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1.
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
2.
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
3.
本文以沈阳市五种绿化植物为材料，分析其叶片含氟量，旨在用叶片含氟量指示大气氟污染状况。结果证实：叶片含氟量呈秋叶＞夏叶＞春叶，成叶＞幼叶的规律．秋季成熟叶片能较好地反映一个生长季内的氟污染情况。根据（μ＋ｓ）统计原理，以山毛桃叶片含氟量为指标，将沈阳市中环路各地段划分为四个污染等级。 相似文献
4.
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
5.
利用BPCL型微弱发光测量仪测量了袋鼠花同一枝条上不同叶位的叶片超弱发光的变化;利用紫外可见分光光度计测定了与生理状态相关的过氧化物岐化酶(SOD)、叶绿素含量随叶位的变化规律.结果发现:随叶龄的增加,叶片的自身超弱发光强度和延迟发光衰减参数先增加,然后达到一个相对稳定阶段,随后又开始减弱;SOD、叶绿素的活性改变与超弱发光之间有一定的联系,叶片在生长过程中叶绿素含量逐渐降低,SOD活性随叶龄的增加是下降的.认为衰老是生物体系生理状态变化的体现,超弱发光可以作为一个整体性指标从体系内部各组成之间的相互关系上研究叶片的衰老过程及衰老机理. 相似文献
6.
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
7.
周泉澄 《南京晓庄学院学报》2011,(6):73-76
以高产小麦宁麦8号和宁麦9号为研究对象,对两材料整个衰老过程中旗叶脂肪酸含量的变化进行了研究．结果表明：实验中两材料旗叶脂肪酸中14：0、16：0、18：1和18：2的含量呈现上升趋势;而16：1和18：3的含量则呈现下降趋势．脂肪酸不饱和指数也呈下降态势,其中18：3的变化对脂肪酸不饱和指数影响最大．宁麦9号较宁麦8号在不同脂肪酸变化上比较缓慢,表明宁麦9号膜结构在整个旗叶衰老期间相对稳定,这可能是宁麦9号高产抗早衰的基础之一．脂肪酸不饱和指数和16：1含量可以作为育种中抗早衰的指标． 相似文献
8.
傅志军 《陕西理工学院学报(社会科学版)》1998,(3)
太白红杉是秦岭太白山森林生态系统中的一个正常的成熟种群．它在系统内各个层次和各体积级中都具有相当数量的个体,显示出种群在系统内的优势地位．太白红杉叶中元素含量有着N＞Ca＞P＞Mg＞Fe＞Mn＞Zn的顺序,而土壤中元素含量顺序是N＞P＞Ca＞Gg＞Fe＞Mn＞Zn．影响太白红杉种群结构的根本原因不是土壤中元素舍量大小,而是海拔高度的变化引起生境条件的变化所致． 相似文献
9.
采用干法灰化处理植物体样品,湿法处理土壤样品.用火焰原子吸收法测定香附子与大香附中Mg、Cr、Mn、Fe、Ni、Cu、Pb等7种微量元素的含量.结果显示：香附中各元素的总体含Mg＞ Fe＞ Ni＞ Mn＞Cu＞ Pb＞Cr,大香附Mg＞Fe＞ Mn＞ Ni＞Cu＞ Pb＞Cr.两种植物对Mg外的6种元素的富集系数都小于1.同种元素在同一植株中不同部位的含量不同.香附中：Mg元素叶＞根＞茎;Fe、Cr、Ni、Pb四种元素含量根＞叶＞茎;Cu、Mn是叶＞茎＞根.大香附中：Mg元素叶＞根＞茎;Cr、Mn、Ni三元素含量根＞茎＞叶;Fe根＞叶＞茎;Cu、Pb的含量茎＞根＞叶.两种草药的Cr、Pb含量均超过2000年的《中国药典（一部）》标准. 相似文献
10.
在蚕豆离体叶片衰老过程中,叶绿体色素和蛋白质含量均不断降低。用50m g.L-1的三唑酮溶液处理蚕豆离体叶片,能显著抑制其叶绿素a、叶绿素b、类胡萝卜素、水溶性蛋白质及非水溶性蛋白质含量的下降,表明三唑酮具有延缓蚕豆离体叶片衰老的作用。 相似文献
11.
北方桑树中1-脱氧野尻霉素含量的测定 总被引：1，自引：0，他引：1
用改进的高效液相色谱-紫外吸收方法(HPLC-UV)对8个北方桑树品种中的1-脱氧野尻霉素(1-deoxynojirimycin,DNJ)含量测定。结果表明:0.05 mol/L HCl提取桑树叶片DNJ,经9-芴甲基酰氯(FMOC-Cl)衍生化,可快速而比较准确地测定桑树叶片中DNJ含量。8个桑树品种中部叶片的DNJ含量高于上、下部叶片,北方当地品种"泰来桑"叶片中DNJ含量高于外引品种。 相似文献
12.
Blue jays (Cyanocitta cristata) responded to projected black-and-white silhouettes of cherry leaves that were either undamaged or were damaged by either cryptic caterpillars that disguise leaf damage due to their feeding or by noncryptic caterpillars that do not disguise leaf damage due to their feeding. Pecks to the key on which the images were projected were reinforced only if interresponse times fell within specified temporal boundaries. These boundaries were different in the presence of the two types of leaf damage. Following training with one exemplar of each damage type, the jays correctly categorized novel instances of both types. They categorized novel undamaged leaves as if they were examples of leaves showing damage by cryptic caterpillars. Results suggest that the jays can readily discriminate and generalize to new members of a polymorphous stimulus class. The results suggest that techniques for the study of concept formation in animals can be applied to an animal’s ability to categorize stimuli that are involved in a potential prey-predator relationship. 相似文献
13.
