-
1.
Morel Production Related to Soil Microbial Diversity and Evenness.
Tan, H, Liu, T, Yu, Y, Tang, J, Jiang, L, Martin, FM, Peng, W
Microbiology spectrum. 2021;(2):e0022921
Abstract
Black morel is a widely prized ascomycetous mushroom with culinary value. It was once uncultivable but can now be cultivated routinely in ordinary farmland soils. Large-scale morel farming sometimes encounters nonfructification for unknown reasons. In spring 2020, many morel farms in the area of Chengdu-Plain, China, exhibited no fructification at all, causing disastrous economic loss to the farmers. To determine potential ecological factors associated with the different performance of morel production in these farms, 21 affected sites versus 11 sites with normal fructification performance were analyzed to compare soil microbiota and physiochemical characteristics during fructification. The results indicated that soil physiochemical characteristics were unlikely to be a major reason for the difference between successful fructification and nonfructification. The soils with successful fructification had significantly higher diversity in both the fungal and bacterial communities than those with nonfructification. Morel yield was positively correlated with the α-diversity of fungal communities. The higher diversity of the successfully fructified soils was contributed by community evenness rather than taxonomic richness. In contrast, most nonfructification soils were dominated by a high proportion of a certain fungal genus, typically Acremonium or Mortierella, in the fungal communities. Our findings demonstrate the importance of microbial ecology to the large-scale agroindustry of soil-cultivated mushrooms. IMPORTANCE Saprotrophic mushrooms cultivated in soils are subject to complex influences from soil microbial communities. Research on growing edible mushrooms has revealed connections between fungi and a few species of growth-promoting bacteria colonizing the mycosphere. The composition and diversity of the whole microbial community may also have an influence on the growth and production of soil-saprotrophic mushrooms. Morel mushrooms (Morchella spp.) are economically and culturally important and are widely prized throughout the world. This study used the large-scale farming of morels as an example of an agroecosystem for soil-saprotrophic mushroom cultivation. It demonstrated a typical pattern of how the microbial ecology in soil agroecosystems, especially the α-diversity level and community evenness among soil fungal taxa, could affect the production of high-value cash crops and the income of farmers.
-
2.
Molecular Modifications and Control of Processes to Facilitate the Synergistic Degradation of Polybrominated Diphenyl Ethers in Soil by Plants and Microorganisms Based on Queuing Scoring Method.
Wu, T, Li, Y, Xiao, H, Fu, M
Molecules (Basel, Switzerland). 2021;(13)
Abstract
In this paper, a combination of modification of the source and regulation of the process was used to control the degradation of PBDEs by plants and microorganisms. First, the key proteins that can degrade PBDEs in plants and microorganisms were searched in the PDB (Protein Data Bank), and a molecular docking method was used to characterize the binding ability of PBDEs to two key proteins. Next, the synergistic binding ability of PBDEs to the two key proteins was evaluated based on the queuing integral method. Based on this, three groups of three-dimensional quantitative structure-activity relationship (3D-QSAR) models of plant-microbial synergistic degradation were constructed. A total of 30 PBDE derivatives were designed using BDE-3 as the template molecule. Among them, the effect on the synergistic degradation of six PBDE derivatives, including BDE-3-4, was significantly improved (increased by more than 20%) and the environment-friendly and functional evaluation parameters were improved. Subsequently, studies on the synergistic degradation of PBDEs and their derivatives by plants and microorganisms, based on the molecular docking method, found that the addition of lipophilic groups by modification is beneficial to enhance the efficiency of synergistic degradation of PBDEs by plants and microorganisms. Further, while docking PBDEs, the number of amino acids was increased and the binding bond length was decreased compared to the template molecules, i.e., PBDE derivatives could be naturally degraded more efficiently. Finally, molecular dynamics simulation by the Taguchi orthogonal experiment and a full factorial experimental design were used to simulate the effects of various regulatory schemes on the synergistic degradation of PBDEs by plants and microorganisms. It was found that optimal regulation occurred when the appropriate amount of carbon dioxide was supplied to the plant and microbial systems. This paper aims to provide theoretical support for enhancing the synergistic degradation of PBDEs by plants and microorganisms in e-waste dismantling sites and their surrounding polluted areas, as well as, realize the research and development of green alternatives to PBDE flame retardants.
-
3.
Soil cadmium and lead affecting biochemical properties of Matricaria chamomilla L. at different growth stages in the greenhouse and field.
