Table 2.
Examples of PTEs phytoremediation studies involving the use of comparative proteomics from 2015 to date.
| PTEs | Plant species | Plant parts | PTEs concentration/exposure time/media | Technology used | Key findings | References |
|---|---|---|---|---|---|---|
| As | Artemisia annua L. | Shoot Root |
100 μm Na2HAsO4.7H2O/3 days Hoagland nutrient’s solution | 2-DE PAGE, MALDI-TOF-MS | Upregulation of secondary metabolites-related genes enhances as tolerance. Biomass, carotenoid, flavonoids were enhanced, whereas total chlorophyll pigment was reduced under As treatment. | Kumari and Pandey-Rai, 2018 |
| Brassica napus | Leaves | 200 μmoll−1 NaAsO2/ 7 days/ 50% Hoagland solution | LC–MS/MS, SEM, TOF-MS, qRT-PCR | Photosystem II (PSII) and photosystem I (PSI) proteins were upregulated. Secondary metabolites biosynthesis increased. | Farooq et al., 2021 | |
| Oryza sativa L. | Leaves Root |
NaAsO2; 25 μM /7 d/ modified Hewitt’s media | 2-DE, MALDI-TOF-TOF | The sulfur treatment alleviates As stress by forming disulfide linkage in proteins involved in glycolysis, TCA cycle, energy metabolism, and photosynthesis. | Dixit et al., 2015 | |
| Populus (deltoides cv. “zhonglin 2025” and euramericana cv. ‘I-45/51’) | Leaves Root |
Na3AsO4·12H2O 50, 100 μM/21 days/Hoagland’s nutrient solution | MALDI-TOF/TOF MS, 2-DE, RT-PCR | Overexpression of photosynthetic and antioxidative responsive proteins in As tolerant cultivar | Liu et al., 2017 | |
| Cd | Arabidopsis thaliana L. | Leaves, Root | 100 μm CdCl2/7-days/1/2 MS solid media | 2D-GE, MALDI-TOF/TOF-MS | The natural accession Chernobyl-07 (Che) has a higher Cd tolerance than normal accessions. This accession particularly changed the expression related to ROS protection and energy modulation proteins for obtaining tolerance. | Klimenko et al., 2019 |
| Brassica campestris | Root | 50 μm CdCl2/1-day/ hydroponic | 2D-GE, MALDI-TOF/TOF-MS | Hydrogen gas (H2) and nitric oxide (NO) enhance the antioxidant capabilities of B. campestris seedlings in response to Cd toxicity. | Su et al., 2019 | |
| Brassica napus | Xylem sap | 10 μm CdCl2/3-days/hydroponic | LC–MS/MS | Cd stress-induced the overexpression of stress response-related proteins. | Luo and Zhang, 2019 | |
| Medicago sativa | Stem | 88.9 μm CdSO4/4-months/potted soil | 2D-GE, MALDI-TOF/TOF-MS | Cd stress caused the differential expression of proteins involved in cell wall remodeling, defense response, carbohydrate metabolism, and promotion of the lignification process. | Gutsch et al., 2019a | |
| Microsorum pteropus | Leaves, Root | 100, 250 and 500 μm CdCl2/7-days/hydroponic | 2D-GE, MALDI-TOF/TOF-MS | Different protein expression patterns were observed involving related functions of energy metabolism and antioxidant activity in the root, cellular metabolism, protein metabolism, and photosynthesis in leaves. | Lan et al., 2018 | |
| Sorghum bicolor | Shoot | 100 and 150 μm CdCl2/5-days/semi hydroponic | 2D-GE, MALDI-TOF/TOF-MS | Cd stress inhibits carbon fixation, ATP production, and the regulation of protein synthesis. | Roy et al., 2016 | |
| Cr | Brassica napus L. | Leaves | 100 μm K2Cr2O7/3-days/hydroponics | 2-DE, MALDI-TOF/TOF MS | Increased abundance of defense-related proteins such as antioxidant enzymes, molecular chaperones involved in scavenging the excess ROS, and refolding of misfolded proteins under Cr stress. | Yıldız and Terzi, 2016 |
| Callitriche cophocarpa | Shoot | 1 mm K2CrO4/3-days/liquid MS medium | SDS-PAGE, 2DE, MS/MS | Quinone dehydrogenase, FQR1 (NAD(P)H) newly identified to act as a detoxification protein by protecting the cells against oxidative damage. | Kaszycki et al., 2018 | |
| Nicotiana tabacum | Shoot | 100 μm K2Cr2O7/5-days/hydroponic | 2D-GE, MALDI-TOF/TOF-MS | Twelve Cr-tolerance-associated proteins were identified. These include mitochondrial processing peptidase, dehydrin, superoxide dismutase, adenine phosphoribosyltransferase, and mitochondrial malate dehydrogenase proteins. | Bukhari et al., 2016 | |
| Pteris alba | Leaves Root | 146.7 ~ 261.5 mm Cr/4-years/waste landfill field | 2D-GE, Nano HPLC MS/MS | ROS scavenging proteins assist poplar threes long-term adaptation to Cr polluted environments. | Szuba and Lorenc-Plucińska, 2018 | |
| Cu | Agrostis capillaris L. | Shoot | 1–50 μm CuSO4/90-days/semi hydroponic | 2D-GE, LC–MS/MS | Overexpression of a Heat shock protein 70 (HSP70) may be pivotal for Cu tolerance by protecting protein metabolism. | Hego et al., 2016 |
