Effect of Previous Exposure to Hydroxamic Acids in Probing Behavior of Aphid Sitobion fragariae on Wheat Seedlings

We hypothesized that aphids after previous exposure to hydroxamic acids (Hx), a family of secondary plant compounds deleterious to aphids, are able to reduce their subsequent exposure to them. This hypothesis was tested by evaluating the time to produce salivation into a sieve element (SSE) by the aphid Sitobion fragariae on seedlings of two wheat cultivars of Triticum aestivum differing in their concentration of Hx. The total time to produce a first SSE was significantly longer in the high-Hx cultivar; however, the subsequent, second SSE (first SSE after interruption of probing) in this cultivar was significantly reduced, reaching the level observed in the low-Hx plants. Therefore, a strategy to reduce the exposure to secondary compounds was observed only in the second SSE in high-Hx plants. When the experimental plant was replaced by a new unattacked plant after the first SSE, aphids did not change the behavior described, thus excluding an aphid-induced plant susceptibility. The number of cell punctures and accumulated duration was not affected by previous exposure to Hx, either in low or high Hx cultivars. Total time and pathway time but not cell punctures, seem to be the variables affected by previous exposure to Hx.     

环保酵素施用对土地与植物生长状况的影响研究

简要剖析当时中国土地面对的现状,发现长时间施氮肥土壤蓝菌数量显著降低。由于中国是农业大国,施化学肥料是保证粮食高产出、稳产的一种重要措施。同时概括了环保酵素的理论知识以及简要阐述其制作方法。着重分析了环保酵素改良土壤后各项指标的变化,通过栽种作物的生长得出的数据进行验证,环保酵素对作物的生长有一定的作用。     

甘薯淀粉高吸水树脂促进干旱条件下小麦种子萌发和幼苗生长的研究

主要研究了干旱条件下,甘薯淀粉高吸水树脂作为包衣剂对小麦种子萌发和幼苗生长的影响规律,为该高吸水树脂在农业生产中的应用提供依据。实验在模拟干旱条件下,考查了未包衣与有包衣(甘薯淀粉高吸水树脂与小麦质量比分别为1∶30,1∶40,1∶50,1∶60,1∶70)下小麦种子的发芽率、苗高,还考查了小麦幼苗的H_2O_2、MDA、叶绿素含量,幼苗自由基清除相关酶SOD、CAT、POD、GPX、APX活性与自由基清除剂GSH、ASA含量的变化。结果表明:小麦种子经甘薯淀粉高吸水树脂包衣后,提高了种子的发芽率、幼苗自由基清除相关酶的活性及自由基清除剂的含量,有效减轻了小麦幼苗的膜脂过氧化作用,大大改善了干旱胁迫下小麦幼苗的生长状况。同时不同包衣质量比下的差异也较大,质量比1∶50效果最好。     

植物源生长调节剂对小麦生理生长的影响

用浓度均为100mg/L的植物源生长调节剂(T)、赤霉素(GA3)和油菜素内酯(BR)分别在小麦苗期、拔节期、孕穗期、灌浆期进行叶面喷洒,清水对照(CK)。结果表明,植物源生长调节剂、赤霉素和油菜素内酯分别使小麦叶片中叶绿素含量较对照平均增加了10.77%、4.95%、5.54%;使叶片可溶性糖含量分别平均增加了23.83%、16.65%、14.66%;硝酸还原酶(NR)活性平均提高16.14%、18.26%和12.32%,而对类黄酮含量的影响不明显。这说明植物源生长调节剂能够延缓叶片衰老,促进光合作用,延长叶片对氮素的利用和转化时间,促进同化物质的积累,对小麦的生理生长具有明显的促进作用。     

环境监测工作在环境保护中的重要性

随着社会的不断进步,人们对于环境保护工作越来越重视。在环境保护工作中,环境监测是非常重要的一部分,通过环境监测能够及时监测到相关的环境数据,然后对环境问题进行有针对的治理。主要对环境监测在环境保护中的重要性和提高环境监测工作质量的措施进行了阐述。     

Importance of Tyrosine Phosphorylation in Hormone-Regulated Plant Growth and Development

Protein phosphorylation is the most frequent post-translational modification (PTM) that plays important regulatory roles in a wide range of biological processes. Phosphorylation mainly occurs on serine (Ser), threonine (Thr), and tyrosine (Tyr) residues, with the phosphorylated Tyr sites accounting for ~1–2% of all phosphorylated residues. Tyr phosphorylation was initially believed to be less common in plants compared to animals; however, recent investigation indicates otherwise. Although they lack typical protein Tyr kinases, plants possess many dual-specificity protein kinases that were implicated in diverse cellular processes by phosphorylating Ser, Thr, and Tyr residues. Analyses of sequenced plant genomes also identified protein Tyr phosphatases and dual-specificity protein phosphatases. Recent studies have revealed important regulatory roles of Tyr phosphorylation in many different aspects of plant growth and development and plant interactions with the environment. This short review summarizes studies that implicated the Tyr phosphorylation in biosynthesis and signaling of plant hormones.     

