Biochemical, transcriptomic, gut microbiome responses and defense mechanisms of the earthworm Eisenia fetida to salt stress

• Published in: Ecotoxicology and environmental safety 2022-07, Vol.239, p.113684-113684, Article 113684
• Main Authors: Yang, Xuelian, Shang, Guangshen, Wang, Xing
• Format: Article
• Language: English
• Subjects: DNA damage; Ecotoxicity; Reproduction; ROS; Soil invertebrate
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.113684

The accumulation of sodium chloride (NaCl) in soil is a worldwide problem with detrimental effects on the survival of soil animals. The effects of NaCl on earthworms remain unclear. Here, we show that the growth rate, cocoon production rate, annetocin precursor (ANN) mRNA level, and superoxide dismutase and catalase activities in earthworms were reduced under NaCl stress, whereas the mortality rate, reactive oxygen species (ROS) and malondialdehyde activity level increased. Histological damage to the earthworm body wall and intestine were observed under NaCl stress. NaCl stress increased DNA damage in the seminal vesicle and coelomocytes. The mRNA level of lumbrokinase, 1,3-beta-glucanse, coelomic cytolytic factor (CCF1), and alpha-amylase was significantly down-regulated, whereas that of earthworm excitatory peptides2 (EEP2) was up-regulated. From 16 S rRNA sequencing, the earthworm gut microbiota diversity decreased under NaCl stress. However, Verminephrobacter, Kluyvera, Lactobacillus, and Ochrobactrum increased under NaCl stress. These findings contribute to the risk assessment of the salt stress on soil organisms. [Display omitted] •NaCl stress reduced the growth and reproduction, increased mortality.•Histological damage to the body wall and hindgut were observed.•Coelomocytes were more sensitive than seminal vesicle cells based on DNA damage levels.•CCF mRNA was related to chloragogenous tissue injury and microbial community changes.•NaCl induced ROS and oxidative stress in earthworms.