitive to changes in the environment. This study aimed to elucidate the effect of altitude on the photosynthetic characteristics and reproductive strategies of P. viviparum. This study was conducted to investigate the responses of photosynthetic, vegetative, and reproductive traits of P. viviparum populations along six altitudinal gradients in the eastern part of the Qilian Mountains in China. Our results indicated that, with increasing altitude, the net photosynthetic rate of P. viviparum showed an increasing trend, reaching its maximum value (14.39 μmol m–2 s–1) at 3 700 m above sea level. The transpiration rate showed an increasing trend, followed by a decreasing trend, and the intercellular CO2 concentration did not differ significantly between altitudes. With increasing altitude, the plant height and leaf area of P. viviparum showed a downward trend, the aboveground and underground biomass decreased, and the specific leaf area initially decreased and then increased. However, the leaf greenness index showed an upward trend, and the number of stomata in the upper and lower epidermis of leaves initially increased and then decreased. With increasing altitude, the proportion of inflorescence length per plant (the ratio of inflorescence length to plant height), the proportion of bulbil length per inflorescence (the ratio of bulbil length to inflorescence height), and the proportion of the number of bulbils per inflorescence (the ratio of the number of bulbils to the total number of flowers and bulbils) showed an increasing trend. Air temperature and light intensity are the major environmental factors affecting the photosynthetic characteristics and functional traits of P. viviparum. Thus, P. viviparum is exposed to more environmental stresses and obtains less energy when altitude increases, but it adapts to the harsh alpine environment by increasing the photosynthetic capability per unit area. With increasing altitude, P. viviparum populations may be sustained by investing less energy in vegetation and more in reproduction, especially asexual reproduction. © 2022 Science Press. All rights reserved.  相似文献   

3.
外源NO和水杨酸对盐胁迫下番茄幼苗光合机构的保护作用   总被引:2,自引:0,他引:2  
以番茄品种‘秦丰保冠’为试材,在水培条件下研究单独和复配施用一氧化氮(NO)供体硝普钠(SNP)、水杨酸(SA)对100 mmol/L NaCl胁迫下番茄幼苗叶片气体交换、叶绿素荧光、CO_2响应曲线、光合色素含量和叶黄素循环的影响.结果显示:(1)单独或复配外施SNP、SA均能使受Na Cl胁迫处理的番茄幼苗叶片净光合速率(Pn)、气孔导度(Gs)、PSⅡ最大光化学效率(F_v/F_m)、天线转化效率(F_v′/F_m′)、实际光化学效率(ΦPSⅡ)、光化学猝灭系数(qP)和叶绿素荧光衰减率(Rfd)不同程度升高,胞间CO2浓度(C_i)、初始荧光(Fo)和PSⅡ非光化学荧光猝灭系数(NPQ)显著降低,其中以SNP和SA复配处理的综合效果最好.(2)NaCl胁迫下,番茄幼苗叶片CO2羧化效率(CE)、Ru BP最大再生速率(J_(max))、RuBisCO及其活化酶活性和最大羧化速率(V_(c max))的下降均能在单独或复配施用SNP、SA的处理下得到有效缓解,并以SNP和SA复配处理更佳.(3)SNP、SA单独或复配处理均能有效抑制NaCl胁迫下番茄幼苗叶片光合色素(Chl a、Chl b和Car)含量、Chl a/b值和叶黄素循环库(V+A+Z)的下降及叶黄素循环脱环氧化程度(A+Z)/(V+A+Z)的升高,且以SA和SNP复配处理效果最明显.本研究表明,NaCl胁迫下依赖叶黄素循环的天线热耗散不是外源NO、SA单独或复配处理保护番茄幼苗叶片光合机构的生理机制,对PSⅡ及其初级电子受体醌(QA)下游电子传递通畅性的保护,以及对CO_2同化活性的改善才是外源NO、SA提高番茄幼苗叶片光合功能、增强其耐盐能力的主要原因,其中NO和SA复配处理时具有协同增效作用.  相似文献   

