Glutamic acid assisted phyto-management of silver-contaminated soils through sunflower; physiological and biochemical response

Abstract

Phytoremediation is a cost-effective and eco-friendly technique for the removal of heavy metal-contaminated soils and water. The less availability and mobility of heavy metals in medium decreased the efficiency of this technique. The mobility and availability of these metals in the medium can be enhanced by the addition of organic chelators. The present study was conducted to investigate the possibility of glutamic acid (GA) in improving silver (Ag) phytoextraction by sunflower (Helianthus annuus L.). Different concentrations of Ag and GA were supplied in solution form in different combinations after defined intervals. Results depicted that increasing concentration of Ag significantly reduced the plant biomass, photosynthetic pigments, and antioxidant enzyme activities (like catalase, peroxidase, ascorbate, peroxidase, superoxide dismutase). Furthermore, Ag stress increased the Ag concentration and the production of reactive oxygen species (ROS) in sunflower plants. The addition of GA alleviated the Ag-induced toxicity in plants and enhanced Ag concentration and accumulation in sunflower. The addition of GA enhanced Ag accumulation in sunflower roots by 70, 79, 58, and 66% at 0-, 100-, 250-, and 500-μM Ag treatments, respectively, as compared to control plants. In conclusion, the results showed that Ag significantly reduced the physiological and biochemical attributes in term of reduced growth of sunflower and the addition of GA alleviated the Ag induced toxicity and enhanced Ag uptake. The results suggested that sunflower can be used as hyper-accumulator plant for the removal of Ag under GA. Further studies are required to understand the role of GA at gene and microscopic level in plants.

Glutamic Acid-Assisted Phytomanagement of Chromium Contaminated Soil by Sunflower (Helianthus annuus L.): Morphophysiological and Biochemical Alterations

“…The increased Cr concentrations led to a significant decrease in the growth of the sunflower plants ( Table 1). Several studies regarding Cr-induced toxic effects on sunflower plant have been widely reported (Farid et al, 2017a;Farid et al, 2018a;Farid et al, 2018b). Chromium-induced toxicity was shown to severely impair nutrient uptake in plants, leading to reduced biomass production and stunted growth (Tauqeer et al, 2016;Fozia et al, 2008).…”

“…Heavy metals can also enter the food chain and accumulate in plant and human body tissues (Rizwan et al, 2016). Chromium is a relatively abundant heavy metal in the topsoil owing to its utility in various industrial processes (Farid et al, 2018a). It is used both in the electroplating industry as an anticorrosive and antibiofouling agent, as well as in steel and automobile manufacturing (Farid et al, 2017a).…”

“…However, there are only few studies reported on the chelating effect of glutamic acid (GA). Farid et al (2018a;2018b) reported that the translocation and accumulation of Cr and Ni were increased in sunflower plants treated with organic chelating acids. Artificially prepared chelators have been extensively used for the plant-mediated extraction of toxic metals in both water and soil media (Huang et al, 1997;Epstein et al, 1999); however, the risks of leaching into groundwater and heavy metal persistence renders them unsuitable for this technique (Farid et al, 2015).…”

Physiological and Biochemical Response of Alternanthera bettzickiana (Regel) G. Nicholson under Acetic Acid Assisted Phytoextraction of Lead

“…Similar toxic effects of Pb were reported in Brassica napus [ 24 ] and A. bettzickiana [ 15 ]. Similar to other organic acids, the AA growth-promoting effect is confirmed in the literature where organic acids such as citric acid (2.5, 5, and 10 mM), glutamic acid (2.5 and 5 mM), and ascorbic acid (5 mM) were used for Brassica napus, sunflower [ 24 , 25 ], Lemna minor L. [ 26 ], and Solanum nigrum L. [ 27 ], respectively, in the presence of HMs stress.…”

Benefits of Ryegrass on Multicontaminated Soils Part 1: Effects of Fertilizers on Bioavailability and Accumulation of Metals

“…Among these organic compounds, flavonoids, lipids, sugars, amino acids, and LMWOAs such as acetic, citric, oxalic, propionic, butyric, malic, fumaric, malonic, and succinic acids have been widely found in the plant's rhizosphere [68][69][70]. These organic compounds react with metals to form complexes, which are adsorbed by the roots and then translocated into the aboveground parts of plants, and have been recently used as environmental friendly remediation of contaminated soils [71,72]. For a better understanding of our results, chemical extraction was firstly performed on unamended and amended soils with a mixture of organic acids and then, the metal phytoavailability was studied using three indicators.…”