α-NAA和UV-B辐射对栝楼幼苗光合色素及保护酶活性的影响

温室条件下研究 UV- B辐射 ( 0 .0 2 9J/( m2·s) )和外施 α-萘乙酸 ( α- NAA) ( 2 mg/L)对栝楼叶片光合色素及保护酶活性的影响。实验结果表明 :外施α- NAA,能提高栝楼幼苗叶片叶绿素及类胡萝卜素的含量 ,提高保护酶 SOD、CAT、POD、ASP的活性 ,细胞膜相对透性和膜脂过氧化产物 MDA含量相对稳定。UV- B辐射单独处理 ,则极显著地降低叶绿素 a的含量 ,叶绿素 b含量也呈明显地下降趋势 ,类胡萝卜素含量稍有下降 ,极显著降低栝楼幼苗叶片 SOD、POD、CAT、ASP活性 ,引起细胞膜相对透性明显增大 ,MDA含量显著增加。α- NAA与 UV- B辐射共同处理栝楼幼苗 ,与 UV- B辐射处理相比 ,叶绿体色素含量都有不同程度增加 ,而细胞膜相对透性、MDA含量则有不同程度降低 ,SOD、POD、ASP活性上升 ,CAT活性显著上升。以上结果暗示 ,UV- B辐射对生长的影响可能是 :( 1 )破坏光合色素而导致光合能力下降 ;( 2 )降低保护酶 SOD、POD、CAT、ASP活性 ,导致膜脂过氧化 ,膜结构遭到破坏 ,膜透性增加。而外施α- NAA,能部分减轻由增强的 UV- B辐射对栝楼幼苗造成的这种伤害 ,其原因可能是 α- NAA提高了保护酶活性 ,维持了活性氧产生与清除之间的平衡 ,即是维持了膜结构的稳定性。可见 ,α- NAA能增加栝楼对 UV- B辐射的抗性。     

百日草链格孢菌毒素对加拿大一枝黄花叶片伤害的生理生化研究

采用植物抗性生理和光合生理的分析测定技术,研究了分离自罹病苍耳植株上的百日草链格孢菌产生的毒素对加拿大一枝黄花叶组织细胞膜透性、丙二醛(M DA)含量、光合能力以及过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)和过氧化氢酶(CAT)活性的影响.结果表明,百日草链格孢菌毒素使加拿大一枝黄花叶组织细胞膜透性上升,膜脂过氧化加强,M DA含量上升;叶片的POD、APX和CAT的活性均较对照降低,其光合作用明显地受到抑制.说明百日草链格孢菌毒素具有防除加拿大一枝黄花的潜力.     

不同光照强度下豆链格孢菌对白车轴草生理生化特性的影响

通过盆栽实验研究了不同光照强度下,接种豆链格孢菌(Alternariaazukiae(hara)comb.nov)对白车轴草(TrifoliumrepensL.)叶组织细胞膜透性、色素含量、丙二醛(MDA)含量、蛋白质含量、脯氨酸含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响。结果表明:豆链格孢菌使白车轴草叶组织细胞膜透性上升,电导率显著升高,膜脂过氧化加强,MDA水平上升,色素含量、蛋白质含量以及脯氨酸含量下降。随着处理光照强度的减弱,以上各生理指标的变化趋势更为明显,电导率和MDA含量均与光照强度显著负相关,而色素含量、蛋白质含量及脯氨酸含量均与光照强度显著正相关。接种豆链格孢菌后,色素含量明显下降,且弱光下(75%遮阳),豆链格孢菌对白车轴草叶片色素含量的影响更为明显,对照组的叶绿素a、叶绿素b、叶绿素(a b)和类胡萝卜素含量均显著高于接种组的色素含量。在豆链格孢菌的刺激下,活性氧清除系统遭到破坏,保护酶系统失衡,其中SOD和CAT活性显著下降,而POD活性却明显上升,并且SOD、POD和CAT三种酶活性均与光照强度存在着明显的负相关系。     

