Barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] is a problematic weed in rice (Oryza sativa L.) fields. Overapplication of herbicides causes environmental pollution and the emergence of resistant weeds, and integrated weed management methods can reduce dependence on herbicides. The growth of E. crus-galli and rice seedlings was shown to be significantly inhibited by high concentrations of fulvic acid (FA, C14H12O8) under flooding conditions (HF, 0.80 g L−1) (P < 0.05). In contrast, seedling growth was promoted by the application of very low concentrations of FA (LF, 0.02 g L−1). The activities of glutathione S-transferase (GST) and antioxidant enzymes, including total superoxide dismutase (T-SOD), peroxidase (POD), and catalase (CAT), in E. crus-galli seedlings were enhanced by the LF treatment; while POD activity decreased and GST, T-SOD, and CAT activity was not significantly altered by the HF treatment. The metabolomic and transcriptomic analyses showed that FA regulated E. crus-galli seedling growth by affecting the synthesis of indole derivatives and flavonoid compounds. Compared with the blank control (CK, 0 g L−1), the levels of four indole derivatives were upregulated under the HF treatment, and the indole derivatives were slightly downregulated under the LF treatment. The flavonoids, including naringenin, naringenin chalcone, eriodictyol, kaempferol, and epigallocatechin, were downregulated under HF treatment, and the growth of E. crus-galli was reduced. In contrast, the metabolism and transcription of flavonoids were not significantly altered by the LF treatment. The addition of 0.80 g L−1 FA obviously inhibited the growth of newly sprouted E. crus-galli, whereas rice growth was significantly promoted 8 d after rice planting (P < 0.05). The application of FA, therefore, might be a potential integrated weed management method to control the damage caused by E. crus-galli in paddy fields.

An experimental turfgrass growth regulator, V-10029, was compared with trinexapac-ethyl, a growth regulator used commonly on highly maintained turfgrasses, to evaluate growth suppression patterns and suppression of seedhead formation; the latter was evaluated on turfgrass species and annual bluegrass, a weedy species that appeared and developed seedheads in tall fescue. Plugs of creeping red fescue, Kentucky bluegrass, perennial ryegrass, and creeping bentgrass were taken from the field into a greenhouse. V-10029 at three rates (0.015, 0.029, and 0.059 kg/ha) was compared to an untreated control and trinexapac-ethyl at a label rate (0.382 kg/ha for perennial ryegrass and 0.287 kg/ha for the other four species). Of the eight replications for each treatment, four were not mowed for the purpose of evaluating suppression of seedhead formation, and four were used for weekly clipping collection to evaluate growth suppression. Compared to the untreated control, V-10029 at all three applied rates caused significant seedhead suppression in both tall fescue infested with annual bluegrass (> 90%) and perennial ryegrass (50 to 80%). Trinexapac-ethyl was not as effective, causing seedhead suppression levels of 57% in annual bluegrass found in tall fescue and 43% in perennial ryegrass. V-10029 caused unacceptable levels of discoloration (> 20%) in all turfgrass species, and discoloration increased with increasing rates of application. Patterns of growth suppression for tall fescue, Kentucky bluegrass, and perennial ryegrass, in response to V-10029 at all rates and to trinexapac-ethyl, were similar on a percent of suppression basis. Growth of creeping bentgrass was suppressed by V-10029 only at high rates. In contrast, creeping red fescue was significantly injured by V-10029 at all rates. The greatest growth suppression, in response for all treatments, occurred 2 to 3 wk after application. The effect of trinexapac-ethyl dissipated after 4 wk, while V-10029 was effective until 5 to 7 wk after treatment. Observed effects of V-10029 were consistent with its activity as an ALS-inhibiting herbicide and, therefore, as a Class D turfgrass growth regulator.

