Exogenous treatment with salicylic acid leads to increased antioxidant capacity in leaves of barley plants exposed to paraquat

Our previous study suggests that salicylic acid mediates tolerance in barley plants to paraquat (Ananieva et al. 2002). To further define the role of SA in paraquat induced responses, we analysed the capacity of the antioxidative defence system by measuring the activities of several antioxidative enzymes: superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2), dehydroascorbate reductase (DHAR, EC 1.8.5.1), catalase (CAT, EC 1.11.1.6), and guaiacol peroxidase (POX, EC 1.11.1.7). Twelve-day-old barley seedlings were supplied with 500 micromol/L SA or 10 micromol/L Pq via the transpiration stream and kept in the dark for 24 h. Then they were exposed to 100 micromol m(-2) s(-1) PAR and samples were taken 6 h after the light exposure. Treatment of seedlings with 10 micromol/L Pq reduced the activity of APX and GR, did not affect the activity of POX and DHAR but caused over a 40% increase in the activity of CAT. Pre-treatment with 500 micromol/L SA for 24 h in the dark before Pq application increased the activities of the studied enzymes in both the chloroplasts (SOD activity) and the other compartments of the cell (POX, CAT activity). The effect of SA pre-treatment was highly expressed on DHAR and POX activity. The data suggest that SA antagonizes Pq effects, via elicitation of an antioxidative response in barley plants.     

In vivo fluorometric method for early detection of cyanobacterial waterblooms

A specific method was developed for monitoring the concentration of cyanobacteria (blue-green algae) before waterblooms, based on their characteristics ofin vivo fluorescence. The excitation and emission spectra of cyanobacteria are very different from those of eukaryotic algae, due to the importance of phycocyanin, rather than chlorophylla, in determining the fluorescence characteristics. Our results, based on four cyanobacteria:Microcystis aeruginosa, Anabaena cylindrica, Phormidium tenue andSpirulina platensis, indicate that excitation at 620 nm and its emission at 645 nm is a sensitive and specific method for their detection. Furthermore, the addition of 10 M photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) induced only 3% increase in phycocyanin fluorescence, suggesting that this measurement is almost independent of the ongoing rate of photosynthesis.Author for correspondence     

水杨酸诱导下蝙蝠蛾拟青霉转录组分析及虫草酸代谢途径关键酶基因挖掘

【目的】虫草酸是虫草中重要的活性成分之一,但其低含量极大地限制了其工业应用。水杨酸(salicylic acid, SA)是一种非生物诱导子,可以显著提高蝙蝠蛾拟青霉中虫草酸的合成,但蝙蝠蛾拟青霉虫草酸代谢途径及其对水杨酸的响应尚不明确。本研究旨在获得蝙蝠蛾拟青霉响应SA处理的转录组学信息,挖掘蝙蝠蛾拟青霉中虫草酸代谢途径关键酶基因。【方法】采用SA诱导培养蝙蝠蛾拟青霉,8 h后选取诱导和未诱导的菌丝进行转录组高通量测序分析。【结果】测序最终获得40.37 Gb的clean data,拼接得到20 317条unigene,平均长度为1 357.13 bp,功能注释共获得13 592条unigene。差异基因分析共筛选出差异基因2 574个,其中有1 135个上调,1 439个下调。KEGG富集分析表明,差异基因主要富集于细胞周期、减数分裂、半乳糖代谢、DNA复制、糖醇脂类生物合成、甘油脂类代谢等KEGG通路中。进一步分析得到与虫草酸代谢相关的基因13条,其中参与虫草酸生物合成的基因glk、gpi、gla、mpi、fbp、mtld在SA处理后表达量上调,而涉及虫草酸消耗的基因mdh在SA...     

Fungal biotransformation of p-coumaric acid into caffeic acid by Pycnoporus cinnabarinus: an alternative for producing a strong natural antioxidant

Fungal biotransformation of p-coumaric acid into caffeic acid, potentially a strong antioxidant, was evidenced in Pycnoporus cinnabarinus cultures grown with high feeding of p-coumaric acid. Preliminary experiments showed no toxicity of both p-coumaric and caffeic acids at concentrations ranging from 0 to 500 mg l^–1. Feeding 450 mg p-coumaric acid l^–1 into P. cinnabarinus cultures grown on 20 g l^–1 glucose medium resulted in the production of 257 mg caffeic acid l^–1with a molar yield of 21%.     