链格孢菌毒素对紫茎泽兰的致病机理

以叶圆片法分析链格孢菌[Alternaria alternata(Fr.)Keissler]毒素对紫茎泽兰（Eupatorium adenophorum Spreng.)叶组织细胞膜透性、过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）活性以及丙二醛（MDA）含量的影响,结果表明,链格孢菌毒素使紫茎泽兰叶组织细胞膜透性上升,Na^ 和K^ 渗漏量增加,膜脂过氧化加强,MDA含量上升;链格孢菌毒素处理的紫茎泽兰叶片中POD、APX和CAT的活性均较对照降低。     

豆链格孢菌对白车轴草生理代谢及活性氧清除系统酶的影响

通过盆栽实验,研究了接种豆链格孢菌对白车轴草叶组织细胞膜透性、色素含量、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响.结果表明,豆链格孢菌使白车轴草叶组织细胞膜透性上升,电导率显著升高,膜脂过氧化加强,MDA水平上升,色素含量下降.电导率和MDA含量均与感病时间呈显著正相关,而色素含量与感病时间呈显著负相关.豆链格孢菌刺激其寄主白车轴草叶片膜脂过氧化作用发生,积累大量的活性氧,使其超出防御酶的清除能力,致使活性氧清除系统遭到破坏,保护酶系统失衡,其中SOD和CAT活性显著下降,而POD活性明显上升.接种12d后,SOD和CAT分别降低了55.2%和37.8%,而POD比对照升高约1.6倍.     

低温条件下O3对红桃采后几种生理指标的影响

低温条件下,8 mg·m-3O3可延缓采后红桃果肉硬度下降以及呼吸速率和乙烯释放峰值出现时间,抑制丙二醛(MDA)含量和相对细胞膜透性的升高,过氧化氢酶(CAT)的活性保持相对较高水平,淀粉酶、过氧化物酶(POD)和多酚氧化酶(PPO)活性均明显受抑制,腐烂率下降.     

硅对受土壤中镉污染的白菜生长和抗胁迫能力的影响

在土培盆栽条件下,硅可提高白菜的地上部鲜重和茎鲜重,但根鲜重下降,叶鲜重略有下降。硅可抑制白菜吸收镉,在0.3、0.6、1.2mg·kg~(-1)镉水平下,施硅可显著降低白菜地上部的镉含量,并在一定程度上提高叶中过氧化物酶(POD)活性,但降低超氧化物歧化酶(SOD)活性。0.5、1.0 g·kg~(-1)硅可提高白菜的叶绿素含量和过氧化氢酶(CAT)活性,降低叶细胞膜透性,从而提高其对镉胁迫的耐受力。较高的硅浓度对植物有一定的毒性,叶绿素含量和CAT活性都下降,细胞膜透性也增加。     

壳聚糖提高香蕉幼苗抗冷性的效应

壳聚糖(CS)预处理可降低低温胁迫下香蕉幼苗叶细胞膜脂过氧化水平和膜透性增加的程度以及超氧化物歧化酶(SOD)、过氧化物酶(POD)活性的下降幅度,提高过氧化氢酶(CAT)的活性;0.3%的壳聚糖的保护效果最好.     

外源6-BA对缺镁胁迫下两优培九幼苗的缓解效应

以三叶一心期的两优培九幼苗为材料,比较研究了缺镁及叶面喷施6-BA对缺镁胁迫下两优培九叶绿素含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、硝酸还原酶(NR)活性,可溶性蛋白含量及细胞膜透性的影响。结果表明:随着两优培九缺镁胁迫程度的加剧,叶绿素含量、可溶性蛋白含量呈下降趋势,SOD、POD、CAT活性呈现先上升后下降的趋势,而细胞膜透性、NR活性则呈现升高的趋势;喷施6-BA对缺镁胁迫具有一定程度的缓解作用。因而可推测外源6-BA可在一定程度上改善由于缺镁而造成的营养缺乏症。     

