Soil fertility interactions with Sinorhizobium-legume symbiosis in a simulated Martian regolith; effects on nitrogen content and plant health

Due to increasing population growth and declining arable land on Earth, astroagriculture will be vital to terraform Martian regolith for settlement. Nodulating plants and their N-fixing symbionts may play a role in increasing Martian soil fertility. On Earth, clover (Melilotus officinalis) forms a symbiotic relationship with the N-fixing bacteria Sinorhizobium meliloti; clover has been previously grown in simulated regolith yet without bacterial inoculation. In this study, we inoculated clover with S. meliloti grown in potting soil and regolith to test the hypothesis that plants grown in regolith can form the same symbiotic associations as in soils and to determine if greater plant biomass occurs in the presence of S. meliloti regardless of growth media. We also examined soil NH4 concentrations to evaluate soil augmentation properties of nodulating plants and symbionts. Greater biomass occurred in inoculated compared to uninoculated groups; the inoculated average biomass in potting mix and regolith (2.23 and 0.29 g, respectively) was greater than the uninoculated group (0.11 and 0.01 g, respectively). However, no significant differences existed in NH4 composition between potting mix and regolith simulant. Linear regression analysis results showed that: i) symbiotic plant-bacteria relationships differed between regolith and potting mix, with plant biomass positively correlated to regolith-bacteria interactions; and, ii) NH4 production was limited to plant uptake yet the relationships in regolith and potting mix were similar. It is promising that plant-legume symbiosis is a possibility for Martian soil colonization.

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Strategies for Soil Fertility Improvement of Arable Land in China

Chinese Journal of Engineering Science ◽

10.15302/j-sscae-2018.05.013 ◽

2018 ◽

Vol 20 (5) ◽

pp. 84

Author(s):

Yingjie Hu ◽

Xiangbin Kong ◽

Yuzhen Zhang

Keyword(s):

Soil Fertility ◽

Arable Land ◽

Soil Fertility Improvement

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APPLICATION OF THE INTENSIVE CROP GROWING TECHNOLOGIES IN CROP ROTATION IS THE STABILITY CONDITION OF THE HUMUS CONTENT OF SOIL

Vestnik of the Russian agricultural science ◽

10.30850/vrsn/2018/3/52-56 ◽

1970 ◽

pp. 52-56

Author(s):

V. А. Shchedrin

Keyword(s):

Soil Fertility ◽

Crop Rotation ◽

Humus Content ◽

Arable Land ◽

Weighted Average ◽

Cropping System ◽

Investment Project ◽

Crop Rotations ◽

High Productivity ◽

Labile Phosphorus

In OOO “Dubovitskoe” which was organized in 2006 as investment project of the AO “Shchelkovo Agrokhim” for 2010 – 2012 three advanced crop rotations have been developed. Before their introduction the grain crops fraction in the cropping system was 62%, then it fell to 49%. At the same time the portion of raw crops increased from 15 to 20%, legumes from 6 to 8%, others (buckwheat, grain maize, etc.) - up to 23%. As of 2017, the crops of leguminous crops have increased noteworthily. There are two predominant soil types here heavy clay loam podzolized chernozem (6615 ha) and grey forest soil (856 ha). Weighted average indicators (as of 2017): humus content in the soils of arable land is 5, 34%; acidity pH is 4.92; labile phosphorus - 111.8 mg / kg soil; exchange potassium - 144 mg / kg soil. The coefficient of the soil fertility in the enterprise (weighted average) is 0.66. This means that maintaining and increasing the soil fertility for arable land of the enterprise is critical task. As a result of the research, it has been established that the technologies introduced in the crop vegetation management (CVS) in the crop rotation conditions ensure high productivity of cultivated crops and stability of humus content in soils as an energy basis and a guarantor of increasing fertility. The indicators of the labile phosphorus Р205 and exchange potassium К20 in the soils depending on the crop rotation vary from a certain decrease to expressed steady growth. Therefore it is necessary to specify seeding rates based on actual data. Sustainable soil acidification in the crop rotations under crop cultivation in OOO “Dubovitskoe” it is the result of the acid feterlizers high rates application, during studying period did not carried out required agromelioration with calcium contenting elements.