Eighteen volatile monoterpenes, which are among the major constituents of essential oils from plants, were screened for phytotoxicity to several crop and weed species. Several monoterpenes containing an oxygen function severely inhibited germination of four different annual weeds while concurrently displaying little effect on soybean germination. Soybeans varied in their sensitivity to various monoterpenes (measured by seedling growth), with α-terpineol and geraniol selectivity inhibiting weed seed germination while having little or no effect on soybeans. All of the monoterpenes tested exhibited relatively high germination and growth inhibition to corn and wheat.

Velvetleaf (Abutilon theophrasti Medic. ♯3 ABUTH) and Powell amaranth (Amaranthus powellii S. Wats. ♯ AMAPO) control with pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] was dependent on proper timing of application. Preemergence and early postemergence pendimethalin treatments provided effective control, but control rapidly diminished with later postemergence treatments, particularly on Powell amaranth. Time-course studies on the effects of pendimethalin on the growth of these species indicated that pendimethalin inhibited shoot growth by slowing or stopping the production of leaves and branches, as well as reducing leaf size and internode length. Pendimethalin appeared to have its greatest effect on portions of the shoot undergoing cell division.

The preemergence herbicide cinmethylin is a benzyl ether derivative of the monoterpene 1,4-cineole. Other oxygenated monoterpenes (carvone, citronellol, fenchone, geraniol, and pulegone) were previously found to inhibit the germination and growth of several weed species while exhibiting low phytotoxicity to soybean. Benzyl ether derivatives of these oxygenated monoterpenes were synthesized and examined for preemergence and postemergence activity towards corn, soybean, wheat, and velvetleaf. Benzyl pulegyl ether exhibited the most preemergence activity when applied directly to the soil, completely inhibiting wheat and velvetleaf emergence at 1.0 kg ha−1 while reducing soybean emergence 80%. Several of the benzyl ethers were more inhibitory to velvetleaf radicle elongation relative to cinmethylin but less inhibitory to corn and wheat radicle elongation in petri dish bioassays. Several of the benzyl ethers exhibited limited postemergence activity when applied at 1.0 kg ha−1 to seedlings of the test species 10 d after emergence. The benzyl ether derivatives demonstrated altered selectivity and sensitivity as compared to the parent compounds and cinmethylin.

In the field, soybeans [Glycine max (L.) Merr. ‘Amsoy 71′] required 4 to 6 weeks free of sunflower (Helianthus annuus L.) competition for maximum yield. Competition studies suggested that more than one type of interference was involved when sunflowers grew with soybeans. In greenhouse studies, soybean height, fresh weight, and dry weight were significantly reduced at certain sunflower and soybean densities and levels of competition. Sunflower height was not reduced by any level of competition, but sunflower fresh and dry weights were reduced with high sunflower and soybean populations. Two percent (w/w) or greater amounts of ground, mature sunflower leaves mixed into the soil reduced emergence and growth of soybeans, sorghum [Sorghum bicolor (L.) Moench ‘G-625 GBR′], and sunflower. A mixture of powdered stems and branches of sunflower also reduced growth of the three species, although it was not as phytotoxic as ground leaves. Sunflower roots apparently released exudates into the nutrient solution and soil. Sunflower root exudates inhibited sunflower emergence, and reduced sorghum, soybean, and sunflower height, fresh weight, and dry weight.

Triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid}, 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], and 3,6-dichloropicolinic acid were applied to the foliage of juvenile crop plants at 0.002, 0.009, 0.03, 0.14, and 0.56 kg/ha. Corn (Zea mays L.), oat (Avena sativa L.), wheat (Triticum aestivum L.), grain sorghum [Sorghum bicolor (L.) Moench], and kleingrass (Panicum coloratum L.) were generally more tolerant to the herbicides than were peanuts (Arachis hypogaea L.), cotton (Gossypium hirsutum L.), cucumber (Cucumis sativus L.), and soybean (Glycine max [L.] Merr.). Triclopyr was usually more phytotoxic to corn, oat, grain sorghum, and kleingrass than either 2,4,5-T or 3,6-dichloropicolinic acid at 0.14 and 0.56 kg/ha, but few differences occurred among herbicides at lower rates. Kleingrass was not affected at any rate of 3,6-dichloropicolinic acid. Wheat tolerated most rates of all three herbicides. At 0.56 kg/ha, triclopyr and 3,6-dichloropicolinic acid caused greater injury to peanuts than did 2,4,5-T; whereas, 2,4,5-T and triclopyr were more damaging to cotton and cucumber than 3,6-dichloropicolinic acid. The three herbicides at 0.14 and 0.56 kg/ha killed soybeans. Soybean injury varied from none to severe at 0.002 to 0.03 kg/ha, depending upon species investigated, but many plants showed morphological symptoms typical of the auxin-type herbicides.