莠去津对核桃幼苗生长量及生理效应的影响

试验通过常用除草剂莠去津在3种浓度处理下核桃苗叶片内叶绿素含量、丙二醛含量(MDA)、可溶性糖含量及生长量的测定，来研究莠去津对核桃幼苗生长发育的影响。试验结果表明，莠去津对核桃幼苗的叶绿素含量、可溶性糖含量及生长量的影响，在各浓度问存在显著差异。施用莠去津时，在苗木萌芽之前，建议采用13g／L喷雾或土壤处理，在发芽后施用时，采用浓度为6．5g／L，或者按常用浓度施用时，对苗木应采取一定的保护措施。     

丙环唑对小麦生长的调节作用

室内生测试验结果指出，用丙环唑浸麦种后，抑制小麦幼苗地上部生长，促进根伸长，提高小麦幼苗根冠比，增强根系活力，增加单位重量叶片叶绿素含量。大田试验结果证实，用丙环唑拌种，推迟出苗日期，影响出苗率，在苗期抑制上部生长，成株期对地上部生长有促进作用，显著增加小麦的穗粒粒及百穗重。试验结果表明，丙环唑对小麦的生长和发育有一定的调节作用，其作用随剂量的提高而增大。     

通气量和CO2对Nannochloropsis sp.在光生物反应器中的生长和EPA合成的影响

实验考察了在气升式内环流光生物反应器中通气量、CO2含量等培养条件对Nannochloropsis sp.生长及EPA合成的影响. 结果表明,在气升式内环流光生物反应器中培养,Nannochloropsis sp.生长速率显著提高. 培养8 d,Nannochloropsis sp.生物量(干重)可达857 mg/L,是摇床培养的2倍. 在一定范围内,Nannochloropsis sp.的生长速率随通气量的增加而增加,在本实验条件下,通气量为500 mL/min时生长最快,而过高的通气量则对Nannochloropsis sp.的生长没有促进作用. 在通气中含1%(j) CO2时,可加快藻细胞的生长,最大生长速率可达不配加CO2时的1.8倍. 通气量和CO2对Nannochloropsis sp.细胞内总脂肪酸及EPA的积累有显著影响. 在通气量为400 mL/min及CO2含量为0.5%时,培养液中EPA产量最高,达到39.0 mg/L.     

浅析环境监测工作的重要性

随着社会的进步,经济的飞速发展,人们已经不再单纯只关注于最基本的生存条件,也越来越关注能满足于人们生活的更好的可以反映人生活质量和品质的生活条件。比如,环境对人的影响这一方面越来越受到人们的重视和关注,同时人们对于环境质量的要求也越来越高。好的环境质量不仅关系到自然的美观程度,更是直接能和人们的身体健康息息相关的。所以,基于环境对人的重要性影响,通过开展环境监测工作来进行一系列探讨和研究。     

环境因子对破乳优势菌生长的影响

从油田油泥中富集、培养筛选出两株具有破乳活性的优势菌，并对影响破乳菌生长的主要环境因素进行了试验研究。试验表明：这两株破乳优势菌的最佳生长周期为60～72h，最佳温度为30℃左右，最佳pH值为6-8之间。     

Effect of Two Wheat Cultivars Differing in Hydroxamic Acid Concentration on Detoxification Metabolism in the AphidSitobion avenae

Hydroxamic acids (Hx) are wheat secondary metabolites conferring resistance for cereals against aphids. The activity of five enzymatic systems were evaluated in the aphid Sitobion avenae reared on the high-Hx wheat cultivar Chagual and the low-Hx wheat cultivar Huayún for 10 generations. Enzyme solutions were prepared from aphid homogenates and assayed for mixed function oxidases (including cytochrome P-450 monooxygenases and NADPH cytochrome c reductase), glutathione S-transferases, esterases, and catalase. Specific activities per aphid individual of cytochrome P-450 monooxygenases, NADPH cytochrome c reductase, glutathione S-transferases, and esterases were significantly increased in wheat cultivars relative to oat (only marginal increase of esterases in Chagual). Aphids fed on cv. Huayún showed an overall higher induction of enzymatic systems than those fed on cv. Chagual. Comparison of these results with reported effects of Hx on detoxifying enzymes in other insects, including aphids, support the hypothesis that these enzymatic pathways play an important role in the detoxification of toxic host-plant secondary metabolites.     