Regulation of phosphoglycerate mutase in developing forespores and dormant spores ofBacillus megaterium by thein vivo levels of phosphoglycerate mutase inhibitor

Bacillus megaterium accumulated 3-phosphoglycerate during sporulation which was utilized during spore germination. During sporulation a protein was synthesized before or at the start of 3-phosphoglycerate accumulation inside the developing spores about 1.5 h before dipicolinic acid accumulation. This protein has an affinity for Mn²⁺ and other divalent metal ions and inhibits phosphoglycerate mutase activity which has been shown to require Mn²⁺ However, the levels of the inhibitor decreased considerably (75–85%) during spore germination. No appreciable amount of the inhibitor was detected in the vegetable cell and mother cell compartment; however, the forespore compartment possesses an activity comparable to that of dormant spores. The partially purified inhibitor has a molecular weight of 11,000 and possesses both high and low affinity binding sites for Mn²⁺ and Ca²⁺ as determined by Scatchard plot analysis.     

水杨酸对铜胁迫下菊芋的生理调控及根系FTIR分析

为阐明水杨酸(salicylic acid,SA)对菊芋吸收铜的影响机理,以耐铜性差异较大的徐州菊芋(Helianthus tubeuosus)和潍坊菊芋作为试验材料,通过盆栽试验,探究外源SA对铜胁迫下菊芋的光合作用、叶片抗氧化系统及必需矿质营养元素吸收的影响,并对其耐铜机理进行探究。结果表明,300mg/kg铜胁迫抑制了两地菊芋光合电子传递效率和PSⅡ活性,对抗氧化系统产生损伤并造成膜脂过氧化,显著增加了根、茎、叶中铜含量,同时削弱了菊芋对钾、钙、镁和锌的吸收能力。喷施1 mmol/L外源SA可通过调控根系中各官能团的比例,加强其对Cu^(2+)的固定作用,促进矿质营养元素的吸收及渗透调节物质的积累,提高菊芋抗氧化和光合作用能力,有效缓解铜对菊芋生长的抑制作用。本研究初步揭示了SA对铜胁迫下菊芋的生理调控,可为种植菊芋修复土壤铜污染提供科学参考和依据。     

In vivo and in vitro investigation of salt tolerance in three anthocyaninless mutants in tomato (Lycopersicon esculentum Mill.)

Growth responses of a tomato cultivar Ailsa Craig and the ah-, aw- and bls-isogenic/near isogenic lines (IL/NIL) from it were evaluated and compared at cotyledons stage under salt treatment in vivo and in vitro experiments. No differences in hypocotyl and root growth responses were detected between the anthocyanin-containing and the anthocyaninless lines within the in vivo experiments. The anthocyaninless mutants, (except in some cases the bls mutant), exhibited higher callogenic and shoot-forming capacity on both, control and salinized media. It was concluded that for this reason it would be difficult to determine the relationship between the in vivo and in vitro responses of the lines studied and as well as to evaluate the usefulness of the in vitro method in testing these lines for salt tolerance.     

Involvement of protein kinase A and casein kinase II in thein vivo protein kinase activities in prophase arrested Xenopus oocytes

In vivo casein phosphorylation was analysed in Xenopus full-grown oocytes arrested in the prophase of the meiotic cell division. The phosphorylation was inhibited by the protein kinase inhibitor (PKI) and also by heparin (3 g/ml; final concentration). casein phosphorylation was increased by spermine (2 mM). Therefore, protein kinase A and casein kinase II are both activein vivo in full-grown oocytes and may be involved in the prophase arrest of meiotic cell division.     

Salicylic acid inhibits the biosynthesis of ethylene in detached rice leaves

The effects of salicylic acid (SA) on ethylene biosynthesis in detached rice leaves were investigated. SA at pH 3.5 effectively inhibited ethylene production within 2 h of its application. It inhibited the conversion of ACC to ethylene, but did not affect the levels of ACC and conjugated ACC. Thus, the inhibitory effect of SA resulted from the inhibition of both synthesis of ACC and the conversion of ACC to ethylene.Abbreviations ACC 1-aminocyclopropane-1-carboxylic acid - EFE ethylene-forming enzyme - SA salicylic acid     

A simple and inexpensive multiple tube system for thein situ measurement of phytoplankton production by the14C method

A cheap and simple multiple tube incubation system is described for the in situ measurement of phytoplankton production by the ¹⁴C method. Incubation takes place in Pyrex glass tubes sealed with rubber suba-seal caps which are suitable for field, laboratory and incubator work. Comparison of production in the tubes with that in standard pyrex bottles showed no significant difference during both field and laboratory incubations. The in situ suspension system is transported in units and can be assembled into ladders in the field.     

