坡柳种子提取物对菜青虫取食和生长发育的影响

研究了坡柳种子乙醇提取物对菜青虫4龄幼虫的拒食作用和生长发育的影响。结果表明,坡柳种子乙醇提取物对菜青虫4龄幼虫有显著的拒食活性,24、48h的非选择性拒食性AFC50值分别为742.14、1099.93mg/L;选择性拒食AFC50值分别为1081.15、1553.2mg/L;乙醇提取物对菜青虫4龄幼虫的生长发育抑制作用明显,随施药剂量的增加,生长抑制率增大,化蛹率降低,处理剂量为5000mg/L时,生长抑制率大于100%,化蛹率仅为13.33%。     

Foliar Spraying of Silicon Associated with Salicylic Acid Increases Silicon Absorption and Peanut Growth

Silicon - Silicon (Si) combined with foliar spraying of salicylic acid (SA) can affect the absorption of this beneficial element. A study with Si non-accumulators plants (soybean and bean) observed...     

Biosynthesis and Roles of Salicylic Acid in Balancing Stress Response and Growth in Plants

Salicylic acid (SA) is an important plant hormone with a critical role in plant defense against pathogen infection. Despite extensive research over the past 30 year or so, SA biosynthesis and its complex roles in plant defense are still not fully understood. Even though earlier biochemical studies suggested that plants synthesize SA from cinnamate produced by phenylalanine ammonia lyase (PAL), genetic analysis has indicated that in Arabidopsis, the bulk of SA is synthesized from isochorismate (IC) produced by IC synthase (ICS). Recent studies have further established the enzymes responsible for the conversion of IC to SA in Arabidopsis. However, it remains unclear whether other plants also rely on the ICS pathway for SA biosynthesis. SA induces defense genes against biotrophic pathogens, but represses genes involved in growth for balancing defense and growth to a great extent through crosstalk with the growth-promoting plant hormone auxin. Important progress has been made recently in understanding how SA attenuates plant growth by regulating the biosynthesis, transport, and signaling of auxin. In this review, we summarize recent progress in the biosynthesis and the broad roles of SA in regulating plant growth during defense responses. Further understanding of SA production and its regulation of both defense and growth will be critical for developing better knowledge to improve the disease resistance and fitness of crops.     

Encapsulation Reduces the Deleterious Effects of Salicylic Acid Treatments on Root Growth and Gravitropic Response

The role of salicylic acid (SA) on plant responses to biotic and abiotic stresses is well documented. However, the mechanism by which exogenous SA protects plants and its interactions with other phytohormones remains elusive. SA effect, both free and encapsulated (using silica and chitosan capsules), on Arabidopsis thaliana development was studied. The effect of SA on roots and rosettes was analysed, determining plant morphological characteristics and hormone endogenous levels. Free SA treatment affected length, growth rate, gravitropic response of roots and rosette size in a dose-dependent manner. This damage was due to the increase of root endogenous SA concentration that led to a reduction in auxin levels. The encapsulation process reduced the deleterious effects of free SA on root and rosette growth and in the gravitropic response. Encapsulation allowed for a controlled release of the SA, reducing the amount of hormone available and the uptake by the plant, mitigating the deleterious effects of the free SA treatment. Although both capsules are suitable as SA carrier matrices, slightly better results were found with chitosan. Encapsulation appears as an attractive technology to deliver phytohormones when crops are cultivated under adverse conditions. Moreover, it can be a good tool to perform basic experiments on phytohormone interactions.     

丙溴磷,杀螨隆,氟铃脲等防治小菜蛾及菜青虫试验

试验结果表明，丙溴磷、杀螨隆、氟铃脲等对小菜蛾均有效，且持效期长，丙溴磷具有速效性及对菜青虫高效。     

Symptomless Endophytic Fungi Suppress Endogenous Levels of Salicylic Acid and Interact With the Jasmonate-Dependent Indirect Defense Traits of Their Host,Lima Bean (Phaseolus lunatus)

