Methyl benzoate fumigation for control of post-harvest pests and its effects on apple quality

Methyl benzoate is a newly discovered natural insecticide. In this study, we evaluated methyl benzoate as a potential fumigant for controlling four pests including western flower thrips (WFT), Frankliniella occidentalis, lettuce aphid, Nasonovia ribisnigri, rice weevil, Sitophilus oryzae, and bulb mites, Rhizoglyphus spp., at different temperatures and effects on post-harvest quality of apples. Methyl benzoate fumigations were effective against all four pests. Complete control of WFT and lettuce aphid was both achieved in 8, 16 and 24 hr at 25, 13 and 2°C, respectively. For rice weevil, complete control was achieved in 16 and 72 hr with and without rice at 25°C, respectively. Complete control of bulb mites was achieved in 64 hr at 25°C on peanut. In addition, a 24 hr methyl benzoate fumigation at 2°C had complete control of WFT but had no negative impact on visual quality of apples of three varieties 4 weeks after fumigation. These results suggest that methyl benzoate fumigation has potential to be an alternative treatment to methyl bromide fumigation, which has been phased out, for post-harvest pest control for stored products and may also have potential to control other pests on fresh products.     

Interaction of HaNPVs with two novel insecticides against Helicoverpa armigera Hubner (Noctuidae: Lepidoptera)

Nucleopolyhedrosis viruses can be utilized for effective management of agriculture pests. Their efficacy can be increased if they are mixed with certain insecticides. In the current study, HaNPV was mixed with two insecticides: spinetoram and emamectin benzoate in various combinations and applied to larvae of H. armigera in laboratory conditions. There were a total of 15 combinations of HaNPV with each of the two insecticides in addition to five doses of HaNPV and three doses of insecticides alone. The synergistic and antagonistic effects of combinations were explored. The results revealed that there was synergistic effect of HaNPV @ 0.5 × 10⁹ PIB/ml × Spinetoram @ 40, 20, 10 ml/100 L of water. In case of emamectin benzoate, synergistic effects were recorded at 1 × 10⁹ PIB/ml HaNPV × emamectin benzoate @ 100 ml/100 L of water. However, 0.5 × 10⁹ PIB/ml HaNPV has synergistic effects with all three doses of emamectin benzoate. The results suggested that HaNPV can be used in combination with spinetoram and emamectin benzoate for the management of resistant population of H. armigera.     

pH-stat fed-batch process to enhance the production of cis, cis-muconate from benzoate by Pseudomonas putida KT2440-JD1

Pseudomonas putida KT2440-JD1 is able to cometabolize benzoate to cis, cis-muconate in the presence of glucose as growth substrate. P. putida KT2440-JD1 was unable to grow in the presence of concentrations above 50 mM benzoate or 600 mM cis, cis-muconate. The inhibitory effects of both compounds were cumulative. The maximum specific uptake rate of benzoate was higher than the specific production rate of cis, cis-muconate during growth on glucose in the presence of benzoate, indicating that a benzoate derivative accumulated in the cells, which is likely to be catechol. Catechol was shown to reduce the expression level of the ben operon, which encodes the conversion of benzoate to cis, cis-muconate. To prevent overdoses of benzoate, a pH-stat fed-batch process for the production of cis, cis-muconate from benzoate was developed, in which the addition of benzoate was coupled to the acidification of the medium. The maximum specific production rate during the pH-stat fed-batch process was 0.6 g (4.3 mmol) g dry cell weight(-1) h(-1), whereas 18.5 g L(-1) cis, cis-muconate accumulated in the culture medium with a molar product yield of close to 100%. Proteome analysis revealed that the outer membrane protein H1 was upregulated during the pH-stat fed-batch process, whereas the expression of 10 other proteins was reduced. The identified proteins are involved in energy household, transport, translation of RNA, and motility.     

The F-box protein CPR1/CPR30 negatively regulates R protein SNC1 accumulation

Disease resistance (R) proteins, as central regulators of plant immunity, are tightly regulated for effective defense responses and to prevent constitutive defense activation under non-pathogenic conditions. Here we report the identification of an F-box protein CPR1/CPR30 as a negative regulator of an R protein SNC1 likely through SCF (Skp1-cullin-F-box) mediated protein degradation. The cpr1-2 (cpr30-1) loss-of-function mutant has constitutive defense responses, and it interacts synergistically with a gain-of function mutant snc1-1 and a bon1-1 mutant where SNC1 is upregulated. The loss of SNC1 function suppresses the mutant phenotypes of cpr1-2 and cpr1-2 bon1-1, while overexpression of CPR1 rescues mutant phenotypes of both bon1-1 and snc1-1. Furthermore, the amount of SNC1 protein is upregulated in the cpr1-2 mutant and down-regulated when CPR1 is overexpressed. The regulation of SNC1 by CPR1 is dependent on the 26S proteosome as a protease inhibitor MG132 stabilizes SNC1 and reverses the effect of CPR1 on SNC1. Interestingly, CPR1 is induced after infection of both virulent and avirulent pathogens similarly to the other negative defense regulator BON1. Thus, this study reveals a new mechanism in R protein regulation likely through protein degradation and suggests negative regulation as a critical component in fine control of plant immunity.     

