Wyerone Acid Phytoalexin Synthesis and Peroxidase Activity as Markers for Resistance of Broad Beans to Chocolate Spot Disease

Infection of broad bean (Vicia faba L.) leaves with Botrytis fabae (Sard.) resulted in wyerone acid phytoalexin accumulation and increase in peroxidase activities in resistant and susceptible broad bean cultivars. Rapid wyerone acid accumulation was observed in leaves of resistant cultivars that reached levels greater than twofold of the susceptible cultivars. Following infection of broad bean cultivars, either resistant or susceptible to B. fabae, wyerone acid synthesis in resistant cultivars peaked at 5 days then declined, whereas in susceptible cultivars synthesis gradually decreased. While the ethanol‐extract of wyerone acid significantly reduced B. fabae spore germination with increased concentrations, the phytoalexin had no effect on in vitro B. fabae germ‐tube growth. Peroxidase activity in infected leaves of resistant was 10 times higher than the susceptible cultivars and eight times higher in uninfected leaves of the resistant than the susceptible cultivars. Peroxidase activity in infected leaves was greater than twofold in resistant cultivars and less than twofold in susceptible cultivars, when compared with uninfected leaves. The ratio of peroxidase activity in infected to uninfected leaves increased over time in susceptible cultivars but remained unchanged in resistant cultivars. Peroxidase activity in uninfected and infected leaves and wyerone acid biosynthesis in infected broad bean plants were successfully used to ascertain the resistance and susceptibility of four broad bean cultivars to B. fabae. Using wyerone acid synthesis and peroxidase activity as preliminary markers for resistance of broad bean to chocolate spot disease, caused by B. fabae, is suggested in this study.     

秋水仙碱诱导重瓣大岩桐(Sinningia speciosa)多倍体的研究

以重瓣大岩桐叶片为外植体,经秋水仙碱处理得到大量的多倍体植株。在培养基中加入秋水仙碱２０ｍｇ Ｌ＾－１处理一周,可使重瓣大岩桐的诱变率达到６２．５％,对再生植株进行形态学观察表明,多倍体植株比二倍体的茎粗壮,叶片增大,加厚。细胞学鉴定四倍体染色体数为２ｎ＝４ｘ＝５２,而二倍体的染色体数为２ｎ＝２６。     

Alterations in peroxidase activity and peroxidase isozymes in virus-infected plants

Peroxidase activity and isozyme patterns were investigated in two leguminous species infected with viruses which produced either local necrotic or systemic chlorotic symptoms. Highest peroxidase activity was recorded when the hosts reacted to infection with necrotic local lesions. No new virus-specific isozymes were found as a result of infection, but some isozymes, apparently associated with senescence, appeared earlier in extracts from leaves showing necrosis than in extracts from healthy leaves, or from infected leaves showing only very mild chlorosis. Increase in peroxidase activity was accompanied by alteration in isozyme pattern.     

镉胁迫下大豆生长发育的生理生态特征

采用土壤盆栽试验方法,研究了不同浓度Cd2+胁迫对大豆整个生长发育周期的生长以及叶片叶绿素含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和丙二醛(MDA)含量的生理生态适应性变化过程。结果表明,(1)Cd2+胁迫对大豆整个生活周期的叶绿素含量、POD活性、SOD活性及MDA含量的影响都是极显著的(P0.01);(2)短时间、低浓度的Cd2+胁迫对大豆植株的生长发育有刺激效应,高浓度、长时间的Cd2+胁迫对大豆植株构成明显的抑制效应;大豆株高增长开始受到抑制的Cd2+浓度为1.00mg·kg-1,远低于大豆生物量的增长开始受抑制的Cd2+浓度(2.50mg·kg-1);(3)当Cd2+浓度超过一定水平时,大豆植株生物量和株高的抑制程度与外源Cd2+浓度呈极显著的正相关(P0.01),对土壤Cd2+污染程度具有指示作用,且大豆植株高度与其生物量相比,株高对Cd2+污染具有更好的指示作用;大豆幼苗期叶绿素含量对镉的敏感性高于开花结荚期和成熟期的敏感性;(4)大豆POD、SOD活性的增加,能在一定程度上减轻Cd2+胁迫引起的膜脂过氧化造成的伤害作用;在Cd2+达到2.50mg·kg-1水平时,植物保护性酶系统活性的提高已经不足以弥补因Cd2+胁迫对大豆植株造成的伤害;大豆幼苗期和花荚期叶片的POD活性对土壤Cd2+污染程度具有较好的指示作用,而大豆花荚期和成熟期叶片的SOD活性对土壤Cd2+污染程度具有较好的指示作用;在Cd2+胁迫下大豆MDA含量增加,表明细胞膜脂过氧化作用加强。     

