Due to excessive industrialization, urbanization and rising level of pollutants, the water bodies are continuously exposed to diverse group of toxic pollutants whose concentration, chemical forms and bioavailability in the aqueous system are governed by natural geochemical cycles as well as human activities. Chemical form or species of these toxic compounds or heavy metals is governed by the prevailing specific physical and chemical parameters like pH, salinity, dissolved organics, hardness and sedimentary load which impacts their mobility, bio-availability and hence toxicity. To overcome the challenging situation, an increased emphasis has been given on in-situ innovative technologies like phytoremediation, capable of detoxification of contaminated water bodies. The use of inherent aquatic plants along with recent omics tools can improve their phytoremediation ability to a great extent. These plants have an extensive root system which can filter and immobilize sediments, contaminants, fertilizer and pesticide run-off thereby reducing water pollution. Thus, the assortment and improvement of plants phytoremediation ability using the modern biotechnological tools and techniques, can be a suitable approach for successful remediation of contaminated water bodies.
This review article focuses on the different biotechnological strategems like omics, proteomics, genomics, metabolomics and CRISPR in order to ameliorate the phytoremediation potential of the aquatic plants. The recent ground-breaking advancements to achieve desired genetic modification uses, CRISPR technology, to transfer a target set of genes to be assimilated into the plant genome of interest. Two variants of this technology, i.e. CRISPR-Cas9 as well as CRISPR-Cpf1 can be used for producing knock-outs, making gene substitutions, and targeting transcription and its regulation in the particular plant genome, to improve its phytoremediation efficiency.
Water bodies are considered as apposite places for disposing off the domestic and industrial wastes which drains ultimately into the sea (Jadia and Fulekar, 2009). Rapid expansion in urban areas and booming population worldwide have exacted a huge toll on the rivers and streams leading to their pollution. As stated by reports of Central Pollution Control Board (CPCB, 2016), India that 63% of the urban sewage discharged into rivers (approximately 62 billion liters a day) is untreated. However, the increase in noxious wastes and mistreatment of the water resources by agricultural fields, industrial and thermal power plants, in order to meet the requirements of the increasing population, has significantly reduced the assimilative ability of such contaminants in the environment (Bin-Dahman and Saleh, 2020, Saleh et al., 2019). Thus, the two-fold stress put forth on the aquatic systems is eventually confronted by the biota inhabiting them. Among other aquatic life forms, fish is the primary aquatic community concerning the health of human beings (Datta, 2015). Since the healthy aquatic ecosystem relies on a complex web of interaction among plants, animals, and other living organisms dwelling in the system and affecting each other directly or indirectly. So the harmful effect on one of the community can lead to chain-effect and jeopardizing entire ecosystem (Hoang et al., 2020).
Aquatic plants holds a remarkable importance in phytoremediation of water bodies owing to their dense root system and higher biomass production rates. Also, these hyperaccumulator plants holds molecular variability, wide range of enzymes activity, expression of stress responsive genes, and protein profiling against a range of organic and inorganic pollutants. These hyperaccumulator plants which could be harnessed as a detoxification strategy for the contaminated water and soil systems. Apart from their natural potential, hyperaccumulator plants can substantially be improved over time with the use of genetic tools and other engineering technologies, in order to achieve productive results in phytoremediation and can be attributed in strategic management of such wastewater systems.