Impact of aphid alarm pheromone release on virus transmission efficiency: When pest control strategy could induce higher virus dispersion.

Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-ß-farnesene (EßF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EßF release on aphid and virus dispersion under laboratory conditions. EßF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals.

New flavonoid from Patrinia villosa.

CONTEXT: Patrinia villosa (Thunb.) Juss (Valerianaceae) is an important ancient herbal medicine widely used for inflammation, wound healing, and abdominal pain. But little is known of the phytochemical constituents of this herbal plant. OBJECTIVE: The objective of this study is to isolate and identify the bioactive components from P. villosa. MATERIALS AND METHODS: A 70% EtOH extract of P. villosa was subjected to normal-phase silica, ODS silica gel column chromatography, and semi-preparative HPLC chromatography after partitioned successively with light petroleum, dichloromethane and n-BuOH. Chemical structures of the compounds were elucidated by spectroscopic methods including UV, 1D-NMR, 2D-NMR, HR-ESI-MS, and CD spectra. The cytotoxic activity of the new component was determined with the SMMC-7721 cell line using the MTT method after incubation for 48 h. RESULTS: A new flavonoid named patriniaflavanone A (1) along with four known compounds was isolated from P. villosa. The four known compounds were identified as luteolin 7-O-glucuronide-6″-methyl ester (2), p-hydroxyphenylacetic acid methyl ester (3), trans-caffeic acid (4), and trans-caffeic acid methylate (5) by comparison of their spectral data with the reported data. The IC50 value of patriniaflavanone A (1) on SMMC-7721 was 61.27 µM. DISCUSSION AND CONCLUSION: This is the first report on the isolation and identification of patriniaflavanone A (1), and compounds 2-5 were isolated for the first time from the title plant. Patriniaflavanone A (1) exhibited moderate cytotoxic activity.

[Ecological functions of E-ß-farnesene on aphids and their natural enemies in potato field.] / 反-ß-æ³•å°¼çƒ¯å¯¹é©¬é“ƒè–¯èšœè™«åŠå ¶å¤©æ•Œçš„ç”Ÿæ€æ•ˆåº”.

As a most common component of aphid alarm pheromone, E-ß-farnesene (EßF) could not only dispel aphids, but also modify some behavioral responses of their natural enemies. In order to investigate the ecological function of EßF, its influence on the population dynamics of Myzus persicae (Sulzer), Aphis gossypii (Glover), Macrosiphum euphorbiaein (Thomas) and their natural enemies was studied in potato fields. The results showed that there were significantly lower aphid abundance (2012, 2013), higher ladybird beetle abundance (2012, 2013), and higher mummified aphid abundance (2012) on potato plants in EßF treated plots (100 µL per week). The numbers of aphids at the distances of 1 m and 5 m from EßF releaser were significantly lower compared to 10 m in 2012, and the aphid number was significantly lower at the distance of 1 m compared to 5 m and 10 m in 2013. Moreover, significantly higher parasitoid and hoverfly numbers in 2012 and higher numbers of ladybird beetles in 2013 were observed in yellow traps in EßF treated plots. The results suggested that EßF could suppress aphid population growth within a certain distance in potato fields.

Solanum Nigrum polysaccharide (SNL) extract effects in transplanted tumor-bearing mice--erythrocyte membrane fluidity and blocking of functions.

BACKGROUND: Solanum nigrum L. has been used in traditional Chinese medicine because of its diuretic and antipyretic effects. The present research concerned effects of crude polysaccharides isolated from Solanum nigrum L. on erythrocyte membranes of tumor-bearing S180 and H22 in mice. MATERIALS AND METHODS: Fluorescence- labeled red blood cell membranes were used with DPH fluorescence spectrophotometry to examine erythrocyte membrane fluidity, and colorimetry to determine degree of erythrocyte surface membrane blocking. Extent of reaction by tumor-bearing mice with the enzyme erythrocyte membrane bubble shadow detection of red cell membrane variation in the degree of closure before and after administration. RESULTS: Solanum nigrum polysaccharide could significantly improve the S180 and H22 tumor-bearing mice erythrocyte membrane fluidity, compared with the control group, the difference was significant (p<0.01), SNL can significantly improve the red blood cell membrane and then S180 tumor-bearing mice sealing ability, compared with the negative control group, the difference was significant(p<0.05, p<0.01). H22 tumor-bearing mice can increase red cell membrane and then sealing ability, the difference was significant (p<0.05). Solanum nigrum polysaccharide degree of fluidity and blocking two transplanted tumors in mice restored the ability to raise the red cell membrane has a significant effect. CONCLUSIONS: Solanum nigrum L.-type mice transplanted tumor can affect the red blood cell membrane fluidity and re-closed, through the red cell membrane of red blood cells to enhance the immune function of the possibility of erythrocyte immunity against tumor formation garland provide experimental basis.

Plasmodium yoelii: influence of antimalarial treatment on acquisition of immunity in BALB/c and DBA/2 mice.

The effect of antimalarial drugs on immune responses to the malaria infection is evaluated in vivo using two experimental self-cured rodent models. BALB/c and DBA/2 mice were infected by Plasmodium yoelii 17XNL and 17XL strains, respectively, and then treated with different doses of antimalarial drugs: chloroquine (228mg/kg or 114mg/kg of the body weight) or artesunate (78mg/kg or 39mg/kg). The effect of antimalarial drugs on host immune responses was evaluated by parasitemia, splenocyte IFN-gamma production level, and parasite-specific IgG level in the serum, however, no significant differences were observed between drug-treated and untreated groups. Moreover, most of the infected mice of all groups showed the ability to resist homologous reinfection (challenged on day 60 post-infection), only a few mice experienced transient, low parasitemia. The rechallenged mice were accompanied by high level of parasite-specific IgG. Therefore, this research implicated that, for BALB/c and DBA/2 mice, chloroquine or artesunate treatment of blood-stage P. yoelii infections does not compromise acquired immunity to malaria in either primary infection or upon rechallenge.