水分条件对豌豆保护酶活性及膜脂过氧化的影响

为探讨不同水分条件对豌豆保护酶系统和膜脂过氧化的影响,采用盆栽人工控水试验方法,模拟干旱胁迫及复水条件,研究了不同水分处理对花荚期豌豆叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及过氧化产物丙二醛(MDA)含量和脂膜相对透性(RC)的影响,并对花荚期豌豆抗氧化能力进行了综合评价.结果表明:不同程度干旱胁迫历时5 d时并未影响豌豆叶片SOD、CAT活性,但有明显的滞后效应.重度干旱胁迫历时10 d可显著降低豌豆叶片SOD、CAT活性,显著提高MDA含量.不同程度的干旱胁迫均导致豌豆叶片POD活性提高,膜脂相对透性加大.复水可对干旱胁迫所造成的CAT、POD活性变化产生显著补偿作用,对SOD活性变化产生超补偿作用.同时,可显著降低MDA含量和脂膜相对透性;干旱胁迫历时10 d内和复水历时10 d内,豌豆有较强的抗氧化能力,仅在重度胁迫10 d后复水历时达到10 d时抗氧化能力趋弱.     

苗期干旱胁迫及复水对玉米植株生长及抗氧化酶活性的影响

采用盆栽控水试验,研究了对水分敏感性不同的2个玉米品种酒单2号和豫玉22号幼苗在水分胁迫及复水后株高、植株生物量、叶片MDA含量、SOD、POD及CAT等酶活性的变化,以探讨干旱胁迫及复水对玉米生长发育及抗氧化酶的影响机制。结果表明,干旱胁迫可抑制2个玉米品种苗期植株生长,导致株高、地上部生物量显著下降,酒单2号对干旱的敏感性高于豫玉22号。复水后,2个品种的株高、生物量都产生了补偿效应,豫玉22号更明显。干旱胁迫增加了2个品种叶片的丙二醛含量,豫玉22号变化幅度小于酒单2号。复水后豫玉22号叶片中MDA含量更接近于对照水平。干旱胁迫下,豫玉22号通过保持较高的SOD活性来减弱活性氧伤害,而复水后通过较高的SOD、POD协同作用有效清除活性氧,避免对细胞膜造成伤害。     

甜菜碱对干旱胁迫下棉花幼苗生理特性的影响

以新疆广泛种植的棉花品种新陆早18号为试材,通过测定棉花幼苗体内脯氨酸、可溶性糖和丙二醛（MDA）的含量及抗氧化酶包括超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）的活性,研究叶面喷施不同浓度甜菜碱（Glycine betaine,GB）对干旱胁迫下棉花幼苗生理特性的影响。结果表明,干旱胁迫下,与对照相比,脯氨酸、可溶性糖、MDA含量及SOD和POD活性都显著提高,喷施甜菜碱后促进脯氨酸和可溶性糖含量进一步提高,酶活也显著升高,同时有效抑制了丙二醛含量的增加,CAT活性受干旱胁迫及甜菜碱的影响较小。研究表明喷施低浓度甜菜碱在一定程度上可以缓解干旱胁迫对棉花幼苗的伤害。     

不同氮营养对干旱逆境下水稻生长及抗氧化性能的影响研究

局部无菌培养条件下,采用聚乙二醇(PEG6000)模拟水稻幼苗的干旱逆境,研究不同氮营养对其生长及抗氧化性能的影响。结果表明,与缺氮及无机氮处理相比,干旱胁迫后,有机氮营养处理的水稻具有较强的叶片抗脱水能力及茎叶干物质积累能力,并可维持相对较高的叶水势;抗氧化性能方面,有机氮营养的水稻叶片保护酶(SOD、POD、CAT)在干旱胁迫后可维持相对较高活性或受抑程度较低,所受膜脂过氧化(MDA含量)程度亦相对较低。     

