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1.
为了深入探索Trxs基因的功能,给转基因大麦育种提供理论依据,以啤酒大麦品种Harrington及其过量表达硫氧还蛋白S基因(Trxs)的转基因大麦株系为试验材料,对籽粒灌浆后期旗叶中还原型谷胱甘肽(GSH)含量、抗坏血酸过氧化物酶(APX)活性、叶绿素荧光特性以及不同发育阶段籽粒中GSH含量和产量性状进行研究.结果显示:(1)籽粒灌浆后期转基因大麦旗叶GSH含量与APX活性显著高于非转基因对照;(2)花后15 d时各测定时间点和籽粒灌浆后期不同测定时间转基因大麦旗叶叶绿素荧光参数Fv/Fm与Fv/Fo值普遍高于对照;(3)转基因大麦的产量性状优于对照,其千粒重、单株穗数和单株产量平均分别比对照提高了12.29%、34.34%与41.01%.这些结果表明,Trxs通过影响旗叶和籽粒中GSH含量和旗叶中APX活性,提高了籽粒灌浆后期转基因啤酒大麦抗逆境胁迫的能力,改善了啤酒大麦转基因株系在籽粒灌浆后期的光合性能,有利于提高了单株产量.  相似文献   

2.
采用10%聚乙二醇6000模拟干旱胁迫,研究稀土元素钕对干旱胁迫下玉米幼苗根系抗旱性的影响。结果表明,干旱胁迫显著提高根系丙二醛(MDA)含量和过氧化氢(H_2O_2)含量,提高超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,显著降低了过氧化物酶(POD)、谷胱苷肽转移酶(GST)、谷胱甘肽过氧化物酶(GPX)活性,显著降低抗坏血酸(As A)和谷胱苷肽(GSH)含量及根系生物量。干旱胁迫加剧了根系的氧化胁迫,玉米幼苗根系通过增强抗氧化酶活性抵抗干旱胁迫。外源氯化钕(NdCl_3)处理可显著提高干旱胁迫下玉米幼苗根系抗氧化酶SOD、POD、CAT、GST、GPX活性,显著提高AsA和GSH含量和根系生物量,显著降低MDA和H_2O_2含量,对APX活性无显著影响。盆栽实验结果进一步说明,NdCl_3对轻度和中度土壤干旱下玉米幼苗抗旱性均具有促进作用,对中度土壤干旱下玉米幼苗的抗旱性促进作用更佳。NdCl_3可提高玉米幼苗根系的抗旱能力,缓解干旱胁迫造成的伤害。  相似文献   

3.
水杨酸对干旱胁迫下小麦幼苗抗氧化特性的影响   总被引:3,自引:0,他引:3       下载免费PDF全文
为了给水杨酸在小麦栽培中的应用提供参考依据,以小麦品种百农AK58为材料,用17.5%聚乙二醇6000(PEG6000)模拟干旱胁迫,研究了外源水杨酸对干旱胁迫下小麦幼苗叶片和根系抗氧化特性的影响。结果表明,干旱胁迫显著提高了根、叶细胞质膜透性、丙二醛(MDA)含量及过氧化物岐化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)等抗氧化酶活性。与单独干旱胁迫处理相比,外源施加水杨酸可使干旱下小麦幼苗根系APX、POD、SOD和CAT活性分别增加190.9%、20.4%、42.3%和89.4%,使其膜透性和MDA含量分别降低19.7%和54.6%;对叶片而言,水杨酸可使其APX和POD活性分别增加31.5%和159.6%,使其膜透性和MDA含量分别降低23.7%和53.9%。上述结果说明,干旱胁迫加剧了小麦的氧化胁迫,小麦幼苗则通过增强根、叶抗氧化酶活性以抵抗氧化伤害。外源施加水杨酸可增强小麦幼苗根、叶相关抗氧化酶的活性,从而缓解小麦在干旱下所遭受的氧化伤害,增强其抗旱性。  相似文献   

4.
外源一氧化氮对盐胁迫下水稻根部脂质过氧化的缓解作用   总被引:26,自引:0,他引:26  
 在100 mmol/L NaCl的胁迫条件下,研究了两种浓度的一氧化氮供体硝普钠(sodium nitroprusside,SNP)处理对水稻幼苗根部脂质过氧化的影响。低浓度(10 μmol/L)的SNP处理明显缓解盐胁迫下水稻幼苗根组织膜脂过氧化产物MDA的累积,显著提高可溶性蛋白含量,并诱导根系APX、POD和SOD活性的上升;而高浓度(50 μmol/L)SNP处理的效果则基本相反。表明外源低浓度NO可以通过提高盐胁迫下水稻幼苗根组织的抗氧化能力来缓解氧化损伤。  相似文献   

5.
为探讨GLP7基因参与植物抗氧化胁迫的作用机制及其生物学功能,以转GLP7基因大豆T2代株系及其受体品种垦丰16为材料,在氧化剂甲基紫精(MV)胁迫条件下,测定植株叶绿素、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性的变化情况.结果表明:相对于非转基因大豆,转基因大豆在MV氧化胁迫下MDA含量降低,总叶绿素含量增加,SOD、CAT活性显著提高.初步证明GLP7的过量表达提高了大豆的抗氧化能力,降低了氧化胁迫对大豆幼苗的损伤.  相似文献   

