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1.
不同水稻品系幼苗对砷(As)的耐性、吸收及转运   总被引:8,自引:0,他引:8       下载免费PDF全文
刘志彦  陈桂珠  田耀武 《生态学报》2008,28(7):3228-3235
利用琼脂培养基模拟水稻生长的厌氧环境,研究了As对不同水稻品系幼苗生长的影响以及As在其体内的积累及转运特性.结果表明,不同浓度(0~4.0mg/L)的As对供试水稻品系根部干物质积累无显著影响(P>0.05).杂交稻与糯稻的地上部干物质积累随基质中As浓度的增加呈减小趋势,但低剂量的As(0.5mg/L)促进常规稻的生长.水稻地上部的As积累量随基质中As浓度的升高总体均呈增加趋势.水稻根系对As具有较强的吸收与累积能力.水稻根部As的积累量为156.31~504 03mg/kg,占总As含量的63.40~81.90%,远远高于其地上部As的积累量.相比于其它两个品系,糯稻的生物量积累高,耐性指数较大,根部及地上部对As的积累量较低,因此更适合种植在As污染土壤.  相似文献   

2.
The effects of arsenite [As(III)] and arsenate [As(V)] on the growth of roots, stems, and leaves and the uptake of arsenic (As), micro- and macronutrients, and total amylolytic activity were investigated to elucidate the phytotoxicity of As to the mesquite plant (Prosopis juliflora x P. velutina). The plant growth was evaluated by measuring the root and shoot length, and the element uptake was determined using inductively coupled plasma optical emission spectroscopy. The root and leaf elongation decreased significantly with increasing As(III) and As(V) concentrations; whereas, stem elongation remained unchanged. The As uptake increased with increasing As(III) or As(V) concentrations in the medium. Plants treated with 50 mg/L As(III) accumulated up to 920 mg/kg dry weight (d wt) in roots and 522 mg/kg d wt in leaves, while plants exposed to 50 mg/L As(V) accumulated 1980 and 210 mg/kg d wt in roots and leaves, respectively. Increasing the As(V) concentration up to 20 mg/L resulted in a decrease in the total amylolytic activity. On the contrary, total amylolytic activity in As(III)-treated plants increased with increasing As concentration up to 20 mg/L. The macro- and micronutrient concentrations changed in As-treated plants. In shoots, Mo and K were reduced but Ca was increased, while in roots Fe and Ca were increased but K was reduced. These changes reduced the size of the plants, mainly in the As(III)-treated plants; however, there were no visible sign of As toxicity.  相似文献   

3.
水稻砷污染及其对砷的吸收和代谢机制   总被引:7,自引:0,他引:7       下载免费PDF全文
彭小燕  王茂意  刘凤杰  叶志鸿 《生态学报》2010,30(17):4782-4791
水稻是当今世界大部分地区(尤其是东南亚)的主要的粮食作物之一,同时也是砷(As)进入食物链的主要途径之一。日益严重的水稻田As污染,不但影响了稻米的产量和品质,而且通过食物链威胁着人体健康。如何减少水稻地上部(尤其是米粒)As的含量和降低其毒性,及提高水稻As耐性是亟需解决的世界食品安全问题。深入了解水稻对As的吸收、积累和代谢的生理及分子生物学机制是解决水稻As污染的关键途径。综述国内外研究,对今后深入研究提出建议。  相似文献   

4.
5.
褐稻虱生物型变异动态监测及抗虫品种资源推荐   总被引:6,自引:1,他引:6  
谭玉娟  张扬 《昆虫学报》1997,40(1):32-39
本文报道近十多年来广东省褐稻虱Nilaparvata lugens(Stal)生物型变异动态监测的研究结果,针对当前褐稻虱优势生物型及发展趋势,推荐优良的抗褐稻虱品种资源。监测结果表明;根据苗期抗性反应,分蘖期生存率测定,田间系统调查监测,广州褐稻虱田间种群对带有Bph1抗性基因的代表品种IR26的致害力不断增强,1992年以来抗性反应达生物型2的水平。1992~1994年在全省7个不同生态类型地区取样测定及验证试验结果表明,生物型 2已上升为广东褐稻虱田间主害代的优势种群。多年的抗性鉴定结果证实,外引品种IR56、IR50404同其对应亲本PTB33、Babawee一样,对褐稻虱的抗性稳定,已推荐用作进一步抗 性育种的优良抗源。粳籼89等23个品种能抗褐稻虱生物型1和2,可及时替代带即BPh1抗性 基因的品种。  相似文献   