NA-MY助剂对玉米萌发及苗期抗旱性的影响

为探究干旱条件下玉米种衣剂功能助剂对玉米种子萌发及幼苗生长的影响,将自行研制NA-MY助剂和种衣剂混合后对郑单958种子包衣,用15%PEG-6000溶液模拟土壤干旱环境,分别测定了干旱胁迫下比拌种衣剂单独包衣,以及NA-MY助剂和比拌种衣剂混合后包衣的玉米种子在萌发及幼苗生长中的各项生理指标。结果表明,干旱胁迫下玉米发芽能力显著低于正常水分条件,幼苗中SOD、POD、CAT活性,相对电导率和MDA含量均增加,但叶绿素a+b含量、类胡萝卜素含量和根系活力降低。NA-MY助剂与比拌种衣剂混合后包衣可显著促进干旱胁迫下玉米种子的萌发和幼苗根系生长,有效提高幼苗活性氧清除系统中抗氧化酶活性和抗氧化物的含量,减少电解质渗出率和MDA的积累。由此可见,应用NA-MY助剂包衣可以减轻干旱胁迫对玉米萌发和幼苗伤害,提高玉米抗旱性。本研究结果为NA-MY助剂在田间的应用提供了参考数据。     

干旱胁迫及复水对大豆关键生育时期叶片生理特性的影响

以“辽豆15”为试材，在开花期和鼓粒期设置轻度干旱（土壤相对湿度65%±5%）和重度干旱（土壤相对湿度50%±5%）以及对照（土壤相对湿度80%±5%）处理，开展大豆干旱及复水控制试验。干旱处理持续7d、14d和21d，并在胁迫结束后进行复水，复水水平与对照处理一致。达到胁迫时间当日和复水后第7天取大豆倒三叶叶片，测定叶片可溶性蛋白和丙二醛（MDA）含量以及超氧化物歧化酶（SOD）和过氧化物酶（POD）活性，研究干旱胁迫对以上生理指标的影响以及复水后补偿效应。结果表明：开花期，轻度干旱和重度干旱胁迫均使叶片可溶性蛋白和MDA含量以及POD活性显著升高，轻度干旱胁迫使SOD活性显著升高。鼓粒期，大豆受干旱胁迫影响后，叶片可溶性蛋白含量、MDA含量、SOD活性显著升高，但POD活性显著降低。复水对大豆叶片可溶性蛋白含量、MDA含量和SOD活性均出现补偿效应，但对POD补偿效应不明显。由此可见，干旱会对大豆叶片造成过氧化伤害，主要表现在抗氧化酶和渗透调节物质含量的提高，同时复水可使大豆叶片由干旱造成的过氧化伤害得到缓解，表现出不同程度的补偿效应。     

长期铈喂养对鲤鱼肝胰脏、肾脏抗氧化酶活性的影响

为了探讨稀土元素铈对鱼类的生态毒理学效应,在基础饲料中分别添加0(对照)、20、42、65mg·kg-1的硝酸铈饲喂鲤鱼60 d,研究铈对鲤鱼肝胰脏、肾脏自由基的清除能力和抗氧化酶活性的影响。结果表明,与对照组相比,42、65mg·kg-1组能显著提高鲤鱼的抗氧化防御能力,42 mg·kg-1为最佳添加量。20 mg·kg-1组,除肝胰脏、肾脏GSH-Px活性显著升高,肝胰脏内抑制羟自由基能力显著降低外,其它均无明显变化。42 mg·kg-1组,肝胰脏、肾脏抑制羟自由基能力、CAT、MAO活性、肾MDA含量、肝胰脏SOD活性、抗超氧阴离子自由基能力均显著降低,而肾SOD活力显著升高。65 mg·kg-1组,肝胰脏、肾脏抑制羟自由基能力、CAT、MAO活性、肾MDA含量及肝胰脏抗超氧阴离子自由基能力、SOD、GSH-Px活性均显著降低,肾SOD、GSH-Px活性却显著升高。此外,肝胰脏比肾脏对硝酸铈更趋敏感。由此可见,饲料中适当添加稀土元素铈能提高鱼的抗氧化防御能力。本研究结果为稀土元素在饮料添加中的合理应用及相关研究提供了参考。     

