共查询到19条相似文献，搜索用时 307 毫秒
1.
Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance （TBARS） and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant （wild type）. Leaf discs were incubated in 20%, 40% （w/v） polyethylene glycol （PEG） 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/（m^2·s）]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase （SOD）, catalases （CAT）, ascorbate peroxidase （APX）, guaiacol peroxidase （GPX） and dehydroascorbate reductase （DHAR） were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation （TBARS content） was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress. 相似文献
2.
Oil spills may considerably damage sensitive coastal wetlands. The phytoremediation potential and restoration of a dominant coastal marsh plant, Cyperus rotundus, for diesel pollutant and its phytoremediation effectiveness were investigated in this open-air pot experiment. Cyperus rotundus was transplanted into soil contaminated with diesel at concentrations of 1 000, 5 000, 10 000, 15 000, 20 000 mg/kg. In order to better elucidate the biochemical and physiological responses to diesel pollutants, activity of the antioxidant enzymes peroxidase （POD）, catalase （CAT） and ascorbic acid oxidase （AAO） were determined in the plant tissue after 50 d treatment at the levels mentioned above. The results showed that CAT and AAO of stem and leaf exhibited peak enzyme activities on 15 000 mg/kg soil and 10 000 mg/kg soil respectively, and declined at higher concentrations. Additionally, the increment of biomass and the content of soluble protein, as well as chlorophyll content were affected by diesel. The highest restoration effectiveness appeared at the level of 5 000 mg/kg. Collectively, Cyperus rotundus is a potential plant which can be used for restoring the diesel-contaminated soil. 相似文献
3.
Jaleel CA Gopi R Manivannan P Kishorekumar A Gomathinayagam M Panneerselvam R 《Journal of Zhejiang University. Science. B》2007,8(4):283-288
The ability of triadimefon(TDM),a triazolic fungicide,to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam(Dioscorea rotundata Poir.) tubers during storage under(30±2) °C in the dark,was studied.TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10,25 and 40 d after storage(DAS).Starch,sugars,protein,amino acid contents as well as protease and α-amylase activities were estimated on 15,30 and 45 DAS from two physiological regions viz.,apical and basal regions of the tubers.In normal conditions(control) sprouting occurred on 70 to 80 DAS.The starch content decreased,while protein,amino acid,sugar contents and protease and α-amylase activities were increased due to TDM treatment and led to early sprouting. 相似文献
4.
In this study,we investigated the effects of 6-benzylaminopurine(6-BA)–calcium chloride(CaCl_2)–salicylic acid(SA) treatment on the yellowing and reactive oxygen metabolism of harvested broccoli heads. We dipped fresh broccoli heads in a compound solution(0.6 mmol/L 6-BA + 40 mmol/L CaCl_2 + 3 mmol/L SA) for 5 min and then stored them at 23 °C for 4 days. The results showed that the 6-BA–CaCl_2 –SA postharvest treatment effectively retarded the increase in color values(e.g.,variations from black to white,from green to red,and from blue to yellow) and the decline in chlorophyll content of the broccoli heads. Compared with the control broccoli,the rate of superoxide anion radical(O_2~( ·-)) production and the hydrogen peroxide(H_2O_2) content were lowered by the treatment. We also found significant diff erences in the activities of superoxide dismutase(SOD),catalase(CAT) and peroxidase(POD) in the treated broccoli. Based on these results,we consider 6-BA–CaCl_2 –SA to inhibit the accumulation of reactive oxygen,delay the degradation of chlorophyll,and prolong the shelf life of broccoli heads at 23 °C. 相似文献
5.
Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At ＞250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast＞cell wall＞soluble fraction＞other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels＞250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels＞250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens. 相似文献
6.
Muhammad Abubakkar Azmat Iqrar Ahmad Khan Hafiza Masooma Naseer Cheema Ishtiaq Ahmad Rajwana Ahmad Sattar Khan Asif Ali Khan 《Journal of Zhejiang University. Science. B》2012,13(4):239-243
Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems. 相似文献
7.