Salicylic acid induces amelioration of chromium toxicity and affects antioxidant enzyme activity in Sorghum bicolor L.

Aim: Chromium (Cr(VI)) would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. Cr(VI) toxicity is often associated with oxidative stress, caused by the excessive formation of reactive oxygen species (ROS). In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. Salicylic acid (SA) plays a key role in the signal transduction pathways of various stress responses, demonstrating the protective effect of SA against abiotic stress factors. So, the present investigation was carried out to study the amelioration of pernicious effects of different concentration of Cr(VI) (0.0, 2.0, and 4.0?mg Cr(VI) kg^?1 soil in the form of potassium dichromate) by treatments of salicylic acid solution viz. pretreatment and foliar spray via antioxidative enzymes and their metabolites.

Results: With different treatments of salicylic acid solution, the reinstatement from ill effects of Cr(VI) toxicity was contemplated but the most conspicuous effect was observed when salicylic acid solution was supplied through the foliar spray (0.50?mM). This was accompanied with an increase in ascorbate peroxidase activity and hydrogen peroxide content and decrease in peroxidase activity and ascorbic acid content.

Significance of the study: This study suggests that salicylic acid when applied through pre-treatment of seeds or through a foliar spray can be used to ameliorate the toxic effects of chromium (VI). Salicylic acid has the great potential for reducing the toxicity of heavy metals without negatively impacting the growth of the plants.     

Effect of salicylic acid on protein composition of Tatar buckwheat Fagopyrum tataricum calluses with different ability for morphogenesis

The effect of salicylic acid on the content of soluble proteins and individual polypeptides in Tatar buckwheat Fagopyrum tataricum calluses differing in ability for morphogenesis was studied. Changes in the protein composition of the calluses cultivated in the dark and in the light indicated the higher sensitivity of the non-morphogenic callus. Different response of callus cultures to salicylic acid and conditions of cultivation (light, darkness) is suggested to be associated with the antioxidant defense system, which is, in particular, characterized by the hydrogen peroxide content in the calluses. Salicylic acid increased the H₂O₂ content in non-morphogenic calluses more strongly than in morphogenic calluses, and the difference was more significant for the calluses cultivated in the light.Translated from Biokhimiya, Vol. 70, No. 3, 2005, pp. 390–396.Original Russian Text Copyright © 2005 by Maksyutova, Galeeva, Rumyantseva, Viktorova.     

Synthesis of neoglycopeptides and analyses of their biodistributionin vivo to identify tissue specific uptake and novel putative membrane lectins

Complex typeN-linked oligosaccharides derived from fetuin, fibrinogen and thyroglobulin were coupled to acetyltyrosine affording a series of neoglycopeptides with retention of terminal structures and the -anomeric configuration of their reducing endN-acetylglycosamine residue. The neoglycopeptides thus synthesized could be labelled to high specific activities with¹²⁵I in the aromatic side chain of tyrosine. Analysis of the fate of these neoglycopeptides in conjunction with inhibition with asialofetuin and oligosaccharides of defined structure in micein vivo revealed the uptake of galactosylated biantennary compound by kidneys, in addition to the known itinerary of triantennary galactosylated complex oligosaccharide from fetuin to liver and the galactosylated biantennary chain with fucosylation in the core to bone marrows. On the other hand, the agalacto, aglucosamino biantennary chains with and without fucosylation in the core region are taken up by submaxillary glands while the conserved trimannosyl core with fucose is primarily concentrated in stomach tissue. These studies thus define new routes for the uptake of complexN-linked glycans and also subserve to identify lectins presumably involved in their recognition.     

