Plants

Research

34 pages, 2361 KiB

Open AccessArticle

Response to Hypersalinity of Four Halophytes Growing in Hydroponic Floating Systems: Prospects in the Phytomanagement of High Saline Wastewaters and Extreme Environments

by Meri Barbafieri, Francesca Bretzel, Andrea Scartazza, Daniela Di Baccio, Irene Rosellini, Martina Grifoni, Roberto Pini, Alice Clementi and Elisabetta Franchi

Plants 2023, 12(9), 1737; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12091737 - 22 Apr 2023

Cited by 1 | Viewed by 1355

Abstract

Hypersaline environments occur naturally worldwide in arid and semiarid regions or in artificial areas where the discharge of highly saline wastewaters, such as produced water (PW) from oil and gas industrial setups, has concentrated salt (NaCl). Halophytes can tolerate high NaCl concentrations by [...] Read more.

Hypersaline environments occur naturally worldwide in arid and semiarid regions or in artificial areas where the discharge of highly saline wastewaters, such as produced water (PW) from oil and gas industrial setups, has concentrated salt (NaCl). Halophytes can tolerate high NaCl concentrations by adopting ion extrusion and inclusion mechanisms at cell, tissue, and organ levels; however, there is still much that is not clear in the response of these plants to salinity and completely unknown issues in hypersaline conditions. Mechanisms of tolerance to saline and hypersaline conditions of four different halophytes (Suaeda fruticosa (L.) Forssk, Halocnemum strobilaceum (Pall.) M. Bieb., Juncus maritimus Lam. and Phragmites australis (Cav.) Trin. ex Steudel) were assessed by analysing growth, chlorophyll fluorescence and photosynthetic pigment parameters, nutrients, and sodium (Na) uptake and distribution in different organs. Plants were exposed to high saline (257 mM or 15 g L⁻¹ NaCl) and extremely high or hypersaline (514, 856, and 1712 mM or 30, 50, and 100 g L⁻¹ NaCl) salt concentrations in a hydroponic floating culture system for 28 days. The two dicotyledonous S. fruticosa and H. strobilaceum resulted in greater tolerance to hypersaline concentrations than the two monocotyledonous species J. maritimus and P. australis. Plant biomass and major cation (K, Ca, and Mg) distributions among above- and below-ground organs evidenced the osmoprotectant roles of K in the leaves of S. fruticosa, and of Ca and Mg in the leaves and stem of H. strobilaceum. In J. maritimus and P. australis the rhizome modulated the reduced uptake and translocation of nutrients and Na to shoot with increasing salinity levels. S. fruticosa and H. strobilaceum absorbed and accumulated elevated Na amounts in the aerial parts at all the NaCl doses tested, with high bioaccumulation (from 0.5 to 8.3) and translocation (1.7–16.2) factors. In the two monocotyledons, Na increased in the root and rhizome with the increasing concentration of external NaCl, dramatically reducing the growth in J. maritimus at both 50 and 100 g L⁻¹ NaCl and compromising the survival of P. australis at 30 g L⁻¹ NaCl and over after two weeks of treatment. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

13 pages, 1567 KiB

Open AccessArticle

Hormesis Responses of Growth and Photosynthetic Characteristics in Lonicera japonica Thunb. to Cadmium Stress: Whether Electric Field Can Improve or Not?

by Zhouli Liu, Lei Tian, Mengdi Chen, Luhua Zhang, Qingxuan Lu, Jianbing Wei and Xiangbo Duan

Plants 2023, 12(4), 933; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12040933 - 18 Feb 2023

Cited by 7 | Viewed by 1327

Abstract

“Hormesis” is considered a dose–response phenomenon mainly observed at hyperaccumulator plants under heavy metals stress. In this study, the effects of electric fields on hormesis responses in Lonicera japonica Thunb. under cadmium (Cd) treatments were investigated by assessing the plant growth and photosynthetic [...] Read more.