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Inoculation with Efficient Nitrogen Fixing and Indoleacetic Acid Producing Bacterial Microsymbiont Enhance Tolerance of the Model LegumeMedicago truncatulato Iron Deficiency

BioMed Research International ◽

10.1155/2018/9134716 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 5

Author(s):

Nadia Kallala ◽

Wissal M’sehli ◽

Karima Jelali ◽

Zribi Kais ◽

Haythem Mhadhbi

Keyword(s):

Oxidative Stress ◽

Iron Deficiency ◽

Medicago Truncatula ◽

Sinorhizobium Meliloti ◽

Plant Biomass ◽

High Growth ◽

Fe Deficiency ◽

Nitrogen Fixing ◽

Bacterial Strains ◽

Negative Effect

The aim of this study was to assess the effect of symbiotic bacteria inoculation on the response ofMedicago truncatulagenotypes to iron deficiency. The present work was conducted on threeMedicago truncatulagenotypes: A17, TN8.20, and TN1.11. Three treatments were performed: control (C), direct Fe deficiency (DD), and induced Fe deficiency by bicarbonate (ID). Plants were nitrogen-fertilized (T) or inoculated with two bacterial strains:Sinorhizobium melilotiTII7 andSinorhizobium medicaeSII4. Biometric, physiological, and biochemical parameters were analyzed. Iron deficiency had a significant lowering effect on plant biomass and chlorophyll content in allMedicago truncatulagenotypes. TN1.11 showed the highest lipid peroxidation and leakage of electrolyte under iron deficiency conditions, which suggest that TN1.11 was more affected than A17 and TN8.20 by Fe starvation. Iron deficiency affected symbiotic performance indices of allMedicago truncatulagenotypes inoculated with bothSinorhizobiumstrains, mainly nodules number and biomass as well as nitrogen-fixing capacity. Nevertheless, inoculation withSinorhizobiumstrains mitigates the negative effect of Fe deficiency on plant growth and oxidative stress compared to nitrogen-fertilized plants. The highest auxin producing strain, TII7, preserves relatively high growth and root biomass and length when inoculated to TN8.20 and A17. On the other hand, both TII7 and SII4 strains improve the performance of sensitive genotype TN1.11 through reduction of the negative effect of iron deficiency on chlorophyll and plant Fe content. The bacterial inoculation improved Fe-deficient plant response to oxidative stress via the induction of the activities of antioxidant enzymes.

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Basic principles of reclaimed agricultural landscapes sustainability formation

Ecology and water management ◽

10.31774/2658-7890-2021-3-1-1-10 ◽

2021 ◽

Author(s):

S. M. Vasilyev ◽

◽

A. N. Babichev ◽

Keyword(s):

Soil Fertility ◽

Natural Environment ◽

Agricultural Landscape ◽

Agricultural Land ◽

Arable Land ◽

Agricultural Landscapes ◽

Forest Steppe ◽

Basic Principles ◽

Moisture Supply ◽

Irrigated Lands

Purpose: to establish the basic principles of the organization of reclamed agricultural landscapes and to substantiate the use of the agricultural landscape approach in the organization of the territory. Materials and Methods. When preparing this article, the materials of Russian scientists dealing with the issues of soil fertility conservation and ecological sustainability of reclaimed agricultural landscapes were considered. The methods used were analysis, generalization, synthesis and other methods of working with literary sources on this issue. Results. In performing the work, the main principles and indicators were determined, such as productivity, sustainability, the rule of transforming measures for the natural environment, optimization of the agricultural landscape, authenticity, principles of the formation of reclaimed agricultural landscapes, the complexity of the reclamation impact, the required diversity, the uniqueness of the reclamation impact. The basic requirements for the preservation of soil fertility of reclaimed irrigated agricultural landscape have been established. It was found that to maintain ecological balance within the irrigated agricultural landscape, it is necessary to adhere to the indicators of the reclamation load of the natural environment. The limits of agricultural lands saturation in reclaimed agricultural landscapes for various agro-climatic zones have been substantiated and recommended. Conclusions. It has been determined that the coefficient of reclamation loading of irrigated lands, showing the maximum share of irrigated lands that can be irrigated in a particular climatic zone, varies from 0.3 in the forest-steppe zone to 0.60–0.85 in the semi-desert and desert zone. This suggests that with an increase in moisture supply, this indicator decreases, the recommended amount of agricultural land in various agroclimatic zones varies from 30 to 87 %, while the area of arable land should not exceed 20–25 % in a very dry zone, and with an increase in moisture supply, it can increase up to 80 % in the semi-arid zone. The amount of irrigated land in the reclaimed agricultural landscape should not exceed 18–20 %. Irrigated meadows and pastures should account for 1–2 to 5–6 % of the area.

