The fungal endophyteFusarium solaniprovokes differential effects on the energy balance of twoLotusspecies

2019 ◽  
Author(s):  
Amira S. Nieva ◽  
Juan M. Vilas ◽  
Andrés Gárriz ◽  
Santiago J. Maiale ◽  
Ana B. Menéndez ◽  
...  

AbstractBackground and aimsThe interactions established between plants and endophytic fungi span acontinuumfrom beneficial to pathogenic associations. The aim of this work was to explore the mechanisms underlying the potentially beneficial effects provoked by a fungal strain in legume species of the genusLotus.MethodsThe ability to solubilise phosphorous was evaluated in nine fungal strains isolated from roots ofL. tenuis. A selected strain was further assessed for its ability to colonize plant roots in differentLotusspecies. The effects of the two interactions were assessed by analysis of the photosynthesis, sugar amount, and macronutrient status of leaves and roots.ResultsA fungal isolate identified asFusarium solanishows the highest phosphate-solubilisation activity and grows endophytically in roots ofL. japonicusandL. tenuis. Fungal invasion enhances plant growth inL. japonicusbut provokes a contrasting effect inL. tenuis. Photosynthesis, sugars and K content showed a differential effect in both plant species.ConclusionsOur results indicate neither of the plant species evaluated in this work were significantly stressed byF. solani. Thus, the differential responses observed are due to distinct mechanisms involving photosynthesis, potassium homeostasis, and carbohydrate metabolism that are employed by plants to maintain fitness during the endophytic interaction.

2009 ◽  
Vol 57 (1) ◽  
pp. 57-65
Author(s):  
R. Thamizh Vendan ◽  
M. Thangaraju

The nitrogen-fixing rhizobacterium Azospirillum lives in close association with plant roots, where it exerts beneficial effects on the plant growth and yield of many crops of agronomic importance. As carrier-based inoculants have a short shelf life and poor quality, new liquid and cyst formulations of inoculants have been developed and standardized for Azospirillum . In the present investigation, experiments were conducted to study the effect of liquid and cyst formulations of Azospirillum , combined with inorganic nitrogen, on the growth and yield of rice. Inoculation with the cyst formulation of Azospirillum enhanced the plant height, biomass and N uptake of the plants, the available nitrogen content of the soil and the yield of rice to the greatest extent when compared to carrier-based Azospirillum , followed by the liquid formulation. The results of the present study clearly indicated that the cyst and liquid formulations of Azospirillum could be used as bioinoculants more effectively than the carrier-based one.


2021 ◽  
Author(s):  
Christopher Blake ◽  
Mathilde Nordgaard Christensen ◽  
Gergely Maróti ◽  
Ákos T. Kovács

SummaryThe soil bacterium Bacillus subtilis is known to suppress pathogens as well as promote plant growth. However, in order to fully exploit the potential as natural fertilizer, we need a better understanding of the interactions between B. subtilis and plants. Here, B. subtilis was examined for root colonization through experimental evolution on Arabidopsis thaliana. The populations evolved rapidly, improved in root colonization and diversified into three distinct morphotypes. In order to better understand the adaptation that had taken place, single evolved isolates from the final transfer were randomly selected for further characterization, revealing changes in growth and pellicle formation in medium supplemented with plant polysaccharides. Intriguingly, certain evolved isolates showed improved root colonization only on the plant species they evolved on, but not on another plant species, namely tomato, suggesting A. thaliana specific adaption paths. Finally, synergism in plant root colonization was observed for a mix of all three morphotypes, as the mix performed better than the sum of its constituents in monoculture. Our results suggest, that genetic diversification occurs in an ecological relevant setting on plant roots and proves to be a stable strategy for root colonization.Significance StatementUnderstanding how plant-growth-promoting rhizobacteria colonize plant roots is crucial to fully utilize their potential for agricultural applications. Here, we utilized experimental evolution of the PGPR Bacillus subtilis on Arabidopsis thaliana to study root colonization. We revealed that evolving populations rapidly improve in root colonization and diversify into distinct morphotypes. Notably, improved root colonization by evolved isolates was observed on A. thaliana, not on tomato. Moreover, isolates of distinct morphotypes interacted during root colonization and the mixture of morphotypes showed higher productivity then predicted. These findings suggest that genetic diversification might be a stable strategy to maximize root colonization.