几种杀虫剂胁迫对黄瓜幼苗抗氧化酶活性和相关生理指标的影响

明确杀虫剂多次施用后对黄瓜幼苗抗氧化酶活性和相关生理指标的影响,对指导黄瓜(Cucumis sativus L.)合理用药具有重要作用。本研究以室内盆栽的黄瓜幼苗为试材,研究了几种常用化学杀虫剂吡虫啉、啶虫脒、溴氰菊酯及生物杀虫剂玫烟色棒束孢对黄瓜幼苗抗氧化酶活性(SOD、POD、CAT)及丙二醛MDA、脯氨酸和蛋白质含量的影响。结果表明:不同杀虫剂对黄瓜幼苗抗氧化酶活性及相关生理指标的影响不同。当供试3种化学杀虫剂胁迫黄瓜幼苗2 d时,其体内SOD、POD、CAT活性与对照无显著差异;当胁迫时间延长到4 d时,溴氰菊酯和啶虫脒处理的黄瓜幼苗体内3种抗氧化酶活均明显升高且与对照差异显著;当胁迫时间延长到6 d时,3种化学杀虫剂均造成黄瓜幼苗体内SOD、POD活性升高且与对照差异显著,其中溴氰菊酯影响较吡虫啉和啶虫咪严重;胁迫8~10 d后,各处理黄瓜幼苗体内3种抗氧化酶活性均开始下降或恢复正常。同时,3种化学杀虫剂胁迫黄瓜幼苗4~8 d时,MDA和脯氨酸含量升高并与对照差异显著;胁迫10 d时,啶虫咪和溴氰菊酯胁迫的黄瓜幼苗MDA含量仍显著高于对照,而脯氨酸含量开始下降并趋于正常。此外,3种化学杀虫剂胁迫黄瓜幼苗2~8 d时均造成其蛋白质含量的降低,而生物杀虫剂玫烟色棒束孢胁迫对黄瓜幼苗SOD、POD、CAT活性及MDA、脯氨酸和蛋白质含量均没有显著影响。可见生物杀虫剂玫烟色棒束孢较3种化学杀虫剂对黄瓜幼苗安全,黄瓜幼苗受化学杀虫剂胁迫后需要一个过程才能修复杀虫剂对其自身造成的伤害。     

氯化胆碱对干旱胁迫下地黄抗氧化代谢及梓醇含量的影响

用100,300,500 mg/L的氯化胆碱(CC)水溶液喷施干旱胁迫下的地黄叶片,研究了CC对干旱胁迫下地黄叶片抗氧化代谢、细胞膜稳定性、叶绿素荧光参数及块根中梓醇含量的影响.结果表明,叶面喷施CC有效调节了干旱胁迫下地黄叶片的抗氧化酶SOD、APX、CAT的活性,降低了叶片MDA的含量和相对电导率,减缓了叶绿素的降解.因此,使地黄叶片在干旱胁迫条件下维持较高的通过PSI的电子传递速率(Fv/Fo)、PS Ⅱ最大光化学效率(Fv/Fm)、实际光化学效率(ΦPS Ⅱ)和光化学猝灭系数(qP),从而提高了干旱胁迫下地黄块根的产量和梓醇含量,其中以300 mg/L的CC浓度效果较好.     

