title: A novel high-throughput nematicidal assay using embryo cells and larvae of Caenorhabditis elegans.
abstract: Human health safety and environmental concerns have resulted in the widespread deregistration of several agronomic important nematicides. New and safer nematicides are urgently needed. However, a high-throughput bioassay for screening potential nematicides has not been established. We developed a two-step high-throughput nematicidal screening method to combine a cell-based MTS colorimetric assay with Caenorhabditis elegans embryo cells for preliminary cytotoxicity screening (step 1) followed by in vitro larval assay for nematicidal activity (step 2). Based on three conventional nematicides' test, high correlations were obtained between cell viability and larval viability and "r" values were 0.78 for Avermectin, 0.95 for Fosthiazate, and 0.65 for Formaldehyde solution. Further assays with 60 fungal secondary metabolites (extracts, fractions and pure compounds) also demonstrated the high correlation between cell viability and larval viability (r=0.60) and between the C. elegans cell viability and the juvenile viability of soybean cyst nematode Heterodera glycines (r=0.48) and pine wood nematode Bursaphelenchus xylophilus (r=0.56). Six metabolites with high cytotoxicity have performed high larval mortality with a LC50 range of 6.8-500μg/ml. These results indicate that the proposed two-step screening assay represents an efficient and labor-saving method for screening natural nematicidal products.
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China.
authors.forename: Yiling
authors.initials: Y
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China. Electronic address: xiangmc@im.ac.cn.
authors.forename: Meichun
authors.initials: M
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China.
authors.forename: Shuchun
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China.
authors.forename: Erwei
authors.initials: E
authors.lastname: Li
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China; Beijing Institute of Pharmacology and Toxicology, No. 27 Taiping Road, Haidian District, Beijing 100850, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Che
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Road, Chaoyang District, Beijing 100101, China. Electronic address: liuxz@im.ac.cn.
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000494:pharmacology* / Q000633:toxicity; D001681:Biological Assay / Q000379:methods / Q000592:standards; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D003124:Colorimetry; D004305:Dose-Response Relationship, Drug; D005658:Fungi / Q000737:chemistry; D057166:High-Throughput Screening Assays / Q000379:methods* / Q000592:standards; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D010935:Plant Diseases / Q000469:parasitology / Q000517:prevention & control; D010944:Plants / Q000187:drug effects / Q000469:parasitology; D017187:Tylenchida / Q000187:drug effects; D014431:Tylenchoidea / Q000187:drug effects
chemical_list: D000969:Antinematodal Agents
keywords: Caenorhabditis elegans; Cytotoxicity; High-throughput screening; Nematicides