4.
To reveal the response of non-structural carbohydrates (NSC) and carbon and nitrogen isotopes in plant leaves to global warming, we conducted soil warming experiments in the Fujian Sanming Forest Ecosystem and Global Change National Observation and Research Station of China. We designed two treatments: control (CT) and warming (W; cable heating, +4 ℃). Heating cables were installed 20 cm from each other at a depth of 10 cm and were heated in March 2016. In this study, Cunninghamia lanceolata saplings were used to analyze seasonal changes in leaf non-structural carbohydrates, and carbon and nitrogen isotopes. The results showed that (1) warming significantly reduced the soluble sugar, starch, and NSC content of leaves in spring but without any significant difference during other seasons. (2) Leaf δ13C increased significantly in spring and winter after warming, whereas leaf δ15N did not change significantly. (3) No significant correlation was observed between leaf δ13C, δ15N, or NSC content during the warming treatment, but a negative correlation was observed between leaf δ15N, δ13C, and sugar to starch ratio. A positive correlation between leaf δ15N and starch content was identified. In summary, when temperature increases, plants adjust the NSC content during different seasons for osmotic regulation, change the characteristics of the nutrient cycle, and alter the plant water and nutrient use strategies to maintain plant growth. In the future, we should further study the seasonal variation characteristics of NSC content and isotopes and the relationship between NSC content and the carbon and nitrogen cycles in plants under the context of long-term warming. © 2022 Science Press. All rights reserved.  相似文献   

5.
In this study, three rice varieties, Byou268 (low light-sensitive type), Nei5you768 (intermediate type), and Yixiangyou1108 (low light-tolerant), were used as experimental materials to investigate the yield and quality responses of different rice varieties to low light stress under normal light (CK) and low light (SH). The results showed the following: (1) Compared with normal light, the decrease in Yixiangyou1108’s 1 000-grain weight, grain number per spike, and seed setting rate under low light treatment were much lower than those of Nei5you768 and Byou268. The yield decline of Yixiangyou1108 (46.5%) was significantly lower than that of Nei5you768 (56.5%) and Byou268 (69.8%). Yixiangyou1108 showed strong tolerance to low light stress in terms of 1 000-grain weight, seed setting rate, grain number per panicle, and yield. (2) Compared with normal light, the reduction in grain length and width of Yixiangyou1108 under low-light treatment was significantly greater than that of Byou268; however, the reduction in the length-width ratio did not reach a significant level. The amylose content and gel consistency of the rice were significantly reduced. The reduction in amylose content of Yixiangyou1108 (24.5%) was significantly lower than that of Nei5you768 (28.1%) and Byou268 (30.6%); however, the decrease in gel consistency of Yixiangyou1108 (14.7%) was significantly higher than that of Nei5you768 (9.8%) and Byou268 (8.1%). After low light treatment, the characteristic values of the RVA curve of rice changed. The peak viscosity and breakdown viscosity of Yixiangyou1108, Nei5you768, and Byou268 were significantly decreased, but the cold glue viscosity and setback viscosity were significantly increased, while there was no significant difference in the peak time and peak temperature. The response of 1 000-grain weight, grain number per spike, and seed setting rate under low light stress can be used as a yield index of rice breeding with low light tolerance; rice grain type, amylose, and gel consistency; and peak viscosity and hot paset viscosity in RVA characteristic values can be used as quality indexes of low-light-tolerant rice material breeding. © 2022 Science Press. All rights reserved.  相似文献   

6.
Warming and nitrogen deposition directly or indirectly affect the plant-soil element cycle under global change. To examine the effects of warming and nitrogen deposition on leaf and soil carbon (C), nitrogen (N), phosphorus (P) contents, and their stoichiometric ratios in Cunninghamia lanceolata saplings, four types of treatments were assigned: control (CT), warming (W, + 4 ºC), nitrogen deposition (N, 40 kg ha-1 a-1), and warming + nitrogen deposition (WN) treatments. The results showed that: (1) compared with CT, W treatment significantly decreased leaf P content by 54.54% and increased leaf C/P and N/P by 85.26% and 83.39%, respectively; WN treatment significantly decreased leaf C content and P content by 1.99% and 51.03%, respectively, but increased the leaf C/P by 68.01% with no significant differences in leaf N content among treatments. The leaf N/P ratio of each treatment was less than 10, but that of the W and WN treatments were closer to 10 than that of the CT treatment. Meanwhile, W and WN treatments significantly increased tree height. (2) No significant differences were observed in soil total carbon (TC), total nitrogen (TN), and total phosphorus (TP) contents among treatments. Compared with CT, W treatment significantly decreased soil C/N by 4.09%, while neither W nor WN treatment affected soil C/P and N/P. W treatment increased the available soil content compared to CT treatment. (3) The correlation analysis showed that leaf N content was significantly negatively correlated with soil C/N in the CT treatment; in the W treatment leaf N content and N/P were significantly positively correlated with soil TN and TP content, respectively. Leaf N content was significantly negatively correlated with soil TC and TN in the N treatment, and leaf contents had no significant correlation with soil C, N, and P contents or their stoichiometric characteristics in the WN treatment. This study showed that N limitation still exists in C. lanceolata saplings. Warming and the interaction between warming and nitrogen deposition could alleviate N limitation and promote the growth of C. lanceolata. © 2022 Authors. All rights reserved.  相似文献   