Effects of cogongrass foliage and rhizome plus root residues on germination and shoot and root growth of barnyardgrass, bermudagrass, browntop millet, hemp sesbania, Italian ryegrass, and prickly sida were investigated in greenhouse experiments. Ground residues of dried cogongrass foliage and rhizomes plus roots were mixed separately with sterilized sand to obtain residue concentrations of 0, 0.25, 0.5, 1, 2, 4, and 8%. These residue concentrations were investigated on bermudagrass and Italian ryegrass, and the 8% residue concentrations were also evaluated on hemp sesbania, prickly sida, barnyardgrass, and browntop millet. Foliage and rhizome plus root residues at concentrations as low as 0.25% inhibited seed germination and shoot and root growth of all species except hemp sesbania. Germination of bermudagrass and Italian ryegrass was reduced by as much as 97% and shoot and root growth by as much as 94% at the highest residue concentrations. Rhizome plus root residues reduced germination and shoot and root growth of bermudagrass and Italian ryegrass more than foliage residues. Foliage and rhizome plus root residues reduced germination and shoot and root biomass of prickly sida, barnyardgrass, and browntop millet at similar levels. Results indicate that cogongrass tissue may contain allelochemicals that contribute to its invasiveness and extreme competitiveness.

Vibrio harveyi is the main pathogen of the European abaloneHaliotis tuberculata, and recently caused important mortalities at theproduction sites of this marine gastropod in France. In the present work, the monthlyantibacterial activity of two red seaweed species from the French Atlantic coast, thenative Palmaria palmata and the introduced Grateloupiaturuturu, were investigated against the abalone pathogen Vibrio harveyistrain ORM4. Water-soluble extracts were screened using the microplate method.Grateloupia turuturu showed an antibacterial activity with a maximalgrowth inhibition in spring of around 16%. In contrast, Palmaria palmatawas inactive, as further growth of the bacteria was observed. Preliminaryone-dimensional proton nuclear magnetic-resonance (1H NMR) profiles identified thedifferences between the two water-soluble extracts.

The activity of human milk on cell growth has been evaluated on two cell lines, MDCK and Caco-2. The proportion of human milk samples that reduced by half the growth of MDCK cells was of 36%. This inhibitory activity was associated with casein and not the whey fraction. Great variability was found in the degree of inhibitory activity depending on the milk sample. The susceptibility of Caco-2 cells to milk inhibitory activity was lower than that of MDCK. Bovine milk did not have any effect on cell growth, either as skimmed milk or as whey or casein. Morphology of cells incubated with active human casein showed abnormal features, such as chromatin condensation, reduced cellular volume and apoptotic bodies, and also fragmented DNA, which are all features of apoptosis.