“Hormesis” is considered a dose–response phenomenon mainly observed at hyperaccumulator plants under heavy metals stress. In this study, the effects of electric fields on hormesis responses in Lonicera japonica Thunb. under cadmium (Cd) treatments were investigated by assessing the plant growth and photosynthetic characteristics. Under Cd treatments without electric fields, the parameters of plant growth and photosynthetic characteristics increased significantly when exposed to 5 mg L⁻¹ Cd, and decreased slightly when exposed to 25 mg L⁻¹ Cd, showing an inverted U-shaped trend, which confirmed that low concentration Cd has a hormesis effect on L. japonica. Under electric fields, different voltages significantly promoted the inverted U-shaped trend of the hormesis effect on the plant, especially by 2 V cm⁻¹ voltage. Under 2 V cm⁻¹ voltage, the dry weight of the root and leaf biomass exposed to 5 mg L⁻¹ Cd increased significantly by 38.38% and 42.14%, and the photosynthetic pigment contents and photosynthetic parameters were also increased significantly relative to the control, indicating that a suitable electric field provides better improvements for the hormesis responses of the plant under Cd treatments. The synergistic benefits of the 5 mg L⁻¹ Cd and 2 V cm⁻¹ electric field in terms of the enhanced hormesis responses of growth and photosynthetic characteristics could contribute to the promoted application of electro-phytotechnology. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

18 pages, 1518 KiB

Open AccessArticle

Treatment of Landfill Leachate by Short-Rotation Willow Coppice Plantations in a Large-Scale Experiment in Eastern Canada

by Patrick Benoist, Adam Parrott, Xavier Lachapelle-T., Louis-Clément Barbeau, Yves Comeau, Frédéric E. Pitre and Michel Labrecque

Plants 2023, 12(2), 372; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12020372 - 13 Jan 2023

Cited by 1 | Viewed by 1819

Abstract

The treatment of leachate by vegetative filters composed of short-rotation willow coppice (SRWC) has been shown to be a cost-effective alternative to conventional and costly methods. However, few studies have considered the treatment capability of willow filters at a scale large enough to [...] Read more.

The treatment of leachate by vegetative filters composed of short-rotation willow coppice (SRWC) has been shown to be a cost-effective alternative to conventional and costly methods. However, few studies have considered the treatment capability of willow filters at a scale large enough to meet the industrial requirements of private landfill owners in North America. We report here on a field trial (0.5 ha) in which a willow plantation was irrigated with groundwater (D0) or aged leachate at two different loadings (D1 and D2, which was twice that of D1). Additionally, half of the D2-irrigated plots were amended with phosphorus (D2P). The system, which operated for 131 days, was highly efficient, causing the chemical oxygen demand concentration to drop significantly with the total removal of ammonia (seasonal average removal by a concentration of 99–100%). D2P efficacy was higher than that of D2, indicating that P increased the performance of the system. It also increased the willow biomass 2.5-fold compared to water irrigation. Leaf tissue analysis revealed significant differences in the concentrations of total nitrogen, boron, and zinc, according to the treatment applied, suggesting that the absorption capacity of willows was modified with leachate irrigation. These results indicate that the willow plantation can be effective for the treatment of landfill leachate in respect of environmental requirements. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

14 pages, 2020 KiB

Open AccessArticle

Effect of Exogenous Plant Debris and Microbial Agents on Phytoremediation of Copper-Contaminated Soil in Shanghai

by Qian Zhang, Hailan Fang and Kankan Shang

Plants 2022, 11(22), 3056; https://0-doi-org.brum.beds.ac.uk/10.3390/plants11223056 - 11 Nov 2022

Viewed by 1060

Abstract

Bioaugmentation is an important measure for improving the efficiency of phytoremediation. The objective was to identify the role of exogenous plant debris with different processing and microbial agents for soil characteristics, copper bioavailability and phytoextraction. The experimental design consisted of four blocks, which [...] Read more.

Bioaugmentation is an important measure for improving the efficiency of phytoremediation. The objective was to identify the role of exogenous plant debris with different processing and microbial agents for soil characteristics, copper bioavailability and phytoextraction. The experimental design consisted of four blocks, which were divided into 48 plots. Each plot was planted with Fraxinus chinensis and Salix matsudana × alba, which was added to plant composts, woody chips and effective microorganisms (EM) agents, using an orthogonal experimental design. The results showed that the order of bioaugmentation materials on the Cu phytoextraction of two woody species was plant composts > wood chips > EM agents. The best performance of F. chinensis was in the T15 treatment (30% plant composts + 7.5% wood chips + 40 mL·m⁻²), with phytoextraction of 33.66 mg·m⁻², as well as 4.32 mg·m⁻² in the T16 treatment (30% plant composts + 15% wood chips) of S. matsudana × alba. Cu was accumulated mainly in the roots of the two woody plants. The phytoextraction of the above-ground parts was promoted by bioaugmentation, due to the improvement in the physical soil characteristics and Cu bioavailability. The phytoextraction performance of F. chinensis was promoted by the improvement in the Cu concentration after treatments, while for S. matsudana × alba, it was the dry biomass. Thus, targeted strengthening measures should be to applied, to improve the efficiency of phytoremediation. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

