Uptake of thallium from naturally-contaminated soils into vegetables

Thallium transfer from naturally (pedogeochemically) contaminated soils into vegetables was studied. Three different types of top-soil (heavy, medium, and light) were used for pot experiments. The soils were collected from areas with low, medium, and high levels of pedogeochemical thallium (0.3, 1.5 and 3.3 mg kg^-1). The samples of vegetables were collected and analysed. The total content of thallium in soil and the type of soil (heavy, medium and light), plant species and plant variety were found to be the main factors influencing thallium uptake by plants. The uptake of thallium from soils with naturally high pedogeochemical content of this element can be high enough to seriously endanger the food chain. These findings are very important because of the high toxicity of thallium and the absence of threshold limits for thallium in soils, agricultural products, feedstuffs and foodstuffs in most countries, including the Czech Republic.     

Effect of Rare Earths on Plants under Supplementary Ultraviolet-B Radiation: Ⅱ. Effect of Cerium on Antioxidant Defense System in Rape Seedlings under Supplementary Ultraviolet-B Radiation

Effects of cerium (Ce3 ) on membranous protective enzymes in rape seedlings exposed to two levels of enhanced ultraviolet-B radiation (UV-B, 280 ～ 320 nm) were studied by hydroponics in the laboratory. The results show that the chlorophyll content decreases and membrane permeability increases in the leaves under UV-B irradiation with an intenposed to a low level of UV-B radiation. POD activity in leaves exposed to a high level of UV-B radiation is enhanced constantly. The sensitivities of these enzymes to UV-B radiation are SOD ＞ CAT ＞ POD. The injury by UV-B radiation on the functions of protective enzymes is lightened, their ability to scavenge radicals is improved, and the membrane permeability is maintained by Ce. Furthermore, the protective effect of cerium is more obvious in plants exposed to low levels of UV-B radiation than to high levels of it. Accordingly, all results prove that the protective effect of Ce on plants under UV-B radiation is realized through the protective system of plants.     

Effect of Neodymium on Physiological Activities in Oilseed Rape during Calcium Starvation

The effects of RE on increasing crop productivity and stress tolerance were reported inpast years[' '2). La ion acts as a calcium-influxinhibitor by displacing Ca2 from cell wallsand occupying Ca2 -binding sites on the plasmalemma, as effective as Ca in the deferral ofsenescence. Besides blocking calcium channels, La has been frequently reported to mimicCa2 effect on plant ion transport. Migliaccioet al. found that both Ca2 and La3 stimulated auxin uptake into pea epicotyl segmentsfr…     

Additives for Rape Seed Oil 3: Synthesis and Tribological Behaviour of Boron‐Sulphur‐Modified Rape Seed Oil Lubricant Additive

A type of boron‐sulphur‐modified rape seed oil for use as a lubricant additive was prepared. The tribological properties of the additive in rape seed oil were evaluated using a friction tester. The morphologies and tribochemical species of the worn surfaces of the test balls were analysed by means of X‐ray photo‐electron spectroscopy. The results show that the additive is very good in increasing the load‐carrying capacity and improving the antiwear and friction‐reducing properties of a rape seed base oil. The inferred lubrication mechanism is that a high‐strength adsorption film and a tribochemical reaction film form on rubbing surfaces due to the carrier effect of the long‐chain fatty acid molecules, to the high reactivities of sulphur and boron, and to the electron deficiency of boron, and their synergism.     

Genome Mining and Evaluation of the Biocontrol Potential of Pseudomonas fluorescens BRZ63, a New Endophyte of Oilseed Rape (Brassica napus L.) against Fungal Pathogens

Endophytic bacteria hold tremendous potential for use as biocontrol agents. Our study aimed to investigate the biocontrol activity of Pseudomonas fluorescens BRZ63, a new endophyte of oilseed rape (Brassica napus L.) against Rhizoctonia solani W70, Colletotrichum dematium K, Sclerotinia sclerotiorum K2291, and Fusarium avenaceum. In addition, features crucial for biocontrol, plant growth promotion, and colonization were assessed and linked with the genome sequences. The in vitro tests showed that BRZ63 significantly inhibited the mycelium growth of all tested pathogens and stimulated germination and growth of oilseed rape seedlings treated with fungal pathogens. The BRZ63 strain can benefit plants by producing biosurfactants, siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia as well as phosphate solubilization. The abilities of exopolysaccharide production, autoaggregation, and biofilm formation additionally underline its potential to plant colonization and hence biocontrol. The effective colonization properties of the BRZ63 strain were confirmed by microscopy observations of EGFP-expressing cells colonizing the root surface and epidermal cells of Arabidopsis thaliana Col-0. Genome mining identified many genes related to the biocontrol process, such as transporters, siderophores, and other secondary metabolites. All analyses revealed that the BRZ63 strain is an excellent endophytic candidate for biocontrol of various plant pathogens and plant growth promotion.     