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8.
Protein ubiquitination regulates many aspects of plant development and stress response. The RING-finger type E3 ubiquitin ligase SDIR1 (salt and drought induced ring finger 1) gene plays a key role in plant stress response. In this study, the full-length cDNA and the promoter sequences of CsSDIR1 were isolated from tea plants using the RT-PCR technology, and its bioinformatics characteristics were systematically analyzed. The expression patterns of CsSDIR1 in various tissues and in response to cold, drought, salt, and ABA treatments were also investigated by quantitative real-time RT-PCR (qRT-PCR). The sequence of CsSDIR1 contains a complete open reading frame of 831 bp, coding for a 276-long amino acid protein with a molecular weight of (Mr) 30.085 × 103 and a theoretical isoelectric point of 6.54. CsSDIR1 was predicted to be a hydrophobic protein localized on the intracellular membranes. The analysis of the amino acid sequence characteristics showed that CsSDIR1 contains two putative transmembrane domains at the N-terminus and a C3H2C3 RING-finger domain at the C-terminus; it shares high similarity with other plants' SDIR1, and has the closest relationship to Actinidia sinensis. A cis-acting regulatory elements prediction showed that the CsSDIR1 promoter contains many cis-acting elements, especially drought and salt stress response elements. The qRT-PCR analysis indicated that the CsSDIR1 gene has a high expression level in stems, followed by roots, leaves, and flowers; the expression of the CsSDIR1 gene is up-regulated by ABA, salt, and drought treatments, whereas it is down-regulated in response to cold stress. These results demonstrated that the CsSDIR1 gene might be involved in the plant stress response of tea trees. © 2018 Science Press. All rights reserved.  相似文献   

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11.
Inonotus hispidus is a kind of rare medicinal fungus, and its natural resources are very scarce. Currently, the artificial cultivation technology of I. hispidus is not completely developed, and this reflects on its extremely low biological conversion rate and long cultivation period. In order to improve the bioconversion rate and shorten the production cycle of I. hispidus, we first analyzed the mycelia culture conditions of the collected I. hispidus, and then we further explore the method of domesticated cultivation of its fruiting body in rice medium. During the process of mycelial culture, the suitable temperature, pH, carbon source, and nitrogen source for mycelial growth were selected using the mycelial growth rate as index. During the domesticated cultivation of the fruiting body, the suitable culture medium for its growth was selected using the bioconversion rate as index. Screening results of mycelial culture conditions showed that the optimal culture conditions for the growth of mycelium of the wild I. hispidus were: temperature of 25 °C, initial pH of 6.0, glucose as the carbon source, and yeast extract powder as the source of nitrogen. The results of the domesticated cultivation showed that the biotransformation rate of I. hispidus was higher when using rice as the main medium substrate. The optimal cultivation conditions were: a 0.2% yeast extract content in the nutrient solution, a 1:1.6 ratio of rice to nutrient solution, and a 4 mL inoculum of the liquid strain. Under these conditions, it took about 4 days for the mycelium to grow over the cultivation medium. The time required for the differentiation of the primordium to form fruit bodies was about 20 days, and the bioconversion rate reached 28.70% ± 5.05%. The results of this study indicate the feasibility of using rice as the main substrate for the cultivation of I. hispidus, and it also provide new insights for the finding of new cultivation substrates for other rare medicinal fungi. © 2018 Science Press. All rights reserved.  相似文献   