6.
铝(Al)和锰(Mn)是限制酸性土壤作物生长的两大主要因素。以耐铝性差异较大的两个大麦品种为材料,研究了不同处理对大麦生长、叶片功能和氧化胁迫指标的影响。结果表明,与对照相比,铝毒害导致大麦根长下降,根系干物质量降低,锰毒害显著降低植株株高和地上部干物质量,铝锰共存时锰加重大麦铝毒害。铝锰胁迫降低功能叶叶绿素含量和光合能力,复合处理下叶片功能指标下降幅度高于单独铝或锰处理。胁迫处理下叶片功能指标的下降幅度以叶绿素a含量和叶片蒸腾速率最明显。胁迫处理对铝敏感品种的生长和叶片功能毒害强于耐铝品种。铝锰胁迫引起大麦功能叶丙二醛(MDA)含量增加,过氧化物酶(POD)和 超氧化物歧化酶(SOD)活性增强,铝敏感品种增幅更大,复合处理时两品种叶片 MDA 积累量及铝敏感品种 POD 和 SOD 活性增幅显著高于单独铝或锰处理。  相似文献   

7.
干旱胁迫对大麦幼苗根系的影响   总被引:1,自引:0,他引:1  
为了解干旱胁迫对大麦幼苗根系生长的影响,采用盆栽称重控制土壤含水量的方法,测定了土壤含水量为田间持水量的85%、55%、45%和35%等4个处理下, 4个抗旱性不同的大麦品种的幼苗根系形态和根系吸收能力等相关指标。结果表明,随着土壤含水量的减少,大麦幼苗的最长种子根、根尖数、根组织含水量均呈下降趋势;根分支数和根冠比总体呈上升趋势;根鞘大小和根毛密度整体上呈先上升后下降的趋势;根系活力与根总吸收面积和根活性吸收面积之间存在一定的互补效应。抗旱性较强的大麦品种较抗旱性较弱的品种,在干旱胁迫下能够保持更庞大的根系、更大的根-土交互面和更高的根系吸收能力。幼苗根系形态可以作为大麦耐旱性的筛选指标。  相似文献   

8.
为探究低磷胁迫下外源褪黑素(Melatonin,MT)对大麦幼苗根系生长发育调控作用,以磷敏感型大麦品种GN42为试验材料,设置正常磷(CK)、低磷和低磷添加MT 3个处理,比较分析了不同处理间大麦幼苗根系表型特征、解剖构造和相关基因表达量的差异。结果表明,低磷胁迫后大麦幼苗根系生长受到抑制,表现为根系总长度、表面积和体积均不同程度下降,且根冠厚度减少,活性氧(ROS)过量积累,花青素含量增加,根系磷转运蛋白相关基因Hvpht1;1上调表达,花青素合成基因Hvant和MT合成基因Hvcomt均下调表达。低磷胁迫下添加外源MT后,幼苗根系生长受抑制程度缓解,根系总长、表面积和体积均显著增加,根冠厚度也显著增加,ROS积累量明显变少,且3种基因都不同程度上调表达。由此说明,外源MT可以有效缓解低磷胁迫对大麦幼苗生长发育的不利影响,提高植株对低磷胁迫的适应性。  相似文献   

9.
《杂交水稻》2017,(1):74-77
通过添加外源H_2O_2的方式,研究了H_2O_2对盐胁迫下水稻幼苗根系形态和抗氧化系统的影响。结果表明,低浓度的H_2O_2(5~100μmol/L)均可促进盐胁迫下水稻幼苗根系生长和根毛分化,诱导根系SOD、POD和CAT活性增强,增加脯氨酸含量,降低MDA含量,增强其抗盐性,但H_2O_2处理浓度过高(500μmol/L)时反而加重了根系的氧化胁迫伤害。  相似文献   

10.
为探讨外源亚精胺(Spd)对燕麦幼苗生长和抗旱性的影响,选用燕麦品种坝莜1号为材料,以PEG-6000模拟水分胁迫,采用砂培法研究了叶面喷施不同浓度(0.3、0.6、0.9和1.2mmol·L~(-1))外源Spd后燕麦幼苗生长、活性氧代谢、抗氧化酶活性及非酶抗氧化剂和渗透调节物质含量的变化。结果表明,PEG胁迫显著抑制了燕麦幼苗生长。在PEG胁迫下,与只喷施蒸馏水的对照相比,0.6mmol·L~(-1) Spd处理对燕麦幼苗根系活力、抗坏血酸(ASA)含量和抗坏血酸过氧化酶(APX)活性具有显著的促进作用;喷施0.9mmol·L~(-1)外源Spd明显提高了燕麦幼苗的株高、根长、生物量积累,抑制了O_2~-·、H_2O_2和膜脂过氧化产物MDA的生成,增强了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和谷胱甘肽还原酶(GR)的活性,降低了游离氨基酸含量,促进了脯氨酸、可溶性糖和可溶性蛋白的积累,维持了较高的渗透调节能力;1.2mmol·L~(-1)外源Spd处理后幼苗生长、抗氧化能力和渗透调节作用出现下降趋势。综合来看,在PEG胁迫下,叶面喷施0.9mmol·L~(-1)Spd可通过提高幼苗抗氧化和渗透能力,维持生物膜系统的稳定,减轻渗透胁迫对幼苗的伤害,促进生长和增强抗旱性。  相似文献   

11.
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.  相似文献   

12.
Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.
  相似文献   

13.
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.  相似文献   

14.
SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.  相似文献   

15.
Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.  相似文献   

16.
Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.  相似文献   

17.
Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.  相似文献   

18.
Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.  相似文献   

19.
Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.  相似文献   

20.
In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.  相似文献   

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