6.
The quantitative trait loci (QTLs) associated with arsenic (As) accumulation in rice were mapped using a doubled haploid population established by anther culture of F1 plants from a cross between a Japonica cultivar CJ06 and an Indica cultivar TN1 (Oryza sativa). Four QTLs for arsenic (As) concentrations were detected in the map. At the seedling stage, one QTL was mapped on chromosome 2 for As concentrations in shoots with 24.4% phenotypic variance and one QTL for As concentrations in roots was detected on chromosome 3. At maturity, two QTLs for As concentrations in grains were found on chromosomes 6 and 8, with 26.3 and 35.2% phenotypic variance, respectively. No common loci were detected among these three traits. Interestingly, the QTL on chromosome 8 was found to be colocated for As concentrations in grain at maturity and shoot phosphorus (P) concentrations at seedling stage. These results provide an insight into the genetic basis of As uptake and accumulation in rice, and will be useful in identifying genes associated with As accumulation.  相似文献   

7.
    
Differentiated cells telomere length is an indicator of senescence or lifespan; however, in peripheral blood leukocytes the relative shortening of the telomere has been considered as a biological marker of aging, and lengthening telomere as an associated risk to cancer. Individual’s age, type of tissue, lifestyle, and environmental factors make telomere length variable. The presence of environmental carcinogens such as arsenic (As) influence as causal agents of these alterations, the main modes of action for As described are oxidative stress, reduction in DNA repair capacity, overexpression of genes, alteration of telomerase activity, and damage to telomeres. The telomeres of leukocytes resulting a finite capacity of replication due to the low or no activity of the telomerase enzyme, therefore, elongation telomere in this kind of cells is a potential biological marker associated with the development of chronic diseases and carcinogenesis.  相似文献   

8.
Ancheng  Luo  Jianming  Xu  Xiaoe  Yang 《Plant and Soil》1993,155(1):395-398
Although NH4 + has generally been accepted as the preferred N source for fertilising rice, some workers have concluded tha NO3 - is as effective as NH4 +. The present glasshouse study exmined the relative uptake of NH4 + and NO3 - from solution and cultures containing 5–120 mg N/L supplied as NH4NO3 by a hybrid rice (India) and a conventional rice cultivar (Japonica). At all levels of N supply, the hybrid rice had higher leaf area and higher rates of uptake of total N than the conventional cultivar. Net photosynthesis rates were similar for both cultivars at the highest rates of N supply, but were lower at 5–40 mg N/L for the hybrid cultivar than for the conventional cultivar. At all levels of N supply, the conventional rice cultivar absorbed more NH4 + than NO3 -. In contrast, the hybrid rice absorbed more NH4 + than NO3 - at the low levels of N supply (5–40 mg N/L), but more NO3 - than NH4 + at the high levels of at 80 and 120 mg N/L. It is concluded that the uptake of N by rice is under genetic control and also dependent on levels of N supply. Thus the appropriate form of N fertiliser for rice may depend on cultivar and rates of N supply.  相似文献   

9.
This field-scale hydroponic experiment investigated the effects of plant density and nutrient levels on arsenic (As) removal by the As-hyperaccumulator Pteris vittata L. (Chinese brake fern). All ferns were grown in plastic tanks containing 30 L of As-contaminated groundwater (130 microg x L(-1) As) collected from South Florida. The treatments consisted of four plant densities (zero, one, two, or four plants per 30 L), two nitrogen (N) concentrations (50% or 100% of 0.25-strength Hoagland solution [HS]), and two phosphorous (P) concentrations (15% and 30% of 0.25 strength HS). While low P was more effective than high P for plant As removal initially, N levels showed little effect. At 15% P, it took 3 wk for the ferns at a plant density of four to reduce As to less than 10 microg L(-1) (USEPA and WHO standard), whereas it took 4-6 wk at plant densities of one or two. For reused ferns, established plants with more extensive roots than "first-time" ferns, a low plant density of one plant/30 L was more effective, reducing As in water to less than 10 microg L(-1) in 8 h. This translates to an As removal rate of 400 microg h(-l) plant(-1), which is the highest rate reported to date. Arsenic-concentration in tanks with no plants as a control remained high throughout the experiment. Using more established ferns supplemented with dilute nutrients (0.25 HS with 25% N and 15% P) with optimized plant density (one plant per 30 L) reduced interplant competition and secondary contamination from nutrients, and can be recommended for phytofiltration of As-contaminated groundwater. This study demonstrated that P. vittata is effective in remediating As-contaminated groundwater to meet recommended standards.  相似文献   