氯化胆碱对干旱胁迫下玉米幼苗叶片膜结构保护机制的研究

用300 m g/L氯化胆碱(CC)浸种与叶面喷施相结合作预处理,然后用15% PEG- 6000 模拟干旱胁迫。发现CC在干旱条件下可减缓CAT、POD活力和类胡罗卜素含量的降低, 特别是改变了SOD活力在干旱胁迫下通常呈波浪式变化的规律, 使其在实验条件下一直呈上升趋势。这些可能是膜结构得到保护, 从而使膜脂过氧化产物MDA 产生及细胞电解质渗漏都明显减少的主要原因。     

剑麻提取物对福寿螺的毒理效应

为探讨剑麻对福寿螺的防治效果及其作用机制,利用浸杀试验法,评价了剑麻鲜叶水浸液、叶干粉正丁醇提取物和乙醇提取物对福寿螺的毒杀效果,并测定了59 mg·L-1、96 mg·L-1的正丁醇提取物和180 mg·L-1、325 mg·L-1的乙醇提取物对福寿螺肝组织超氧化物岐化酶(SOD)、胆碱酯酶(ChE)、腺苷三磷酸酶(ATPase)酶活性的影响。结果表明:剑麻鲜叶水浸液、正丁醇提取物和乙醇提取物对福寿螺均具有一定的毒杀效果,处理72 h后,对福寿螺的半致死浓度(LC50)分别为35.3 g·L-1、93.3 mg·L-1、298.6 mg·L-1,其对应的95%的置信区间为32.9~37.7 g·L-1、87.6~99.7 mg·L-1、272.9~318.7 mg·L-1。剑麻乙醇提取物和正丁醇提取物处理福寿螺12h后,肝组织SOD活性均表现为在低浓度下变化不大,在高浓度下酶活性显著增加;处理48 h后,在高浓度正丁醇提取物作用下,SOD活性仍显著高于清水对照,而在高、低浓度乙醇提取物作用下,其SOD活性与对照之间均无显著差异。剑麻提取物一定程度上诱导了福寿螺肝组织ChE的活性,其中正丁醇提取物对ChE影响较大,96 mg·L-1处理螺48 h后,酶活性显著高于对照(P<0.05)。正丁醇提取物对福寿螺肝组织ATPase活性的影响,总体表现为低浓度促进高浓度抑制,而乙醇提取物对其影响无明显规律。因此,剑麻对福寿螺有一定的防治效果,具有良好的应用前景。     

干旱胁迫下甜橙叶片保护酶体系的变化研究

对2年生枳[Poncirus.trifoliate(L.)Raf.]砧无病毒奉节72-1脐橙[Citrus.sinensis(L.)Osbeck.cv.Fengjie.72-1.navel]嫁接苗进行持续性干旱胁迫处理,研究干旱胁迫期间甜橙叶片保护酶活性和丙二醛(MDA)含量随土壤和植株水分变化的生理适应性。结果表明,干旱胁迫明显导致了过氧化氢酶(CAT)活性下降,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性上升,而MDA含量变化不明显。干旱胁迫初期或轻度胁迫期,保护酶活性已具有明显的适应性反应;当处于中度胁迫时,POD和SOD依然保持很高活性。在防止MDA产生中,CAT的作用不明显,POD和SOD起主要的协同作用。     

Effects of Bt-maize material on the life cycle of the land snail Cantareus aspersus

Insect resistant Bt-maize (MON 810) expresses active Cry1Ab endotoxin derived from Bacillus thuringiensis (Bt). Snails constitute non-target soil species potentially exposed to Bt-toxin through consumption of plant material and soil in fields where transgenic plants have been grown. We studied the effect of the Cry1Ab toxin on survival, growth and egg hatchability of the snail Cantareus aspersus. From the age of 4 to 88 weeks, snails were fed either powdered Bt-maize or non-Bt-maize and exposed to soil samples collected after harvesting either the Bt-maize or non-Bt-maize. We applied four treatments: non-Bt soil + non-Bt-maize (MM); Bt soil + Bt-maize (BB), non-Bt soil + Bt-maize (MB), Bt soil + non-Bt-maize (BM). Eggs laid by snails not exposed to Bt-toxin were also exposed to the two types of soils (Bt and non-Bt soil).At the end of growth (47 weeks of exposure), snails exposed to Bt-toxin in food and soil (BB) had a growth coefficient (GC) 25% lower than unexposed snails (MM). After the first period of reproduction (68 weeks) a significant difference remained for body mass GC between the BB and MM treatments. Differences in body mass were not significant at the end of exposure (88 weeks). For snails not previously exposed to Bt material, hatchability of eggs was similar in the soils tested. The outcome of the experiments indicates that, in growing snails, long-term exposure is needed to reveal an effect of Bt-maize. The hazard analysis of Bt-maize which we performed, based on a worst-case scenario, i.e. snails having no food choice, should now be complemented by other simple measurements, e.g. food intake, to understand the underlying mechanisms involved.     

