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Meng Q.-W.,Nanjing Agricultural University | Liu X.-P.,Nanjing Agricultural University | Lu F.-G.,Nanjing Agricultural University | Fu K.-Y.,Nanjing Agricultural University | And 2 more authors.

Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-. C and LdAS-. B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-. C and LdAS-. B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of ds. LdAS-. C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of ds. LdAS-. B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of ds. LdAS-. C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of ds. LdAS-. C and ds. LdAS-. B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis. © 2014. Source

Li S.,Huanggang Normal University | Li S.,Rutgers University | Wang H.,Shaklee Corp. | Guo L.,Xinjiang Academy of Agricultural Science | And 2 more authors.
Journal of Functional Foods

The studies of nobiletin and other polymethoxyflavones from citrus peels become prevalent in recent years due to many well-established evidences showing their multiple efficacious biological activities. The biotransformation study of polymethoxyflavones, particularly nobiletin has emerged along with the significant findings of nobiletin bioactivity. Major nobiletin metabolites from rodent biofluids have been successfully characterized, isolated or synthesized for the evaluation of their biological activities and subsequently revealed that nobiletin metabolites demonstrate similar efficacies or more potent anti-oxidant activity and scavenging property against free radicals and in the inhibition of inflammation and cancer growth, and the prevention of metabolic syndrome and cardiovascular diseases. This review starts with basic chemistry of nobiletin and other polymethoxyflavones, highlights their biological properties and recent findings and summarizes nobiletin's biotransformation and biological activities of the main nobiletin metabolites. © 2013 Elsevier Ltd. Source

Shi Y.,Xinjiang Academy of Agricultural Science
Wei sheng wu xue bao = Acta microbiologica Sinica

The aim of this study was to investigate the composition and distribution variation of endophytic bacteria and fungi in Achnatherum inebrians. The DNA of seed, leaf, stem and root was extracted with liquid nitrogen grinding method. Then, 16S rDNA and Internally Transcribed Spacer (ITS) sequence were digested with restriction enzymes Hha I , Rsa I and Hhae III, Hinf I to obtain terminal restriction fragments. The terminal restriction fragments were matched to bacterial and fungal genera by the T-RFLP Analysis Program, and the community component and similarity of endophyte in Achnatherum inebrians were analyzed. The diversity of endophytic bacteria and fungi was the most abundant in root and seed of Achnatherum inebrians. All the predominant bacterial population was Bacillus (above 29%) in different organs of Achnatherum inebrians. The predominant fungal population was Mycosphaerella (6.5%), Teratosphaeria (4.5%), Fragum (1.1%), Sebacina (11.3%) in seed, leaf, stem and root, respectively. The structure of the bacterial communities in the stem and leaf were similar, whereas the structure of the bacterial communities in the seed and other tissue were different. The structure of the fungi communities in the stem and seed were similar, whereas the structure of the fungi communities in the leaf and other tissue were different. There was abundant endophytic microbial diversity in Achnatherum inebrians. Source

Jiang W.-H.,Nanjing Agricultural University | Lu W.-P.,Nanjing Agricultural University | Guo W.-C.,Xinjiang Academy of Agricultural Science | Xia Z.-H.,Station of Agricultural Techniques Extension in Yili | And 2 more authors.
Journal of Economic Entomology

The Colorado potato beetle (Leptinotarsa decemlineata (Say)) in the north Xinjiang Uygur autonomous region has evolved resistance to various types of insecticides. Chlorantraniliprole is a novel anthranilic diamide insecticide that binds and activates ryanodine receptors. It exhibited excellent efficacy against L. decemlineata in several field trails in Europe. In the present paper, the susceptibility of L. decemlineata fourth-instar larvae derived from six field populations and L. decemlineata adults derived from three field populations to chlorantraniliprole was determined by a topical application. The fourth-instar larvae were substantially more susceptible to chlorantraniliprole than adults, although the range of susceptibility was far greater among the fourth-instar larvae. Regarding stomach toxicities, adult beetles were less susceptible to chlorantraniliprole than larvae. Chlorantraniliprole was most toxic to second-instar larvae, followed by third-and fourth-instar larvae. These data suggested that the appropriate timing for chlorantraniliprole spraying is the early larval stage. More-over, the synergistic activities of chlorantraniliprole in combination with triphenyl phosphate, diethyl maleate, or piperonyl butoxide against fourth-instar larvae from two field populations and adults from one field population were tested. Piperonyl butoxide had synergistic effects with chlorantraniliprole against fourth-instar larvae but not against adult beetles. Conversely, triphenyl phosphate and diethyl maleate exerted little synergistic effects. It appears that there is a potential risk of resistance against chlorantraniliprole resulting from cytochrome P450 monooxygenase activity. © 2012 Entomological Society of America. Source

Objective: To optimize the condition for fermentation of recombinant Cl02 strain producing cold-adapted lipase by response surface methodology (RSM). Methods: The effects of content of yeast as nitrogen source, pH value as well as glycerol and methanol contents in medium on enzyme activity were investigated by single-factor test, based on which the main influencing factors of enzyme production were determined. The effects of various factors on activity of cold-adapted lipase were evaluated by RSM of three factors at four levels according to Box-Benheken center combination test design principles, based on which a multivariate quadratic regression model was established. Results: The content of yeast as nitrogen source, pH value and methanol content in medium showed significant effect on enzyme activity. The optimal content of yeast as nitrogen, pH value and methanol content for production of cold-adapted lipase were 7.3 g/L, 6.0 and 9.1 g/L respectively. Under the optimal condition, the activity of cold-adapted lipase was 42.25 IU/ml, which increased by 50.9% as compared with that before optimization (28.0 IU/ml). Conclusion: The optimization of fermentation condition by RSM increased the cold-adapted lipase-producing ability of recombinant strain significantly, which laid a foundation of industrial production of the enzyme. Source

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