scholarly journals Phosphate-Dependent Regulation of Growth and Stresses Management in Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Noura Bechtaoui ◽  
Muhammad Kabir Rabiu ◽  
Anas Raklami ◽  
Khalid Oufdou ◽  
Mohamed Hafidi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Plant Growth ◽  
Abiotic Stresses ◽  
Heavy Metal Stress ◽  
Growth Function ◽  
Regulatory Pathways ◽  
Chlorophyll Contents ◽  
Pi Starvation ◽  
Dry Biomass

The importance of phosphorus in the regulation of plant growth function is well studied. However, the role of the inorganic phosphate (Pi) molecule in the mitigation of abiotic stresses such as drought, salinity, heavy metal, heat, and acid stresses are poorly understood. We revisited peer-reviewed articles on plant growth characteristics that are phosphorus (P)-dependently regulated under the sufficient-P and low/no-P starvation alone or either combined with one of the mentioned stress. We found that the photosynthesis rate and stomatal conductance decreased under Pi-starved conditions. The total chlorophyll contents were increased in the P-deficient plants, owing to the lack of Pi molecules to sustain the photosynthesis functioning, particularly, the Rubisco and fructose-1,6-bisphosphatase function. The dry biomass of shoots, roots, and P concentrations were significantly reduced under Pi starvation with marketable effects in the cereal than in the legumes. To mitigate P stress, plants activate alternative regulatory pathways, the Pi-dependent glycolysis, and mitochondrial respiration in the cytoplasm. Plants grown under well-Pi supplementation of drought stress exhibited higher dry biomass of shoots than the no-P treated ones. The Pi supply to plants grown under heavy metals stress reduced the metal concentrations in the leaves for the cadmium (Cd) and lead (Pb), but could not prevent them from absorbing heavy metals from soils. To detoxify from heavy metal stress, plants enhance the catalase and ascorbate peroxidase activity that prevents lipid peroxidation in the leaves. The HvPIP and PHO1 genes were over-expressed under both Pi starvation alone and Pi plus drought, or Pi plus salinity stress combination, implying their key roles to mediate the stress mitigations. Agronomy Pi-based interventions to increase Pi at the on-farm levels were discussed. Revisiting the roles of P in growth and its better management in agricultural lands or where P is supplemented as fertilizer could help the plants to survive under abiotic stresses.

Amelioration of heavy metal stress by endophytic Bacillus amyloliquefaciens RWL-1 in rice by regulating metabolic changes: potential for bacterial bioremediation

2019 ◽  
Vol 476 (21) ◽  
pp. 3385-3400
Author(s):  
Raheem Shahzad ◽  
Saqib Bilal ◽  
Muhammad Imran ◽  
Abdul Latif Khan ◽  
Areej Ahmed Alosaimi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Plant Growth ◽  
Bacillus Amyloliquefaciens ◽  
Heavy Metal Stress ◽  
Cu Stress ◽  
Seedling Biomass ◽  
Plant Growth Promoting ◽  
Carbohydrate Levels ◽  
Dose Dependent Increase

This study aimed to investigate the bioremediation efficiency of phytohormone-producing endophytic Bacillus amyloliquefaciens RWL-1 isolated from rice seeds. In this study, we tested RWL-1 against various heavy metals (Cu, Cr, Pb, and Cd). Among the tested heavy metals, RWL-1 showed the highest tolerance for Cu stress and we observed alterations in growth kinetics with various Cu concentrations (1, 2.5, and 5 mM). We confirmed the biosorption potential of RWL-1 by scanning electron microscopy coupled with energy-dispersive X-ray spectrometry showing that Cu ions were adsorbed on RWL-1 cell surfaces. We further tested RWL-1 for its plant growth promoting and stress reliance efficiency in response to a dose-dependent increase in soil Cu (1, 2.5, and 5 mM). The RWL-1 inoculation significantly increased seedling biomass and growth attributes compared with non-inoculated control seedlings with and without Cu stress. Moreover, RWL-1 inoculation significantly promoted a physiochemical response in seedlings with and without Cu stress by reducing Cu uptake, improving carbohydrate levels (glucose, sucrose, fructose, and raffinose), enhancing amino acids regulation, and augmenting antioxidant levels (POD, PPO, and GHS). Levels of stress-responsive phytohormones such as abscisic acid (ABA) and jasmonic acid were significantly reduced in RWL-1-inoculated seedlings as compared with non-inoculated control seedlings under normal condition and same levels of Cu stress. In conclusion, the inoculation of B. amyloliquefaciens RWL-1 can significantly improve plant growth in Cu-contaminated soil and reduce metal accumulation, thus making plants safer for consumption. This approach could be tremendously helpful for safe and sustainable agriculture in heavy metal-contaminated areas.