Bagheri, M, Javanmard, HR, Naderi, MR
Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. 2021;(4):881-893
Abstract
Heavy metals bioremediation by medicinal plants is an important research issue, which has yet to be investigated. Matricaria chamomilla accumulation of soil cadmium (Cd, 0, 10 and 40 mg/kg) and lead (Pb, 0, 60 and 180 mg/kg) affecting plant biochemical properties L. at different growth stages in the greenhouse and field was investigated. The 10-kg experimental pots (located in the greenhouse and field with 80% of field capacity moisture) were filled with the treated soils, and were planted with M. chamomilla L. seeds (three replicates). Plants were sampled to determine their biochemical properties including Cd and Pb contents, pigments, proline (Pro), leaf relative water (LRW), lipid peroxidation (LX), and superoxide dismutase (SOD, EC 1.15. 1.1), and catalase (CAT, EC 1.11.1.6) activities. Soil final concentration of Cd and Pb was also determined. Heavy metal stress significantly decreased plant pigment contents; however, it significantly increased plant PRO, LRW, LX and SOD, and not CAT. Heavy metal, growth stage, growth location, and their interactions significantly affected plant heavy metal concentrations. Interestingly, although significantly higher concentration of Cd was observed in plant aerial part under greenhouse conditions, plant roots had significantly higher concentrations of Cd under field conditions, and it was reverse for Pb. Increased concentration of Cd and Pb significantly enhanced plant Pro content and the highest one was resulted by Pb3 (913.46 mg/g fresh weight) significantly higher than other treatments including Cd3 (595.34 mg/g fresh weight). M. chamomilla is a suitable species for the bioremediation of soils polluted with Cd and Pb.
-
4.
The role of soils in regulation of freshwater and coastal water quality.
Cheng, K, Xu, X, Cui, L, Li, Y, Zheng, J, Wu, W, Sun, J, Pan, G
Philosophical transactions of the Royal Society of London. Series B, Biological sciences. 2021;(1834):20200176
-
-
Free full text
-
Abstract
Water quality regulation is an important ecosystem service function of soil. In this study, the mechanism by which soil regulates water quality was reviewed, and the effects of soil management on water quality were explored. A scientometrics analysis was also conducted to explore the research fields and hotspots of water quality regulation of soil in the past 5 years. This review found that the pollutants entering the soil can be mitigated by precipitation, adsorption and desorption, ion exchange, redox and metabolic decomposition. As an optimal substrate, soil in constructed wetlands has perfect performance in the adsorption and passivation of pollutants such as nitrogen, phosphorus and heavy metals in water, and degradation of pesticides and emerging contaminants. Mangrove wetlands play an important role in coastal zone protection and coastal water quality restoration. However, the excessive application of agricultural chemicals causes soil overload, which leads to the occurrence of agricultural non-point source pollution. Under the dual pressures of climate change and food insecurity in the future, developing environmentally friendly and economically feasible sustainable soil management measures is crucial for maintaining the water purification function of soil by relying on the accurate quantification of soil function based on big data and modelling. This article is part of the theme issue 'The role of soils in delivering Nature's Contributions to People'.
-
5.
Linking plant and soil indices for water stress management in black gram.
Khorsand, A, Rezaverdinejad, V, Asgarzadeh, H, Majnooni-Heris, A, Rahimi, A, Besharat, S, Sadraddini, AA
Scientific reports. 2021;(1):869
Abstract
Measurement of plant and soil indices as well as their combinations are generally used for irrigation scheduling and water stress management of crops and horticulture. Rapid and accurate determination of irrigation time is one of the most important issues of sustainable water management in order to prevent plant water stress. The objectives of this study are to develop baselines and provide irrigation scheduling relationships during different stages of black gram growth, determine the critical limits of plant and soil indices, and also determine the relationships between plant physiology and soil indices. This study was conducted in a randomized complete block design at the four irrigation levels 50 (I1), 75 (I2), 100 (I3 or non-stress treatment) and 125 (I4) percent of crop's water requirement with three replications in Urmia region in Iran in order to irrigation scheduling of black gram using indices such as canopy temperature (Tc), crop water stress index (CWSI), relative water content (RWC), leaf water potential (LWP), soil water (SW) and penetration resistance (Q) of soil under one-row drip irrigation. The plant irrigation scheduling was performed by using the experimental crop water stress index (CWSI) method. The upper and lower baseline equations as well as CWSI were calculated for the three treatments of I1, I2 and I3 during the plant growth period. Using the extracted baselines, the mean CWSI values for the three treatments of I1, I2 and I3 were calculated to be 0.37, 0.23 and 0.15, respectively, during the growth season. Finally, using CWSI, the necessary equations were provided to determine the irrigation schedule for the four growing stages of black gram, i.e. floral induction-flowering, pod formation, seed and pod filling and physiological maturity, as (Tc - Ta)c = 1.9498 - 0.1579(AVPD), (Tc - Ta)c = 4.4395 - 0.1585(AVPD), (Tc - Ta)c = 2.4676 - 0.0578(AVPD) and (Tc - Ta)c = 5.7532 - 0.1462(AVPD), respectively. In this study, soil and crop indices, which were measured simultaneously at maximum stress time, were used as a complementary index to remove CWSI constraints. It should be noted that in Urmia, the critical difference between the canopy temperature and air temperature (Tc - Ta), soil penetration resistance (Q), soil water (SW) and relative water content (RWC) for the whole growth period of black gram were - 0.036 °C, 10.43 MPa and 0.14 cm3 cm-3 and 0.76, respectively. Ideal point error (IPE) was also used to estimate RWC, (Tc - Ta) and LWP as well as to select the best regression model. According to the results, black gram would reduce its RWC less through reducing its transpiration and water management. Therefore, it can be used as a low-water-consuming crop. Furthermore, in light of available facilities, the farmer can use the regression equations between the obtained soil and plant indices and the critical boundaries for the irrigation scheduling of the field.
