Alfalfa (Medicago Sativa L.): Genotypic Diversity and Transgenic Alfalfa for Phytoremediation

Abstract

Soil contamination caused by industrial and agricultural activities is an environmental problem that poses a serious risk to human health and the ecosystem. Persistent organic pollutants (POPs) are organic chemicals that persist in the environment for long periods because of their high resistance to photolytic, chemical, and biological degradation. Besides POPs, high concentrations of non-essential heavy metals and metalloids, such as arsenic, cadmium, and lead, are increasingly becoming a problem worldwide. Remediation strategies for organic and inorganic pollutants in the environment have received global attention. For organic or inorganic contaminants, phytoremediation is the strategy of choice because of a green technology that uses plants and solar energy to clean hyper-accumulated toxic pollutants from the environment. Some plant species have a high capacity to grow and survive in elevated levels of contaminants. With a long cultivation history and adaptability to a wide range of territories, alfalfa has not only widely been used for animal feed and a medicinal herb but is also an ideal natural resource and model plant for remediation of contaminated soils, offering a variety of elite characteristics. This review provides, firstly, abundant genomic information on the genetic diversity and population structure of alfalfa. Secondly, we focused on the transgenic alfalfa plants for enhanced phytoremediation of POPs, such as atrazine, polychlorinated biphenyl (PCB), and trichloroethylene (TCE), as well as phytoremediation of petroleum and heavy metals. Thirdly, the future perspective of enhancement of phytoremediation efficiency was discussed in depth. This review is intended to provide a comprehensive overview of the phytoremediation capabilities of transgenic alfalfa plants, presenting fundamental information for future research studies for enhancing phytoremediation efficiency.

Utilization of Legume-Nodule Bacterial Symbiosis in Phytoremediation of Heavy Metal-Contaminated Soils

“…In addition to the exploration of plant-microbe interactions or nanotechnology, the solution may lie in genetic engineering of plants and their microsymbionts toward optimization of the metal remediation potential [305]. So far, many transgenic plants have successfully improved phytoremediation efficiency, including legumes (Table 3) [306,307]. Transgenesis consists in insertion of gene(s) from another organism, even distantly related, into the genome of recipient cells.…”

Effects of a dark septate endophyte and extracellular metabolites on alfalfa root exudates: a non‐targeted metabolomics analysis

“…Alfalfa (Medicago sativa L.) is a widely cultivated, high-yielding and high-quality forage legume (Hawkins & Yu, 2018). It is also commonly used as a model plant in soil remediation (Tussipkan & Manabayeva, 2022), with characteristics such as drought resistance (Mouradi et al, 2016), high salinity resistance (Guiza et al, 2021), rapid growth, and a very effective root system (Clement et al, 2022).…”

“…Alfalfa ( Medicago sativa L.) is a widely cultivated, high‐yielding and high‐quality forage legume (Hawkins & Yu, 2018). It is also commonly used as a model plant in soil remediation (Tussipkan & Manabayeva, 2022), with characteristics such as drought resistance (Mouradi et al, 2016), high salinity resistance (Guiza et al, 2021), rapid growth, and a very effective root system (Clement et al, 2022). Numerous studies indicate that DSE can promote alfalfa growth (Gao et al, 2022), nutrient uptake (Hou et al, 2020) and root development (Deng et al, 2020; Newsham, 2011; Xie et al, 2021).…”

Arbuscular Mycorrhizal Fungi Selectively Promoted the Growth of Three Ecological Restoration Plants

“…Therefore, in this study, we chose three degraded grassland restoration grasses for experimentation: Medicago sativa L. is a perennial herbaceous plant belonging to the Fabaceae family, Trifolieae tribe, and is one of the most widely grown forage legumes in the world [ 16 ]. Due to its high grass yield, strong adaptability, and rich protein and mineral content, it is known as the “king of forage” [ 17 ]. Planting alfalfa can modify soil conditions and improve soil nutrient utilization by promoting the proliferation of beneficial microbiota groups and thus repair degraded soil [ 18 ].…”