Responses of Ceriops Roxburghiana to NaCl Stress

Responses of Ceriops roxburghiana Arn. leaves to the sodium chloride, applied at different concentrations (ranging from 100 to 600 mM), has been evaluated. Total amino acid content decreased with increasing NaCl concentration, while the protein content increased significantly up to 400 mM concentration and decreased thereafter. Total sugar content decreased at concentrations beyond 400 mM. Proline and glycine betaine were accumulated with increasing NaCl concentration. Protease and ATPase activities were increased whereas proline oxidase activity were decreased with increasing salinity. Peroxidase and malate dehydrogenase (NADH-MDH) activities did not significantly differ under various NaCl concentrations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Systemic Responses in Arabidopsis thaliana Infected and Challenged with Pseudomonas syringae pv syringae

Attack of plants by necrotizing pathogens leads to acquired resistance to the same or other pathogens in tissues adjacent to or remotely located from the site of initial attack. We have used Arabidopsis thaliana inoculated with the incompatible pathogen Pseudomonas syringae pv syringae on the lower leaves to test the induction of systemic reactions. When plants were challenged with Pseudomonas syringae pv syringae in the upper leaves, bacterial titers remained stable in those preinfected on the lower leaves. However, there was a distinct decrease in symptoms that correlated with a local and systemic increase in salicylic acid (SA) and in chitinase activity. Peroxidase activity only increased at the site of infection. No changes in catalase activity were observed, either at the local or at the systemic level. No inhibition of catalase could be detected in tissue in which the endogenous levels of SA were elevated either naturally (after infection) or artificially (after feeding SA to the roots). The activity of catalase in homogenates of A. thaliana leaves could not be inhibited in vitro by SA. SA accumulation was induced by H2O2 in leaves, suggesting a link between H2O2 from the oxidative burst commonly observed during the hypersensitive reaction and the induction of a putative signaling molecule leading to system acquired resistance.     

Peroxidase Activity in the Abscission Zone of Bean Leaves during Abscission

Peroxidase activity and localization in the abscission zone of bean leaves were studied histochemically and by gel electrophoresis. Deblading of bean leaves resulted in an increase in peroxidase activity in the abscission zone 2 to 4 days after deblading with highest activity just prior to separation. In debladed plants, the cell division in six to eight layers of cells preceded separation. An ethylene treatment (8 microliters per liter) induced separation of debladed petioles in approximately 24 hours and of intact plants in 36 to 48 hours. Ethylene treatment produced similar results in both debladed and intact plants. In ethylene-treated plants, whether debladed or not, enzyme localization was restricted to only two to three layers of cells with no cell division apparent prior to separation. Infrequent cell divisions were observed after treatment with 2-chloroethylphosphonic acid (1000 micrograms per liter) (Ethephon); however, other changes were similar to those observed with ethylene. Deblading and ethylene treatment resulted in changes in the six peroxidase isozymes observed in the abscission zone. Only four were observed in samples collected 2 centimeters below the abscission zone. Peroxidase bands IV and V increased significantly in debladed and ethylene-treated plants and peroxidase VI decreased only in debladed plants. The changes in peroxidase activity were invariably observed prior to separation in all treatments.     