A brief Survey of Assessment models to Predict stress Level of Heavy Metals in Soils

2020 ◽  
Vol 13 ◽  
Author(s):  
Sangeetha Annam ◽  
Anshu Singla
Keyword(s):  
Economic Growth ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Stress Level ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Human Life ◽  
High Stress ◽  
Heavy Metal Stress

Abstract: Soil is a major and important natural resource, which not only supports human life but also furnish commodities for ecological and economic growth. Ecological risk has posed a serious threat to the ecosystem by the degradation of soil. The high-stress level of heavy metals like chromium, copper, cadmium, etc. produce ecological risks which include: decrease in the fertility of the soil; reduction in crop yield & degradation of metabolism of living beings, and hence ecological health. The ecological risk associated, demands the assessment of heavy metal stress levels in soils. As the rate of stress level of heavy metals is exponentially increasing in recent times, it is apparent to assess or predict heavy metal contamination in soil. The assessment will help the concerned authorities to take corrective as well as preventive measures to enhance the ecological and hence economic growth. This study reviews the efficient assessment models to predict soil heavy metal contamination.

scholarly journals Scope and future perspectives of phytoremediation

2021 ◽  
Vol 16 (AAEBSSD) ◽  
pp. 77-85
Author(s):  
Sridevi Tallapragada ◽  
Rajesh Lather ◽  
Vandana ◽  
Gurnam Singh
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Genetic Engineering ◽  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Large Scale ◽  
Negative Impact ◽  
Heavy Metal Accumulation ◽  
Plant Growth Promoting Bacteria ◽  
Runoff Water

Phytoremediation is the plant-based technology that has emerged as a novel cost effective and ecofriendly technology in which green plants are used for extraction, sequestration and/or detoxification of the pollutants. Plants possess the natural ability to degrade heavy metals and this property of plants to detoxify contaminants can be used by genetic engineering approach. Currently, the quality of soil and water has degraded considerably due heavy metal accumulation through discharge of industrial, agricultural and domestic waste. Heavy metal pollution is a global concern and a major health threat worldwide. They are toxic, and can damage living organisms even at low concentrations and tend to accumulate in the food chain. The most common heavy metal contaminants are: As, Cd, Cr, Cu, Hg, Pb and Zn. High levels of metals in soil can be phytotoxic, leading to poor plant growth and soil cover due to metal toxicity and can lead to metal mobilization in runoff water and thus have a negative impact on the whole ecosystem. Phytoremediation is a green strategy that uses hyperaccumulator plants and their rhizospheric micro-organisms to stabilize, transfer or degrade pollutants in soil, water and environment. Mechanisms used to remediate contaminated soil includes phytoextraction, phytostabilization, phytotransformation, phytostimulation, phytovolatilization and rhizofiltration. Traditional phytoremediation method presents some limitations regarding their applications at large scale, so the application of genetic engineering approaches such as transgenic transformation, nanoparticles addition and phytoremediation assisted with phytohormones, plant growth-promoting bacteria and Arbuscular mycorrhizal fungi (AMF) inoculation has been applied to ameliorate the efficacy of plants for heavy metals decontamination. In this review, some recent innovative technologies for improving phytoremediation and heavy metals toxicity and their depollution procedures are highlighted.

scholarly journals Role of nitric oxide in plant responses to heavy metal stress: exogenous application versus endogenous production

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
Keyword(s):  
Nitric Oxide ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Human Health Risk ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Future Research ◽  
Plant Responses ◽  
Research Perspectives

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.