福寿螺对水体环境与水体微生物的影响

福寿螺为首批入侵中国的16种危害最大的外来物种之一,它适应性强、食性广泛、繁殖速度快,近年来对稻田等水体生态系统造成了较大危害。本研究通过室内养殖试验,探讨了福寿螺对水体环境,以及福寿螺养殖液对水体放线菌和酵母菌的影响效应。结果发现,与对照处理相比,养殖福寿螺的水体呈弱酸性,水体的浊度、总氮、总磷等含量随着养殖时间的延长而增大。同时,福寿螺养殖液使水体中总细菌的数量显著增加,对酵母菌的生长有促进效应,但不同密度福寿螺的养殖液对酵母菌和放线菌的生长均无显著差异。本研究表明,福寿螺入侵可能会导致水体富营养化和水质恶化等环境问题。这些研究结果可为福寿螺入侵的生态危害及风险评价提供参考依据。     

旱涝急转对玉米叶片衰老特性和产量的影响

为研究旱涝急转对玉米叶片衰老特性和产量的影响,以春玉米“宜丹629”为供试材料,2021年在测坑条件下,设置拔节期旱（drought,D）、涝（waterlogging,W）、旱急转轻涝（drought-light waterlogging,D-LW）、旱急转中涝（drought-moderate waterlogging,D-MW）、旱急转重涝（drought-heave waterlogging,D-HW）、和正常供水（control,CK）6个处理。测定不同处理组合下玉米大喇叭口期、抽雄期和灌浆期叶片叶绿素仪（soil and plant analyzer development,SPAD）值、过氧化物歧化酶（superoxide dismutase,SOD）、过氧化物酶（peroxidase,POD）、过氧化氢酶（catalase,CAT）活性、丙二醛（malondialdehyde,MDA）、可溶性蛋白含量和净光合速率（net photosynthetic rate,P_n）,成熟期籽粒产量及其构成。结果表明,与CK相比,D-LW处理抽雄期和灌浆期玉米叶片的SPAD值、SOD、POD、CAT活性、可溶性蛋白含量、P_n及成熟期穗数、穗粒数和千粒质量差异不显著,使其籽粒产量维持在较高水平（7810.3 kg/hm²）。说明旱急转轻涝不会加速玉米叶片的衰老,从而稳定籽粒产量。而其他水分胁迫处理显著降低各监测时期玉米叶片SPAD值、SOD、POD、CAT活性、可溶性蛋白含量和P_n,明显提高MDA含量,使穗数、穗粒数和千粒质量减少,最终显著降低产量（较CK的值下降13.3%~72.7%）。整体上,D-MW和D-HW处理明显加速玉米叶片衰老,严重抑制最终产量。综上,拔节期旱后急转轻涝对玉米叶片SPAD值、抗氧化酶活性、可溶性蛋白含量和P_n有补偿作用,从而获得较高的籽粒产量。该研究结果为玉米应对旱涝急转灾害和灌排管理提供一定理论依据。     

Inducing drought tolerance in wheat by applying natural and synthetic plant growth promoters