四棱豆不同生育期叶片中过氧化物酶活力测定

比较了四棱豆不同生育期叶片中过氧化物酶活性,结果表明：该酶活力和比活力在不同生育期存在着明显差异,蛋白质含量变化不大。在成熟期,随着植株节位升高,酶活力及比活力均呈下降趋势,蛋白质含量则呈上升趋势。     

Induction of early blight resistance in tomato by <Emphasis Type="Italic">Quercus infectoria</Emphasis> gall extract in association with accumulation of phenolics and defense-related enzymes

Treatment of tomato leaves with aqueous extract (0.5%) of the galls of Quercus infectoria significantly reduced infection from subsequent inoculation with Alternaria solani, the tomato early blight pathogen. When the leaves were challenge-inoculated with A. solani 3 d after application of Q. infectoria gall extract (QIGE), the percent defoliation decreased from 33.6 to 7.3. Two to three day pre-treatment with QIGE reduced the percent defoliation by 77 percent. The biochemical responses of tomato plants to QIGE were also studied. In tomato plants treated with QIGE, phenolic content increased rapidly, reached the maximum at 2 d after treatment. Phenylalanine ammonia-lyase (PAL) activity increased significantly from 1 d after treatment and the maximum enzyme activity was recorded 2 d after treatment at which period a 3-fold increase in PAL activity was observed when compared to the control. Peroxidase (PO) activity was also significantly increased 1 d after treatment and the maximum activity was reached 2 d after treatment. Peroxidase isozyme analysis indicated that PO-1 was increased dramatically in tomato leaves 1 d after treatment and maintained at the same level throughout the experimental period of 6 d. When tomato leaves were treated with QIGE, a two-fold increase in chitinase and β-1,3-glucanase activities was recorded 2 and 3 d respectively, after treatment. The enhanced activities of defense-related enzymes and elevated levels of phenolics in QIGE-treated tomato plants between 1 and 3 d after treatment suggest that these induced biochemical defenses may be involved in the suppression of early blight by QIGE.     

Influence of supplemental UV-B radiation on photosynthetic characteristics of rice plants

In a field experiment with rice (Oryza sativa L. cv. Saket 4) grown under ambient and supplemental ultraviolet-B (UV-B) radiation at 20 % ozone depletion, differences in gas exchange, concentrations of photosynthetic pigments, anthocyanins and flavonoids, biomass accumulation, catalase and peroxidase activities, and contents of ascorbic acid and phenol were determined. Decline in photosynthesis was associated with reductions in stomatal conductance and concentrations of photosynthetic pigments. Enhanced UV-B radiation (eUV-B) increased the contents of flavonoid and phenolic compounds in leaves. Peroxidase activity increased and catalase activity was always lower at eUV-B. The total plant biomass decreased at eUV-B.     

Influence of supplemental UV-B radiation on photosynthetic characteristics of rice plants

In a field experiment with rice (Oryza sativa L. cv. Saket 4) grown under ambient and supplemental ultraviolet-B (UV-B) radiation at 20 % ozone depletion, differences in gas exchange, concentrations of photosynthetic pigments, anthocyanins and flavonoids, biomass accumulation, catalase and peroxidase activities, and contents of ascorbic acid and phenol were determined. Decline in photosynthesis was associated with reductions in stomatal conductance and concentrations of photosynthetic pigments. Enhanced UV-B radiation (eUV-B) increased the contents of flavonoid and phenolic compounds in leaves. Peroxidase activity increased and catalase activity was always lower at eUV-B. The total plant biomass decreased at eUV-B.     

Purification of plant complex protein extracts in non-denaturing conditions by in-solution isoelectric focusing

An alternative approach for plant complex protein extracts pre-purification by in-solution isoelectric focusing in non-denaturing conditions is presented. The separation of biologically active proteins, in narrow ranges of isoelectric point (pI) was obtained by a modified OFFGEL electrophoresis. Two different water-soluble protein extracts from Phragmites leaves were fractionated into 24 fractions within a 3–10 pI range at 10 °C in the absence of denaturing/reducing agents. One-dimensional electrophoretic analysis revealed different protein distribution patterns and the effective fractionation of both protein extracts. Peroxidase activity of each fraction confirmed that proteins remained active and pre-purification occurred. Biological triplicates assured the needed reproducibility.     