外源芦丁预处理对水分胁迫下玉米幼苗的生理效应

以玉米(Zeamays L.)品种'郏单958'为材料.采用营养液水培法,研究了外源芦丁(Rutin)对聚乙二醇(PEG)胁迫下幼苗叶片质膜相对透性、脯氨酸、可溶性糖含量及保护酶活性的影响.结果显示:(1)在15%PEG-6000胁迫下,玉米叶片的MDA含量、质膜相对透性、脯氨酸和可溶性蛋白质含量均显著增加,保护酶SOD、CAT、POD活性显著升高.(2)一定浓度芦丁(>0.40 g/L)预处理可显著抑制水分胁迫下玉米幼苗叶片MDA含量的上升,降低叶片质膜相对透性,并诱导SOD、POD和CAT活性提高.降低脯氨酸和可溶性蛋白质含量.说明外源芦丁能够提高玉米幼苗的抗氧化作用,缓解水分胁迫引起的膜脂过氧化,保护细胞膜免受或减少损伤·达到提高植物抗旱性的目的.     

Effect of Zeatin on H202 Scavenging System of Vitis vulpina Leaf Disks Under Salt Stress

Leaf disks of Vitis vulpina L. were incubated in hquid media containing 0,75,100, 125,150,200 and 225 mmol•L-1 NaCl with or without 1 μmol•L-1 zeatin, at 25 ℃ ,under 1 000 μmol • m-2 • s-1 continuous illumination, leaf relative permeability, contents of photosynthetic pigments and soluble protein, and activities of catalase (CAT), ascorbate peroxidase (AsA-POD) and guaiacol peroxidase(G-POD) were compared. The results showed that relative leaf permeability was increased following the increase of NaC1 concentration, whereas activities of leaf CAT, AsA-POD and G-POD, and contents of leaf photosynthetic pigments were reduced significanfiy. These effects of salt stress were significantly inhibited in the presence of zeatin. The ,relationship between relative leaf permeability and activities of H2O2 scavenging enzymes were discussed.     

黄瓜叶片衰老过程中抗坏血酸含量与生理指标关系的研究

研究了黄瓜叶片衰老过程中抗坏血酸(ASA)含量及相关生理指标的变化,进一步分析了ASA与各相关生理指标之间的关系。结果显示,随着叶片逐渐衰老,丙二醛(MDA)含量、相对电导率(REC)及过氧化物酶(POD)活性显著升高;光合色素、可溶性蛋白质含量、超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活性及ASA含量显著降低;ASA与MDA含量、REC、POD活性之间呈显著负相关关系,ASA与CAT及SOD活性之间呈显著正相关关系。研究表明,ASA对减缓叶片衰老有重要作用。     

土壤水分和氮素有效性对刺槐幼苗叶片活性氧产生和清除的影响

采用施加氮肥和人工控水的方法,以一年生刺槐幼苗为材料进行盆栽实验,探讨提高土壤氮素含量对不同土壤水分条件下刺槐幼苗叶片中活性氧产生和清除的影响。结果表明:(1)相同氮素水平下,降低土壤水分含量引起刺槐生物量和叶片光合色素含量降低,而过氧化氢(H2O2)含量升高;抗氧化酶系统中的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性和过氧化氢酶(CAT)活性不同程度降低;抗氧化剂中抗坏血酸(ASA)含量和还原型谷胱甘肽(GSH)含量均有所提高;MDA含量逐渐升高,而同期细胞膜相对电导率显著升高。(2)相同水分条件下,提高土壤氮素水平显著提高了刺槐幼苗叶片光合色素含量,同时也一定程度提高了总生物量,显著降低了H2O2含量;SOD、POD和CAT活性不同程度升高;ASA含量和GSH含量则表现出不同程度下降;相对电导率显著降低同时MDA含量一定程度降低。因此,增加土壤氮素有效性可显著提高刺槐幼苗叶片光合色素含量,显著抑制活性氧的产生,一定程度提高总生物量和抗氧化酶活性,降低膜脂过氧化程度,从而有利于缓解干旱引起的伤害。     

Retardation of Leaf Senescence by Triadimefon Treatment in Mung Bean Seedling

Treatment of triadimefon on detached leaves of mung bean (Phaseolus radiatus L. ) seedlings increased the levels of chlorophyll and soluble proteins. Declined activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate-peroxidase (AsA-POD) and contents of ascorbate (ASA) and glutathione (GSH) were observed during the senescence of detached young leaves. Triadimefon at concentration of 20 mg/L promoted the activities of POD, AsA-POD and levels of AsA and GSH, but had no effect on the activities of SOD and CAT. On the other hand, the levels of malondialdehyde (MDA) were increased and the increase of which was markedly negative correlated with the activities of POD, AsA-POD and with the contents of AsA and GSH during the senescence of leaves. MDA contents were decreased by triadimefon treatment. These resuits suggested that triadimefon retarded the senescence of leaves in mung bean seedlings in terms of enhancing the protective ability of plant tissues against membrane lipid peroxidation.     