白肋烟TN90成熟期叶绿体色素及糖类物质动态初探 总被引：2，自引：0，他引：2
随烟叶成熟进程推进 ,可溶性总糖、还原糖、淀粉及比叶重增加 ,过熟时稍有回落 ,峰值下、中、上各部位分别在封顶后第 3,4 ,5周 ,正置其适熟期 ,且各时期的值是上部叶 >中部叶 >下部叶 ;chla ,chlb ,类胡萝卜素 (CTk)下降 ,但降幅是chla >chlb >CTk ,致使chla/chlb ,chl/CTk比值减小 .以上生理生化变化与白肋烟的生长发育吻合 ,证实在当地生态环境和栽培措施下 ,TN90上、中、下各叶位成熟期分别为封顶后 3,4 ,5周 ,兼顾三部位 ,封顶后第四周砍株晾制 ,可获最佳品质 .这为诊断白肋烟成熟及适时砍收提供了技术参数和理论依据 相似文献
14.
Gama-aminobutyric acid accumulation in Elsholtzia splendens in response to copper toxicity 总被引：3，自引：0，他引：3
A solution with different Cu supply levels was cultured to investigate gama-aminobutyric acid (GABA) accumulation in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species. Increasing Cu from 0.25 to 500 μmol/L significantly enhanced levels of GABA and histidine (His), but considerably decreased levels of aspartate (Asp) and glutamate (Glu) in the leaves. The leaf Asp level negatively correlated with leaf Cu level, while leaf GABA level positively correlated with leaf Cu level. The leaf Glu level negatively correlated with leaf GABA level in Elsholtzia splendens. The depletion of leaf Glu may be related to the enhanced synthesis of leaf GABA under Cu stress. 相似文献
15.
钱和 《浙江大学学报(A卷英文版)》2004,5(6)
Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 (15.5 and 511.6(6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH˙) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH˙ color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC90) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants. 相似文献
16.
Yue ZHANG Hai-peng LV Cheng-ying MA Li GUO Jun-feng TAN Qun-hua PENG Zhi LIN 《Journal of Zhejiang University. Science. B》2015,16(2):103-112
目的:从茶树中克隆一种可以催化表没食子儿茶素没食子酸酯(EGCG)生成甲基化EGCG的酶——咖啡酰辅酶A氧甲基转移酶(CCo AOMT),实现甲基化EGCG的酶学合成,为甲基化EGCG的进一步开发利用提供理论依据和技术指导。创新点:本研究首次从茶树中克隆了一条CCo AOMT基因组序列;分析了CCo AOMT基因在不同茶树品种和不同成熟度茶鲜叶中的基因表达规律;证明了CCo AOMT具有催化合成甲基化EGCG的生物活性。方法:采用聚合酶链式反应(PCR)和序列分析获得CCo AOMT的编码序列和基因组序列;采用高效液相色谱-四级杆-飞行时间串联质谱技术(HPLC-QTOF-MS)分析酶促反应生成的甲基化EGCG产物(图4);采用实时荧光定量PCR分析CCo AOMT基因的表达差异(图5)。结论:本研究从茶树中克隆了CCo AOMT基因的编码序列(738 bp)和基因组序列(2678 bp),明确了该基因具有4个内含子和5个外显子;揭示了CCo AOMT可以催化EGCG生成EGCG4"Me、EGCG3"Me和EGCG3’Me等多种甲基化产物;证明了CCo AOMT具有催化生成甲基化EGCG的活性;并发现该基因的表达量高低与茶鲜叶的成熟度呈正相关关系。 相似文献
17.
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
18.
Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes of Sedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations supplied as Pb(NO3)2. Lead concentrations in leaves and stems of the accumulating ecotype were 4-9 times and 3-5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of the accumulating ecotype were 4-9 times and 8-11 times higher than those of the non-accumulating ecotype, respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots to shoots. The subcellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fraction in stems of the accumulating ecotype and the percentage increased to 80% both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb. 相似文献
19.
INTRODUCTIONLead (Pb)existsinmanyformsinnaturalsourcesthroughouttheworld ,andisnowoneofthemostwidelyandevenlydistributedtracemet als (Nriagu ,1 992 ) .Soilandplantscanbecon taminatedbyPbfrompaints,gasolineadditives,Pbsmeltingandrefining ,pesticideproducti… 相似文献
20.
A field experiment was conducted to study the response of individual leaf spectral reflectance to five levels of nitrogen
fertilizer treatments in rice (Oriza sativa L.) plants. Sampling was combined through a rice canopy at upper, medium and low levels for biomass, nitrogen and water content
measurements with spectral signals from the leaves. The vertical gradients of leaf biomass, nitrogen and water contents were
associated with the nitrogen availability during tillering, panicle formation, initial heading and heading. Rice plants treated
with the lowest rate of N could be characterized with the lowest value of gradient in leaf biomass and leaf water content
and the highest value of gradient in leaf N concentration. A spectral gradient of single reflectance (R), ratio (RVI) and
normalized difference (ND) of two individual reflectances was defined as this yielded a better relationship between the spectral
data and leaf nitrogen concentration. The results suggested the spectral gradients may be used as an improved diagnostic tool
for nitrogen status.
Project (49771056) supported by Natural Science Foundation of China(NSFC). 相似文献