Although many data are available concerning anticarcinogenic effects of industrial conjugated linoleic acid (CLA), few studies have reported the antitumour properties of CLA mixtures originating from ruminant products. The aim of the present study was to investigate the in vitro antiproliferative effects of beef CLA mixtures on breast, lung, colon, melanoma and ovarian human cancer cell lines. For this purpose, four fatty acid (FA) extracts prepared from beef lipid and varying in their CLA composition, their corresponding purified CLA-enriched fractions, and mixtures of pure synthetic CLA, the composition of which reproduced that of the four selected beef samples, were tested on cancer cell lines. Cancer cells were exposed for 48h to medium containing 100μm-FA and their proliferation was determined by quantifying cellular DNA content (Hoechst 33342 dye). Compared with cells incubated without FA, the number of cancer cells was reduced from 25 to 67% (P<0·0001) following FA treatment. Antiproliferative effects of CLA mixtures varied in magnitude according to the source of FA, the CLA composition and the cell lines. CLA mixtures naturally present in beef inhibited the proliferation of human cancer cell lines, a high content in cis-trans isomers allowing the most important antiproliferative effect. Beef total FA exhibited a greater growth-inhibitory activity than their corresponding CLA-enriched fractions. These results suggested that either beef FA other than beef CLA could possess antiproliferative properties and/or the existence of complementary effects of non-conjugated FA and CLA, which could favour the antiproliferative properties of beef total FA.

Root bark extracts of five Meliaceae species (Turraea abyssinica Hochst., Turraea wakefeldii Oliv., Turraea mombassana Hiern ex C.DC., Trichilia roka (Forsk) Chiov. and Melia volkensii Guerke.) and different fractions thereof (following chloroform extraction and column chromatographic separation) were compared for their immediate toxicity and long-term effects on Anopheles gambiae Giles sensu stricto (Diptera: Culicidae). Larvicidal effects of the extracts appeared to be largely associated with limonoids of medium polarity with M. volkensii and T. mombassana extracts being more potent than those of the other Meliaceae. Long-term (6–8 days post-exposure) observations at lower doses showed that 100% cumulative mortality can be achieved with some extracts (particularly those of T. mombassana and M. volkensii) with interesting growth-inhibition effects. Follow-up studies that are needed and practical implications of the results in terms of development of larval control strategies for African malaria vectors are discussed.

We evaluated the growth inhibitory efficacy of the imidazole derivatives, clotrimazole (CLT) and ketoconazole (KC), and the herbicide clodinafop-propargyl (CP), in in vitro cultures of Babesia bovis and B. bigemina. Clotrimazole was effective in a dose range of 15 to 60 μM (IC50: 11 and 23·5 μM), followed by KC (50 to 100 μM; IC50: 50 and 32 μM) and CP (500 μM; IC50: 265 and 390 μM). In transmission electron microscopy, extensive damage was observed in the cytoplasm of drug-treated parasites. Combinations of CLT/KC, CLT/CP and CLT/KC/CP acted synergistically in both parasites. In contrast, the combination of KC/CP was exclusively effective in B. bovis, but not in B. bigemina.

Crude fractions of aerial parts of Andrographis paniculata (Burm.f.) (Acanthaceae) were evaluated for antifeedant, growth-inhibitory and oviposition-deterrent activity against larval and adult stages of the Bihar hairy caterpillar, Spilarctia obliqua (Arctiidae). The methanol fraction had the highest growth-inhibitory activity. Further fractionation resulted in nine sub-fractions of which the most active, identified as the diterpene andrographolide, displayed significant growth-inhibitory and antifeedant properties with GI50 and FD50 values of 100.4 and 159.7 μg/g diet respectively. The ethyl acetate fraction possessed the highest oviposition-deterrent activity.

Escherichia coli rRNA contains 10 pseudouridines of unknown function. They are made by synthases, each of which is specific for one or more pseudouridines. Here we show that the sfhB (yfiI) ORF of E. coli is a pseudouridine synthase gene by cloning, protein overexpression, and reaction in vitro with rRNA transcripts. Gene disruption by miniTn10(cam) insertion revealed that this synthase gene, here renamed rluD, codes for a synthase which is solely responsible in vivo for synthesis of the three pseudouridines clustered in a stem-loop at positions 1911, 1915, and 1917 of 23S RNA. The absence of RluD results in severe growth inhibition. Both the absence of pseudouridine and the growth defect could be reversed by insertion of a plasmid carrying the rluD gene into the mutant cell, clearly linking both effects to the absence of RluD. This is the first report of a major physiological defect due to the deletion of any pseudouridine synthase. Growth inhibition may be due to the lack of one or more of the 23S RNA pseudouridines made by this synthase since pseudouridines 1915 and 1917 are universally conserved and are located in proximity to the decoding center of the ribosome where they could be involved in modulating codon recognition.