大气CO2浓度升高对毛竹叶片膜脂过氧化和抗氧化系统的影响

为了解竹子对大气CO2浓度升高的生理响应,为气候变化背景下的竹林适应性管理提供理论依据,运用开顶式气室(OTCs)设置了3个CO2处理浓度(环境大气、500和700μmol·mol-1),探讨了大气CO2浓度升高对毛竹(Phyllostachys edulis)叶片光合色素、膜脂过氧化和抗氧化系统的影响。结果表明:与环境大气比较,500μmol·mol-1浓度处理30d时对毛竹叶片光合色素、膜脂过氧化和抗氧化系统影响并不明显,仅叶片CAT活性显著降低;随着处理时间的延长,对毛竹叶片膜脂过氧化和抗氧化系统的影响逐渐显现,至处理90d时,除叶片可溶性糖含量无明显变化,其他测定指标均有显著变化;700μmol·mol-1浓度处理在不同时间上对毛竹叶片膜脂过氧化和抗氧化系统的影响均较500μmol·mol-1CO2浓度处理明显,处理30d时毛竹叶片可溶性糖含量和抗氧化酶活性有明显变化,处理90d时,各项测定指标均有显著变化;研究表明大气CO2浓度升高一定程度上能增强毛竹的抗氧化能力,但光合产物的过量积累也会造成碳水化合物源-库失衡和Rubisco的再生受到反馈作用抑制。     

NaCl胁迫对互花米草细胞膜和光响应曲线特征参数的影响

以大米草的互花米草为材料,研究了不同盐浓度对其细胞膜透性、丙二醛(MDA)含量和光响应曲线的特征参数的变化情况。结果表明:盐浓度低于300mmol·L-1时,互花米草细胞膜透性和MDA含量较对照组无显著差异;其较高的最大光合速率(>30μmol·m-2·s-1),表观量子效率(>0.05mol·mol-1Photons)以及较低的暗呼吸速率(<1.5μmolCO2·m-2·s-1)和光补偿点(<20μmol·m-2·s-1)为其有机物质积累、竞争、建立种群并扩散提供条件。盐浓度高于500mmol·L-1时,互花米草膜透性和MDA含量显著上升,最大光合速率(Amax)及表观量子效率(Q)显著下降,暗呼吸速率(Rday)和光补偿点(LCP)上升。表明细胞膜和光合作用有关酶受到迫害,抑制了其正常生长。盐胁迫下互花米草光合速率降低,但蒸腾速率的显著下降提高了单叶水分利用效率,从而部分缓解了渗透势变化对细胞的迫害,为其生存和生长提供条件。     

Effect of La(III) on the growth and aging of root of loquat plantlet in vitro

The effect of lanthanum on the adventitious root growth, activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), O₂ production rate, MDA content, and the relative plasma membrane permeability in roots of loquat test-tube plantlet were studied. Addition of lanthanum chloride (0.5 μmol/L) to the culture medium significantly increased the length of roots, increased the dry weight, enhanced the activities of SOD, CAT, and POD, decreased O₂ production rate, malondialdehyde (MDA) contents, and the relative plasma membrane permeability. The relatively stable membrane structure of cell could defer the root aging of the plantlet in vitro. There are important theory meaning and practical value in applying LaCl₃ in the rooting medium to raise the rate of rooting and transplant for wood plant.     

