Transcriptomics-based analysis of genes related to lead stress and their expression in the roots of Pogonatherum crinitum

Analysis of differentially expressed proteins and related metabolic pathways in response to lead stress in the leaves of Pogonatherum crinitum

Proteomics provides an essential means of explaining the mechanisms underlying gene expression regulation. The proteomic mechanisms by which heavy metal hyperaccumulators respond to lead (Pb) stress remain largely unclear. To this end, we examined Pogonatherum crinitum (Thunb.) Kunth and employed proteomic sequencing technology to screen for differential proteins that respond to Pb stress. The connection between Pb-tolerant proteins in metabolic pathways and their functions were analyzed. Differences in the downstream molecules of Pb-resistant proteins in P. crinitum were also assessed. Furthermore, we utilized Parallel Reaction Monitoring (PRM) technology to validate the selected Pb-tolerant differential proteins across various stress concentration gradients. A total of 5275 protein families were identified, and 118 DEPs were observed between the stressed and control groups, including 76 upregulated and 42 downregulated proteins. Functional annotation analysis using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes revealed that Pb stress led to the upregulation of 16 proteins within P. crinitum leaves. These proteins were primarily involved in the metabolic processes of energy and carbohydrate metabolism (PcCht1, PcSPS5, PcGME-1, and PcPEP4) as well as protein translation and oxidative stress (PcHSP26.7, PcHSP18, PcCAT3, and PcCAT1). Bioinformatic analysis indicated that DEPs responding to Pb stress were primarily related to the MAPK signaling pathway, amino sugar and nucleotide sugar metabolism, and starch and sucrose metabolism. Pathway analysis revealed maltose, acetylcholine, N-acetylglucosamine, and oxalic acid as the downstream products. Moreover, the levels of these indicators all increased with increasing Pb concentrations. PRM of the 16 DEPs revealed that nine proteins were upregulated under different Pb concentrations. PRM and data-independent acquisition results for the upregulation of these nine DEPs were identical, suggesting the reliability of our analytical outcomes. In conclusion, the upregulation of specific proteins in P. crinitum enables the regulation of glucose metabolism and antioxidant balance within the plant and represents a mechanism underlying its Pb stress response.

Plants' molecular behavior to heavy metals: from criticality to toxicity

The contamination of soil and water with high levels of heavy metals (HMs) has emerged as a significant obstacle to agricultural productivity and overall crop quality. Certain HMs, although serving as essential micronutrients, are required in smaller quantities for plant growth. However, when present in higher concentrations, they become very toxic. Several studies have shown that to balance out the harmful effects of HMs, complex systems are needed at the molecular, physiological, biochemical, cellular, tissue, and whole plant levels. This could lead to more crops being grown. Our review focused on HMs' resources, occurrences, and agricultural implications. This review will also look at how plants react to HMs and how they affect seed performance as well as the benefits that HMs provide for plants. Furthermore, the review examines HMs' transport genes in plants and their molecular, biochemical, and metabolic responses to HMs. We have also examined the obstacles and potential for HMs in plants and their management strategies.

Toxicological effects and mechanisms of lithium on growth, photosynthesis and antioxidant system in the freshwater microalga Chromochloris zofingiensis

The growing prevalence of lithium (Li) batteries has drawn public attention to Li as an emerging pollutant. The present study investigates the toxicity of Li+ on Chromochloris zofingiensis, examining physiological, biochemical and omics aspects. Results reveal hormesis effects of Li+ on C. zofingiensis growth. At Li+ concentrations below 5 mg L-1, Li+ can enhance chlorophyll content, mitochondrial activity, and antioxidant capacity, leading to increased dry cell weight and cell number. Conversely, when it exceeded 10 mg L-1, Li+ can reduce chlorophyll content, induce oxidative stress, and disrupt chloroplast and mitochondria structure and function, ultimately impeding cell growth. In addition, under 50 mg L-1 Li+ stress, microalgae optimize absorbed light energy use (increasing Fv/Fm and E TR ) and respond to stress by up-regulating genes in starch and lipid biosynthesis pathways, promoting the accumulation of storage components. Weighted gene co-expression network analysis indicates that peptidylprolyl cis/trans isomerase, GTPase and L-ascorbate oxidase might be the key regulators in response to Li+ stress. This research marks the toxic effects and molecular mechanisms of Li+ on freshwater microalga, which would improve our understanding of Li's toxicology and contributing to the establishment of Li pollution standards.