Enhanced disappearance of mesotrione and fomesafen by water hyacinth (Eichhornia crassipes) in water

Detoxification and catabolism of mesotrione and fomesafen facilitated by a Phase II reaction acetyltransferase in rice

INTRODUCTION

The excessive dosage of pesticides required for agronomic reality results in growing contamination of pesticide residues in environment, thus bringing high risks to crop production and human health.

OBJECTIVES

This study aims to unveil a novel mechanism for catabolism of two pesticides MTR and FSA facilitated by an uncharacterized Phase II reaction enzyme termed acetyltransferase-1 (ACE1) in rice and to make assessment of its potential for bioremediation to minimize the risks to crop production and food safety.

METHODS

We developed genetically improved cultivars overexpressing OsACE1 (OE) and knockout mutant lines by CRISPR-Cas9 technology to identify the MTR and FSA detoxic and metabolic functions and characterized their metabolites and conjugates by HPLC-LTQ-MS/MS.

RESULTS

OsACE1 overexpression conferred rice resistance to toxicity of MTR/FSA compared to wild-type, manifested by improved plant elongation and biomass, attenuated cellular injury, and increased chlorophyll accumulation. The OE plants accumulated significantly less parent MTR/FSA and more degradative metabolites, and removed MTR/FSA from their growth medium by 1.38 and 1.61 folds over the wild-type. In contrast, knocking out OsACE1 led to compromised growth fitness and intensified toxic symptoms under MTR/FSA stress and accumulation of more toxic MTR and FSA in rice. The reduced metabolites of MTR and FSA detected in the Cas9 plants suggest the impaired capability of OsACE1 function.

CONCLUSIONS

These results signified that OsACE1 expression is required for detoxifying the two poisoning chemicals in rice and plays a critical role in accelerating breakdown of the pesticides mainly through Phase II reaction mechanism pathways.

An integrated biorefinery approach for the valorization of water hyacinth towards circular bioeconomy: a review

Water hyacinth (WH) has become a considerable concern for people across the globe due to its environmental and socio-economic hazards. Researchers are still trying to control this aquatic weed effectively without other environmental or economic losses. Research on WH focuses on converting this omnipresent excessive biomass into value-added products. The potential use of WH for phytoremediation and utilizing waste biomass in various industries, including agriculture, pharmaceuticals, and bioenergy, has piqued interest. The use of waste WH biomass as a feedstock for producing bioenergy and value-added chemicals has emerged as an eco-friendly step towards the circular economy concept. Here, we have discussed the extraction of bio-actives and cellulose as primary bioproducts, followed by a detailed discussion on different biomass conversion routes to obtain secondary bioproducts. The suggested multi-objective approach will lead to cost-effective and efficient utilization of waste WH biomass. Additionally, the present review includes a discussion of the SWOT analysis for WH biomass and the scope for future studies. An integrated biorefinery scheme is proposed for the holistic utilization of this feedstock in a cascading manner to promote the sustainable and zero-waste circular bio-economy concept.

The Multifaceted Function of Water Hyacinth in Maintaining Environmental Sustainability and the Underlying Mechanisms: A Mini Review

Water hyacinth (Eichhornia crassipes) (WH) is a widespread aquatic plant. As a top invasive macrophyte, WH causes enormous economic and ecological losses. To control it, various physical, chemical and biological methods have been developed. However, multiple drawbacks of these methods limited their application. While being a noxious macrophyte, WH has great potential in many areas, such as phytoremediation, manufacture of value-added products, and so on. Resource utilization of WH has enormous benefits and therefore, is a sustainable strategy for its control. In accordance with the increasing urgency of maintaining environmental sustainability, this review concisely introduced up to date WH utilization specifically in pollution remediation and curbing the global warming crisis and discussed the underlying mechanisms.

Removal of organic pollutants in water using water hyacinth (Eichhornia crassipes)

Globally, water hyacinth is recognized as an invasive species that threatens the survival of aquatic organisms. Its removal from water is performed manually or physically to avoid the secondary water pollution that results through the usage of chemically synthesised herbicides for its control, thus generating solid waste. Among other things, scientists have proposed the conversion of this waste into adsorbents that can be utilized for the remediation of water resources. This is essentially significant as the quality of water remains a necessity in all spheres of life. In this paper, the remediation strategies that have been proposed for the remediation of water resources through the removal of organic pollutants using water hyacinth are reviewed. Phytoremediation and removal of organics through adsorption using water hyacinth have been extensively investigated. From this review, it can be observed that the majority of the reviewed work focussed more on the removal of organic dyes from water. In this context, the mechanisms involved during the adsorption processes are discussed. In the end, future research that is likely to assist in the environmental management of water resources through their remediation with water hyacinth is suggested.

Phytoremediation of azoxystrobin and imidacloprid by wetland plant species Juncus effusus, Pontederia cordata and Sagittaria latifolia

Azoxystrobin (strobilurin fungicide) and imidacloprid (neonicotinoid insecticide) have been detected in surface waters near treated agricultural, urban, and mixed landscapes. The hazards of pesticide runoff can be prevented through best management practices, including the establishment of diverse wetland plant barriers that can phytoremediate the chemicals in which they come into contact with. In this study, the wetland plant species softrush (Juncus effusus), pickerelweed (Pontederia cordata), and arrowhead (Sagittaria latifolia) were planted in sandy soil containers that were then placed in azoxystrobin or imidacloprid treated water. Every week for 2 months, water samples were collected for pesticide residue analysis using high-performance liquid chromatography (HPLC). At 14, 28, and 56 days after initiation, plants were destructively harvested and analyzed for pesticide residue in soil, above-ground vegetation, and below-ground vegetation. Results from this study report P. cordata reduced greater azoxystrobin (51.7% reduction compared to treated non-planted containers) compared to J. effusus and S. latifolia (24.9% and 28.7% reduction from non-planted containers) at 56 days. However, S. latifolia reduced greater imidacloprid (79.3% reduction compared to non-planted containers) compared to J. effusus and P. cordata (36.0% and 37.1% reduction from non-planted containers) at 56 days.Novelty statement: While research has found that wetland plants can absorb and remediate synthetic chemicals, this practice is only sustainable if used with native plants that require low maintenance and are tolerant to the applied substances. Various previous studies observe plants that are fast-growing, tolerant to environmental conditions, require low-maintenance, and are hardy. However, these plant species are not always suitable for any location and are often considered invasive and/or weed-like. The present research initiates a list of plant species which can be used within the southeastern United States and similar areas to phytoremediate commonly used pesticides azoxystrobin and imidacloprid and prevent off-target movement into sensitive water systems.

Phytoremediation and Bioremediation of Pesticide-Contaminated Soil

Management and destruction of obsolete pesticides and the remediation of pesticide-contaminated soil are significant global issues with importance in agriculture, environmental health and quality of life. Pesticide use and management have a history of problems because of insufficient knowledge of proper planning, storage, and use. This manuscript reviews recent literature with an emphasis on the management of obsolete pesticides and remediation of pesticide-contaminated soil. The rhizosphere of plants is a zone of active remediation. Plants also take up contaminated water and remove pesticides from soil. The beneficial effects of growing plants in pesticide-contaminated soil include pesticide transformation by both plant and microbial enzymes. This review addresses recent advances in the remediation of pesticide-contaminated soil with an emphasis on processes that are simple and can be applied widely in any country.