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Photosynthetic activity and antioxidative response of seagrass Thalassia hemprichii to trace metal stress

Acta Oceanologica Sinica 2012年第3期31卷 98-108页

作者： LI Lei HUANG Xiaoping Devajit Borthakur NI Hui State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Graduate University of Chinese Academy of Sciences Beijing 100049China Tropical Marine Biological Research Station in Hainan Chinese Academy of SciencesSanya 572200China The Science and Technology Library of Guangdong Province Guangzhou 510070China Tocklai Experimental Station Tea Research AssociationJorhatAssam 785008India Foreign Language Department Heze UniversityHeze 274000China

This study concerned the accumulation of trace metals in tissues of seagrass ( Thalassia hemprichii) exposed to various concentrations of Zn2+,Cd2+,Pb2+ and Cu2+ for 10 d,and the effect of excessive metals on quantum yield (△F/F′m),photosynthetic pigments and antioxidative enzymes like superoxide dismutase (SOD),guaiacol peroxidase (POD) were also *** was the most highly accumulated ***,high metals levels led to a remarkable breakdown of photosynthetic ***,△F/F′m,chlorophyll and carotenoid were significantly low during prolonged Cu ***,△F/F′m was more severely depressed by Cu and Zn than Pb and ***,*** had positive response by increasing the activity of SOD and *** results indicate that *** is the most sensitive to Cu,and the antioxidative protection mechanisms of *** are more efficiently activated to avoid damage of Zn,Cd and Pb stress. Finally,due to the high Cd-accumulation and strong Cd-tolerance capacity,*** can be used for phytoremediation in Cd-contaminated areas.

关键词： Thalassia hemprichii metal stress photosynthetic pigments quantum yield antioxidant enzymes

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Assessment of Castor Plant (Ricinus communis L.) Tolerance to Heavy metal stress-A Review

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Phyton-International Journal of Experimental Botany 2020年第3期89卷 453-472页

作者： Akwasi Yeboah Jiannong Lu Ting Yang Yuzhen Shi Hanna Amoanimaa-Dede Kwadwo Gyapong Agyenim Boateng Xuegui Yin Department of Crop Breeding and Genetics College of Agricultural SciencesGuangdong Ocean UniversityZhanjiang524088China The National Engineering Laboratory for Crop Molecular Breeding MARA Key Laboratory of Soybean Biology(Beijing)Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing100081China

Increased urbanization and industrialization have greatly contributed to the emission of higher amount of heavy metals such as cadmium,nickel,and lead into the *** metals are non-biodegradable and toxic,causing much effects on plants and by extension to animals and humans,which have become a major global *** inherent ability of plants to resist heavy metal toxicity seems to be the most sustainable and cost-effective *** plant is widely studied due to its tolerance to the effects of heavy metal contaminated soils,owing to its large biomass content and high accumulating *** plants to some extent can tolerate elevated levels of heavy metals through several developed mechanisms,such as activation of antioxidant enzymes,exclusion,accumulation of proline,compartmentalization,organic acid exudation,and *** studies have identified some stress-responsive to aid the tolerance of heavy metals in *** caused by heavy metal toxicity affects seedling growth,biomass,photosynthetic pigments,protein level,and nutrient uptake of castor *** response of castor,however,to these stresses differs among cultivars,metal type and concentration,and time of metal *** review aims to summarize the physiological responses and various defense mechanisms of castor to tolerate and eradicate heavy metal toxicity and some stress-responsive genes identified at transcriptional and posttranscriptional levels that confer metal tolerance in this plant.