12.
Activated carbon (AC)-supported copper or zinc made from ion exchange resin (IRCu-C and IRZn-C) have an increased metal load of 557.3 mg·g^-1 and 502.8 mg·g^-1 compared to those prepared by the traditional method involving impregnation with AC and copper (II) citrate or zinc citrate solution (LaCu-C and LaZn-C) of 12.9 mg·g^-1 and 46.0 mg·g^-1 respectively. When applied to decompose 2,2',4,4',5,5'-hexachlorobiphenyl at 250 ℃, IRCu-C achieved higher activity of 99.0% decomposition efficiency than LaCu-C of 84.7%, IRZn-C of 90.5% and LaZn-C of 62.7%. When the reaction temperature rose to 350 ℃, all the four kinds of reactants can decompose PCB- 153 with efficiency above 90%. Further, X-ray photoelec- tron spectroscopy characterization of IRCu-C before and after the reaction indicated transformation of 19.1% of Cu atoms into Cu^2+, illustrating that Cu is the active ingredient or electron donor promoting the decomposition of PCB- 153. The mechanism underlying this process differs from a traditional H donor. However, there is no significant change on the surface of IRZn-C before and after the reaction, suggesting that Zn acts as catalyst during the process of PCB-153 decomposition.  相似文献   

13.
The experiments were conducted to investigate the tolerance and enrichment capabilities by elucidating the physiological response and cadmium impact on iron and potassium accumulation amounts of brassica rape hairy roots under different cadmium concentrations by using liquid suspension culture method. The results showed the following. (1) The growth of hairy roots was not significantly different under low cadmium concentrations (below 100 μmol/L), whereas it was obviously inhibited under high cadmium concentrations (more than 100 μmol/L). Further, the maximum fresh weight of brassica rape hairy roots reached 4.34 g under 25 μmol/L cadmium stress after 7 days. (2) The content of ROS in brassica rape hairy roots increased with increasing concentrations of cadmium; the antioxidant enzyme activities of brassica rape hairy roots (SOD, POD, and CAT) decreased first and then increased with increasing cadmium concentrations under 1-day stress, whereas showed an opposite trend under 7-day stress. (3) PI staining and MDA content indicated that cellular damage was more serious with increasing cadmium concentrations. (4) With the increase of cadmium concentrations, cadmium content of hairy roots increased and reached maximum of 2.97 mg/g under 400 μmol/L cadmium stress after 7 days. The iron content also increased significantly with the maximal weight of 14.52 mg/g after 1-day cadmium stress, whereas no significant difference was noted under 7-day cadmium stress. The potassium content under 7-day cadmium stress was 1.6 times of that after 1-day stress (15.73 mg/g). The study showed that the physiological response of Brassica rape hairy roots was correlated with the concentration and time of cadmium stress. Moreover, cadmium stress caused metabolic disorders of iron and potassium in the hairy roots, but the hairy roots of Brassica rape had better enrichment effect on cadmium. © 2018 Science Press. All rights reserved.  相似文献   

14.
Nitrogen (N) loss in irrigated croplands from coupled nitrification and denitrification shows considerable differences due to differences in soil properties and agricultural management practices. Previous research has demonstrated that soil physicochemical properties strongly affect nitrification and denitrification capacities of cropland soils. However, existing research on soil nitrification and denitrification following the conversion of native desert soils to irrigated croplands lacks long-term tracking and monitoring capabilities. Therefore, six types of reclamation years of irrigated croplands and uncultivated sandy land in the Hexi Corridor marginal oasis in northwestern China were selected for study, and the differences in soil nitrification and denitrification rates and physicochemical properties were studied over 42 sites in the desert-oasis ecotone derived from seven reclamation sequences, including the years of 0, 15, 30, 50, 80, 100, and 150. The results showed that the nitrification and denitrification rates of soil first increased and then decreased with the increase in reclamation years. The highest soil nitrification rate and denitrification rate were observed at 80 years of cultivation (101.4 μg g-1 d-1) and 100 years of cultivation (0.93 μg g-1 d-1), respectively. In addition, the soil nitrification and denitrification rates in the natural sandy land were significantly lower than those in the cultivated croplands (P < 0.05). There were significant correlations among soil nutrients, soil moisture, and soil particle size composition between the nitrification and denitrification rates (P < 0.05). Regression analysis showed that environmental variables accounted for 69.7% and 75.7% of the variation in nitrification and denitrification rates, respectively. Among them, organic matter content, pH, soil moisture, and NH4+-N content were the key factors affecting the change in soil denitrification rate, while organic matter content, NO3--N, pH, and clay content were the key factors affecting the change in soil denitrification rate. © 2022 Science Press. All rights reserved.  相似文献   