Overcoming the Bacteriostatic Effects of Heavy Metals on A. thiooxidans Direct Bioleaching of Saprolitic Ni Laterite Ores

2015 ◽  
Vol 1130 ◽  
pp. 263-267 ◽  
Author(s):  
Hee Chan Jang ◽  
Marjorie Valix
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Stress ◽  
Lag Phase ◽  
Tolerance Index ◽  
Acid Generation ◽  
Laterite Ores ◽  
Laterite Ore

In this study, the adaptation of A. thiooxidans to heavy metals leached from saprolitic Ni laterite ores was performed by gradual acclimatisation. The bacteria was cultivated in heavy metals (Ni, Co, Fe, Mg, Cr and Mn) with total concentrations of 2400 to 24000 ppm equivalent to total dissolution of 1 to 10% (w/v) pulp densities of the saprolitic Ni laterite ore. Adaptation evolution mapped from its tolerance index was found to be dependent on metal concentration, acid generation, and period of adaptation. Bio-stimulation of cell growth and acid production was promoted by heavy metal stress on the bacteria. Pre-established heavy metal tolerance of the bacteria improved the leaching rate in its early phase; 20% and 7% increase in Ni and Co metal recoveries were observed in using adapted bacteria. However heavy metal tolerance was also achieved by the bacteria during the leaching process, albeit delayed by a lag phase. These results confirm the robust nature and suitability of A. thiooxidans in direct biomining of Ni ores.

scholarly journals Silicon Mechanisms to Ameliorate Heavy Metal Stress in Plants

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Abolghassem Emamverdian ◽  
Yulong Ding ◽  
Yinfeng Xie ◽  
Sirous Sangari
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Enzyme Activity ◽  
Metal Uptake ◽  
Ph Value ◽  
Anthropogenic Activities ◽  
Heavy Metal Stress ◽  
Heavy Metal Uptake ◽  
Stimulation Of

The increased contaminants caused by anthropogenic activities in the environment and the importance of finding pathways to reduce pollution caused the silicon application to be considered an important detoxification agent. Silicon, as a beneficial element, plays an important role in amelioration of abiotic stress, such as an extreme dose of heavy metal in plants. There are several mechanisms involved in silicon mediation in plants, including the reduction of heavy metal uptake by plants, changing pH value, formation of Si heavy metals, and stimulation of enzyme activity, which can work by chemical and physical pathways. The aim of this paper is to investigate the major silicon-related mechanisms that reduce the toxicity of heavy metals in plants and then to assess the role of silicon in increasing the antioxidant enzyme and nonenzyme activities to protect the plant cell.

Heavy metal detoxification and tolerance mechanisms in plants: Implications for phytoremediation

2016 ◽  
Vol 24 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Anamika Kushwaha ◽  
Radha Rani ◽  
Sanjay Kumar ◽  
Aishvarya Gautam
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Plant Cell Wall ◽  
Heavy Metal Stress ◽  
Heavy Metal Detoxification ◽  
Mycorrhizal Association ◽  
Copper Manganese ◽  
Living Organisms ◽  
Detoxification Mechanisms ◽  
Harmful Effects

Heavy metals, such as cobalt, copper, manganese, molybdenum, and zinc, are essential in trace amounts for growth by plants and other living organisms. However, in excessive amounts these heavy metals have deleterious effects. Like other organisms, plants possess a variety of detoxification mechanisms to counter the harmful effects of heavy metals. These include the restriction of heavy metals by mycorrhizal association, binding with plant cell wall and root excretions, metal efflux from the plasma membrane, metal chelation by phytochelatins and metallothioneins, and compartmentalization within the vacuole. Phytoremediation is an emerging technology that uses plants and their associated rhizospheric microorganisms to remove pollutants from contaminated sites. This technology is inexpensive, efficient, and ecofriendly. This review focuses on potential cellular and molecular adaptations by plants that are necessary to tolerate heavy metal stress.

scholarly journals Activation of phenylpropanoid pathway in legume plants exposed to heavy metals. Part II. Profiling of isoflavonoids and their glycoconjugates induced in roots of lupine (Lupinus luteus) seedlings treated with cadmium and lead.

2011 ◽  
Vol 58 (2) ◽  
Author(s):  
Sylwia Pawlak-Sprada ◽  
Maciej Stobiecki ◽  
Joanna Deckert
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Stress ◽  
Phenylpropanoid Pathway ◽  
Metal Stress ◽  
Lupinus Luteus ◽  
Response To Treatment ◽  
Positional Isomers ◽  
Root Extracts ◽  
Cadmium And Lead

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.

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