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Genome-Editing Strategy for Medicinal Plants Growing under Adverse Environmental Pollution
Published in Azamal Husen, Environmental Pollution and Medicinal Plants, 2022
In situ removal of contaminants from the environment (soil, water, air, etc.) by plants is called phytoremediation. With the advances of science and technology, engineered plants are being used for the removal, degradation, and containment of contaminants (Sarma et al. 2021). There are two major categories of pollutants: organic and inorganic. Further, organic pollutants are divided into PCBs (polychlorinated biphenyls), PAHs (polycyclic aromatic hydrocarbons), halogenated hydrocarbons, and chlorinated solvents (Borji et al. 2020). Being less reactive and non-accumulative, organic pollutants are less toxic to plants (Tripathi et al. 2019). Inorganic contaminants are heavy metals (mercury, lead, cadmium), non-metallic compounds (arsenic), and radionuclides (uranium, caesium, chromium, etc.). Heavy metals are also important for the growth and development of plants but, at the same time, they are toxic at higher concentrations. They cause damage to the cells and tissues by inducing oxidative damage, generate free radicles, interfere with the structure of proteins, and replace other essential nutrients (Cherian and Oliveira 2005; Iqbal 2015; Ansari et al. 2021) (Figure 13.4). Some pollutants usually enter the plant body through the natural system of nutrient absorption. Plants use various means to protect themselves from these pollutants. Some plants called hyperaccumulators can accumulate a huge number of toxic metals and other radionuclides in their tissues (Peer et al. 2006). Information on different plant species and heavy metal contaminants is compiled in Table 13.1. However, the absorption of any metal by plants depends on its bioavailability in the soil or water. Further, pH or other changes in the soil chemistry may increase the bioavailability of these metals. The use of mycorrhizae was also found to have a profound effect on the absorption of metals by plants (Shetty et al. 1994).
Potential of Syzygium cumini for Biocontrol and Phytoremediation
Published in K. N. Nair, The Genus Syzygium, 2017
S. K. Tewari, R. C. Nainwal, Devendra Singh
Plants have various adaptive mechanisms to strive and survive in stressful environments, such as high salinity, extreme heat, drought, and freezing temperatures. Modern environmental biotechnology researches are now focusing on such adaptive traits in plants and modifying these traits for developing ecofriendly and sustainable technologies to combat environmental pollution, ecosystem degradation, climate change, and other problems. Phytoremediators are plants that are used for cleaning up soil in contaminated areas. They not only function as salt tolerant, but also can reduce some of the negative effects of soil salinity and sodicity by working as ion accumulators or excretors, and tend to promote soil permeability. Combined with accurate water management strategies, they can also remove heavy metals, arsenic, lead, aluminum (Al), and many other toxic elements from the soil. A study revealed that high population density of monoculture plantations may increase the C and N contents, up to six times in surface soil (0.15 m) in eight-year-old plantations (Garg 1998; Garg and Jain 1992). The soil properties are largely influenced by the dynamics of litter and fine roots in forest ecosystems, and both fluxes are equally important. Litter performs a major role in soil fertility, and fine roots contribute substantially in improving soil structure, pH, resource acquisition, and water permeability (Singh 1996). Phytoremediation, often referred to as bioremediation, botanical bioremediation, or green remediation, is the use of plants to make contaminants nontoxic. Phytoremediation includes rhizofiltration (absorption, concentration, and precipitation of heavy metals by plant roots), phytoextraction (extraction and accumulation of contaminants in harvestable plant tissue such as roots and shoots), and phytostabilization (absorption and precipitation of contaminants by plants) (Miller 1996). Phytoremediation is characterized by the use of vegetative species for in situ treatment of land areas polluted by a variety of hazardous substances (Sykes et al. 1999). The ideal type of phytoremediator is a species that creates a large biomass, grows quickly, has an extensive root system, and must be easily cultivated and harvested (Clemens et al. 2002).
Review of Antimicrobial and Other Health Effects in 5 Essential Oil Producing Grass Species
Published in Journal of Dietary Supplements, 2023
The agar dilution method showed that a vetiver grass root extract was effective against several pathogenic organisms including Microsporum canis, M. gypseum, Trichophyton mentagrophytes, T. rubrum, and Candida albicans (Dos Santos et al. 2014). Dos Santos et al. (2014) observed several biochemicals in this vetiver grass root extract including β-vetivenene, khusimol, vetiselinenol, isovalencenol, vetivenic acid, α-vetivone, and β-vetivone. Vetiver grass root extract at 1024 µg/ml has shown to be effective against the biofilm formation of Staphylococcus aureus and the main biochemicals were types of sesquiterpenes (Kannappan et al. 2017). Vetiver oil has also been shown to be effective against several gram positive bacterial strains and one Candida glabrata strain (Burger et al. 2017). Interestingly, bacteria may aid in vetiver oil synthesis which could be used to change the oil molecular structure (Del Giudice et al. 2008). Saikia et al. (2012) reported that vetiver grass root extract at a concentration of 500 µg/ml had antituberculosis activity. Combining Santalum spp. and Vetiveria zizanioides (synonym of Chrysopogon zizanioides) oils contributed to antimicrobial activity against wound pathogens (Orchard et al. 2018). Phytoremediation has potential to improve the health properties of contaminated soils by reducing or eliminating toxic metals and organic wastes so that food plants can be grown using vetiver grass (Mirza et al. 2017).
Global impact of trace non-essential heavy metal contaminants in industrial cannabis bioeconomy
Published in Toxin Reviews, 2022
Louis Bengyella, Mohammed Kuddus, Piyali Mukherjee, Dobgima J. Fonmboh, John E. Kaminski
Increasing detection of HMs load in Cannabis species on one hand emerged as the ultimate answer to land remediation efforts owing to its unique morphological characteristics such as long-stem length, fast growth at the vegetative stage, root area and leaf surface, high photosynthetic activity, fewer nutrient requirements for survival, and shorter life cycle (∼180 days). Cannabis species exhibit a great geo-demographic diversity showing prominence in the wild and cultivated lands (Mura et al. 2004) and on soil pH 5.0 − 7.0 which are excellent attributes for phytoremediation. The use of plants to remove, transfer, stabilize and destroy contaminants in the soil and groundwater (Figure 1) is called phytoremediation. Cannabis species are endowed with stress-tolerant genes which ensure in part their phenotypic and chemotypic plasticity as mechanisms for adaptation in an ecological niche. Cannabis species act as hyper-accumulators of radioactive elements, toxins, pesticides, and polycyclic aromatic hydrocarbons such as chrysene and benzo[a]pyrene through the fundamental processes of phytoaccumulation, phytovolatilization, and phytodegradation in their leaves (Campbell et al. 2002, Greipsson 2011, Morin-Crini et al. 2018).
Spatial distribution of heavy metals in rice grains, rice husk, and arable soil, their bioaccumulation and associated health risks in Haryana, India
Published in Toxin Reviews, 2021
Renu Daulta, Tallapragada Sridevi, Vinod Kumar Garg
CDD of Fe, Pb, and Cu at some locations was more than the permissible limits. HQ indicated that the consumption of rice might cause non-carcinogenic health risks at some locations. It is evident from the results that rice grown in the study area is safe for consumption at most of the locations except for a few. It is recommended that at problematic locations, crop rotation should be adopted. Some non-edible crops such as cotton, biodiesel plant, and other non-edible plants may be cultivated. Farmers can also look for a phytoremediation approach at problematic locations.