Studium der terminaloxidasen in durch obligatparasiten infizierten getreideblättern

In wheat leaves infected with yellow rust (Puccinia striiformis West.) and in barley leaves infected with powdery mildew (Erysiphe graminis DC.) the effect of respiratory inhibitorsin vivo and terminal oxidases activityin vitro were studied. In the experiments the first leaves of seedlings grown in glasshouse were used. The influence of infection was shown by activation of respiration and terminal oxidases (Fe- and Cu-oxidases), first of all cytochrome oxidase and peroxidase. There might be involved also the increased role of ascorbic acid oxidase and phenolase. Peroxidase activation was found to be much higher in susceptible varieties than in resistant ones. Neither in wheat nor in barley the catecholase activity was detected; on the contrary the enzymatic oxidation of floroglucine was found to be also in barley leaves, the intensity of which being dependend on resistance or susceptibility to powdery mildew. Thus, it is not excluded, that in contact establishing between obligate parasite and the host the significant role may be played by specific phenolase and phenolic substances. It suggests itself, that due to the participating in ATP-formation the cytochrome system in terminal oxidation of cereals, infected with obligate parasites, may have centrale position.     

PEROXIDASE LOCALIZATION,ACTIVITY, AND ISOZYME PATTERNS IN THE DEVELOPING SEEDLING OF VANDA (ORCHIDACEAE)

Peroxidase activity in the seedling of Vanda was investigated at various stages of development. Active sites were demonstrated histochemically and soluble proteins and peroxidase isozymes were resolved by disc electrophoresis at progressive stages of growth. Activity, which is highest in the early stages of development and lowest at the stage when maximum differentiation occurs, is confined to the epidermal layer and outer surface of the seedling in early stages of development, It is also present in the vascular tissues of the leaves, root, and parenchymatous region at later stages. Indoleacetic acid raises peroxidase activity when present in the growth medium in physiological concentrations. The number of isoperoxidases varies with developmental stage and is lowest in the stage at which leaves and roots are initiated. These observations are discussed in relation to the hypothesis that the peroxidases play a role in morphogenesis as a part of the indoleacetic acid-oxidase system.     

NAD(P)H oxidase and peroxidase activities in purified plasma membranes from cauliflower inflorescences

An NAD(P)H oxidase activity stimulated by phenolic compounds has been investigated in purified plasma membranes (pm) and in an intracellular membrane (icm) fraction depleted in plasma membranes, both obtained from a microsomal fraction from cauliflower inflorescences ( Brassica oleracea L.). The phenolic compounds salicylhydroxamic acid (SHAM), ferulic acid, coniferyl alcohol, n -propyl gallate, naringenin, kaempferol and caffeic acid all strongly stimulated the activity. Peroxidase (EC 1.11.1.7), or a peroxidase-like enzyme, was responsible for the NAD(P)H oxidase activity, which proceeded through a free-radical chain reaction and was inhibited by catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and KCN. Most of the total activity was soluble; however, the membrane-bound activity was highly enriched in the pm compared to the icm. The catalase activity was 6 times higher in the icm-fraction than in the pm-fraction, but this was not the reason for the much lower phenol-stimulated NADH oxidase activity in the icm. Peroxidase activity measured with o -dianisidine and H₂O₂ had about the same specific activities in the pm-and icm-fractions.
Neither the phenol-stimulated NADH oxidase nor the peroxidase activity could be washed away from the pm even by 0.7 M NaCl, indicating that these activities are truly membrane-bound. SHAM as well as the other phenolic compounds capable of stimulating the NADH oxidase reaction were potent inhibitors of blue light-induced cytochrome b -reduction in the pm fraction.     