Symptomless ‘type II’ fungal endophytes colonize their plant host horizontally and exert diverse effects on its resistance phenotype. Here, we used wild Lima bean (Phaseolus lunatus) plants that were experimentally colonized with one of three strains of natural endophytes (Bartalinia pondoensis, Fusarium sp., or Cochliobolus lunatus) to investigate the effects of fungal colonization on the endogenous levels of salicylic acid (SA) and jasmonic acid (JA) and on two JA-dependent indirect defense traits. Colonization with Fusarium sp. enhanced JA levels in intact leaves, whereas B. pondoensis suppressed the induction of endogenous JA in mechanically damaged leaves. Endogenous SA levels in intact leaves were significantly decreased by all strains and B. pondoensis and Fusarium sp. decreased SA levels after mechanical damage. Colonization with Fusarium sp. or C. lunatus enhanced the number of detectable volatile organic compounds (VOCs) emitted from intact leaves, and all three strains enhanced the relative amount of several VOCs emitted from intact leaves as well as the number of detectable VOCs emitted from slightly damaged leaves. All three strains completely suppressed the induced secretion of extrafloral nectar (EFN) after the exogenous application of JA. Symptomless endophytes interact in complex and strain-specific ways with the endogenous levels of SA and JA and with the defense traits that are controlled by these hormones. These interactions can occur both upstream and downstream of the defense hormones.     

显色试剂5-(5-羧基-1,2,4-三氮唑偶氮基)水杨酸的合成及其与铜的显色反应

合成了新的显色试剂 5 -( 5 -羧基 -1 ,2 ,4-三氮唑偶氮基 )水杨酸 ,研究了它与铜的显色反应 ,铜与试剂于 1 0 .7～ 1 1 .2的缓冲介质中形成稳定的 1∶1橙红色络合物 ,在表面活性剂土耳其红油存在下表观摩尔吸光系数ε540　 =1 .0 3× 1 0 5L·mol-1·cm-1,Cu(Ⅱ )的质量浓度在 0～ 40 0 μg/L范围内符合比尔定律。该法灵敏度高 ,选择性好 ,线性范围宽 ,可用于废水和环境水样中微量铜的测定。     

硝酸生产中氨氧化接触时间的计算及确定原则

论述了硝酸生产中氨氧化铂网接触时间的确定原则,提出了通过铂网燃氨强度、氨空混合气的气量、氨空混合气穿过铂网的气速和氨氧化率计算铂网接触时间的4种方法。     

腐植酸精制有机肥在小麦和水稻上的应用效果研究

在小麦和水稻上,以复混肥为对照的田间试验表明,腐植酸精制有机肥可以明显提高作物产量。小麦增产比复混肥增加1.31%～8.69%;水稻增产比复混肥增加0.75%～8.02%;施用腐植酸精制有机肥能够增加经济收入,小麦亩净收益比复混肥增加15.96～75.67元;水稻亩净收益比复混肥增加12.21～105.73元。     

腐植酸在作物生长发育化学控制中的作用及机理探讨

腐植酸在作物生长发育化学控制中有刺激生长、改善品质和提高抗逆能力等作用。其作用机制在于可促进对营养物质的吸收、提高酶的活性、调节内源激素合成、增强呼吸强度和提高光合作用效率等。     

无机肥料配合腐植酸铵、复硝酚钠对玉米生长的影响

通过盆栽试验,研究了无机肥料配合腐植酸铵及不同浓度的复硝酚钠对玉米株高、叶面积、地上生物量干重、全氮全磷全钾总含量的影响。结果表明,无机肥料与腐植酸铵配合使用比单独使用无机肥料效果要好,能明显增加玉米株高2.45%、叶面积4.86%、地上生物量干重5.75%、全氮4.1%、全磷9.25%、全钾5.43%;无机肥料与腐植酸铵和复硝酚钠配合使用比单独使用无机肥料效果更好,能明显增加玉米株高6.58%、叶面积10.99%、地上生物量干重13.62%、全氮9.92%、全磷15.03%、全钾12.14%;复硝酚钠在玉米肥料上的添加浓度按0.2%最好。     

The Relative Proportions of Different Lipid Classes and their Fatty Acid Compositions Change with Culture Age in the Cariogenic Dental Pathogen Streptococcus mutans UA159

