Molecular Mechanisms that Control Plant Tolerance to Heavy Metals and Possible Roles in Manipulating Metal Accumulation

Abstract:: The emerging field of hydrogen biology has to date mainly been applied in medicine. However, hydrogen biology can also enable positive outcomes in agriculture. Agriculture faces significant challenges resulting from a growing population, climate change, natural disasters, environment pollution, and food safety issues. In fact, hydrogen agriculture is a practical application of hydrogen biology, which may assist in addressing many of these challenges. It has been demonstrated that hydrogen gas (H2) may enhance plant tolerance towards abiotic and biotic stresses, regulate plant growth and development, increase nutritional values, prolong the shelf life, and decrease the nitrite accumulation during the storage of vegetables, as well as increase the resilience of livestock to pathogens. Our field trials show that H2 may have a promising potential to increase yield and improve the quality of agricultural products. This review aims to elucidate mechanisms for a novel agricultural application of H2 in China. Future development of hydrogen agriculture is proposed as well. Obviously, hydrogen agriculture belongs to low carbon economy, and has great potential to provide “safe, tasty, healthy, and highyield” agricultural products so that it may improve the sustainability of agriculture.

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Heavy metal levels in cattle egrets (Bubulcus ibis) foraging in some abattoirs in Lagos State metropolis

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00529-7 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Elijah Abakpa Adegbe ◽

Oluwaseyi Oluwabukola Babajide ◽

Lois Riyo Maina ◽

Shola Elijah Adeniji

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Metal Accumulation ◽

Heavy Metal Contamination ◽

Heavy Metal Accumulation ◽

Bubulcus Ibis ◽

Significant Difference ◽

Metal Levels ◽

Lagos State ◽

The Mean

Abstract Background Heavy metal accumulation in the ecosystem constitutes a potential toxic effect which is hazardous to human health. Increasing environmental pollution has necessitated the use of cattle egrets to evaluate the levels of heavy metal contamination, to establish their use in biomonitoring of heavy metals and to provide data for monitoring pollution in the environment. Results The present study assessed the utilization of Bubulcus ibis in monitoring pollution in five abattoirs, namely Agege, Bariga, Kara, Itire and Idi-Araba, all situated in Lagos State. The concentration of five (5) heavy metals, cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) was determined in the liver, muscle and feather of Bubulcus ibis using the atomic absorption spectrophotometer. The trend of metal accumulation was in the order: Zn > Cu > Pb > Cd > Ni for all the sampled tissues. The mean tissue concentrations of the metals were significantly different (p < 0.05) among the sites. The highest levels of metal concentration were reported in the liver in all the locations. Mean concentration of Cd in Kara (0.003 ± 0.00058) was significantly (p < 0.05) higher than those found at Agege (0.0013 ± 0.00058) and Idi-Araba (0.001 ± 0.001). A significant difference (p < 0.05) was also observed between the mean concentrations of Cu in Bariga (0.01 ± 0.001) and Idi-Araba (0.003 ± 0.001). Conclusion All the studied heavy metals were present in the liver, muscle and feathers of the cattle egrets. The contamination levels were ascertained from the study which indicated that cattle egrets are useful in biomonitoring studies and the generated data will serve as baseline data which could be compared with data from other locations for monitoring heavy metal pollution.

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Effects of road traffic on photosynthetic pigments and heavy metal accumulation in tree species of Kumasi Metropolis, Ghana

SN Applied Sciences ◽

10.1007/s42452-020-04027-9 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Ufere N. Uka ◽

