Mengyu Li,Shike Xia,Tao Zhang,Livy Williams III,Haijun Xiao,Yanhui Lu
Herbivore-induced plant volatiles (HIPVs), chemicals produced by plants infested by herbivorous insects, can act as kairomones that recruit natural enemies of the pest herbivore.Agrotis segetum(Denis and Schiffermüller) is a common, important pest of seedling cotton in Xinjiang Province, China, and the braconidMicroplitis mediator(Haliday) is an important mortality factor of this pest’s larvae. In olfactometer tests, which included healthy foliage, infested foliage, or infested roots,M. mediatorpreferredA. segetum-infested cotton plants to healthy cotton plants. In GC-MS analyses of plant-emitted volatiles, we found that compounds emitted increased 14.9- and 13.3- fold after leaf infestation and root infestation, respectively, compared to healthy control plants. The volatiles were mainly p-xylene, nonanal, tetradecane, decanal, benzaldehyde, β-caryophyllene, and humulene, while linalool was only present in the leaf-infestation treatment. In addition, principal component analysis indicated that all 18 compounds were associated with the infested plants, especially β-caryophyllene, p-xylene, and decanal. Based on the above studies and previous functional evaluations of the volatile compounds, it can be demonstrated that these compounds play a crucial role in modulating the interactions betweenA. segetumandM. mediatorand regulating parasitoid behavior. It may be possible to enhance the biological control ofA. segetumbyM. mediatorthrough the application of HIPVs.Keywords:turnip moth;parasitoid wasp;herbivore-induced plant volatiles;behavioral response;biological control
The anti-obesity effects of different proanthocyanidin extracts (PE) from Chinese bayberry (Myrica rubra Sieb.et Zucc.) leaves were evaluated in a high-fat (HF) diet-induced obese rat model. The leaves of Chinese bayberry (LCB), a non-desaccharified proanthocyanidin extract (NDPE), and a desaccharified proanthocyanidin extract (DPE) were compared with orlistat, a conventional anti-obesity drug used as a positive control. The rats from all of the PE-treated groups showed obvious weight loss, with the greatest weight loss in the DPE group (P < 0.05). Compared to the HF group, almost all of the PE-treated groups showed significantly reduced levels of serum TC, TG, AST, ALT, ALP, LDL-C, ADP and a LEP/ADP ratio, and increased levels of HDL-C and LEP. Furthermore, the expression levels of SIRT1, PPAR-γ, C/EBP-α, BMP4 and UCP1 were investigated in the liver, kidney, epididymis and abdominal adipose tissue. Compared to the HF group, PPAR-γ and C/EBP-α levels were significantly reduced and SIRT1, BMP4 and UCP1 levels were significantly upregulated in the DPE-treated group. Our results suggested that PE exerted its anti-obesity effects by upregulating the expression of SIRT1, thus inducing the deacetylation of PPAR-γ and downregulating the expression of C/EBP-α, and also upregulating the expression of BMP4 to boost the levels of brown fat.