The oral cariogenic bacterial pathogen Streptococcus mutans strain UA159 has become an important research organism strain since its genome was sequenced. However, there is a paucity of information on its lipidome using direct analytical biochemical approaches. We here report on comprehensive analyses of the major lipid classes and their fatty acids in cells grown in batch standing cultures. Using 2-D high-performance thin-layer chromatography lipid class composition changes were detected with culture age. More lipid components were detected in the stationary-phase compared to log-phase cells. The major lipids identified included 1,3-bis(sn-3′-phosphatidyl)-sn-glycerol (phosphatidylglycerol), 1,3-diphosphatidylglycerol (cardiolipin), aminoacyl-phosphatidylglycerol, monoglucosyldiacylglycerol, diglucosyldiacylglycerol, diglucosylmonoacylglycerol and, glycerophosphoryldiglucosyldiacylglycerol. Culture age also affected the fatty acid composition of the total polar lipid fraction. Thus, the major lipid classes detected in log-phase and stationary-phase cells were isolated and their fatty acids were analyzed by gas–liquid chromatography to determine the basis for the fatty acid compositional changes in the total polar lipid fraction. The analyses showed that the relative proportions of these acids changed with culture age within individual lipid classes. Hence fatty acid changes in the total polar lipid fraction reflected changes in both lipid class composition and fatty acid compositions within individual lipid classes.     

腐植酸对黄瓜植株生长的影响涉及与硝酸盐浓度有关的细胞分裂素、多胺、矿质营养素浓度在植株根系和芽中的变化

许多研究报道腐植酸类物质能够促进不同环境下的幼苗栽培物的生长。然而对腐植酸促进植物生长的作用机理,科学工作者却知之甚少。腐植酸类物质对植物幼苗的影响涉及根质膜H＋-ATP酶活性及根系和芽中硝酸根分布的主要作用,反过来,导致某些细胞分裂素,多聚胺与脱落酸根浓度的变化,从而促进新幼苗生长。这一观点,通过现阶段的试验可以得出。试验结果表明,植物根系所富集的腐植酸能显著增加植物幼苗的生长,这与植物根系H＋-ATP酶活性增强有关,这种活性表现在植物幼芽中硝酸盐浓度的增加,根系浓度降低。这些作用与细胞分裂素和多胺物质的浓度在植物幼芽中显著提高是相伴随的,与植物根系浓度降低有关。同样地,多种细胞分裂素在植物幼芽和根系分布的变化与多种矿物营养素在植物幼芽和根系分布的显著变化是协调一致的。试验结果表明,腐植酸对黄瓜幼苗生长的促进作用与硝酸根的浓度直接有关,而硝酸根浓度的变化又影响了细胞分裂素和多胺物质在植物幼苗中的富集。     

Semisynthetic Ursolic Acid Fluorolactone Derivatives Inhibit Growth with Induction of p21(waf1) and Induce Apoptosis with Upregulation of NOXA and Downregulation of c-FLIP in Cancer Cells

A series of ursolic acid ((1S,2R,4aS,6aR,6aS,6bR,8aR,10S,12aR,14bS)‐10‐hydroxy‐1,2,6a,6b,9,9,12a‐heptamethyl‐2,3,4,5,6,6a,7,8,8a,10,11,12,13,14b‐tetradecahydro‐1H‐picene‐4a‐carboxylic acid) derivatives with a 12‐fluoro‐13,28β‐lactone moiety were synthesized using the electrophilic fluorination reagent Selectfluor. The antiproliferative effects of these novel compounds were evaluated in AsPC‐1 pancreatic cancer cells, and the structure–activity relationships (SARs) were evaluated. Of the compounds synthesized, ursolic acid derivatives carrying a heterocyclic ring, such as imidazole or methylimidazole, and cyanoenones were among the more potent inhibitors of AsPC‐1 pancreatic cancer cell growth. 2‐Cyano‐3‐oxo‐12α‐fluoro‐urs‐1‐en‐13,28β‐olide, compound 20 , was the most effective inhibitor with IC₅₀ values of 0.7, 0.9 and 1.8 μM in pancreatic cancer cell lines AsPC‐1, MIA PaCa‐2 and PANC‐1, respectively. This compound also exhibited better antiproliferative activities against breast (MCF7), prostate (PC‐3), hepatocellular (Hep G2) and lung (A549) cancer cell lines, with IC₅₀ values lower than 1 μM . The mechanism of action by which these compounds exert their biological effect was evaluated in AsPC‐1 cells using the most potent inhibitor synthesized, compound 20 . At 1 μM , the cell cycle arrested at the G1 phase with upregulation of p21^waf1. Apoptosis was induced at an inhibitor concentration of 8 μM with upregulation of NOXA and downregulation of c‐FLIP. These data indicate that fluorolactone derivatives of ursolic acid have improved antiproliferative activity, acting through arrest of the cell cycle and induction of apoptosis.     