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A Sinorhizobium meliloti Lipopolysaccharide Mutant Altered in Cell Surface Sulfation

Journal of Bacteriology ◽

10.1128/jb.184.23.6681-6689.2002 ◽

2002 ◽

Vol 184 (23) ◽

pp. 6681-6689 ◽

Cited By ~ 31

Author(s):

David H. Keating ◽

Michael G. Willits ◽

Sharon R. Long

Keyword(s):

Cell Surface ◽

Sinorhizobium Meliloti ◽

Glucuronic Acid ◽

Initial Study ◽

Nodule Development ◽

Nod Factor ◽

Legume Symbiosis ◽

Surface Polysaccharides

ABSTRACT The Rhizobium-legume symbiosis involves the formation of a novel plant organ, the nodule, in which intracellular bacteria reduce molecular dinitrogen in exchange for plant photosynthates. Nodule development requires a bacterial signal referred to as Nod factor, which in Sinorhizobium meliloti is a β-(1,4)-linked tetramer of N-acetylglucosamine containing N-acyl and O-acetyl modifications at the nonreducing end and a critical 6-O-sulfate at the reducing end. This sulfate modification requires the action of three gene products: nodH, which catalyzes the sulfonyl transfer, and nodPQ, which produce the activated form of sulfate, 3′-phosphoadenosine-5′-phosphosulfate. It was previously reported that S. meliloti cell surface polysaccharides are also covalently modified by sulfate in a reaction dependent on NodPQ. We have further characterized this unique form of bacterial carbohydrate modification. Our studies have determined that one of the nodPQ mutant strains used in the initial study of sulfation of cell surface harbored a second unlinked mutation. We cloned the gene affected by this mutation (referred to as lps-212) and found it to be an allele of lpsL, a gene previously predicted to encode a UDP-glucuronic acid epimerase. We demonstrated that lpsL encoded a UDP-glucuronic acid epimerase activity that was reduced in the lps-212 mutant. The lps-212 mutation resulted in an altered lipopolysaccharide structure that was reduced in sulfate modification in vitro and in vivo. Finally, we determined that the lps-212 mutation resulted in a reduced ability to elicit the formation of plant nodules and by altered infection thread structures that aborted prematurely.

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Important Late-Stage Symbiotic Role of theSinorhizobium melilotiExopolysaccharide Succinoglycan

Journal of Bacteriology ◽

10.1128/jb.00665-17 ◽

2018 ◽

Vol 200 (13) ◽

pp. e00665-17 ◽

Cited By ~ 10

Author(s):

Markus F. F. Arnold ◽

Jon Penterman ◽

Mohammed Shabab ◽

Esther J. Chen ◽

Graham C. Walker

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Late Stage ◽

Sinorhizobium Meliloti ◽

Antimicrobial Action ◽

Protective Function ◽

Content Type ◽

Early Stages ◽

Symbiotic Interactions ◽

Legume Symbiosis

ABSTRACTSinorhizobium melilotienters into beneficial symbiotic interactions withMedicagospecies of legumes. Bacterial exopolysaccharides play critical signaling roles in infection thread initiation and growth during the early stages of root nodule formation. After endocytosis ofS. melilotiby plant cells in the developing nodule, plant-derived nodule-specific cysteine-rich (NCR) peptides mediate terminal differentiation of the bacteria into nitrogen-fixing bacteroids. Previous transcriptional studies showed that the intensively studied cationic peptide NCR247 induces expression of theexogenes that encode the proteins required for succinoglycan biosynthesis. In addition, genetic studies have shown that someexomutants exhibit increased sensitivity to the antimicrobial action of NCR247. Therefore, we investigated whether the symbiotically activeS. melilotiexopolysaccharide succinoglycan can protectS. melilotiagainst the antimicrobial activity of NCR247. We discovered that high-molecular-weight forms of succinoglycan have the ability to protectS. melilotifrom the antimicrobial action of the NCR247 peptide but low-molecular-weight forms of wild-type succinoglycan do not. The protective function of high-molecular-weight succinoglycan occurs via direct molecular interactions between anionic succinoglycan and the cationic NCR247 peptide, but this interaction is not chiral. Taken together, our observations suggest thatS. melilotiexopolysaccharides not only may be critical during early stages of nodule invasion but also are upregulated at a late stage of symbiosis to protect bacteria against the bactericidal action of cationic NCR peptides. Our findings represent an important step forward in fully understanding the complete set of exopolysaccharide functions during legume symbiosis.IMPORTANCESymbiotic interactions between rhizobia and legumes are economically important for global food production. The legume symbiosis also is a major part of the global nitrogen cycle and is an ideal model system to study host-microbe interactions. Signaling between legumes and rhizobia is essential to establish symbiosis, and understanding these signals is a major goal in the field. Exopolysaccharides are important in the symbiotic context because they are essential signaling molecules during early-stage symbiosis. In this study, we provide evidence suggesting that theSinorhizobium melilotiexopolysaccharide succinoglycan also protects the bacteria against the antimicrobial action of essential late-stage symbiosis plant peptides.

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