Laboratory studies were conducted to assess the toxicity and growth-inhibitory activity against Aedes aegypti larvae, of the crude acetone extracts of Polygonum senegalense (Meissn.) leaves, its flavonoid component 2',6'-dihydroxy-4'-methoxydihydrochalcone and the internal tissue flavanol quercetin. The first two showed significantly high insecticidal and growth-inhibitory activity even at low concentrations, whereas quercetin was toxic only at concentrations above 7μg/ml.

The chronic, recrudescent nature of malaria has been linked to antigenic diversity of the parasite in which protective immunity against Plasmodium falciparum may be obtained after repeated exposure to infection during a long time. In this study we show that parasite populations with decreased sensitivity to antibody-mediated growth inhibition are readily generated in vitro. A laboratory strain, F32, was cultured for long periods (10–12 weeks) in the presence of suboptimal inhibitory antibody concentrations. The antibodies used were the human monoclonal antibody 33G2 reacting with a linear epitope of the P. falciparum blood-stage antigen 332 and rabbit antibodies to repeat sequences of the blood-stage antigen Pf155/RESA. Our data indicate that the P. falciparum parasites adapt to antibody pressure as reflected by their specifically decreased sensitivity to growth inhibition. A relative resistance of the parasite to growth inhibition mediated by the antibodies used in the culture developed successively, while the parasite remained sensitive to growth inhibition by other antibodies. When the antibody pressure was removed a successive return of sensitivity to growth inhibition developed. Immunofluorescence did not reveal any significant difference in antigen expression between the parasite populations. However, PCR analysis showed that a new population appeared in the parasites grown in the presence of mAb 33G2, while no such change was detected in those grown in the presence of the rabbit antibodies. Our data suggest that the specific decrease in sensitivity to growth inhibition may either be due to down-regulation of antigen synthesis or expression by antibody pressure or, that antibody pressure selects for parasites with low expression of a specific antigen from a heterogeneous parasite population.

Postembryonic development and adult emergence of Tribolium castaneum (Herbst) were adversely affected in varying degrees when its larval stage was reared on wheat flour treated separately (at concentrations of 0.001–1.0%) with one of the following commercially available extracts: roots of both sweet flag, Acorus calamus Linn. and Java devil pep per, Rauwolfia serpentina Benth ex Kurz, fruit cortex of soap nut, Sapindus trifoliatus Linn. and gum of Indian Myrrh Commiphora mukul Jacq. A marked decline in the reproductive potential, in terms of female fecundity and egg hatchability was observed when the extracts were applied topically or administered orally through diet.

The soybean plant introduction (PI)227687 is highly resistant to 16 different insect pests of soybean in Australia, Brazil, Taiwan and the United States. In most of the pest Lepidoptera, resistance is expressed as greatly increased mortality in the later larval instars. The soybean looper, Pseudoplusia includens (Walker) is most severely affected in the final larval instar. Antibiotic effects include reduced weight gain, growth rate and increased mortality. These effects are enhanced by mechanically wounding foliage 24 hr prior to larval consumption. Antibiosis appears to be due to the combined effects of a feeding deterrent and a growth inhibitor. Resistance is location-specific on (PI)227687 plants and occurs abruptly on the third fully-expanded leaf from the plant apex. Larval growth on leaves of the susceptible variety ‘Davis’ is similar to or greater than that of the upper, susceptible leaves of (PI)227687. Resistance appears to be chemically based, since larvae fed artificial diets containing leaf extracts exhibit antibiotic symptoms similar to those fed fresh (PI)227687 leaves.