Are the spectral Doppler indices of ovarian arteries indicative of antral follicular development and predictive of ovulatory responses and embryo yields in superovulated ewes?

Nineteen ewes received 200 mg of pFSH administered in eight decreasing doses from Days 1 to 4, starting three days before CIDR® device removal. Ten ewes received an injection of 350 μg of estradiol benzoate at CIDR® device insertion (Group E) and nine animals served as controls (Group C). B-mode and spectral Doppler ultrasonographic examinations were performed daily throughout superovulatory treatment to enumerate ovarian antral follicles and to determine ovarian blood flow indices, respectively. There were no differences (P > 0.05) in superovulatory responses between left and right ovaries/uterine horns or the two groups of animals. End-diastolic velocity (EDV) and mean velocity (Vm) values were greater (P < 0.05) on Days 1 and 2, and peak systolic velocity (SVp) was greater (P < 0.05) on Day 3 in Group C than in Group E. In Group E 15 correlations was recorded among indices (SVp, Vm, EDV, flow velocity integral-FVI, and pulsatility index-PI) and follicles numbers in different size classes on Days 1, 2 and 4, and seven correlations among indices (SVp, EDV, Vm, and vascular resistance index-RI) and superovulatory/embryo results (numbers of regressing corpora lutea, numbers/percentages of degenerated embryos and viability rates) on Days 1, 2 and 3. In Group C, there were three correlations among EDV and RI and medium-sized/large follicle numbers on Days 1 and 3, and five correlations among indices (EDV, RI and PI) and superovulatory/embryo results (numbers of luteinized unovulated follicles, degenerated embryos and unfertilized eggs) on Days 2 or 4. There was a lack of consistency in the velocimetric correlates of antral follicle numbers and superovulatory responses between the left and right side. Therefore, the usefulness of ovarian arterial indices to predict ovine superovulatory outcomes remains equivocal and requires further confirmatory studies.     

Modulation of human erythrocyte Ca2+/Mg2+ ATPase activity by phospholipase A2 and proteases. A comparison with calmodulin

The human erythrocyte membrane $\text{Ca}{}^{\mathrm{2+}}\text{Mg}{}^{\mathrm{2+}}$ ATPase responded to the presence of an acidic phospholipase A₂ and to low levels of trypsin (and chymotrypsin) in much the same way as it did to calmodulin isolated from human erythrocytes. The increased concentration of ATP hydrolyzed in 1 hour was similar to that observed when calmodulin had been added to a suspension of membranes during the assay. The observations reported here strongly suggest that activation of the $\text{Ca}{}^{\mathrm{2+}}\text{M}{}^{\mathrm{2+}}$ ATPase can proceed by introducing apparently distinct perturbations either to the protein or to phospholipid domains of the erythrocyte membrane.     

Deterrence of feeding and oviposition responses of adult Heliothis virescens by some compounds bitter-tasting to humans

Some compounds that are bitter-tasting to humans, both alkaloidal (quinine, quinidine, atropine, caffeine) and non-alkaloidal (denatonium benzoate, sucrose octaacetate, naringin), deterred feeding and oviposition by Heliothis virescens (F.) in laboratory and field cage experiments. Preliminary electrophysiological studies of gustatory sensilla on the ovipositor of H. virescens provided evidence of 3 neurons, one of which is responsive to sucrose. Preliminary indications are that responses of this neuron may be inhibited by quinine and denatonium benzoate.     

Inhibition of <Emphasis Type="SmallCaps">d</Emphasis>-Amino-Acid Oxidase Activity Induces Pain Relief in Mice

(1). We investigated the effects of inhibiting d-amino-acid oxidase (DAO) activity on nociceptive responses through the use of mutant ddY/DAO⁻ mice, which lack DAO activity, and through the application of a selective inhibitor of DAO, sodium benzoate, in the tail flick test, hot-plate test, formalin test, and acetic acid-induced writhing test. (2). Compared with normal ddY/DAO⁺ mice, ddY/DAO⁻ mice showed significantly prolonged tail withdrawal latency in the tail flick test and licking/jumping latency in the hot-plate test, as well as significantly reduced duration of licking/biting in the late phase of the formalin test and the number of abdominal writhing in the acetic acid-induced writhing test. (3). In addition, we investigated the effects of sodium benzoate in Kunming mice having normal DAO activity. (4). Intravenous administration of sodium benzoate (400 mg/kg) significantly inhibited pain responses of the late phase of the formalin test and abdominal writhing responses in the acetic acid-induced writhing test, with no effects on the early phase flinch responses in the formalin test, nociceptive responses in the tail flick test, or hot-plate test. (5). These results suggest that DAO acts as a pro-nociceptive factor in pain, particularly chronic pain, transmission and modulation, and may be a target for pain treatment.