Activity of salicylic acid on the growth and biochemism of Chlorella vulgaris Beijerinck

This study was conducted to investigate the influence of salicylic acid (SA) on the growth and changes of nucleic acids, protein, photosynthetic pigments, sugar content and photosynthesis levels in the green alga Chlorella vulgaris Beijerinck (Chlorophyceae). The most significant changes in the content of nucleic acids and proteins was observed at the concentration 10⁻⁴ M SA between 8 and 12 day of cultivation. This concentration of SA increased the number of cells (about 40 %) and content of proteins (about 60 %) and its secretion to the medium. The slight stimulation of protein secretion occurred on the 12th day of cultivation at concentration 10⁻⁴ M, while in the range of 10⁻⁵ M to 10⁻⁶ M the protein secretion was inhibited. SA also stimulated the content of nucleic acids, especially RNA by 20–60 %, compared with the control. The most stimulating influence upon the contents of chlorophylls a and b (50–70 %), total carotenoids (25–57 %), sugar (27–41 %) and intensity of net photosynthesis (18–33 %) was found at 10⁻⁴ M of SA. At the concentration of 10⁻⁶ M SA the slight inhibition of growth and biochemical activity of the algae was recorded at the first days of cultivation.     

A comparison ofin vitro andin vivo effect of clay minerals,humic acid and micronutrients on the activity of fungicides againstRhizoctonia solani

Activity of nine fungicides against mycelial growth ofRhizoctonia solani in potato dextrose broth and in pot tests as seed treatment against cowpea seedling rot in infested soil was differentially in fluenced by clay minerals, humic acid and micronutrients. Humic acid, extracted from farmyard manure, considerably lowered the activity, bothin vitro andin vivo, of all fungicides except chloroneb. Montmorillonite caused substantial decrease in disease control by fungicides but enhanced the toxicity of 2-methoxyethyl mercury chloride (MEMC), and quintozene in culture. Kaolinite inactivated carbendazim, benomyl and thiophanatemethyl in nutrient broth but had little effect on disease control by these fugicides. The six micronutrients altered the activity of fungicides to varying levels often without definite correlation betweenin vitro andin vivo results. The results ofin vitro growth inhibition tests are largely inapplicable to dieseas control tests in infested soil mainly due to the differences in the ambient conditions of the two systems.     

Structural characterization andin vivo immunosuppressive activity of neuroblastoma GD2

Shedding of neuroblastoma gangliosides is positively correlated with tumour progression in patients with neuroblastoma. In assessing the biological activity of these ganglioside molecules, we recently found that total human neuroblastoma gangliosides inhibit cellular immune responses. Here, we have studied the major neuroblastoma ganglioside, G_D2. G_D2 was purified by high performance liquid chromatography and structurally characterized by mass spectrometry. Immunoregulatory effects of G_D2 in vivo were then determined in an established murine model. G_D2 significantly downregulated the local cellular immune response to an allogeneic cell challenge; the usual increase in mass of the lymph node draining the injection site was reduced by 88%, from 1.52 to 0.19 mg (control versus G_D2-treated mice;p<0.01). In parallel, lymphocyte recovery from each node was also reduced from 2.4 to 1.2×10⁶ cells, and lymphocyte DNA synthesis was reduced to half of the control level. These results show that certain shed tumour gangliosides, such as G_D2, function as intercellular signalling molecules, downregulate the cellular immune response, and may thereby enhance tumour formation and progression.     

Enzymatic synthesis of water-soluble derivatives of salicylic acid in organic media

A novel enzymatic method for preparing water-soluble derivatives of salicylic acid catalyzed by immobilized lipase was described. This study is the first to describe the enzymatic transesterification of methyl salicylate in organic solvents with different hydroxyl donors. The acyl-transfer between methyl salicylate and sorbitol was best supported by solvents of log P values –0.33 to 1.4. With Candida antarctica lipase in tert-amyl alcohol, a sorbitol conversion yield of 98% can be obtained by transesterification with sorbitol and methyl salicylate in one step.     

桦褐孔菌提取物抗氧化活性研究

以乙酸乙酯和甲醇为提取剂,采用索氏提取法,剩余残渣采用热水浸提,最终得到桦褐孔菌不同极性提取物,对其DPPH自由基、羟基自由基及超氧阴离子自由基清除活性作用进行了研究,确定桦褐孔菌的抗氧化能力,为深入研究和开发桦褐孔菌功能性食品奠定理论基础。实验结果表明桦褐孔菌具有较好的抗氧化活性,其中乙酸乙酯提取物的DPPH自由基清除率、羟基自由基清除率和超氧阴离子自由基清除率均高于其他两组分及BHT,桦褐孔菌提取物有望成为功能性食品组分中合成抗氧化剂的天然替代品。