关键词： Castor metal stress biomass proline tolerance

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Antioxidative Responses and metal Accumulation in Invasive Plant Species Growing on Mine Tailings in Zanjan, Iran

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Pedosphere 2011年第6期21卷 802-812页

作者： M.M.A.BOOJAR Z.TAVAKKOLI Department of Biology Tarbiat Moalem University

Tailings of a Pb and Zn mine as a metal-contaminated area （Zone 1） with two pioneer plant species, Peganum harmala and Zygophyllum fabago, were investigated and compared with a non-contaminated area （Zone 2） in the vicinity. Total concentrations of Pb, Zn, and Cu in the soil of Zone 1 were 1 416, 2 217, and 426 mg kg-1, respectively, and all exceeded their ranges in the normal soils. The soil pH was in the neutral range and most of the physical and chemical characteristics of the soils from both zones were almost similar. The species Z. fabago accumulated higher Cu and Zn in its aerial part and roots than the normal plants. On the other hand, their concentrations did not reach the criteria that the species could be considered as a metal hyperaccumulator. The species P. harmala did not absorb metals in its roots; accordingly, the accumulation factor values of these metals were lower than 1. The contents of chlorophyll, biomass, malondialdehyde, and dityrosine in these two species did not vary significantly between the two zones studied. In Zone 1, leaf vacuoles of Z. fabago stored 35.6% and 43.2% of the total leaf Cu and Zn, respectively. However, in this species, the levels of phytochelatins （PCs） and glutathione （GSH） and antioxidant enzyme activities were significantly higher in Zone 1 than in Zone 2. In conclusion, metal exclusion in P. harmala and metal accumulation in Z. fabago were the basic strategies in the two studied pioneer species growing on the metal-contaminated zone. In response to metal stress, elevation in antioxidant enzyme activities, increases in the PCs and GSH levels in the aerial parts, and metal storage within vacuoles counteracted each other in the invasion mechanism of Z. ]abago.

关键词： accumulation factor antioxidant enzymes glutathione metal stress phytochelatins

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Enhanced carbon acquisition and use efficiency alleviate microbial carbon relative to nitrogen limitation under soil acidification

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Ecological Processes 2021年第1期10卷 428-440页

作者： Tianpeng Li Ruzhen Wang Jiangping Cai Yani Meng Zhirui Wang Xue Feng Heyong Liu Ronald F.Turco Yong Jiang Erguna Forest-Steppe Ecotone Ecosystem Research Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China. University of Chinese Academy of Sciences Beijing 100049China. Department of Agronomy Purdue UniversityWest LafayetteIN 47907USA.

Background:Soil microbial communities cope with an imbalanced supply of resources by adjusting their element acquisition and utilization *** soil pH has long been considered an essential driver of microbial growth and community composition,little is known about how soil acidification affects microbial acquisition and utilization of carbon(C)and nitrogen(N).To close the knowledge gap,we simulated soil acidification and created a pH gradient by adding eight levels of elemental sulfur(S)to the soil in a meadow ***:We found that S-induced soil acidification strongly enhanced the ratio of fungi to bacteria(F:B)and microbial biomass C to N(MBC:MBN)and subsequently decreased the C:N imbalance between microbial biomass and their *** linear decrease in the C:N imbalance with decreasing soil pH implied a conversion from N limitation to C *** cope with enhanced C versus N limitation,soil microbial communities regulated the relative production of enzymes by increasing the ratio ofβ-glucosidase(BG,C-acquiring enzyme)to leucine aminopeptidase(LAP,N-acquiring enzyme),even though both enzymatic activities decreased with S *** equation modeling(SEM)suggested that higher C limitation and C:N-acquiring enzyme stimulated microbial carbon-use efficiency(CUE),which counteracted the negative effect of metal stress(i.e.,aluminum and manganese)under soil ***:Overall,these results highlight the importance of stoichiometric controls in microbial adaption to soil acidification,which may help predict soil microbial responses to future acid deposition.

