Enrichment characteristics of Cd and Hg and regulation of heavy metal transporter signaling in Pleurotus ostreatus

• Published in: The Science of the total environment 2024-12, Vol.955, p.176909, Article 176909
• Main Authors: Liu, Qing, Zheng, Xiukun, Du, Rui, Shao, Yuqiang, Wen, Qing, Shen, Xiaoye, Wang, Fengqin, Qi, Yuancheng, Shen, Jinwen, Hu, Yanru
• Format: Article
• Language: English
• Subjects: Cadmium - metabolism; Enrichment regularity; Heavy metal; Heavy metal transporter; Mercury - metabolism; Metals, Heavy - metabolism; Pleurotus - metabolism; Pleurotus ostreatus; Signal Transduction; Soil Pollutants - metabolism
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.176909

Currently, heavy metal pollution has emerged as a global issue. Compared with green plants, edible fungi, significant crops cultivated worldwide, present a greater capacity to accumulate heavy metals (HMs). However, the enrichment characteristics and functions of heavy metal transporters (HMATs) in the accumulation of HMs in edible fungi are still unclear. Cadmium (Cd) and mercury (Hg) are the primary HMs enriched in edible fungi. This study focused on Pleurotus ostreatus, the second largest edible mushroom worldwide, to examine the enrichment process. In this study, a series of different concentrations of CdCl2 and HgCl2 (0, 0.01, 0.05, 0.5, 2, 5, 10, and 20 mg/L) were used to mimic HMs pollution. HMs in the experimental concentration range did not affect the mycelial growth rate or fruiting body yield of P. ostreatus. However, in the 20 mg/L treatment group, the HMs were mainly concentrated in the cap, with about 4.4 mg/kg Cd and 2.7 mg/kg Hg, and were predominantly present in the most toxic ion exchange state. Thirteen HMATs were identified in the genome database of P. ostreatus. Using RT-qPCR, seven HMATs (24093, 1066001, 1106787, 1066344, 1079972, 1095088, and 1104877) whose expression levels were more than twice that of the control under most concentrations of HMs were selected for further investigation of their transport functions and their involvement in signal regulation. Among them, gene 24093 was involved in the absorption of Cd and Hg. These transporters are regulated by ROS, Ca2+, and NO signals under HM stress. This study provides target genes for reducing the risk of HM accumulation through molecular means, and serves as a reference for HM remediation using edible fungi. [Display omitted] •Cd and Hg were mainly concentrated in the cap of the fruiting body.•The enrichment capacity of Cd and Hg was in the order of Cd > Hg.•Cd and Hg were predominantly present in the ion exchange state.•Gene 24093 of P. ostreatus was involved in the absorption of Cd and Hg.•Regulation of heavy metal transporter signaling exhibits stress difference.