| Hyoscyamus albus L. | Root | 0, 0.1, 1, 20, and 200 μm CuSO4/7-days/cell culture | MALDI-QIT-TOF-MS | High Cu levels enhanced respiration activity and propagated H. albus roots through the activation of the energy supply and anabolism. Increased abundance of proteins involved in carbohydrate metabolism, de novo protein synthesis, cell division, and ATP synthesis, and decreased proteasome. | Sako et al., 2016 | |
| Triticum aestivum L. | Root Leaves |
100 μm CuSO4/3-days/hydroponic | 2D-GE, HPLC-Chip | Cu responsive network of 36 key proteins, most of which may be regulated by abscisic acid (ABA), ethylene, and jasmonic acid (JA). Exogenous JA application showed a protective effect against Cu stress and significantly increased glutathione S-transferase (GST) gene transcripts. | Li et al., 2013 | |
| Hg | Paspalum distichum L. | Root | 1,115 μm Hg/ 60days/contaminated soil in glass box | LC–MS/MS | Observed changes in the expression patterns of metal binding and transport protein. Increased accumulation of photosynthesis and energy metabolism, related proteins. | Ding et al., 2019 |
| Triticum aestivum L. | Root Shoot |
25, 50, 100, 200 and 400 μm HgCl2/3-days /hydroponic | 2D-GE, LC–MS/MS | 49 abscisic acid (ABA) potentially regulated Hg-responsive proteins identified. Exogenous ABA application conferred protection against Hg stress and increased peroxidase enzyme activities, suggesting that it may be an important factor in the Hg signaling pathway. | Kang et al., 2015 | |
| Pb | Cannabis sativa L. | Leaves | Pb(NO3)2 3 g/kg soil /40-days/Potted soil | LC-ESI-MS/MS. SWATH-MS | Adaptation to Pb stress by accelerating adenosine triphosphate (ATP) metabolism; enhancing respiration, light absorption, and light energy transfer; and eliminating reactive oxygen species. | Xia et al., 2019 |
| Chrysopogon zizanioides | Root Shoot |
Pb(NO3)2 400 mg/l, 800 mg/l and 1,200 mg/l/10-days/hydroponic (half strength Hoagland solution) | LC–MS/MS | Increased levels of key metabolites including amino acids, organic acids, and coenzymes in response to Pb. | Pidatala et al., 2018 | |
| Raphanus sativus L. | Root | 1,000 mg/ L Pb(NO3)2/3-days/modified half-strength Hoagland nutrient solution | GC–MS | Pb exposure altered metabolites and divergent expression of enzymes which are responsible for profound biochemical changes, including carbohydrate metabolism, energy metabolism, and glutathione metabolism. | Pang et al., 2015 | |
| Glycine max L. | Nodules | 107.8 μm PbCl2 or 1.84 μm HgCl2/ 60-days /potted peat, perlite, and vermiculite (1:1:1) |
2D-GE, MALDI-TOF MS/MS | Pb stress increased the abundance of defense, development, and repair-related proteins. | Baig et al., 2018 | |
| Zea mays | Root | 18,000 μm Pb (NO3)2/12, 24 and 48 h/semi hydroponic | Nano-LC–MS/MS | Upregulation of stress, redox, signaling, and transport proteins, while proteins related to nucleotide metabolism, amino acid metabolism, RNA, and protein metabolism were down-regulated. | Li et al., 2016 | |
| Se | Allium cepa L. | Root | 10 mg/l Se Na2SeO3/10-days/Hoagland’s nutrient solution | Cap HPLC-ESI-QTOF-MS and MS/MS, nano LC-ESI-Q Orbitrap-MS and MS/MS | Different abundances of proteins involved in transcriptional regulation, protein folding/ assembly, cell cycle, energy/carbohydrate metabolism, stress response, and antioxidant defense were identified in response to Se stress. | Karasinski et al., 2017 |
| Brassica oleracea L. | Florets Leaves |
25 μm Na2SeO4/14-days/Hoagland solution | UPLC–MS/MS, qRT-PCR, LC–MS/MS | Glucosinolate reduction in broccoli leaves and florets is associated with negative effects on precursor amino acids (methionine and phenylalanine), biosynthesis, and glucosinolate-biosynthetic-gene expression in response to Se supplementation. | Tian et al., 2018 | |
| Capsicum annuum L. | Shoot | 100 ppm Na2SeO4/1-day | LC–MS/MS | Overexpression of heat shock and metabolism proteins. Others are involved in post-translational modification, protein turnover, chaperones, and protein processing in the endoplasmic reticulum. | Zhang et al., 2019 | |
| Oryza sativa L. | Shoot Root |
25 μM, NaAsO2 and 25 μm Na2SeO3/15-days/Hewitt nutrient medium | MALDI-TOF/TOF, qRT-PCR, Western blot, | Differentially expressed proteins altered the gene expression related to abiotic and biotic stresses and defense responses such as ROS homeostasis, photosynthesis, energy metabolism, and transport and signaling. | Chauhan et al., 2020 |