15.
Based on observation data of daily sunshine duration from 1961 to 2020 at 175 meteorological observation stations over Qinghai-Tibet Plateau and its surrounding areas, spatial transformation analysis, climate trend analysis and M-K mutation test were used to analyze the temporal and spatial variation characteristics of the seasonal and annual sunshine duration in the region in the last 60 years. The results show that (1) annual average sunshine duration was 2 323 h, the maximum was 3 487 h in Gaer, Tibet, and the minimum was 771 h in Ya'an, Sichuan. The high-value areas were mostly located in western Tibet, northern Qinghai, western Gansu, and Xinjiang, and the low-value areas were mostly located in Nyingchi in Tibet, the mountainous area on the western edge of the Sichuan Basin, and northwestern Yunnan. The highest sunshine duration was recorded in winter (631 h), and the lowest was recorded in autumn (555 h) among the four seasons. (2) The average decrease in annual sunshine duration was 10.27 h/10 a. The largest rates of decrease were mainly in Gannan of Gansu and Ganzi of Sichuan, with the largest rate of decrease of 130 h/10 a. The areas with large rates of increase were mainly in Hotan area of Xinjiang, Liangshan of Sichuan and Lhasa of Tibet, with the largest increase of 61 h/10 a. Among the four seasons, spring exhibited an upward trend, and the remainder exhibited a downward trend. (3) Before 2017, the annual sunshine duration increased but declined after 2017. Spring sunshine duration had the largest number of mutation years, and the earliest mutation time was 1963. Winter had the fewest number of mutation years and the latest mutation time occurred in 2015. In summary, the annual and seasonal sunshine duration of Qinghai-Tibet Plateau vary greatly in space, but with the general characteristics of more sunshine in the northwest and less in the southeast, and sunshine hours were mainly decreasing, with 2017 as a mutation point of annual sunshine duration. Most areas of Qinghai-Tibet Plateau have great potential for photosynthetic production and are suitable for the development of light-loving plants and high-density planting. Shade-loving or shade-tolerant plants, including tea, are suitable for development in remote mountainous areas with low sunshine values in the western part of the basin, including Ya’an, Sichuan, and other areas, such as Medog, Tibet. © 2022 Science Press. All rights reserved.  相似文献   

16.
Epidemiological studies have shown that there is a link between asthma and brain damage,but toxicological studies have not fully confirmed yet,especially the effects of asthma on the brain. In this study,at first,we explore the effects of asthma on the brain through the establishment of an allergic asthma model. Then PM_(2.5),a typical outdoor air pollutant and formaldehyde,a typical indoor air pollutant were selected to be closer to the true environment and find whether there is any synergism between them. In this study,an ovalbumin( OVA)-sensitized mice asthma model was established. 30 male Balb/c mice were randomly divided into 5 groups:( 1) saline control group,( 2) OVA-sensitized group,( 3) OVA-combined with formaldehyde exposure group,( 4) OVA-combined with PM_(2.5) exposure group,( 5) Combination of OVA,formaldehyde and PM_(2.5) exposure group. The mice were inhaled with formaldehyde or/and instilled with PM_(2.5) from day 1 to 18. The mice asthma model was developed by OVA sensitization and challenge. The mice were sensitized with OVA+Al( OH)3( 5 mg OVA and 175 mg Al( OH)3 in 30 m L saline each time) or saline( 30 m L saline each time) by intraperitoneal injection on day 1,7 and 14.This was then followed by an aerosol challenge in 1% OVA( 30 min·d~(-1)) from day 19 to 25( 7 times) using an ultrasonic nebulizer. On the 26 th day,the organ coefficient of mice brain was counted,then the contents of oxidative stress of mice brain were measured,including reactive oxygen species( ROS),glutathione( GSH) and malondialdehyde( MDA),and the concentrations of NF-κB and interleukin-1β( IL-1β) were detected by using ELISA kits.Detection of interleukin-6( IL-6) was made with immunohistochemical method. Histological assay for brain was also conducted. In our results,all the OVA treated groups showed a significant increase of ROS and a significant decrease of GSH contents when compared with the control group. Except OVA-sensitized group,other OVA treated groups also showed a significant increase of MDA contents when compared with the control group,and MDA contents of OVA-sensitized group showed significant change when compared to the combined exposure group. In ROS and GSH,combined exposure showed some joint effect compared with single exposure. When OVA was applied in combination with formaldehyde and PM_(2.5),NF-κB was activated. And all the OVA treated groups showed increased levels of IL-1β and IL-6 compared with the control group. And the combined exposure showed an aggravated effect when compared with OVA-sensitized group. Histopathological observation of the hippocampus in mice brain clearly showed the difference of eosin( EO) stained neurons in the combined exposure group compared with the control group and OVA-sensitized group. The pyramidal neurons of the mice with allergic asthma exposed to formaldehyde and/or PM_(2.5) had been reduced in number,the cells were swollen and the dendrites had disappeared. Allergic asthma can cause damage to the brain through oxidative stress. Exposure to formaldehyde and PM_(2.5) will increase the damage caused by allergic asthma to the brain,which may be mediated by oxidative stress and NF-κB activation.This promotes the release of the inflammatory factors,resulting in increased inflammation.  相似文献   

