Alleviating Effects of Exogenous Glutathione, Glycinebetaine, Brassinosteroids and Salicylic Acid on Cadmium Toxicity in Rice Seedlings (Oryza Sativa)

Abstract

A hydroponic experiment was conducted to study the ameliorative effects of 24 h pretreatment with exogenous glutathione (GSH), glycinebetaine (GB), brassinosteroids (BRs) and salicylic acid (SA) upon 50 μM cadmium (Cd) stress to rice seedlings. The results showed that Cd caused a significant reduction in seedling height, chlorophyll content and biomass, the activity of POD in stems, and shoot Mn, shoot/root Zn and root Cu concentration, but improved SOD and POD activities in leaves with elevated MDA accumulation and Fe concentration. Pretreatment with 100 μM GSH, GB or SA greatly alleviated Cd-induced growth inhibition and suppressed Cd-induced MDA accumulation. Compared with Cd alone treatment, pretreatment of GSH, GB and SA markedly increased chlorophyll content; reduced shoot Cd concentration, and GSH also decrease root Cd content. GSH, GB and SA pretreatments counteracted the pattern of alterations in certain antioxidant enzymes induced by Cd, e.g. significantly suppressed Cd-induced increase of leaf SOD activity, GB and BRs also significantly decreased leaf POD activity; GSH significantly elevated the depressed stem POD and SOD activities; and GB elevated stem SOD activity. Compared with Cd alone, GSH pretreatment significantly relieved Cd-induced reduction in Cu or increase in Fe concentration in leaves; GB pretreatment decreased Cd-induced Fe enhancement; SA pretreatment markedly increased shoot Fe, but reduced Mn concentration. Although BRs pretreatment increased plant dry biomass with no effect on chlorophyll content and MDA accumulation, significantly increased Cd concentration both in shoots and roots.

Magnetic (Fe3O4) Nanoparticles Reduce Heavy Metals Uptake and Mitigate Their Toxicity in Wheat Seedling

“…An increase in the activities of the antioxidative enzyme (SOD and POD) under heavy metal stress could be attributed to the tolerance of heavy metals in plants. Previous study found that Cd stress caused reduction of POD in stems and no effect on roots [10]. Furthermore, no effect on SOD activities in stem and root were noted, while the SOD activity increased in leaf under Cd stress.…”

“…Furthermore, no effect on SOD activities in stem and root were noted, while the SOD activity increased in leaf under Cd stress. Plant growth inhibition induced by the stress of heavy metals has been described by many researchers [10,44] [18]. The MDA concentration is usually used as the general indicator of the extent of lipid peroxidation resulting from oxidative stress [41,56].…”

“…The tolerance to heavy metals can lead to a greater risk to human health [9]. Various plants and crops have been shown to be hyperaccumulators of heavy metals [5,10,11]. Studies have shown that over 80% of heavy metals could be ingested via the food crops [12].…”

Fate and Impacts of Priority Pollutant Metals in Coal Fly Ash–Soil–Switchgrass Plant Mesocosms

“…In this study, soils amended with 7.5% and 15% CFA were moderately contaminated, and the degrees of contamination were decreased by day 90. Also on day 90, the CFAamended soils containing AMF or GSH had a very low degree of contamination, which may be caused by assimilation of the metals into the cell walls of AMF hyphae (Emamverdian et al, 2015;Firmin et al, 2015), whereas exogenous GSH may allow plant assimilation of the metals (Cai et al, 2010;Wei et al, 2010;Cao et al, 2013). According to Rahman et al (2012) and Likuku et al (2013), the PLI proposed by Tomlinson et al (1980) allows the detection of pollution and the necessary actions that need to be taken.…”

“…Huang et al (2005) have shown that AMF (Glomus mosseae) decreased the availability of excessive Zn, Cu, and Pb for maize (Zea mays L.) grown on soil contaminated with HMs. Likewise, exogenous GSH has been demonstrated to protect plants against HM toxicity using hydroponic systems (Cai et al, 2010;Wei et al, 2010;Cao et al, 2013;Mostofa et al, 2014). Hence, this study also investigated the fate and effects of the HMs in the CFA-soil-switchgrass mesocosms with separate applications of AMF (Rhizophagus clarum) and GSH.…”