13 pages, 2166 KiB

Open AccessArticle

Electric Field-Enhanced Cadmium Accumulation and Photosynthesis in a Woody Ornamental Hyperaccumulator—Lonicera japonica Thunb.

by Zhouli Liu, Qinglin Chen, Maosen Lin, Mengdi Chen, Cong Zhao, Qingxuan Lu and Xiangyu Meng

Plants 2022, 11(8), 1040; https://0-doi-org.brum.beds.ac.uk/10.3390/plants11081040 - 11 Apr 2022

Cited by 4 | Viewed by 1508

Abstract

The multi-system of electro-phytotechnology using a woody ornamental cadmium (Cd) hyperaccumulator (Lonicera japonica Thunb.) is a new departure for environmental remediation. The effects of four electric field conditions on Cd accumulation, growth, and photosynthesis of L. japonica under four Cd treatments were [...] Read more.

The multi-system of electro-phytotechnology using a woody ornamental cadmium (Cd) hyperaccumulator (Lonicera japonica Thunb.) is a new departure for environmental remediation. The effects of four electric field conditions on Cd accumulation, growth, and photosynthesis of L. japonica under four Cd treatments were investigated. Under 25 and 50 mg L⁻¹ Cd treatments, Cd accumulation in L. japonica was enhanced significantly compared to the control and reached 1110.79 mg kg⁻¹ in root and 428.67 mg kg⁻¹ in shoots influenced by the electric field, especially at 2 V cm⁻¹, and with higher bioaccumulation coefficient (BC), translocation factor (TF), removal efficiency (RE), and the maximum Cd uptake, indicating that 2 V cm⁻¹ voltage may be the most suitable electric field for consolidating Cd-hyperaccumulator ability. It is accompanied by increased root and shoots biomass and photosynthetic parameters through the electric field effect. These results show that a suitable electric field may improve the growth, hyperaccumulation, and photosynthetic ability of L.japonica. Meanwhile, low Cd supply (5 mg L⁻¹) and medium voltage (2 V cm⁻¹) improved plant growth and photosynthetic capacity, conducive to the practical application to a plant facing low concentration Cd contamination in the real environment. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

Review

Jump to: Research, Other

22 pages, 1407 KiB

Open AccessReview

Beyond Cleansing: Ecosystem Services Related to Phytoremediation

by Werther Guidi Nissim, Stefano Castiglione, Francesco Guarino, Maria Chiara Pastore and Massimo Labra

Plants 2023, 12(5), 1031; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12051031 - 24 Feb 2023

Cited by 7 | Viewed by 2238

Abstract

Phytotechnologies used for cleaning up urban and suburban polluted soils (i.e., brownfields) have shown some weakness in the excessive extent of the timeframe required for them to be effectively operating. This bottleneck is due to technical constraints, mainly related to both the nature [...] Read more.

Phytotechnologies used for cleaning up urban and suburban polluted soils (i.e., brownfields) have shown some weakness in the excessive extent of the timeframe required for them to be effectively operating. This bottleneck is due to technical constraints, mainly related to both the nature of the pollutant itself (e.g., low bio-availability, high recalcitrance, etc.) and the plant (e.g., low pollution tolerance, low pollutant uptake rates, etc.). Despite the great efforts made in the last few decades to overcome these limitations, the technology is in many cases barely competitive compared with conventional remediation techniques. Here, we propose a new outlook on phytoremediation, where the main goal of decontaminating should be re-evaluated, considering additional ecosystem services (ESs) related to the establishment of a new vegetation cover on the site. The aim of this review is to raise awareness and stress the knowledge gap on the importance of ES associated with this technique, which can make phytoremediation a valuable tool to boost an actual green transition process in planning urban green spaces, thereby offering improved resilience to global climate change and a higher quality of life in cities. This review highlights that the reclamation of urban brownfields through phytoremediation may provide several regulating (i.e., urban hydrology, heat mitigation, noise reduction, biodiversity, and CO₂ sequestration), provisional (i.e., bioenergy and added-value chemicals), and cultural (i.e., aesthetic, social cohesion, and health) ESs. Although future research should specifically be addressed to better support these findings, acknowledging ES is crucial for an exhaustive evaluation of phytoremediation as a sustainable and resilient technology. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