17.
Combining the unique advantages of aqueous electrolytes and metallic Zn anode, rechargeable aqueous Zn-ion batteries(ZIBs) are of great promise for large-scale energy storage applications due to their inherent high safety, low cost, and environmental friendliness. As the essential component of ZIBs, Zn metal anode suffers from severe dendrite formation and inevitable side reactions(e.g. corrosion and hydrogen evolution)in aqueous electrolytes, which leads to low Coulombic efficiency and inferior...  相似文献   

18.
The family of Lemnaceae,commonly called duckweed,comprise five genera and 37 species of aquaticmonocotyledonous plants that are endemic to lakes,ponds and brackish water bodies on most continents. They are angiospermsthat have the highest biomass production rate and have been used to remediate wastewater from both municipal andindustrial sources. With these attractive features,duckweed is poised to be a novel agricultural platform that can complementcurrent terrestrial crops. In addition,their remarkable ability to adapt to diverse climates and conditions may provide newunderstanding of stress tolerance and genome adaptability mechanisms. However,one of the first challenges facing theseapplications is to establish reliable and rapid methods for identification of closely related strains that may have very differentbehaviour or properties. This review article summarizes the state of the arts for this endeavour and provides the outlook for thisquest in the near future.  相似文献   

19.
Subcellular distributions and chemical forms of cadmium (Cd) in the leaves, stems and roots were investigated in low-Cd accumulation cultivars and high-Cd accumulation cultivars ofpakchoi (Brassica chinensis L.). Root cell wall played a key role in limiting soil Cd from entering the protoplast, especially in the low-Cd cultivars. The high-Cd cultivars had significantly higher leaf and stem Cd concentrations than the low-Cd cultivars in cell wall fraction, chloroplast/trophoplast fraction, organelle fraction and soluble fraction. In low-Cd cultivars, which were more sensitive and thus had greater physiological needs of Cd detoxification than high-Cd cultivars, leaf vacuole sequestrated higher proportions of Cd. Cd in the form of pectate/protein complexes (extracted by 1 tool. L~ NaC1) played a decisive role in Cd translocation from root to shoot, which might be one of the mechanisms that led to the differences in shoot Cd accumulation between the two types of cultivars. Furthermore, the formation of Cd- phosphate complexes (extracted by 2% HAc) was also involved in Cd detoxification within the roots of pakchoi under high Cd stress, suggesting that the mechanisms of Cd detoxification might be different between low- and high-Cd cultivars.  相似文献   

20.
Surfactants may alter the interaction between engineered nanoparticles (ENP) and coexisting pollutants, and further influence the ecotoxicity of these pollutants. This research aimed to evaluate the impacts of the surfactant sodium dodecyl benzene sulfonate (SDS) on the ecotoxicological effects of TiO2-NP and Cd combined contamination in freshwater sediments by deposit-feeding gastropoda Bellamya aeroginosa. We investigated the effects of TiO2-NP and/or Cd contamination in the presence of different concentrations of SDS on DNA damage, Na+, K+-ATPase activities, malondialdehyde (MDA) levels, and protein carbonyl (PCO) levels in the hepatopancreas of B. aeroginosa following 21-d chronic sediment bioassay. The results showed that low concentration (5 μg g-1) of Cd had no toxicity to B. aeroginosa, while relatively high concentration (25 μg g-1) displayed obvious toxicity, and that SDS could significantly enhance the toxicity of Cd to B. aeroginosa. TiO2-NP with nontoxic concentration could enhance the toxicity of Cd with low concentration to B. aeroginosa, but had no effects on the toxicity of Cd with high concentration. SDS could significantly enhance the toxicity of TiO2-NP and Cd combined contamination to B. aeroginosa in a SDS-concentration-dependent manner. When assessing the potential environmental risk of ENP, we should not only focus on the toxicity of ENP itself, or the interaction between ENP and coexisting contaminants, but also should consider the potential impacts of surfactants and other environmental factors.  相似文献   

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