Nematophin, an Antimicrobial Dipeptide Compound From Xenorhabdus nematophila YL001 as a Potent Biopesticide for Rhizoctonia solani Control

Frontiers in Microbiology

Qi Liu¹  Zhiqiang Yan¹  Xing Zhang¹  Jinghua Han²  Yonghong Wang²  Shujing Zhang²  Yunfei Han³ 

[1] F University, Yangling, China;;Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Research and Development Center of Biorational Pesticides, College of Plant Protection, Northwest A&Plant Quarantine and Protection Bureau of Zhumadian, Zhumadian, China;

关键词: Xenorhabdus nematophila YL001;    dipeptides;    nematophin;    enantiomeric mixture;    antimicrobial activity;    sclerotial development;   

DOI  :  10.3389/fmicb.2019.01765

来源: DOAJ

【 摘 要 】

This study was conducted to purify and identify metabolites of antimicrobial activity against phytopathogens from Xenorhabdus nematophila YL001. Three dipeptide compounds were purified from its cell-free cultural broth and identified as (±)-nematophin, cyclo (L-Pro-Gly), and N, N′-dimethyl-cyclo (L-Phe-L-Leu). Nematophin demonstrated a wider antifungal spectrum than the other two compounds. It also exhibited strong inhibitory effects on mycelial growth of Rhizoctonia solani and Phytophthora infestans with EC50 values of 40.00 and 51.25 μg/ml, respectively. Its (S)-configuration structure [(+)-nematophin] was also synthesized and exhibited higher antimicrobial activity than the enantiomeric mixture. The detached leaf assay revealed that nematophin possessed significant preventive and curative efficacy against R. solani on broad bean leaves showing corresponding control efficacies of 93.01 and 94.93% at 1,000 μg/ml, comparable to those of a chemical fungicide (carbendazim) at 500 μg/ml. Additionally, the pot experiments indicated that nematophin could effectively inhibit the disease extension on rice and broad bean plants caused by R. solani. Nematophin also exerted some adverse influences on the sclerotial development of R. solani by dramatically suppressing their formation and maturation at 40.00 μg/ml, as well as their germination at 15.00 μg/ml. Morphological and ultrastructural observations showed that the hyphae of R. solani became twisted, shriveled, and deformed at the growing points after exposure to nematophin at 40.00 μg/ml, and that the subcellular fractions also became abnormal concurrently, especially the mitochondrial structure. These results indicate that nematophin has great potential to be used as a bio-pesticide in agricultural production.

【 授权许可】

Unknown