关键词： Soil acidification Stoichiometric imbalance metal stress Ecoenzymatic stoichiometry Element-use efficiency

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Silicon and Nitric Oxide-Mediated Regulation of Growth Attributes, Metabolites and Antioxidant Defense System of Radish (Raphanus sativus L.) under Arsenic stress

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Phyton-International Journal of Experimental Botany 2023年第3期92卷 763-782页

作者： Savita Bhardwaj Tunisha Verma Ali Raza Dhriti Kapoor Department of Botany School of Bioengineering and BiosciencesLovely Professional UniversityPhagwara144411India College of Agriculture Fujian Agriculture and Forestry University(FAFU)Fuzhou350002China

Arsenic(As)contaminated food chains have emerged as a serious public concern for humans and animals and are known to affect the cultivation of edible crops throughout the ***,the present study was designed to investigate the individual as well as the combined effects of exogenous silicon(Si)and sodium nitroprusside(SNP),a nitric oxide(NO)donor,on plant growth,metabolites,and antioxidant defense systems of radish(Raphanus sativus L.)plants under three different concentrations of As stress,i.e.,0.3,0.5,and 0.7 mM in a pot *** results showed that As stress reduced the growth parameters of radish plants by increasing the level of oxidative stress markers,i.e.,malondialdehyde and hydrogen ***,foliar application of Si(2 mM)and pretreatment with SNP(100μM)alone as well as in combination with Si improved the plant growth parameters,i.e.,root length,fresh and dry weight of plants under As ***,As stress also reduced protein,and metabolites contents(flavonoids,phenolic and anthocyanin).Activities of antioxidative enzymes such as catalase(CAT),ascorbate peroxidase(APX),guaiacol peroxidase(POD),and polyphenol oxidase(PPO),as well as the content of non-enzymatic antioxidants(glutathione and ascorbic acid)decreased under As *** most of the parameters in radish,As III concentration showed maximum reduction,as compared to As I and II ***,the individual and combined application of Si and NO significantly alleviated the As-mediated oxidative stress in radish plants by increasing the protein,and metabolites *** in the activities of CAT,APX,POD and PPO enzymes were *** of glutathione and ascorbic acid were also enhanced in response to co-application of Si and NO under As *** obtained were more pronounced when Si and NO were applied in combination under As stress,as compared to their individual *** short,the current study highlights that Si and NO synergisticall

关键词： Antioxidant defense system oxidative stress metal stress metabolism reactive oxygen species crop productivity

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两株海洋微生物的活性次级代谢产物研究

两株海洋微生物的活性次级代谢产物研究

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作者： Syed Shams ul Hassan 浙江大学

学位级别：硕士

当今的医药环境迫切地需要新的药物,特别是能杀死具有抗性的病原体的抗生素。尽管在生物合成和化学合成领域,抗生素的合成已经取得了巨大的进步,但自然界仍是新抗生素的最大来源。海洋为海洋生物提供了巨大而多样的栖息地。由于海洋环... 详细信息