Ebenezer J. D. Belford ◽

Florence A. Elebe

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Photosynthetic Pigments ◽

Tree Species ◽

Metal Accumulation ◽

Mangifera Indica ◽

Polluted Site ◽

Vehicular Pollution ◽

Terminalia Catappa ◽

Polyalthia Longifolia

AbstractThis study was undertaken to examine changes in the content of pigments and accumulation of metals from vehicular pollution in selected species of roadside trees under vehicular pollution. A major arterial road with heavy vehicle emissions in the Kumasi Metropolis was designated as the polluted site, while Kwame Nkrumah University of Science and Technology Campus was designated as the control site. Four tree species (Terminalia catappa, Mangifera indica, Ficus platyphylla and Polyalthia longifolia) selected for the study were well distributed and abundant in the polluted and control sites. Photosynthetic pigments and levels of heavy metals (Pb, Cu, Cd and zinc) were assessed in their leaves. Chlorophyll and carotenoid contents were determined by absorption spectrometry, while the metal accumulation index (MAI) was used to determine the total metal accumulation capacity of the tree species. We observed a reduction in photosynthetic pigments in the leaf samples from the polluted site. Ficus platyphylla had the maximum reduction in total chlorophyll (49.34%), whereas Terminalia catappa recorded the lowest reduction (33.88%). Similarly, the largest decrease (31.58%) of carotenoid content was found in Terminalia catappa trees and the lowest in Polyalthia longifolia (16.67%). The Polyalthia longifolia, Ficus platyphylla and Terminalia catappa leaf samples collected at the polluted site recorded a higher ratio of chlorophyll a/b. Heavy metal (Cu, Pb, Zn and Cd) accumulation in leaf samples was higher in the polluted site than in the control, as expected. The highest metal MAI value was recorded in Mangifera indica (5.35) followed by Polyalthia longifolia with 4.30. The findings from this study specifically demonstrate that air contamination induced by vehicles decreases the level of photosynthetic pigments in trees subjected to roadside emissions. It is clear that both chlorophyll a/b and chlorophyll/carotenoid ratios will act as very useful stress-level markers. Elevated heavy metal levels in the tree species along arterial roadsides indicate that they serve as heavy metals sink. The change in MAI resulting from different pollution burden is an indication that the removal capabilities of the tree species differ from each other. We therefore suggest M. indica and P. longifolia as potential species to be used in air pollution reduction plans in the city.

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Plant Morphological, Physiological and Anatomical Adaption to Flooding Stress and the Underlying Molecular Mechanisms

International Journal of Molecular Sciences ◽

10.3390/ijms22031088 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1088

Author(s):

Weitao Jia ◽

Maohua Ma ◽

Jilong Chen ◽

Shengjun Wu

Keyword(s):

Molecular Mechanisms ◽

Sequence Similarity ◽

Survival Strategies ◽

Ethylene Response Factor ◽

Flooding Tolerance ◽

Plant Tolerance ◽

Flooding Stress ◽

Crop Varieties ◽

The Future ◽

Plant Acclimation

Globally, flooding is a major threat causing substantial yield decline of cereal crops, and is expected to be even more serious in many parts of the world due to climatic anomaly in the future. Understanding the mechanisms of plants coping with unanticipated flooding will be crucial for developing new flooding-tolerance crop varieties. Here we describe survival strategies of plants adaptation to flooding stress at the morphological, physiological and anatomical scale systemically, such as the formation of adventitious roots (ARs), aerenchyma and radial O2 loss (ROL) barriers. Then molecular mechanisms underlying the adaptive strategies are summarized, and more than thirty identified functional genes or proteins associated with flooding-tolerance are searched out and expounded. Moreover, we elaborated the regulatory roles of phytohormones in plant against flooding stress, especially ethylene and its relevant transcription factors from the group VII Ethylene Response Factor (ERF-VII) family. ERF-VIIs of main crops and several reported ERF-VIIs involving plant tolerance to flooding stress were collected and analyzed according to sequence similarity, which can provide references for screening flooding-tolerant genes more precisely. Finally, the potential research directions in the future were summarized and discussed. Through this review, we aim to provide references for the studies of plant acclimation to flooding stress and breeding new flooding-resistant crops in the future.

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Molecular mechanisms of resistance to heavy metals in the protistEuglena gracilis

Journal of Environmental Science and Health Part A ◽

10.1080/10934520701480326 ◽

2007 ◽

Vol 42 (10) ◽

pp. 1365-1378 ◽

Cited By ~ 23

Author(s):

José S. RodrÍguez-Zavala ◽

Jorge D. GarcÍa-GarcÍa ◽

Marco A. Ortiz-Cruz ◽

Rafael Moreno-Sánchez

Keyword(s):

Heavy Metals ◽

Molecular Mechanisms ◽

Mechanisms Of Resistance

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Physiological and molecular mechanisms of heavy metal accumulation in nonmycorrhizal versus mycorrhizal plants

Plant Cell & Environment ◽

10.1111/pce.13471 ◽

2018 ◽

Vol 42 (4) ◽

pp. 1087-1103 ◽

Cited By ~ 34

Author(s):

Wenguang Shi ◽

Yuhong Zhang ◽

Shaoliang Chen ◽

Andrea Polle ◽

Heinz Rennenberg ◽

...