-
6.
Soil enzyme responses to land use change in the tropical rainforest of the Colombian Amazon region.
Silva-Olaya, AM, Mora-Motta, DA, Cherubin, MR, Grados, D, Somenahally, A, Ortiz-Morea, FA
PloS one. 2021;(8):e0255669
Abstract
Soil enzymes mediate key processes and functions of the soils, such as organic matter decomposition and nutrient cycling in both natural and agricultural ecosystems. Here, we studied the activity of five extracellular soil enzymes involved in the C, N, and P-mineralizing process in both litter and surface soil layer of rainforest in the northwest region of the Colombian Amazon and the response of those soil enzymes to land use change. The experimental study design included six study sites for comparing long-term pasture systems to native forest and regeneration practices after pasture, within the main landscapes of the region, mountain and hill landscapes separately. Results showed considerable enzymatic activity in the litter layer of the forest, highlighting the vital role of this compartment in the nutrient cycling of low fertility soils from tropical regions. With the land use transition to pastures, changes in soil enzymatic activities were driven by the management of pastures, with SOC and N losses and reduced absolute activity of soil enzymes in long-term pastures under continuous grazing (25 years). However, the enzyme activities expressed per unit of SOC did not show changes in C and N-acquiring enzymes, suggesting a higher mineralization potential in pastures. Enzymatic stoichiometry analysis indicated a microbial P limitation that could lead to a high catabolic activity with a potential increase in the use of SOC by microbial communities in the search for P, thus affecting soil C sequestration, soil quality and the provision of soil-related ecosystem services.
-
7.
Sulfur fertility management to enhance methionine and cysteine in soybeans.
Rushovich, D, Weil, R
Journal of the science of food and agriculture. 2021;(15):6595-6601
Abstract
BACKGROUND Soybeans (Glycine max) are a major protein source both for humans and non-ruminant livestock; however, the usability of soybean protein is limited by the concentration of the essential sulfur (S)-containing amino acids methionine and cysteine (MET+CYS). Traditional efforts to improve protein quality in soybeans have largely been focused on plant breeding but soil S fertility may also influence seed MET+CYS concentration. Crop S deficiencies are increasingly common due to soil depletion by high yields and reduced atmospheric deposition. We report on a survey of commercial soybean fields and two replicated split-plot field experiments in the mid-Atlantic region, USA. The experimental treatments were two levels (0 or 100 kg S ha-1 ) of broadcast gypsum (CaSO4 ) and two levels (0 or 11 kg-S ha-1 ) of foliar Epsom salt (MgSO4 ) applied to two soybean cultivars. The objective was to assess the variability of, and effect of, S fertilization on S and MET+CYS concentrations in soybean seeds. RESULTS Sulfur ranged from 2.35 to 3.54 mg g-1 and MET+CYS ranged from 5.5 to 9.2 mg g-1 protein in seeds from commercial fields surveyed. Sulfur application increased seed MET+CYS concentration 1.3 to twofold in two replicated field experiments. Overall, MET+CYS concentration in protein ranged from 3.9 to 12.8 mg g-1 and was linearly predicted (R2 = 0.65) by seed S. CONCLUSIONS Soybean seed S and MET+CYS concentrations vary widely. We show that field-scale S application can greatly enhance soybean MET+CYS content and therefore protein quality. © 2021 Society of Chemical Industry.
-
8.
Novel sulphur-oxidizing bacteria consummate sulphur deficiency in oil seed crop.
