scholarly journals Evaluation of Free Radical Scavenging Activities Against Multiple Heavy Metals Stress in Avicennia marina (Forsk.) and Rhizophora mucronata Lamk

Author(s):  
Samrina Shams ◽  
Sarwat Ismail ◽  
Muhammad Faheem Siddiqui ◽  
Samin Naurin

The tolerance mechanism of mangrove species (Avicennia marina (Forsk.) and Rhizophora mucronataLamk) was studied by inducing multiple heavy metal stress in roots and leaves of the plants. Mangrove seedlings weretreated with different concentrations of heavy metal solution (Cr, Cd, Pb and Hg) for a period of 2 months. Scavengingantioxidant enzymes like Polyphenol Oxidase (PPO), Glutathione-S-transferase (GSTs) and Guaiacol Peroxidase(POD) were analyzed in both species after appropriate intervals of 15 days. Results revealed that activities of theseantioxidative enzymes were altered due to multiple heavy metals exposure in both mangrove species, whereas leavesexhibited the higher values as compared to the roots. In the leaves of both mangrove plants GSTs exhibited anincreased trend throughout the investigated period whereas, PPO activity initially showed an increasing trend, butgradually decreased with the passage of time in response to heavy metal stress. Furthermore, an increased level ofantioxidants was also observed in A. marina than R. mucronata which proves that the former is a strong candidate forheavy metals phyto-remediation with its viable survival strategies.

Author(s):  
Guo-Yong Huang ◽  
You-Shao Wang ◽  
Cui-Ci Sun ◽  
Jun-De Dong ◽  
Zong-Xun Sun

The effect of multiple heavy metals on ascorbate, glutathione and related enzymes in two mangrove plant seedlings (In this study, the effect of multiple heavy metal stress on ascorbate (AsA), glutathione (GSH) and related enzymes was investigated in the leaves, stems and roots of


2019 ◽  
Vol 70 (17) ◽  
pp. 4477-4488 ◽  
Author(s):  
Laura C Terrón-Camero ◽  
M Ángeles Peláez-Vico ◽  
Coral Del-Val ◽  
Luisa M Sandalio ◽  
María C Romero-Puertas

Abstract Anthropogenic activities, such as industrial processes, mining, and agriculture, lead to an increase in heavy metal concentrations in soil, water, and air. Given their stability in the environment, heavy metals are difficult to eliminate and can constitute a human health risk by entering the food chain through uptake by crop plants. An excess of heavy metals is toxic for plants, which have various mechanisms to prevent their accumulation. However, once metals enter the plant, oxidative damage sometimes occurs, which can lead to plant death. Initial production of nitric oxide (NO), which may play a role in plant perception, signalling, and stress acclimation, has been shown to protect against heavy metals. Very little is known about NO-dependent mechanisms downstream from signalling pathways in plant responses to heavy metal stress. In this review, using bioinformatic techniques, we analyse studies of the involvement of NO in plant responses to heavy metal stress, its possible role as a cytoprotective molecule, and its relationship with reactive oxygen species. Some conclusions are drawn and future research perspectives are outlined to further elucidate the signalling mechanisms underlying the role of NO in plant responses to heavy metal stress.


2011 ◽  
Vol 58 (2) ◽  
Author(s):  
Sylwia Pawlak-Sprada ◽  
Maciej Stobiecki ◽  
Joanna Deckert

We examined changes in profiles of isoflavonoids in roots of lupine (Lupinus luteus L. cv. Juno) seedlings in response to treatment with two heavy metals: cadmium (at 10 mg/l) and lead (at 150 mg/l). Overall, 21 flavonoid conjugates were identified in root extracts, some of them with up to six positional isomers. The total amount of all isoflavonoids increased by about 15 % in cadmium-treated plants and by 46 % in lead-treated ones. Heavy metals markedly increased the content of two compounds: 2'-hydroxygenistein glucoside and 2'-hydroxygenistein 7-O-glucoside malonylated. Possible functions of the identified isoflavonoids in yellow lupine exposed to heavy metal stress are discussed.


2019 ◽  
Vol 25 (3) ◽  
pp. 683-696 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Kirtee Kumar Koul ◽  
...  

2021 ◽  
Author(s):  
Dandan Li ◽  
Guandi He ◽  
Weijun Tian ◽  
Yun Huang ◽  
Lulu Meng ◽  
...  