2021 ◽  
Vol 43 (4) ◽  
Author(s):  
Agnieszka Ostrowska ◽  
Maciej T. Grzesiak ◽  
Tomasz Hura

AbstractSoil drought is a major problem in plant cultivation. This is particularly true for thermophilic plants, such as maize, which grow in areas often affected by precipitation shortage. The problem may be alleviated using plant growth and development stimulators. Therefore, the aim of the study was to analyze the effects of 5-aminolevulinic acid (5-ALA), zearalenone (ZEN), triacontanol (TRIA) and silicon (Si) on water management and photosynthetic activity of maize under soil drought. The experiments covered three developmental stages: three leaves, stem elongation and heading. The impact of these substances applied during drought stress depended on the plant development stage. 5-ALA affected chlorophyll levels, gas exchange and photochemical activity of PSII. Similar effects were observed for ZEN, which additionally induced stem elongation and limited dehydration. Beneficial effects of TRIA were visible at the stage of three leaves and involved leaf hydration and plant growth. A silicon preparation applied at the same developmental stage triggered similar effects and additionally induced changes in chlorophyll levels. All the stimulators significantly affected transpiration intensity at the heading stage.


Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 222
Author(s):  
Kenji Yamane ◽  
Yuuki Kimura ◽  
Keita Takahashi ◽  
Isamu Maeda ◽  
Masayuki Iigo ◽  
...  

Aquaponics is a circulating and sustainable system that combines aquaculture and hydroponics and forms a symbiotic relationship between fish, plants, and microorganisms. We hypothesized that feed alone could support plant growth, but the symbiosis with fish adds some beneficial effects on plant growth in aquaponics. In this study, we created three closed culture systems, namely, aquaponics, hydroponics without nitrogen (N) and phosphorus (P), and aquaculture, and added the same amount of feed containing N and P to all the treatments in order to test the hypothesis. Accumulation of NO3− and PO43− was alleviated in aquaponics and hydroponics as a result of plant uptake. Lettuce plants grown in aquaponics grew vigorously until 2 weeks and contained a constant level of N in plants throughout the production period, whereas those in hydroponics grew slowly in the early stage and then vigorously after 2 weeks with a late increment of N concentration. These results suggest that catfish help with the faster decomposition of the feed, but, in hydroponics, feed can be slowly dissolved and decomposed owing to the absence of the fish. The bacterial community structures of the culture solution were investigated using 16S rRNA gene amplicon sequencing. At the class level, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria were the major microbial groups in the solutions. Aquaponics prevented the pollution of tank solution and maintained a higher water quality compared with hydroponics and aquaculture, suggesting that aquaponics is a more sustainable cultivation system even in a small-scale system.


Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 337
Author(s):  
Sergio de los Santos-Villalobos ◽  
Alondra María Díaz-Rodríguez ◽  
María Fernanda Ávila-Mascareño ◽  
Andrea Denisse Martínez-Vidales ◽  
Fannie Isela Parra-Cota

COLMENA is a microbial culture collection dedicated to the characterization, classification, preservation, and transferal of native microorganisms isolated from various agro-systems and other ecosystems in Mexico. This collection aims to protect microbial diversity, reducing soil degradation, but also exploiting its agro-biotechnological potential. So far, COLMENA has isolated and cryopreserved soil microorganisms from different crops in two major agricultural regions in Mexico, the Yaqui Valley, Sonora, and the Fuerte Valley, Sinaloa. COLMENA has specialized in the identification and characterization of microbial strains with metabolic capacities related to the promotion of plant growth and the biocontrol of phytopathogens. Thus, COLMENA has identified several promising plant growth-promoting microbial (PGPM) strains due to their metabolic and genetic potentials and their beneficial effects in vivo and field trials. These findings demonstrate the biotechnological potential of these strains for their future use in profitable agricultural alternatives focused on enhancing global food security. To share the knowledge and results of the COLMENA team’s scientific research, a virtual platform was created, where the database of the studied and preserved microorganisms is available to professionals, researchers, agricultural workers, and anyone who is interested.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 321
Author(s):  
Hazem S. Elshafie ◽  
Ippolito Camele

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.