13 pages, 1213 KiB

Open AccessReview

Plant-Based Solutions for Non-Productive Sites Useful in the Management of Dry Land

by Ewa Hanus-Fajerska, Katarzyna Kępka, Cezary Kruszyna and Iwona Kamińska

Plants 2023, 12(3), 537; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12030537 - 24 Jan 2023

Viewed by 1361

Abstract

The article presents an overview of research conducted in recent years, i.e., from 2004 until now. The study has been prompted by the threat of drought over large land areas which, as a result of current climate change, may lead to desertification in [...] Read more.

The article presents an overview of research conducted in recent years, i.e., from 2004 until now. The study has been prompted by the threat of drought over large land areas which, as a result of current climate change, may lead to desertification in dry and hot regions of the world. For the same reason, large areas of farmland are affected by drought stress. At the same time, rising air temperatures result in a significant intensification of evaporation and a gradual increase in soil salinity. This applies in particular to acres of farmland, forested areas, and green areas of cities, as well as degraded land or brownfields. As the crop stability is threatened, the food base of the world’s population is at risk and, additionally, in areas of industrial districts, people’s health is in decline. Due to these multistress conditions for plant growth, we propose a review of the current literature which addresses the possibility of counteracting these unfavorable phenomena through the appropriate selection of plant species and, when only applicable, also through specific agroecological treatments. A selection of herbaceous and woody plants useful for cultivation on saline marginal lands was proposed. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

Other

Jump to: Research, Review

9 pages, 881 KiB

Open AccessBrief Report

Effects of Cadmium Stress on Carbon Sequestration and Oxygen Release Characteristics in A Landscaping Hyperaccumulator—Lonicera japonica Thunb.

by Zhouli Liu, Jing An, Qingxuan Lu, Chuanjia Yang, Yitao Mu, Jianbing Wei, Yongxia Hou, Xiangyu Meng, Zhuo Zhao and Maosen Lin

Plants 2023, 12(14), 2689; https://0-doi-org.brum.beds.ac.uk/10.3390/plants12142689 - 19 Jul 2023

Cited by 1 | Viewed by 840

Abstract

The carbon sequestration and oxygen release of landscape plants are dominant ecological service functions, which can play an important role in reducing greenhouse gases, improving the urban heat island effect and achieving carbon peaking and carbon neutrality. In the present study, we are [...] Read more.

The carbon sequestration and oxygen release of landscape plants are dominant ecological service functions, which can play an important role in reducing greenhouse gases, improving the urban heat island effect and achieving carbon peaking and carbon neutrality. In the present study, we are choosing Lonicera japonica Thunb. as a model plant to show the effects of Cd stress on growth, photosynthesis, carbon sequestration and oxygen release characteristics. Under 5 mg kg⁻¹ of Cd treatment, the dry weight of roots and shoots biomass and the net photosynthetic rate (P_N) in L. japonica had a significant increase, and with the increase in Cd treatment concentration, the dry weight of roots and shoots biomass and P_N in the plant began to decrease. When the Cd treatment concentration was up to 125 mg kg⁻¹, the dry weight of root and shoots biomass and P_N in the plant decreased by 5.29%, 1.94% and 2.06%, and they had no significant decrease compared with the control, indicating that the plant still had a good ability for growth and photoenergy utilization even under high concentrations of Cd stress. The carbon sequestration and oxygen release functions in terms of diurnal assimilation amounts (P), carbon sequestration per unit leaf area (W_CO₂), oxygen release per unit leaf area (W_O₂), carbon sequestration per unit land area (P_CO₂) and oxygen release per unit land area (P_O₂) in L. japonica had a similar change trend with the photosynthesis responses under different concentrations of Cd treatments, which indicated that L. japonica as a landscaping Cd-hyperaccumulator, has a good ability for carbon sequestration and oxygen release even under high concentrations of Cd stress. The present study will provide a useful guideline for effectively developing the ecological service functions of landscaping hyperaccumulators under urban Cd-contaminated environment. Full article

(This article belongs to the Special Issue Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Plant-Based Technologies for Environmental Reclamation in Urban and Peri-Urban Areas: From Theory to Practice

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (8 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI