Forests
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2023
·Vol. 14
·期 4
·783
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IF 2.9
Lulu Gao,Aoying Zhang,Shanchun Yan
Heavy metals are serious pollutants that affect the growth and disease resistance of woody plants. Herein, the enrichment characteristics of an essential element (Zn) inPopulus simoniiseedlings, as well as the effects of Zn stress on seedling growth and resistance to leaf rust, were investigated. Zn contents in roots, stems, and leaves of treatment groups were significantly increased. Zn stress at all concentrations significantly inhibited the biomass of seedlings. Under the low, middle, and high Zn treatments, compared with the control group, CAT activity significantly decreased by 36%, 21%, and 14%; SOD activity significantly decreased by 13%, 8%, and 5%; PPO activity significantly decreased by 27%, 31%, and 47%; TI activity significantly decreased by 48%, 55%, and 61%, and CI activity significantly decreased by 10%, 20%, and 14%, respectively. In the natural environment, we accidentally discovered thatP. simoniiwas infected with leaf rust, and Zn stress significantly increased the rust disease index. The disease index correlated positively with Zn content in leaves and negatively with the chemical defense indexes. Taken together, Zn stress causes a strong growth toxicity inP. simoniiseedlings, and the reduced chemical defense under Zn stress increases the susceptibility of seedlings to leaf rust.Keywords:essential element;Populus simonii;growth;chemical defense;leaf rust
研究领域:
环境科学
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植物病理学
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毒理学
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DOI
高影响因子
Insects
·
2021
·Vol. 12
·期 10
·926
·
IF 2.769
Lulu Dai,Haiming Gao,Hui Chen
Simple SummaryThe bark beetle is the most well-known pest in coniferous trees worldwide. These insects only leave the host pine bark when they disperse to locate a new host. Determining howDendroctonus armandiovercome the trees’ terpene-based defense systems has been the key problem in the study of bark beetles. Therefore, the aim of this study was to discover the molecular mechanism of insect detoxification enzymes’ ability to confer resistance to terpenes. For this purpose, the genes of cytochrome P450s, glutathione S-transferases, and carboxylesterases were studied in beetles given diets containing terpenes. The results suggest that beetles express different genes in response to terpenoids, and the responses of multiple detoxifying enzymes indicate these insects’ adaption to their chemical environment.AbstractBark beetles overcome the toxic terpenoids produced by pine trees by both detoxifying and converting them into a pheromone system. Detoxification enzymes such as cytochrome P450s, glutathione S-transferases, and carboxylesterases are involved in the ability ofDendroctonus armandito adapt to its chemical environment. Ten genes from these three major classes of detoxification enzymes were selected to study how these enzymes helpD. armandito respond to the host defenses. The expression profile of these detoxification enzyme genes was observed in adult beetles after feeding on different types of diet. Significant differences were observed between two types of seminatural diet containing the phloem of pines, and a purely artificial diet containing five monoterpenes ((−)-α-pinene, (−)-β-pinene, (+)-3-carene, (±)-limonene, and turpentine oil) also caused differential transcript levels in the detoxification enzyme genes. The results suggest that monoterpenes enter the beetles through different routes (i.e., respiratory and digestive systems) and cause the expression of different genes in response, which might be involved in pheromone metabolism. In addition, the xenobiotic metabolism in bark beetles should be considered as a system comprising multiple detoxifying enzymes.Keywords:artificial feeding;chemical defense;Chinese white pine beetle;cytochrome P450;real-time qPCR
研究领域:
昆虫学
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分子生物学
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DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2015
·Vol. 72
·期 4
·816-827
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IF 2.694
Lulu Dai,Junning Ma,Mingyuan Ma,Haoqiang Zhang,Qi Shi,Ranran Zhang,Hui Chen