Abstract Metal tolerance proteins play an important role in the transport and tolerance of divalent heavy metals in plant species. Potatoes are an important food crop whose yields can be deeply affected by heavy metals. However, there is a lack of information concerning the members and function of the MTP gene family in Solanum tuberosum. In this study, we identified and screened 11 MTP genes in potatoes which we named as StMTP1 to StMTP11 based on their positions on the chromosomes. Phylogenetic analysis divided these 11 MTP genes into three subfamilies; Mn-MTP, Zn-MTP and Zn/Fe-MTP. HXXXD and DXXXD conserved motifs were found on or around the transmembrane domain II and transmembrane domain V of these proteins. The highly conserved histidine and aspartic acid residues may be related to the transport of metal ions. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the expression levels of StMTP9 and StMTP10 in leaf tissues increased by around 24-fold following cadmium stress for 24 hours. We hypothesize that StMTP9 and StMTP10 respond to cadmium stress. StMTP11 showed the highest level of expression in stem tissues after 6 hours of zinc stress at more than 13 times the level of expression in controls indicating that StMTP11 is more sensitive to zinc stress. In summary, our results further the current understanding of the molecular mechanisms regulated by members of the MTP gene family in plant responses to heavy metal stress.


2021 ◽  
Vol 8 ◽  
Author(s):  
Valeria Franco-Franklin ◽  
Sandra Moreno-Riascos ◽  
Thaura Ghneim-Herrera

Plant endophytic bacteria have received special attention in recent decades for their ability to improve plant response to multiple stresses. A positive effect of endophytes on plant’s ability to cope with drought, salinity, nitrogen deficiency, and pathogens have already been demonstrated in numerous studies, and recently this evidence was consolidated in a meta-analysis of published data. Endophytic bacteria have also been implicated in increasing resistance to heavy metals in plants; despite the important biotechnological applications of such effect in heavy metal bioremediation and agriculture, efforts to systematically analyze studies in this field have been limited. In this study, we address this task with the objective of establishing whether the findings made for other types of stresses extend to the response to heavy metals. Specifically, we seek to establish if plant inoculation with plant-growth promoting endophytic bacteria have an impact on their tolerance to heavy metal stress? We carried out a meta-analysis of the effect size of inoculation with endophytic bacteria on the host plant biomass in response to heavy metal stress (aluminum, arsenic, cadmium, copper, chromium, manganese, nickel, lead, and zinc), which included 27 (from 76 published in the last 10 years) studies under controlled conditions that evaluated 19 host plants and 20 bacterial genera. Our results suggest that endophytic bacteria increase the biomass production of host plants subjected to different heavy metals, indicating their effectiveness in protecting plants from a wide range of metal toxicities. Stress mitigation by the bacteria was similar among the different plant groups with the exception of non-accumulating plants that benefit most from the symbiotic association. Host identity and heavy metal concentration seem to influence the effect of the bacteria. Our analysis revealed that bacterial consortia provide the greatest benefit although the most common biotechnological applications are not directed towards them, and support the value of endophytic bacteria as an alternative to mitigate heavy metal stress in a wide variety of hosts.


2003 ◽  
Vol 69 (4) ◽  
pp. 2313-2320 ◽  
Author(s):  
Gail M. Teitzel ◽  
Matthew R. Parsek

ABSTRACT A study was undertaken to examine the effects of the heavy metals copper, lead, and zinc on biofilm and planktonic Pseudomonas aeruginosa. A rotating-disk biofilm reactor was used to generate biofilm and free-swimming cultures to test their relative levels of resistance to heavy metals. It was determined that biofilms were anywhere from 2 to 600 times more resistant to heavy metal stress than free-swimming cells. When planktonic cells at different stages of growth were examined, it was found that logarithmically growing cells were more resistant to copper and lead stress than stationary-phase cells. However, biofilms were observed to be more resistant to heavy metals than either stationary-phase or logarithmically growing planktonic cells. Microscopy was used to evaluate the effect of copper stress on a mature P. aeruginosa biofilm. The exterior of the biofilm was preferentially killed after exposure to elevated concentrations of copper, and the majority of living cells were near the substratum. A potential explanation for this is that the extracellular polymeric substances that encase a biofilm may be responsible for protecting cells from heavy metal stress by binding the heavy metals and retarding their diffusion within the biofilm.


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