Keyword(s):

Heavy Metal ◽

Molecular Mechanisms ◽

Metal Accumulation ◽

Heavy Metal Accumulation ◽

Mycorrhizal Plants

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Advances in 5-Aminolevulinic Acid Priming to Enhance Plant Tolerance to Abiotic Stress

International Journal of Molecular Sciences ◽

10.3390/ijms23020702 ◽

2022 ◽

Vol 23 (2) ◽

pp. 702

Author(s):

Shuya Tan ◽

Jie Cao ◽

Xinli Xia ◽

Zhonghai Li

Keyword(s):

Abiotic Stresses ◽

Nitrogen Assimilation ◽

Molecular Mechanisms ◽

Aminolevulinic Acid ◽

Adaptive Strategy ◽

Forward Genetics ◽

Plant Tolerance ◽

Biotic And Abiotic Stresses ◽

Defense Priming ◽

Made In

Priming is an adaptive strategy that improves plant defenses against biotic and abiotic stresses. Stimuli from chemicals, abiotic cues, and pathogens can trigger the establishment of priming state. Priming with 5-aminolevulinic acid (ALA), a potential plant growth regulator, can enhance plant tolerance to the subsequent abiotic stresses, including salinity, drought, heat, cold, and UV-B. However, the molecular mechanisms underlying the remarkable effects of ALA priming on plant physiology remain to be elucidated. Here, we summarize recent progress made in the stress tolerance conferred by ALA priming in plants and provide the underlying molecular and physiology mechanisms of this phenomenon. Priming with ALA results in changes at the physiological, transcriptional, metabolic, and epigenetic levels, and enhances photosynthesis and antioxidant capacity, as well as nitrogen assimilation, which in turn increases the resistance of abiotic stresses. However, the signaling pathway of ALA, including receptors as well as key components, is currently unknown, which hinders the deeper understanding of the defense priming caused by ALA. In the future, there is an urgent need to reveal the molecular mechanisms by which ALA regulates plant development and enhances plant defense with the help of forward genetics, multi-omics technologies, as well as genome editing technology.

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Mutation in OsFWL7 Affects Cadmium and Micronutrient Metal Accumulation in Rice

International Journal of Molecular Sciences ◽

10.3390/ijms222212583 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12583

Author(s):

Qingsong Gao ◽

Lei Liu ◽

Haiying Zhou ◽

Xi Liu ◽

Wei Li ◽

...

Keyword(s):

Heavy Metal ◽

Molecular Mechanisms ◽

Metal Accumulation ◽

Normal Growth ◽

Growth Conditions ◽

Membrane Microdomains ◽

Metal Transporter ◽

Membrane Microdomain ◽

Marker Proteins ◽

Family Gene

Micronutrient metals, such as Mn, Cu, Fe, and Zn, are essential heavy metals for plant growth and development, while Cd is a nonessential heavy metal that is highly toxic to both plants and humans. Our understanding of the molecular mechanisms underlying Cd and micronutrient metal accumulation in plants remains incomplete. Here, we show that OsFWL7, an FW2.2-like (FWL) family gene in Oryza sativa, is preferentially expressed in the root and encodes a protein localized to the cell membrane. The osfwl7 mutation reduces both the uptake and the root-to-shoot translocation of Cd in rice plants. Additionally, the accumulation of micronutrient metals, including Mn, Cu, and Fe, was lower in osfwl7 mutants than in the wildtype plants under normal growth conditions. Moreover, the osfwl7 mutation affects the expression of several heavy metal transporter genes. Protein interaction analyses reveal that rice FWL proteins interact with themselves and one another, and with several membrane microdomain marker proteins. Our results suggest that OsFWL7 is involved in Cd and micronutrient metal accumulation in rice. Additionally, rice FWL proteins may form oligomers and some of them may be located in membrane microdomains.

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Assessment of heavy metal accumulation in tissues of keperas (Cyclocheilichthys apogon Val. 1842) in Lake Lau Kawar, North Sumatra

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/912/1/012044 ◽

2021 ◽

Vol 912 (1) ◽

pp. 012044

Author(s):

Wahyudi ◽

T A Barus ◽

S Ilyas

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

Volcanic Ash ◽

Local Community ◽

Bioconcentration Factor ◽

Metal Accumulation ◽

Heavy Metal Accumulation ◽

Native Fish ◽

Fish Resources ◽

North Sumatra

Abstract Lake Lau Kawar is one of the exposed areas in North Sumatra by the volcanic ash originating from Mount Sinabung eruption. The lake has been utilized as a tourism site and fish resources for consumption by the local community. Keperas (Cyclocheilichthys apogon Val. 1842) is one of the native fish commonly caught by the community. The aim of this study was to determine the levels of selected heavy metals such as copper (Cu), lead (Pb), and zinc (Zn) accumulated by C. apogon and the ones present in the lake water. The results showed that Zn present in the highest concentration followed by Cu and Pb as similar to the results from bioconcentration factor (BCF). All heavy metals (Cu, Pb, Zn) exhibited their highest concentrations in the gills, while the muscles possessed the lowest concentrations of all metals. Risk assessment based on the national and internasional standard revealed that the concentration of these metals was relatively low and safe for consumption.

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