In order to analyze the characteristics of surface water resource quality for the reconstruction of old water treatment plant, multivariate statistical techniques such as cluster analysis and factor analysis were applied to the data of Yuqiao Reservoir-- surface water resource of the Luan River, China. The results of cluster analysis demonstrate that the months of one year were divided into 3 groups and the characteristic of clusters was agreed with the seasonal characteristics in North China. Three factors were derived from the complicated set using factor analysis. Factor 1 included turbidity and chlorophyll, which seemed to be related to the anthropogenic activities; factor 2 included alkaline and hardness, which were related to the natural characteristic of surface water; and factor 3 included Cl and NO2-N affected by mineral and agricultural activities. The sinusoidal shape of the score plots of the three factors shows that the temporal variations caused by natural and human factors are linked to seasonality. 相似文献
8.
The bioactivity of the aqueous extracts of the leaf and stem bark of the medicinal plant, Alstonia boonei De Wild (Apocyanaceae), against the pink stalk borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae) was studied in a laboratory bioassay. The extracts were incorporated into artificial diet at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). Both extracts significantly (P<0.01) reduced larval survival and weight in a dose dependent manner. The concentrations that killed 50% of the larvae (LC50) for the stem bark extract were 2.8% and 2.1% at 10 and 20 DAI (days after introduction), respectively, while those for the leaves extract were 5.6% and 3.5%. The weights of the larvae also varied significantly (P<0.05) between the treatments in a dose dependent manner. We conclude that both leaf and stem bark extracts of A. boonei are toxic, used as growth inhibitors to S. calamistis larvae, and hold good promise for use as alternative crop protectants against S. calamistis. 相似文献
9.
Sittichai Wichaidit ;Somson Wongyounoi ;Precharn Dechsri ;Parin Chaivisuthangkura 《美中教育评论》2011,(3):333-338
This study examined conceptual change of Thai middle school students after learning photosynthesis with analogy and model. The analogy mapped key features from the analog （cooking food） to the target concept （photosynthesis） Modeling photosynthesis activity provided the opporttmity for students to understand how plants use sugar to synthesize cellulose and starch. To determine students＇ prior knowledge, the photosynthesis questionnaire was administered to 58 Grade 7 students of urban school. The result revealed that students held alternative conceptions in many aspects, including the origin of plant nutrients, the substances required for photosynthesis, the products of photosynthesis and the role of chlorophyll. After the instruction~ the students were post-tested to determine how students＇ conceptions had changed. The result indicated that the students demonstrated better comprehension than that of the we-test. The percentage of students who changed their ideas to the scientific one was reported and discussed. The present study has implication for both science educators and science teachers who are interested in teaching with analogy and model. 相似文献
10.
INTRODUCTION Leaf senescence is a kind of programmed cell death (PCD) in plants that is highly controlled by a genetically programmed process involving degrada-tion of cellular structures, decline of photosynthesis massive generation of active oxygen species (AOS) and mobilization of nutrients (Nam, 1997; Lim et al.,2003). Many environmental factors have been shown to play a role in causing the photosynthetic decline to lead to premature senescence. Leaves exposed to ultraviolet radia… 相似文献
11.
三唑酮对离体叶片衰老的影响 总被引：5，自引：4，他引：5
用三唑酮处理离体叶片．能显著延缓叶绿素的下降．抑制蛋白质含量的下降和丙二醛(MDA)含量的上升；能提高抗氧化剂的含量，降低超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性。对于衰老过程中，过氧化物酶(POD)活性升高的离体叶片，三唑酮能阻止POD活性的上升．而对衰老过程中过氧化物酶(POD)活性降低的离体叶片，则会抑制POD活性的下降。因此，三唑酮对离体叶片衰老具有显著的延缓作用。 相似文献
12.