Endocrinology ◽  
2021 ◽  
Author(s):  
Katharina Schnabl ◽  
Yongguo Li ◽  
Mueez U-Din ◽  
Martin Klingenspor

Abstract The obesity pandemic requires effective preventative and therapeutic intervention strategies. Successful and sustained obesity treatment is currently limited to bariatric surgery. Modulating the release of gut hormones is considered promising to mimic bariatric surgery with its beneficial effects on food intake, body weight and blood glucose levels. The gut peptide secretin was the first molecule to be termed a hormone; nevertheless, it only recently has been established as a legitimate anorexigenic peptide. In contrast to gut hormones that crosstalk with the brain either directly or by afferent neuronal projections, secretin mediates meal-associated brown fat thermogenesis to induce meal termination, thereby qualifying this physiological mechanism as an attractive, peripheral target for the treatment of obesity. In this perspective, it is of pivotal interest to deepen our yet superficial knowledge on the physiological roles of secretin as well as meal-associated thermogenesis in energy balance and body weight regulation. Of note, the emerging differences between meal-associated thermogenesis and cold-induced thermogenesis must be taken into account. In fact, there is no correlation between these two entities. In addition, the investigation of potential effects of secretin in hedonic-driven food intake, bariatric surgery as well as chronic treatment using suitable application strategies to overcome pharmacokinetic limitations will provide further insight into its potential to influence energy balance. The aim of this article is to review the facts on secretin’s metabolic effects, address prevailing gaps in our knowledge, and provide an overview on the opportunities and challenges of the therapeutic potential of secretin in body weight control.


Author(s):  
Aditi Sengupta ◽  
Priyanka Kushwaha ◽  
Antonia Jim ◽  
Peter A. Troch ◽  
Raina Maier

The plant-microbe-soil nexus is critical in maintaining biogeochemical balance of the biosphere. However, soil loss and land degradation are occurring at alarmingly high rates, with soil loss exceeding soil formation rates. This necessitates evaluating marginal soils for their capacity to support and sustain plant growth. In a greenhouse study, we evaluated the capacity of marginal incipient basaltic parent material to support native plant growth, and the associated variation in soil microbial community dynamics. Three plant species, native to the Southwestern Arizona-Sonora region were tested with three soil treatments including basaltic parent material, parent material amended with 20% compost, and potting soil. The parent material with and without compost supported germination and growth of all the plant species, though germination was lower than the potting soil. A 16S rRNA amplicon sequencing approach showed Proteobacteria to be the most abundant phyla in both parent material and potting soil, followed by Actinobacteria. Microbial community composition had strong correlations with soil characteristics but not plant attributes within a given soil material. Predictive functional potential capacity of the communities revealed chemoheterotrophy as the most abundant metabolism within the parent material, while photoheterotrophy and anoxygenic photoautotrophy were prevalent in the potting soil. These results show that marginal incipient basaltic soil has the ability to support native plant species growth, and non-linear associations may exist between plant-marginal soil-microbial interactions.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10053
Author(s):  
Fernando Carlos Gómez-Merino ◽  
Libia Iris Trejo-Téllez ◽  
Atonaltzin García-Jiménez ◽  
Hugo Fernando Escobar-Sepúlveda ◽  
Sara Monzerrat Ramírez-Olvera

