Secondary plant metabolites (SPMEs) play an important role in plant survival in the environment and serve to establish ecological relationships between plants and other organisms. Communication between plants and microorganisms via SPMEs contained in root exudates or derived from litter decomposition is an example of this phenomenon. In this review, the general aspects of rhizodeposition together with the significance of terpenes and phenolic compounds are discussed in detail. We focus specifically on the effect of SPMEs on microbial community structure and metabolic activity in environments contaminated by polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Furthermore, a section is devoted to a complex effect of plants and/or their metabolites contained in litter on bioremediation of contaminated sites. New insights are introduced from a study evaluating the effects of SPMEs derived during decomposition of grapefruit peel, lemon peel, and pears on bacterial communities and their ability to degrade PCBs in a long-term contaminated soil. The presented review supports the “secondary compound hypothesis” and demonstrates the potential of SPMEs for increasing the effectiveness of bioremediation processes.

Subarctic ecosystems provide key services to local communities, yet they are threatened by pollution caused by spills and disposal of petroleum waste. Finding solutions for the remediation and restoration of subarctic soils is valuable for reasons related to human and ecosystem health, as well as environmental justice.

In colorectal cancer, approximately 50% to 70% of metastases go into the liver; however, their molecular signature remains unknown. We aimed to investigate the transcriptome and miRNome profiles of metachronous colorectal liver metastasis (mCLM) within the hepatic microenvironment and to identify key deregulated genes, microRNAs (miRNAs), pathways, and their clinical relevance. We performed differential expression analysis on 36 mCLM and adjacent nonmalignant liver tissue pairs using RNA sequencing. Gene set enrichment analysis and consensus molecular subtype (CMS) classification helped to explore pathways. Tumor samples were stratified based on their KRAS mutation status. miRNA-mRNA interactions were investigated through coexpression and correlation analysis, with prognostic relevance assessed using survival analysis. Validation of key interactions was accomplished using multiMiR. We identified 1809 upregulated and 1639 downregulated genes and 108 upregulated and 92 downregulated miRNAs in mCLM compared with the adjacent nonmalignant liver. Upregulated genes were associated with epithelial-to-mesenchymal transition, G2M checkpoints, and E2F targets. About 47% of samples belonged to CMS2 and 22% to mesenchymal CMS4, with distinct mutational patterns. mRNA coexpression identified 4 clusters (associated with metabolism, cell cycle, DNA metabolism, and oncogenic signaling pathways), and miRNA coexpression identified 6 clusters. The hub miRNAs hsa-let-7c, hsa-miR-21-5p, hsa-miR-106a-5p, hsa-miR-139-5p, hsa-miR-101-3p, and hsa-miR-20b-5p were among the inversely correlated miRNA-mRNA clusters. An integrative analysis highlighted PEA15 interaction with hsa-miR-320b/c, TEX2/CTSO with hsa-miR-103a-3p, and PHLDA3 with hsa-miR-1304, and prognostic relevance for ZNF441, CTSO, TEX2, EID1, CMC1, hsa-miR-4634, hsa-miR-3184-5p, has-miR-320b, hsa-miR-1304-3p, hsa-miR-7-1-3p, hsa-miR-144-3p, hsa-miR-1303, and hsa-miR-660-3p. The miRNA-mRNA interactions were validated using real-time PCR in independent patient cohorts. This study revealed a complex molecular landscape of mCLM within the hepatic microenvironment and novel miRNA-mRNA interactions with potential prognostic and therapeutic implications.