Page 177 - AJWEP-22-6

Zn accumulating behavior of L. uncinatus

1. Introduction Plants selected for the uptake of toxic elements from
soil should be contamination-specific, meaning they
Modern advancements in agriculture, industry, and must be capable of tolerating the specific pollutants
urban development have led to significant growth, but present, thrive under local soil and climatic conditions,
they have also resulted in serious environmental issues, accumulate metals in harvestable tissues, and possess
particularly the accumulation of heavy metals and root systems that spatially align with the geographical
toxic substances in soil. Large regions worldwide are distribution of contaminants. Lupinus species exhibit
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impacted by anthropogenic deposition of heavy metals. ecophysiological traits that enable them to solubilize and
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In recent years, concerns have grown regarding the health absorb toxic elements from soil due to their extensive
and ecological impacts of heavy metals in soil and their and deep root systems. These plants also demonstrate
subsequent absorption by plants, prompting the scientific adaptability to environmental stress factors, such as
community to explore effective mitigation strategies. excess nitrates, low root temperatures, detopping, 22,23
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Human activities such as mining, smelting, waste disposal, lime excess, and salinity, that would otherwise inhibit
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manufacturing, battery disposal, and agricultural practices, normal plant growth. 26
including the use of inorganic fertilizers and pesticides, are Reay and Waugh have reported the uptake of
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recognized as major sources of environmental pollution. manganese (Mn) and aluminum (Al) by Lupinus shoots
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Soil contamination directly affects the health of living and roots, while other studies have shown the absorption
organisms because toxic substances can readily enter the of cadmium (Cd) and mercury (Hg). 28,29 Lupinus albus L.
food chain. As a result, the widespread distribution of has shown the ability to detoxify water by absorbing Cd,
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toxic elements in soil, water, and air poses serious and plumbum (Pb), and chromium (Cr), with Cd retention
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unpredictable risks to human health. 9 attributed to thiol groups in cell walls. These findings
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At low concentrations, however, heavy metals highlight the considerable potential of this genus for
are crucial for biological functions. They serve as remediating contaminated soils. Furthermore, Lupinus
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cofactors for many enzymes, including proteinases, luteus L. (yellow lupine) has been demonstrated to
dehydrogenases, and peptidases. Zinc (Zn), for example, grow without toxicity when exposed to benzo(a)pyrene.
is essential for the synthesis of carbohydrates, proteins, Endophytes associated with this species not only
phosphates, auxins, RNA, and ribosomes, and it enhanced plant growth and tolerance to benzo(a)pyrene
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plays a vital role in the metabolic processes of both but also improved resistance to other organic pollutants
plants and animals. Nevertheless, Zn can accumulate such as diesel and polychlorinated biphenyls. These
to toxic levels in the environment, adversely affecting endophytes were also capable of metabolizing some of
plants as well as soil-dwelling organisms. Although the organic pollutants. 33
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Zn is an integral part of Earth’s biogeochemical Unlike hyperaccumulator plants such as Thalspi
cycles and is required by plants in trace amounts, caerulescense, Lupinus species act as metal excluders,
human activities such as excessive agrochemical use, restricting the movement of metals from roots to shoots
industrial and municipal waste disposal, and mining across a broad range of soil metal concentrations.
have led to elevated Zn concentrations in soils, which This exclusion mechanism may involve alterations in
may become detrimental to plants 12,13 and frequently membrane permeability, changes in the metal-binding
reach toxic levels for soil microbes. Phytoextraction, capacity of cell walls, or the exudation of chelating
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the process of removing heavy metals from soil using substances from roots, as has been proposed for
plants, is increasingly regarded as an eco-friendly and L. albus. 34
cost-effective approach to the remediation of soils In a recent study by Saladin et al., L. albus. exposed
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contaminated with potentially toxic substances. 15-18 for 3 weeks in a greenhouse to soils from former
More broadly, phytoremediation, the use of plants to French mines (Pontgibaud and Vaulry) contaminated
restore polluted soils, is considered an innovative and with metal(loid)s, including high concentrations
promising strategy for soil decontamination, offering of arsenic (As) and Pb (772–1,064 mg/kg and
several advantages over traditional methods, such 121–12,340 mg/kg, respectively), showed less growth
as being in situ, cost-effective, and environmentally inhibition than two other species (common vetch and
friendly. 19,20 Recent studies have demonstrated that buckwheat). This resilience was attributed to lower
certain plant species, due to their unique traits, possess metal(loid) concentrations in the roots and aerial tissues
the capability to absorb and metabolize xenobiotics of lupins, suggesting that L. albus may be the most
contaminating the environment. 21 suitable species for phytostabilization among the crops

Volume 22 Issue 6 (2025) 171 doi: 10.36922/AJWEP025140101