Background Silicon (Si) is categorized as a quasi-essential element for plants thanks to the benefits on growth, development and metabolism in a hormetic manner. Si uptake is cooperatively mediated by Lsi1 and Lsi2. Nevertheless, Lsi channels have not yet been identified and characterized in pepper (Capsicum annuum), while genes involved in major physiological processes in pepper are Si-regulated. Furthermore, Si and phytohormones may act together in regulating plant growth, metabolism and tolerance against stress. Our aim was to identify potential synergies between Si and phytohormones stimulating growth and metabolism in pepper, based on in silico data. Methods We established a hydroponic system to test the effect of Si (0, 60, 125 and 250 mg L−1 Si) on the concentrations of this element in different pepper plant tissues. We also performed an in silico analysis of putative Lsi genes from pepper and other species, including tomato (Solanum lycopersicum), potato (Solanum tuberosum) and Arabidopsis thaliana, to look for cis-acting elements responsive to phytohormones in their promoter regions. With the Lsi1 and Lsi2 protein sequences from various plant species, we performed a phylogenetic analysis. Taking into consideration the Lsi genes retrieved from tomato, potato and Arabidopsis, an expression profiling analysis in different plant tissues was carried out. Expression of Si-regulated genes was also analyzed in response to phytohormones and different plant tissues and developmental stages in Arabidopsis. Results Si concentrations in plant tissues exhibited the following gradient: roots > stems > leaves. We were able to identify 16 Lsi1 and three Lsi2 genes in silico in the pepper genome, while putative Lsi homologs were also found in other plant species. They were mainly expressed in root tissues in the genomes analyzed. Both Lsi and Si-regulated genes displayed cis-acting elements responsive to diverse phytohormones. In Arabidopsis, Si-regulated genes were transcriptionally active in most tissues analyzed, though at different expressed levels. From the set of Si-responsive genes, the NOCS2 gene was highly expressed in germinated seeds, whereas RABH1B, and RBCS-1A, were moderately expressed in developed flowers. All genes analyzed showed responsiveness to phytohormones and phytohormone precursors. Conclusion Pepper root cells are capable of absorbing Si, but small amounts of this element are transported to the upper parts of the plant. We could identify putative Si influx (Lsi1) and efflux (Lsi2) channels that potentially participate in the absorption and transport of Si, since they are mainly expressed in roots. Both Lsi and Si-regulated genes exhibit cis-regulatory elements in their promoter regions, which are involved in phytohormone responses, pointing to a potential connection among Si, phytohormones, plant growth, and other vital physiological processes triggered by Si in pepper.


HortScience ◽  
2013 ◽  
Vol 48 (10) ◽  
pp. 1327-1333 ◽  
Author(s):  
Maria Papafotiou ◽  
Niki Pergialioti ◽  
Lamprini Tassoula ◽  
Ioannis Massas ◽  
Georgios Kargas

Green roofs could be a way to increase vegetation in the center of old Mediterranean cities. The need for conservation of local character and biodiversity requires the use of native plant species, whereas the deficiency of water, particularly in semiarid regions, requires the use of species with reduced irrigation needs. Moreover, the aged buildings lead to the use of lightweight green roof constructions. Therefore, research was undertaken to investigate the possibility of using three Mediterranean aromatic xerophytes, Artemisia absinthium L., Helichrysum italicum Roth., and H. orientale L., at an extensive green roof in Athens, Greece. Simultaneously, the possibility of using locally produced grape marc compost was investigated. Substrate type and depth and irrigation frequency effects on growth of these species were studied. Rooted cuttings were planted mid-May in plastic containers with a green roof infrastructure fitted (moisture retention and protection of the insulation mat, drainage layer, and filter sheet) and placed on a fully exposed third floor flat roof at the Agricultural University of Athens. Two types of substrates were used, grape marc compost:soil:perlite (2:3:5, v/v) and peat:soil:perlite (2:3:5, v/v, as a control), as well as two substrate depths, 7.5 (shallow) and 15 cm (deep), and two irrigation frequencies, sparse (5 or 7 days in shallow and deep substrate, respectively) and normal (3 or 5 days in shallow and deep substrate, respectively). Increased contents of macroelements, total phosphorus (P) and potassium (K) in particular, were recorded in the compost-amended substrate, whereas both substrates had similar physical properties. Plant growth was recorded from May to October. The deep compost-amended substrate, independent of irrigation frequency, resulted in taller plants with bigger diameter and aboveground dry weight in all species. However, a remarkable result was that shallow compost-amended substrate with sparse irrigation resulted in similar or even bigger plant growth of all plant species compared with deep peat-amended substrate with normal irrigation. Thus, all three species were found suitable for use in Mediterranean extensive or semi-intensive green roofs, whereas the use of grape marc compost in the substrate allowed for less water consumption and the reduction of substrate depth without restriction of plant growth at the establishment phase and the first period of drought.


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