Growth Performance,Carcass Characteristics,Fatty Acid Composition,and Blood Biochemical Parameters of Lamb Fed Diet with the Addition of Lingonberry Leaves and Oak Bark

The aim of the study is to determine the effect of natural additives supplemented to the lamb diet on lamb performance, fatty acid (FA) composition of edible parts of lambs, and biochemical plasma indices. The study is carried out on 18 male lambs, allocated to three groups in a randomized complete block design. Control animals (CON) are fed a basic diet, while the experimental lambs additionally receive lingonberry leaves (VVI) or oak bark (QUE) (10 g d^?1), as a different source of tannins. Supplementing lambs with the VVI diet decreases fat content in the longissimus dorsi muscle (MLD). The VVI diet decreases monounsaturated fatty acid (MUFA) concentration (including C18:1 cis‐9) in the MLD, increases the proportion of C16:0, C16:1, C17:1, and C22:6 n‐3 in the semitendinosus muscle, as well as increases the n‐6/n‐3 ratio and thrombogenic index in the liver. The addition of QUE to lamb diets decreases C17:1 concentration and increases the content of C18:1 trans‐11 in the MLD. Tannins‐enriched diets increase low density lipoprotein concentrations in the blood plasma. The VVI diet increases the activity of alkaline phosphatase, while QUE supplementation decreases gamma‐glutamyl transferase activity in blood plasma. Modifications of FA composition in lamb tissues may suggest an indirect effect of tannins on FA ruminal biohydrogenation. Practical Applications: The use of VVI and QUE in lamb nutrition as natural resources is of a great interest to scientists. The present study shows that primarily VVI addition to lamb diets affects the quality of meat, due to higher proportion of catechin than QUE. Decreased concentration of fat, as well as increased proportion of C22:6 n‐3 and desirable fatty acids (including MUFA, polyunsaturated fatty acid, C18:0) after VVI supplementation increases health‐promoting properties of lamb meat and is related to humans. However, the presence of biologically active substances (tannins) in the examined additives makes it necessary to further research and discover their full potential in many areas.     

Cyclization of 1,4‐Phenylenediacrylic Acid with Thionyl Chloride and Subsequent Suzuki–Miyaura Reactions Revisited. The Products are Benzo[1,2‐b;5,6‐b′]dithiophenes and not Benzo[1,2‐b;4,5‐b′]dithiophenes

The reaction of 1,4‐phenylenediacrylic acid with thionyl chloride was reinvestigated. In earlier reports [Liebigs Ann. Chem. 1980 , 1172; Heterocycles 1995 , 41, 2691; Adv. Synth. Catal. 2009 , 351, 2683] it was claimed that 3,7‐dichlorobenzo[1,2‐b;4,5‐b′]dithiophenes were formed in these reactions. Herein, we provide unambiguous evidence that the assignment of these structures is wrong and that, in contrast, 3,6‐dichlorobenzo[1,2‐b;5,6‐b′]dithiophenes are formed. As a consequence, the structures of these parent molecules and of numerous aryl‐substituted derivatives prepared by Pd‐catalyzed cross‐coupling reactions have to be revised. As many of these dithiophenes were reported to show interesting optical, thermal and electronic properties, the theoretical explanations for these properties have to be reconsidered in the light of the corrected structures reported herein. Our structural assignments are based on X‐ray crystal structure analyses of the parent molecules and on NMR spectroscopic studies of the first unsymmetrical derivatives. Besides, mechanistic investigations based on quantum chemical calculations have been carried out which support the formation of the 3,6‐dichlorobenzo[1,2‐b;5,6‐b′]dithiophene isomers.