当今的医药环境迫切地需要新的药物,特别是能杀死具有抗性的病原体的抗生素。尽管在生物合成和化学合成领域,抗生素的合成已经取得了巨大的进步,但自然界仍是新抗生素的最大来源。海洋为海洋生物提供了巨大而多样的栖息地。由于海洋环境多变的性质,如温度、压力、盐度、金属浓度,海洋环境和缺氧海洋沉积物是海洋生物产生新型化合物的重要来源。具有生物多样性的特殊海洋环境是生物活性天然产物的丰富来源,其中许多天然产物在陆地上未能发现。海洋生物的独特性导致海洋天然产物的多样性。近几十年来,由于其多种生物活性和广泛的用途,海洋天然产物受到广泛关注。现如今已有包括萜类化合物、类固醇、酚类化合物、生物碱多糖、肽、聚酮化合物和脂肪酸在内的16000种天然产物已经从海洋中分离出来。海洋微生物,尤其是海洋真菌和放线菌,已经被证明是寻找结构新颖的次级代谢产物的巨大宝库。放线菌在耐火生物材料的回收和具有药物作用的新次级代谢物的生产中发挥重要的生态学作用。放线菌是抗生素的主要生产者,能产生多种次级代谢物。放线菌产生的抗生素约占三分之二。放线菌因其产生次级代谢物的能力而受到广泛关注。生活在严苛环境中的海洋真菌作为新的生物活性产物来源而受到科学工作者关注由于海洋热液口是地球上最有生产力的环境,因此极端微生物的次生代谢物多样性相当高。Loihichelins和Ammonificins是海洋热液口来源的新天然产物的第一份报道。只有少数来自螃蟹的海洋真菌已经被研究。本项研究中,我们选择一株源自东海沉积物的链霉属放线菌H-1003和一株源自台湾龟山岛富含硫的热液口真菌XZ-1。本研究的目的是从海洋放线菌和真菌产生的次级代谢产物中分离具有药用价值的生物活性化合物。本论文将从两个方面研究海洋放线菌和真菌的次级代谢产物。首先,筛选生物活性化合物来从海洋微生物中得到抗生素。其次,运用生物和非生物胁迫的新策略来发现新的生物活性化合物。最后,对微生物产生的生物活性化合物进行评价和表征。真菌和放线菌菌株都在正常和金属胁迫条件下培养。用乙酸乙酯萃取培养基中的代谢产物,并通过TLC、柱色谱、制备型HPLC等不同的光谱技术进行纯化。通过HPLC,UV和NMR鉴定纯化合物的结构。通过Spot方法研究它们对金黄色葡萄球菌,枯草芽孢杆菌和大肠杆菌的体外抗菌活性。微生物具有对生物和非生物胁迫产生抗性并保持其适应性的各种机制。随着分子生物学和化学生物学技术的进步,已经证实次级代谢物在微生物对环境的适应过程中起着重要作用。在病原体攻击,重金属胁迫,伤害,辐射或高可见光水平等生物和非生物胁迫下,微生物会合成抗胁迫化合物。一些研究表明使用生物和非生物诱导剂可以增加海洋微生物次级代谢物的产量。通过化学方法诱导,包括重金属,是药物发现的新技术之一。在本研究中,海洋放线菌菌株H-1003分别在有、无金属胁迫下培养。用不加任何金属离子的空白培养基培养菌株H-1003,但在空白培养基提取物中没有观察到峰。选用Gause,Ml和ISP2这三种不同类型的培养基作为初始培养基。选用0.5mM、1mM、2mM和4mM/L这四种浓度的五种金属Co2+、Ni2+、Zn2+、Cr2+、Cd2+来筛选适合H-1003菌株的金属离子。180转/分钟培养10天后,除去菌丝体,用等体积的EtOAc萃取培养基两次。结果表明,放线菌的代谢模式随Co2+、Cr2+、混合金属(Co2+ + Cd2+)的刺激而改变,产生4种新的代谢物。新产生的代谢产物经制备型高效液相色谱分离,质谱、核磁结构鉴定,被确认为四个已知化合物enterocin(1),anhydromevalonolactone(2),cyclo-trans-4-OH-(D)-Pro-(D)-Phe(3)and L,L-cyclo(phenylalanyl-tryptophyl)(4)。由于化合物1有包含单取代苯环和甲氧基化的α-吡喃酮环的独特骨架以及极强的抗菌活性,使得该化合物与其他代谢产物具有显著地不同。因此利用响应面分析法进一步研究了化合物1 enterocin的产量。优化后的金属胁迫条件为2mM/L浓度的Co2+,20mg淀粉的高氏培养基,培养时间为10天,摇床转速180转每分钟。在此条件下,enterocin的产量被提升至5.33mg/L,这远远高于对照组的产量。化合物1还显示出抗菌活性,对金黄色葡萄球菌MIC值为62.5μg/ml,对大肠杆菌MIC值为31.25μg/ml,对枯草芽孢杆菌MIC值为31.25μg/ml。1mM浓度的Cr2+胁迫菌株H-1003出现化合物2和3的两个新峰。在其他浓度下仅产生化合物2,1mM是得到化合物2和3的最佳浓度。Co2+和Cd2+的混合金属胁迫菌株H-1003产生化合物4的一个新峰。在此之前,使用单一金属胁迫时,在该区域没有观察到峰,使用两种金属一起胁

关键词： Actinobacteria Fungi secondary metabolites metal stress response surface methodology

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