甘肃省春油菜生育及产量形成对气候变化的响应--测试文章

利用甘肃省春油菜种植区甘肃民乐县1987—2006年、合作市1987—1999年油菜生育期、产量资料及光温水气象资料，分析了气候变化特征及与油菜生长发育、产量形成之间的相互关系。结果表明：气候变暖背景下，甘肃油菜产区气温呈升高趋势，气温倾向率在0.28～0.31℃·10a^-1，河西民乐产区气温增幅大于甘南合作产区。降水基本稳定，两地增（民乐）、减（合作）幅较小。关键生育期——苔花期降水民乐呈减少趋势，合作呈增加趋势；气候变暖使油菜生育进程加快，民乐现蕾—开花、开花—绿熟间隔日数减少趋势明显，1997—2006年平均日数较1986—1996年分别减少13 d和4 d；单位气候要素变化导致气候产量敏感程度不一，民乐产区降水影响以正效应为主，水分不足是产量提高的主要限制因子，最大影响时段出现在苔花期。合作产区光温影响以正效应为主，光温条件不足是主要限制因子，其次是现蕾—开花期降水呈正效应。总体而言，气候变化对高寒阴湿区油菜产量增加和品质形成更为有利，不利于温带草原气候区油菜生产，温带草原气候区应积极采取抗旱保墒、播种期提前等应对措施。     

加压条件下油菜籽中硫苷非酶降解性质的研究

研究总结了加压条件下油菜籽中硫苷非酶降解性质，筛选出促进硫苷非酶降解反应的化学试剂，采用响应曲面法分析，优化硫降解条件，成功地使硫苷非酶降解率在１５～２５ｍｉｎ内达到９０％以上，且避免了大量腈类化合物的生成。     

加压条件下油菜籽中硫苷非酶降解规律及其机理

研究了加压条件下油菜籽中硫苷非酶降解规律，探讨了硫苷非酶降解机理。     

Immunological investigation of lipases in germinating oilseed rape,Brassica napus

An anti-lipase antibody has been used to investigate the lipases of cotyledons from germinating seedlings of oilseed rape, Brassica napusL, var Mikado. Immunological and enzymic assays revealed that lipases were confined to germinating seeds and were absent from other tissues, such as developing seeds, leaves, roots and flowers. The antibody totally inhibited microsomal lipase activity at a ratio of 12 μg IgG protein: 10 μg microsomal protein. It was shown by immunoblotting of microsomal, oil-body and total cotyledon proteins separated by gel electrophoresis that, in each case, the antibody specifically bound to a single polypeptide. This polypeptide had an electrophoretic mobility consistent with a molecular weight of 56 kDa. The appearance and subsequent decline of the 56 kDa polypeptide during the first 10 days of germination closely followed that of the lipase activity, both in microsomal protein and total cotyledon protein fractions. An ELISA for the lipase demonstrated that the amount of immunoreactive microsomal lipase present at each stage of germination was proportional to its enzymic activity. The enzymic and immunological activities of the microsomal lipase each exhibited buoyant densities of 1.087 g ml^?1 on sucrose density gradients. Lipases were present in only very small amounts in dry seeds and were synthesised de novo after 2–3 days of germination.     

植物激素对油菜植株富集133Cs和88Sr的影响

通过水培试验,研究外源植物激素(生长素IAA、赤霉素GA、水杨酸SA)对油菜吸收和累积133Cs、88Sr的影响.以西南地区普遍种植的甘蓝型油菜为试验材料,利用火焰原子吸收光谱法对油菜苗进行88Sr和133Cs含量的测定.结果表明:在三种植物激素处理下,油菜地上部和根部的生物量显著高于对照(未加激素),油菜中133Cs...