Protective effects of complementary Ca2+ on low-light-induced oxidative damage in tall fescue

Low-light (LL) intensity is a primary abiotic stressor that negatively influences turf grass quality. In the present experiment, we studied the effect of exogenous Ca²⁺ (0, 10, 50, 100, and 200 mM) on the antioxidant system, the accumulation of MDA and proline, the content of photosynthetic pigments in plant leaves in order to investigate whether exogenous Ca²⁺ treatment improves LL tolerance in tall fescue (Festuca arundinacea Schreb.). We have found that LL significantly reduced a number of growth parameters (plant height, leaf width, leaf fresh weight, root fresh weight, leaf dry weight, and root dry weight), chlorophyll (Chl) a and Chl b contents, and carotenoid (Car) levels, while considerably enhancing electrolyte leakage (EL), MDA accumulation, calcium (Ca²⁺) concentration, and generation of reactive oxygen species (ROS), such as hydrogen peroxide (H₂O₂) and superoxide radical (O ₂ ^·? ). Moreover, LL significantly induced the activities of antioxidant enzymes, such as peroxidase (POD) and catalase (CAT), and slightly increased the activity of superoxide dismutase (SOD) in tall fescue leaves. In contrast, POD and SOD activities declined considerably while CAT activity significantly increased in plant roots under LL stress. The application of 50 mM Ca²⁺ significantly improved the aforementioned growth parameters, the content of photosynthetic pigments, and further enhanced the activities of POD, SOD, and CAT, but decreased electrolyte leakage and MDA and H₂O₂ levels in the leaves and roots of tall fescue under LL stress. These results suggest that Ca²⁺ is likely involved in a resistance to LL by regulating antioxidant enzyme action in tall fescue leaves and roots.     

Arbuscular mycorrhizal influence on growth,photosynthetic pigments,osmotic adjustment and oxidative stress in tomato plants subjected to low temperature stress

The influence of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae, on characteristics of growth, photosynthetic pigments, osmotic adjustment, membrane lipid peroxidation and activity of antioxidant enzymes in leaves of tomato (Lycopersicon esculentum cv Zhongzha105) plants was studied in pot culture under low temperature stress. The tomato plants were placed in a sand and soil mixture at 25°C for 6 weeks, and then subjected to 8°C for 1 week. AM symbiosis decreased malondialdehyde (MDA) content in leaves. The contents of photosynthetic pigments, sugars and soluble protein in leaves were higher, but leaf proline content was lower in mycorrhizal than non-mycorrhizal plants. AM colonization increased the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) in leaves. The results indicate that the AM fungus is capable of alleviating the damage caused by low temperature stress on tomato plants by reducing membrane lipid peroxidation and increasing the photosynthetic pigments, accumulation of osmotic adjustment compounds, and antioxidant enzyme activity. Consequently, arbuscular mycorrhiza formation highly enhanced the cold tolerance of tomato plant, which increased host biomass and promoted plant growth.     

Biochar Application Improves the Drought Tolerance in Maize Seedlings

Application of biochar to agricultural soils is mostly used to improve soil fertility. Experimental treatments were comprised of two factors: i) drought at two level, i.e., 80% and 40% water holding capacity (WHC) which was maintained on gravimetric basis ii) three levels of biochar i.e., control, 2 t ha^-1 and 4 t ha^-1 added to soil. Experimentation was done to examine potential of biochar application to enhance the growth attributes, water relations, photosynthetic pigments and antioxidants activities in maize (Zea mays L.) seedlings. Results of study revealed that biochar application increased the growth qualities (total seedlings biomass, dry weight of shoot and root, shoot length and root length). In addition; contents of photosynthetic pigments (chlorophyll a, b, a + b and a/b), water relation (relative water contents, turgor potential, osmotic potential and water potential) were improved significantly due to addition of biochar. Addition of 4 t ha^-1 biochar led to significant rise activity of enzymatic antioxidant catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) in leaf of maize seedling sunder drought as well as well watered circumstances. However, biochar applied at the rate 4 t ha^-1 improved the all the physiological and biochemical attributes in maize seedlings under drought. From the results it was concluded that biochar application is an efficient way to alleviate adverse effect of drought stress on maize. In drought prone areas, long term impacts of biochar on production of maize and properties of soil could be recommended as upcoming shove.