沙棘(Hippophae spp.)开花座果期体内四种生化指标的研究

测试分析了6种沙棘开花、座果期体内过氧化氢酶(CAT)、过氧化物酶(POD)活性和游离氨基酸、抗坏血酸的含量,进而选出较优良的品种为向阳、优胜和浑金,而齐棘、楚伊和阿亚干卡较差。游离氨基酸、抗坏血酸在沙棘果中含量高于沙棘花;过氧化物酶活性沙棘果强于花;过氧化氢酶花中活性强于果。     

The Relationship Between Peroxidase Activity and the Resistance of Tomatoes (Lycopersicum esculentum) to Verticillium dahliae

The levels of peroxidase activity in roots of non-infected tomato plants resistant to Verticillium dahliae Kleb., were found to be considerably higher than those in the roots of susceptible plants. Similar differences were found in the leaves but were not significant as in the roots. Peroxidase activity increased in leaves, stems and roots of both susceptible and resistant plants after infection with V. dahliae. The ratio of the increase in leaves and roots of susceptible plants was greater than those of resistant plants. A positive correlation was found between the peroxidase activity in the roots of eleven cultivars/breeding lines and presence of Ve gene.     

EFFECTS OF GIBBERELLIN AND AMO-1618 ON GROWTH,DRY-MATTER ACCUMULATION,CHLOROPHYLL CONTENT AND PEROXIDASE ACTIVITY OF CITRUS SEEDLINGS

Monselise , S. P., and A. H. Halevy . (Hebrew U., Rehovot, Israel.) Effects of gibberellin and AMO–1618 on growth, dry-matter accumulation, chlorophyll content and peroxidase activity of citrus seedlings. Amer. Jour. Bot. 49(4): 405–412. Illus. 1962.—Sweet-lime seedlings, 6 months old, were sprayed with gibberellic acid (GA) and a growth retardant, AMO–1618, alone and in combination, at concentrations ranging between SO and 1600 ppm. Increasing concentrations of GA progressively increased shoot and internode length, did not influence number of leaves, and decreased leaf area. Dry weight of shoots was progressively increased up to 400 ppm, while dry weights of leaves and roots were decreased over all GA concentrations. Total dry weight of plants was increased by GA when related to leaf area or weight and to total chlorophyll content, which indicates a higher synthetic efficiency of leaves. This could not be detected by manometric determinations using leaf discs. It is suggested that a short determination period and/or work with detached leaves are responsible for failures to detect increased photosynthetic activity of GA-treated leaves. Chlorophyll content of leaves was decreased by increasing GA concentrations; it is shown that this is not due to “dilution” over a larger area of leaves. Peroxidase activity of leaves was only slightly reduced by GA, while it was increased by AMC–1618, acting as antagonist to GA. This is remarkable, since AMO–1618 did not clearly affect other procperties of citrus seedlings which are only slightly responsive to this chemical.     

The induction of systemic resistance in barley to powdery mildew infection using salicylates and various phenolic acids

Treatment of the first leaves of barley seedlings with either 5, 10, 15 or 20 mM salicylic acid, sodium salicylate or acetylsalicylic acid resulted in significant reductions in powdery mildew infection on the upper, second leaves. In general, the greatest reduction in mildew infection on the second leaves was obtained by spraying the first leaves with a 15 mM concentration of the compounds. Although the largest reduction in mildew infection of the upper leaves was obtained when the compounds were applied to the first leaves 1–2 days before inoculation, very substantial reductions in infection were still obtained if the first leaves were treated 12 days before inoculation. The three compounds had little direct effect on mildew infection. When ¹⁴C-salicylic acid was fed to first leaves of barley seedlings, uptake was rapid and increased with time. Within 6 h, 0.2% of the salicylic acid appeared in the second leaf and by 24 h after feeding, this had increased to 1.4% (1.1 μmol salicylic acid g^-1 fresh wt). The application of various phenolic acids to first leaves also led to reductions in mildew infection on the second leaves. In particular, treatment of the first leaves with 1 mM vanillic acid, isovanillic acid or syringic acid, reduced mildew infection of the second leaves by 81–87%.     

蔗糖基聚合物对妃子笑荔枝座果率及其叶片中几种抗氧化酶活性的影响

用2%浓度的蔗糖基聚合物处理妃子笑荔枝,研究其对荔枝叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响。结果表明,在小果期喷施蔗糖基聚合物可提高妃子笑荔枝座果率,提高SOD、CAT活性,降低POD活性,在植株的抗逆、抗病及防止果实落果方面效果显著。