以蚕豆叶片为试材,对其进行黑暗诱导衰老,研究了三唑酮处理对蚕豆离体叶片过氧化物酶（POD）、超氧化歧化酶（SOD）、过氧化氢酶（CAT）活性的影响．结果显示,在蚕豆离体叶片衰老过程中,POD活性不断升高,特别是在48h之前十分明显,SOD,CAT活性在48h之前上升,然后有所下降;经三唑酮处理蚕豆离体叶片,三种抗氧化酶活性在处理的前期上升速率明显加快,而且维持上升的时间更长．在整过处理过程中三种抗氧化酶活性均远高于对照组．表明三唑酮处理蚕豆离体叶片后,可以通过提高并维持三种抗氧化酶的活性,增强蚕豆叶片抗氧化能力,进而延缓其衰老进程． 相似文献
13.
杂交水稻叶片衰老与膜脂过氧化作用的关系 总被引：9，自引：0，他引：9
杂交水稻汕优63主茎在抽穗后10d，其叶片自上而下表现出叶绿素和蛋白质含量下降．光合作用速率降低．丙二醇和脂质红过氧化物含量明显增加．SOD活性则为倒三叶＞倒四叶＞倒二叶＞旗叶．实验结果表明：叶片自下而上顺序衰老．叶片衰老与膜脂过氧化作用密切相关． 相似文献
14.
用25mg·L-1的三唑酮溶液处理小麦离体叶片,可抑制叶绿素、蛋白质含量的下降,延缓过氧化物酶(POD)活性的升高,表明三唑酮可以延缓小麦离体叶片衰老。 相似文献
15.
杂交水稻离体叶片衰老与蛋白质代谢的关系 总被引：3，自引：0，他引：3
杂交水稻离体叶片衰老时，叶片中的叶绿素和蛋白质含量下降．游离氨基酸含量增加．氨肽酶和内肽酶的活性显著上升，说明在衰老叶片中氨肽醇和内肽酶的作用是蛋白质降解的主要原因． 相似文献
16.
在杂交水稻汕优63始稳期，用15mmol／LCa(2 =)喷施叶面，能增加抽穗结实期间主茎旗叶的叶绿素和可溶性蛋白质含量，提高超氧物歧化酶（SOD）的活性．降低丙二醛（MDA）含量．延缓叶片衰老；同时，Ca(2 )能增加主德的实位数、结实串和千粒重，从而提高谷产量． 相似文献
17.
考察了壳聚糖叶面喷施、丁香提取液叶面喷施以及不同复配浓度的丁香壳聚糖复合剂叶面喷施方式对樱桃番茄苗期生理的影响。结果表明,丁香与壳聚糖复合剂处理可显著提高樱桃番茄苗期叶片的叶绿素、可溶性糖、可溶性蛋白、过氧化氢酶活性,过氧化物酶活性以及脯氨酸含量。确定了壳聚糖、丁香叶面喷施处理的最佳浓度配比。 相似文献
18.
以威优64、陆青早1号为材料,免耕提高了根系的a—萘胺氧化量、呼吸强度、叶片老化指数,降低了功能叶的过氧化物酶含量,延缓了叶片的衰老;主分量分析表明,功能叶光台速率、呼吸速率、绿叶面积、叶绿素含量、可溶性蛋白质含量、叶片含氮量、根系活力等,都可任选其一作为叶片衰老指标。 相似文献
19.
测定了经空间飞行处理和地面存留的番茄种子（ESE、EBS）和幼苗中活性氧代谢的某些指标．结果表明，SES和EBS之间的活性氧代谢存在明显的差异．SES可溶性蛋白质含量和SOD活性高于EBS．SES及其幼苗表现出比EBS较强的代谢强度，在萌发的起始阶段尤其如此．SES幼苗中的SOD活性和SES活性高于EBS，而MDA含量和产生速率比EBS低得多．以上结果提示，SES中保卫酶系统活性的增加，对于促进种子吸胀和萌发阶段膜结构的修复，维持膜结构的完整性以致提高种子的活力可能具有重要的意义． 相似文献