Joshi, N, Gothalwal, R, Singh, M, Dave, K
Archives of microbiology. 2021;(1):1-6
Abstract
Plants absorb sulphate, the oxidized form of elemental sulphur (S°), from soil. Sulphur-oxidizing bacteria play a key role in transformation of sulphur in soil. Oil seed crops require high amount of sulphur and it plays an important role in the formation of proteins, vitamins and enzymes. It increases yield, oil content and protein content in oil seed crops. Sulphur is the important constituent of amino acids, viz. methionine, cystine, and cysteine. It necessitates various enzymatic, metabolic processes such as photosynthesis and nitrogen fixation. In the last few years, the prominence of sulphur in oil seed crop nutrition has been accepted as widespread occurrence of its inadequacy in agricultural soil. Approximately 41% of Indian soil is deficient in sulphur. The soil microbial population is the major enforcement behind sulphur transformation. They mineralize, immobilize, oxidize and reduce the elemental and other reduced forms of sulphur. The main step in transformation is oxidation carried out by microorganisms to convert sulphur into sulphate. The chemolithotrophic bacteria belonging to genus Thiobacillus are of primary importance; there are heterotrophic bacteria also which can oxidize sulphur in soil. The pH reduction at the time of oxidation helps in mineralization and absorption of other essential nutrients also. This property of sulphur-oxidizing bacteria (SOB) shows their potential to be used as bioinoculants. Bioformulations prepared using carrier-based formulations, immobilization, biostimulation, etc., are sustainable forms of fertilizers. These SOB inoculants can be used to increase the fertility and sulphate production in soil.
-
9.
Molecular Mechanism of Lipid Accumulation and Metabolism of Oleaginous Chlorococcum sphacosum GD from Soil under Salt Stress.
Su, H, Feng, J, Lv, J, Liu, Q, Nan, F, Liu, X, Xie, S
International journal of molecular sciences. 2021;(3)
Abstract
The oleaginous microalgae species Chlorococcum sphacosum GD is a promising feedstock for biodiesel production from soil. However, its metabolic mechanism of lipid production remains unclear. In this study, the lipid accumulation and metabolism mechanisms of Chlorococcum sphacosum GD were analyzed under salt stress based on transcriptome sequencing. The biomass and lipid content of the alga strain were determined under different NaCl concentrations, and total RNA from fresh cells were isolated and sequenced by HiSeq 2000 high throughput sequencing technology. As the salt concentration increased in culture medium, the algal lipid content increased but the biomass decreased. Following transcriptome sequencing by assembly and splicing, 24,128 unigenes were annotated, with read lengths mostly distributed in the 200-300 bp interval. Statistically significant differentially expressed unigenes were observed in different experimental groups, with 2051 up-regulated genes and 1835 down-regulated genes. The lipid metabolism pathway analysis showed that, under salt stress, gene-related fatty acid biosynthesis (ACCase, KASII, KAR, HAD, FATA) was significantly up-regulated, but some gene-related fatty acid degradation was significantly down-regulated. The comprehensive results showed that salt concentration can affect the lipid accumulation and metabolism of C. sphacosum GD, and the lipid accumulation is closely related to the fatty acid synthesis pathway.
-
10.
Unraveling the role of plant growth-promoting rhizobacteria in the alleviation of arsenic phytotoxicity: A review.
Mondal, S, Pramanik, K, Ghosh, SK, Pal, P, Mondal, T, Soren, T, Maiti, TK
Microbiological research. 2021;:126809
Abstract
The toxic metalloid arsenic (As), is a major pollutant of soil and water, imposing severe health concerns on human lives. It enters the food chain mainly through As-contaminated crops. The uptake, translocation and accumulation of As in plant tissue are often controlled by certain soil-inhabiting microbial communities. Among them, indigenous, free-living As-resistant plant growth-promoting rhizobacteria (PGPR) plays a pivotal role in As-immobilization. Besides, the plant's inability to withstand As after a threshold level is actively managed by these PGPR increasing As-tolerance in host plants by a synergistic plant-microbe interaction. The dual functionality of As-resistant PGPR i.e., phytostimulation and minimization of As-induced phytotoxic damages are one of the main focal points of this review article. It is known that such PGPR having the functional arsenic-resistant genes (in ars operon) including As-transporters, As-transforming genes contributed to the As accumulation and detoxification/transformation respectively. Apart from assisting in nutrient acquisition and modulating phytohormone levels, As-resistant PGPR also influences the antioxidative defense system in plants by maneuvering multiple enzymatic and non-enzymatic antioxidants. Furthermore, they are effective in reducing membrane damage and electrolyte leakage in plant cells. As-induced photosynthetic damage is also found to be salvaged by As-resistant PGPR. Briefly, the eco-physiological, biochemical and molecular mechanisms of As-resistant PGPR are thus elaborated here with regard to the As-exposed crops.