Crop productivity in future may be limited due to water scarcity. However, foliar spray of plant growth promoters may boost crop production even in adverse environments. In the present study, foliar application of one natural (moringa leaf extract, 3% MLE) and four synthetic (Polydol, Multisol, Classic, and Asahi Star) were applied at tillering, jointing, booting, and heading growth stages of wheat (Triticum aestivum L.) during severe, moderate, and light drought and well‐watered condition. No spray and water spray were taken as controls. Results showed significant reduction in growth parameters such as total dry matter production, mean crop growth rate, net assimilation rate, leaf area index, and duration due to drought employed at various phenophases of wheat. However, improvement in these parameters was observed after foliar application of growth promoters, whereas interactive effects between factors were found non‐significant. The activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were more accelerated under drought treatments from exogenously supplied growth promoters. Foliar application of promoters significantly alleviated drought‐induced reduction of yield and related traits. Grain weight (15%) and grain yield (27%) were improved due to exogenously applied MLE under moderate drought stress treatments relative to controls. Furthermore, 16% higher grain yield and 17% saving of irrigation water over fully irrigated and without promoter treatment (farmers' practice) was recorded from foliar‐applied MLE under skipped irrigation at jointing. In conclusion, foliar‐applied MLE may ameliorate drought‐induced deleterious effects by enhancing antioxidant activities under drought stress.     

不同桃自根砧对干旱胁迫的生理响应及抗逆机理研究

砧木的抗旱能力直接影响桃品种生长发育,选择适宜抗旱性桃砧木对桃产业发展有积极的促进作用。为阐明不同桃砧木对干旱胁迫生理响应机制,以5种桃砧木扦插苗为试材,通过盆栽控水方式,研究不同程度干旱胁迫下5种桃自根砧的叶片水分特性、渗透调节物质、抗氧化物酶及叶绿素含量变化。结果表明,随着干旱程度加重,5种砧木相对含水量、临界含水量下降,自然饱和亏、临界饱和亏及需水程度上升,组织密度和自由水含量逐渐减少,束缚水含量则增大,持水能力、组织水势和耐旱系数下降。各干旱胁迫处理的丙二醛(MDA)含量、 游离脯氨酸(Pro)含量、可溶性糖含量和叶绿素含量均增加;过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性提高,其中随干旱程度加重,丙二醛(MDA)含量、游离脯氨酸(Pro)含量均呈增加趋势,SOD活性、CAT活性也均呈提升趋势,可溶性糖含量、叶绿素含量、POD活性变化不尽相同。综合隶属函数分析可知,桃自根砧品种间抗旱性由强到弱依次为樱桃李5号、RA、樱桃李3号、GF677、樱桃李1号。     

Kinetics of Zinc Uptake and Anatomy of Roots and Leaves of Coffee Trees as Affected by Zinc Nutrition

Abstract

The influence of silicon (Si) (2.5 mM), sodium chloride (NaCl) (100 mM), and Si (2.5 mM) + NaCl (97.5 mM) supply on chlorophyll content, chlorophyll fluorescence, the concentration of malondialdehyde (MDA), H₂O₂ level, and activities of superoxide dismutase (SOD; E.C.1.15.1.1.), ascorbate peroxidase (APx; E.C.1.11.1.11.), catalase (CAT; E.C.1.11.1.6.), guaiacol peroxidase (G-POD; E.C.1.11.1.7.) enzymes, and protein content were studied in tomato (Lycopersicon esculentum Mill c.v.) leaves over 10-day and 27-day periods. The results indicated that silicon partially offset the negative impacts of NaCl stress with increased the tolerance of tomato plants to NaCl salinity by raising SOD and CAT activities, chlorophyll content, and photochemical efficiency of PSII. Salt stress decreased SOD and CAT activities and soluble protein content in the leaves. However, addition of silicon to the nutrient solution enhanced SOD and CAT activities and protein content in tomato leaves under salt stress. In contrast, salt stress slightly promoted APx activity and considerably increased H₂O₂ level and MDA concentration and Si addition slightly decreased APx activity and significantly reduced H₂O₂ level and MDA concentration in the leaves of salt-treated plants. G-POD activity was slightly decreased by addition of salt and Si. Enhanced activities of SOD and CAT by Si addition may protect the plant tissues from oxidative damage induced by salt, thus mitigating salt toxicity and improving the growth of tomato plants. These results confirm that the scavenging system forms the primary defense line in protecting oxidative damage under stress in crop plants.