10.
“吃”砒霜的细菌--解析微生物的砷代谢   总被引:2,自引:0,他引:2       下载免费PDF全文
研究发现一些微生物可以利用剧毒的类金属砷(As)为自身生长获取能量甚至用砷代替磷维持生长。本文综合分析了近期的研究进展,从以下6方面解析微生物多重的砷代谢产能机制:(1)化能无机自养As(Ⅲ)氧化供能;(2)有机异养型As(Ⅲ)氧化供能;(3)呼吸性As(Ⅴ)还原供能;(4)As(Ⅲ)氧化偶联的光合作用;(5)As(Ⅲ)氧化、As(Ⅴ)、还原As(Ⅲ)氧化偶联的光合作用之间的关联;(6)As(Ⅴ)代替磷维持细菌生长。阐明微生物利用砷的机理在生命起源、生命多样性、进化、地球化学循环及污染治理等方面都具有重要价值。  相似文献   

11.
12.
This study describes the impact of sorbitol on plantlets regeneration frequency (PRF) of four rice cultivars (japonica, Oryza sativa L.) both of which mature and immature embryo-derived calli were investigated. The variance analysis results showed that PRF of the three elite upland rice cultivars, Handao297 (HD297), Handao502 (HD502), Handao65 (HD65) and one lowland rice cultivar Zhongzuo93 (ZZ93) were significantly increased with addition of appropriate amount of sorbitol in culture media. Supplementing appropriate sorbitol in the media of a continous culture from induction and maintenance to regeneration for mature embryo-derived calli could improve PRF dramatically, originally from 27.6% up to a maximum of 71.8%. Especially to low regenerative capacity (LRC) cultivar HD65, the PRF was increased over 7-fold (from 9.7% to 74.0%). The optimum concentrations of sorbitol for calli induction, subculture and differentiation were 5, 20 and 40 g/l, respectively. Adding sorbitol, only in maintenance media at concentration of 20 g/l, also enhanced the PRF greatly in all the cultivars from 27.6% to 43.3%. Similar results were observed when incorporating with maltose in regenerating media both in immature and mature embryo-derived calli. The optimal concentration was 25 g/l sorbitol + 20 g/l maltose and 20 g/l sorbitol + 25 g/l maltose, respectively. HD297 appeared to be the most responsive genotype compared to other cultivars in PRF, 99.2% in immature embryo-derived calli and 76.8% in mature embryo-derived calli. The results and relevant conclusions might be valuable to establish an efficient plant regeneration system from somatic embryogenesis culture in upland rice.  相似文献   

13.
14.
    
It was recently reported that arsenic trioxide (As_2O_3) can induce complete remission in patients with acute promyelocytic leukemia (APL). In this present article, the biological effect of As_2O_3 on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrephoresis and in situ cell death detection (TUNEL), it was found that As_2O_3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As_2O_3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As_2O_3 induced apoptosis, which might be relative to preventing the cells from As_2O_3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted, However, it was found that As_2O_3 at a high concentratio  相似文献   

15.
铝对水稻幼苗生长和生理的影响   总被引:20,自引:2,他引:20       下载免费PDF全文
石贵玉 《广西植物》2004,24(1):77-80
以不同浓度的铝处理水稻幼苗 ,研究铝对水稻幼苗的生理生化效应。结果表明 ,5 0 μmol·L 1的铝对水稻幼苗生长有促进作用 ,高于 5 0 μmol·L 1后 ,随着铝浓度的增加 ,植株生长明显受到抑制 ,株高、根长、鲜重和干重均下降 ;叶片叶绿素含量和SOD活性下降 ,POD活性先上升后下降 ,细胞膜透性增大。表明高浓度铝的毒害 ,导致体内保护酶活性受到抑制 ,膜系统受到伤害 ,从而影响水稻幼苗的生长。  相似文献   

16.
Certain plant species have been shown to vigorously accumulate some metals from soil, and thus represent promising and effective remediation alternatives. In order to select the optimum forms of nitrogen (N) fertilizers for the arsenic (As) hyperaccumulator, Pteris vittata L., to maximize As extraction, five forms of N were added individually to different treatments to study the effect of N forms on As uptake of the plants under soil culture in a greenhouse. Although shoot As concentration tended to decrease and As translocation from root to shoot was inhibited, overall As accumulation was greater due to higher biomass when N fertilizer was added. Arsenic accumulation in plants with N fertilization was 100-300% more than in the plants without N fertilization. There were obvious differences in plant biomass and As accumulation among the N forms, i.e., NH4HCO3, (NH4)2S04, Ca(NO3)2, KNO3, urea. The total As accumulation in the plants grown in As-supplied soil, under different forms of N fertilizer, decreased as NH4HCO3>(NH4)2S04 > urea > Ca(NO3)2 >KNO3>CK. The plants treated with N and As accumulated up to 5.3-7.97 mg As/pot and removed 3.7-5.5% As from the soils, compared to approximately 2.3% of As removal in the control. NH4+ -N was apparently more effective than other N fertilizers in stimulating As removal when soil was supplied with As at initiation. No significant differences in available As were found among different forms of N fertilizer after phytoremediation. It is concluded that NH4+ -N was the preferable fertilizer for P. vittata to maximize As removal.  相似文献   