BACKGROUND Bark beetles rely on their detoxifying enzymes to resist the defensive terpenoids of host trees. Glutathione S -transferases (GSTs) conjugate xenobiotic compounds with a glutathione moiety (GSH) and often work in tandem with cytochromes P450 or other enzymes that aid in the detoxification, sequestration or excretion of toxic compounds. RESULT We identified nine new GST genes in the Chinese white pine beetle ( Dendroctonus armandi ) and carried out a bioinformatics analysis on the deduced full-length amino acid sequences. These genes belong to four different classes (epsilon, sigma, omega and theta). Differential transcript levels of each class of GST genes were observed between sexes, and, within these levels, significant differences were found among the different adult substages that were fed phloem of Pinus armandi and exposed to six stimuli [(±)- α -pinene, (−)- α -pinene, (−)- β -pinene, (+)-3-carene, (±)-limonene and turpentine] at 8 and 24 h. CONCLUSION The increased transcription levels of GST genes suggested that they have some relationship with the detoxification of terpenoids that are released by host trees. The mediating oxidative stress that is caused by monoterpene might be the main role of the bark beetle GSTs. © 2015 Society of Chemical Industry
研究领域:
昆虫学
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分子生物学
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生物化学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 21
·15722
·
IF 5.6
Wanwan Wang,Haiyun Rui,Lei Yu,Nuo Jin,Wan Liu,Chen Guo,Yumeng Cheng,Yonggen Lou
Chemical elicitors can increase plant defense against herbivorous insects and pathogens. The use of synthetic chemical elicitors is likely to be an alternative to traditional pesticides for crop pest control. However, only a few synthetic chemicals are reported to protect plants by regulating signaling pathways, increasing the levels of defense metabolites and interfering with insect feeding. Here, we found that the exogenous application of a phenoxycarboxylic compound, 4-chlorophenoxyacetic acid (4-CPA), can induce chemical defenses to protect rice plants from white-backed planthoppers (WBPH,Sogatella furcifera). Four-CPA was rapidly taken up by plant roots and degraded to 4-chlorophenol (4-CP). Four-CPA treatment modulated the activity of peroxidase (POD) and directly induced the deposition of lignin-like polymers using hydrogen peroxide (H2O2) as the electron acceptor. The polymers, which are thought to prevent the planthopper’s stylet from reaching the phloem, were broken down by WBPH nymphs. Meanwhile, 4-CPA increased the levels of flavonoids and phenolamines (PAs). The increased flavonoids and PAs, together with the degradation product of the polymers, avoided nymphal feeding and prolonged the nymphal period for 1 day. These results indicate that 4-CPA has the potential to be used as a chemical elicitor to protect rice from planthoppers. Moreover, these findings also open a pathway for molecule structure design of phenoxycarboxylic compounds as chemical elicitors.Keywords:chemical elicitor;4-chlorophenoxyacetic acid;lignin-like polymers;white-backed planthoppers;rice;chemical defense
研究领域:
植物科学
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昆虫学
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农业化学
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DOI
PubMed
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2025
·
IF 4
Delong Kong,Siquan Ling,Wanru Guo,Eduardo G.P. Fox,Jinzhu Xu,Jiamei Zhong,Desen Wang,Hualong Qiu,Weixin Liu
Millipedes are known to produce a diverse array of chemical defenses against natural predators, notably ants, positioning them as a promising source of natural products useful for pest ant control. A top invasive ant species of international scale is the red imported fire ant, Solenopsis invicta , for which there are numerous studies surveying alternative chemicals, as traditional insecticides have not been able to stop their spread. In this study, we characterized the composition of the defensive secretions from six quinone millipedes and evaluated the fumigant, contact, and repellent activities of some main components against S. invicta workers. In total, 27 components were detected in the defensive secretions of the six millipede species, with 2-methoxy-3-methyl-1,4-benzoquinone being the predominant compound overall. Nine compounds (1,4-benzoquinone, α -pinene, dimethyl trisulfide, β -pinene, 2-methyl-1,4-benzoquinone, 2-methoxy-3-methyl-1,4-benzoquinone, orcinol, 3,4-dimethoxyphenol, and 1-hydroxycyclohexyl phenyl ketone) were selected for bioassays. Among them, the three benzoquinones displayed significant fumigant and contact toxicity, as well as repellent effects against S. invicta . Dimethyl trisulfide exhibited fumigant and repellent activity, while 1-hydroxycyclohexyl phenyl ketone demonstrated just contact toxicity. These findings highlight the potential of millipede-derived compounds as natural agents for S. invicta control, possibly to direct a mixture of chemicals for use against fire ants' infestation in transported goods.
研究领域:
昆虫学
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化学生态学
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害虫管理
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天然产物化学
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入侵物种生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）