油田开采中环境保护的重要性

地球上的生态系统有着永远摆脱不完的依赖性,需要地球源源不断地提供植物和动物的食物,需要有足够厚度的大气层,来保护人类不受过高或过低气温,以及过量紫外线的伤害,需要地球提供足够量的水和氧气来维持生命的存在。保护环境就是保护人类赖以生存的空间,保护环境关系到人类的根本利益。石油人应严格遵守国家环境保护的法律法规,持续治理环保隐患,强化节能减排工作,搞清洁发展。搞好环境保护、建设资源节约型社会,环境友好型社会。     

腐植酸肥料对玉米和小麦生长发育的影响

采用田间试验方法,以兴农998和良兴99作为供试玉米和小麦品种,研究了腐植酸肥料对玉米和小麦生长发育的影响。结果表明,与施用普通复合肥相比较,腐植酸肥料的施用能显著减少玉米秃尖,提高养分,特别是提高氮、钾的利用效率,增产率达到10%以上;与等养分的普通肥料相比,腐植酸肥料的施用能促进小麦植株的个体发育和植株干物质的积累,促进小麦分蘖和后期成穗,小麦增产幅度达到了13.5%~18.7%。     

Solvent Extraction Behavior of Plutonium (IV) Ions in the Presence of Simple Hydroxamic Acids

Abstract

Formo‐ and aceto‐hydroxamic acids are very effective reagents for stripping Pu(IV) ions from a tri‐butyl phosphate phase into nitric acid. Distribution data for Pu(IV) in the presence of these hydroxamate ions have been obtained and trends established. The affinity of aceto‐hydroxamic acid for Pu(IV) ions and its selectivity over U(VI) ions is demonstrated by the values of the stability constants in HClO₄. These data support the applications of simple hydroxamic acids in advanced Purex‐type solvent extraction systems.     

烟酰胺对小麦萌发及幼苗生长的影响

以小麦种子烟农19为试验材料,采用培养皿纸上发芽法,以纯水为对照,研究不同浓度烟酰胺溶液对小麦种子萌发及幼苗生长的影响.结果表明:烟酰胺溶液浓度为25 mg/L时,处理效果最佳.小麦种子发芽势、发芽率显著提高,分别增加了25.27％、15.58％;小麦幼苗的株高、根长,幼苗的鲜重均显著增加,其中株高增加了36.16％,根长增加了131.47％,幼苗的鲜重增加了38.89％,a-淀粉酶和叶绿素也分别增加了98.40％、87.69％,为研究烟酰胺作为小麦种子包衣剂成分提供了较好的试验基础.     

盐胁迫环境下腐植酸类物质对小麦生长及矿物营养吸收的影响

对在不同浓度的盐胁迫条件下,叶面喷施液态腐植酸和土壤施用腐植酸类物质对小麦作物生长和矿物营养吸收的影响进行了研究。通过添加不同量的NaCl得到不同的盐浓度环境。腐植酸类物质在作物种植前一个月施用,液态腐植酸在种苗发芽后20d和35d喷施于小麦叶面。腐植酸类物质的施用量为0、1g/kg、2g/kg,液态腐植酸的浓度为0、0.1%、0.2%。盐度对小麦生长具有负面影响,它会降低小麦对除Na、Mn以外的矿物营养的吸收,影响小麦干重。通过在土壤施用腐植酸类物质可以增加小麦对N的吸收,叶面施用腐植酸可增加其对P、K、Mg、Na、Cu和Zn的吸收。研究结果显示：在土壤中施用腐植酸类物质,不同盐浓度与施用量之间存在较好的相关性,但叶面喷施时盐度和喷施量之间相关性并不明显。在盐胁迫环境的影响下,叶面喷施腐植酸的初始浓度和土壤中施用的腐植酸类物质的初施量都增加了作物对营养元素的吸收。     

The Role of Hydroxamic Acids in the Retention of Fission Products in TBP Diluents. A Quantitative Study in a Model System

Abstract

The degradation with nitric acid of kerosene-type diluents of TBP in the reprocessing of nuclear fuel leads to the formation of primary nitroalkanes. These, under acid conditions, may hydrolyze to hydroxamic acids, HA, which are well-known complex-ing agents of many metal ions, including ⁹⁵Zr. The formation of very stable HA-⁹⁵Zr complexes has been proposed as a rationale for the retention of ⁹⁵Zr in the diluents. However, the results of this study carried out in a model system, the acid-catalyzed conversion of 1-nitropropane to propanhydroxamic acid, and the subsequent hydrolysis to carboxylic acid and hydroxylamine—easily extensible to the actual reprocessing processes—indicate that in these systems the equilibrium concentration of hydroxamic acids attainable is too low (10^?8 to 10^?9 M) to account for the “zirconium retention” phenomenon.     

环境监测在环境影响评价中的重要性分析

环境影响评价的评价初期、建设期、运行期以及后评价期的整个环境评价体系中,均需要环境监测数据来支撑,环境监测贯穿于整个环境影响评价体系之中,是环境影响评价的技术基础,同时还具有较强的监督功能。