17.
We examined the Mn(II) oxidation performance of a bacterium, BY86, collected at Yunotaki Falls Hokkaido, Japan. The bacterium showed rapid oxidation of Mn(II), and brown precipitates containing Mn formed within a few days of incubation. The presence of higher oxidation states of Mn than Mn(II) was ascertained by the UV-vis and XANES sutdy. This bacterium did not oxidize As(III) to As(V) in the absence of Mn. In the presence of Mn, however, As(III) was rapidly oxidized to As(V) on the cell surfaces. These findings indicate that BY86 does not have the ability to directly oxidize As(III) to As(V) within a short period of contact, but indirectly oxidizes it by the Mn oxides generated on the cell surfaces. A phylogenetical study disclosed that BY86 was most closely related to Bacillus cereus with an identity of 99.90%. It is expected that our findings in this study will contribute to the study of Mn(II)-oxidizing bacteria, which play an important role in the biogeochemical cycling of Mn as well as other trace elements including As.  相似文献   

18.
Arbuscular mycorrhizal fungi (AMF) appear to be highly associated with arsenic (As) uptake in host plants because arsenate (As(V)) and phosphorus (P) share the same transporter, whereby AMF can enhance P uptake. A short-term experiment was conducted for low- (0 to 0.05 mM As) and high-affinity (0 to 2.5 mM As) uptake systems, to investigate the AMF role on As uptake mechanism in plants, which may explain As uptake kinetics in upland rice cultivar: Zhonghan 221. When concentration of As ranged from 0 to 0.05 mM, Funneliformis geosporum (Fg) significantly decreased arsenite (As(III)) and monomethylarsonicacid (MMA) uptake when (p < 0.05) compared to non-mycorrhizal (NM) treatment, since the major route for (As(III)) in rice roots—rice silicon transporter Lsi1 would be influenced by Fg inoculation at high As concentrations. Fg can also reduce As(V) uptake significantly (p < 0.05) under both uptake systems relative to NM treatment, whereas, Funneliformis mosseae (Fm) increased As(V) and MMA uptake in rice roots, with MMA uptake rate generally lower than As(III) and As(V). Using suitable AMF species inoculation with rice, As uptake and accumulation in rice grains can be reduced and the risk to human health, once consumed, can be minimized.  相似文献   

19.
Soils from the alluvial flats of the Turia River, Valencia, Spain, which were highly contaminated by decades of industrial activity, were surveyed for native plant species that could be candidates useful in phytoremediation. Concentrations of heavy metals and arsenic (As) in soils reached 25,000 mg Kg(-1) Pb, 12,000 mg Kg(-1) Zn, 70 mg Kg(-1) Cd, and 13500 mg Kg(-1) As. The predominant vegetation was collected and species identified. Soil samples and the corresponding plant shoots were analyzed to determine the amount of As accumulated by the various plant species. Several were able to tolerate more than 1000 mg Kg(-1) As in the soil. Bassia scoparia (Chenopodiaceae) survive in soil with 8375 mg Kg(-1) As. Arsenic accumulation in shoots of the various plant species investigated ranged from 0.1 to 107 mg Kg(-1) dw. Bassia scoparia (Chenopodiaceae), Inula viscosa (Asteraceae), Solanum nigrum (Solanaceae), and Hirschfeldia incana (Brassicaceae) had the highest values for As accumulation.  相似文献   

20.
    
To elucidate the photosynthetic physiological characteristics and the physiological inherited traits of rice (Oryza sativa L.) hybrids and their parents, physiological indices of photosynthetic CO2 exchange and chlorophyll fluorescence parameters were measured in leaves of the maize phosphoenolpyruvate carboxylase (PEPC) transgenic rice as the male parent, sp. japonica rice cv. 9516 as the female parent, and the stable JAAS45 pollen line. The results revealed that the PEPC gene could be stably inherited and trans- ferred from the male parent to the JAAS45 pollen line. Moreover, the JAAS45 pollen line exhibited high levels of PEPC activity, manifesting higher saturated photosynthetic rates, photosynthetic apparent quantum yield (AQY), photochemical efficiency of photosystem II and photochemical and non-photochemical quenching, which indicated that the JAAS45 pollen line has a high tolerance to photo-inhibition/photooxidation under strong light and high temperature. Furthermore, JAAS45 was confirmed to still be a C3 plant by δ^13C carbon isotope determination and was demonstrated to have a limited photosynthetic C4 microcycle by feeding with exogenous C4 primary products, such as oxaloacetate or malate, or phosphoenolpyruvate. The present study explains the physiological inherited properties of PEPC transgenic rice and provides an expectation for the integration of traditional breeding and biological technology.  相似文献   

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