scholarly journals Novel mechanisms for phosphate acquisition in abundant rhizosphere-dwelling Bacteroidetes

2019 ◽  
Author(s):  
Ian D.E.A. Lidbury ◽  
David J. Scanlan ◽  
Andrew R. J. Murphy ◽  
Andrew Bottrill ◽  
Alex Jones ◽  
...  

AbstractGlobal food production is reliant on the application of finite phosphorus (P) fertilisers. Numerous negative consequences associated with intensive P fertilisation have resulted in a high demand to find alternative sustainable methods that will enhance crop P uptake. Bacteroidetes, primarily from the genus Flavobacterium, have recently been shown to be abundant members of the plant microbiome, but their general ecological role and potential to mobilise P in the rhizosphere remains very poorly characterised. Here, we sought to determine the P mobilisation potential of Flavobacterium strains isolated from the rhizosphere of oilseed rape (Brassica napus L.). We show that these Flavobacterium strains possess novel mechanisms for P mobilisation and subsequent acquisition. These include the constitutive and inducible expression of completely novel and phylogenetically distinct phosphatases, the phosphate starvation inducible expression of uncharacterised and hypothetical genes and gene clusters and, for the first time, the involvement of outer membrane SusCD transport complexes (usually associated with carbohydrate transport) in P acquisition. The genes encoding these unusual phosphate starvation inducible proteins were enriched in plant-associated Flavobacterium strains suggesting that this machinery represents niche-adaptive strategies for overcoming P scarcity in this genus. We propose that abundant rhizosphere-dwelling Flavobacterium spp. have evolved unique mechanisms for coping with Pi-stress which may provide novel solutions for future sustainable agricultural practices.


2007 ◽  
Vol 51 (11) ◽  
pp. 4111-4117 ◽  
Author(s):  
M.-C. Domingo ◽  
A. Huletsky ◽  
R. Giroux ◽  
F. J. Picard ◽  
M. G. Bergeron

ABSTRACT A vancomycin-resistant, anaerobic, gram-positive coccus containing the vanD and vanG-like genes (strain CCRI-16110) was isolated from a human fecal specimen during a hospital surveillance program to detect carriers of vancomycin-resistant enterococci. Comparison of the 16S rRNA gene sequence of strain CCRI-16110 with databases revealed a potentially novel Ruminococcus species that was most similar (<94% identity) to Clostridium and Ruminococcus species. Strain CCRI-16110 was highly resistant to vancomycin and teicoplanin (MICs of >256 μg/ml). The complete DNA sequence of the vanD cluster was most similar (98.2% identity) to that of Enterococcus faecium BM4339, containing the vanD1 allele. An intD gene with 99% identity with that of this E. faecium strain was found to be associated with the vanD gene cluster of this novel anaerobic bacterium. Strain CCRI-16110 also harbors genes encoding putative VanSG, VanG, and VanTG proteins displaying 56, 73.6, and 55% amino acid sequence identity, respectively, compared to the corresponding proteins encoded by the vanG1 and vanG2 operons of Enterococcus faecalis BM4518 and N03-0233. This study reports for the first time an anaerobic bacterium containing the vanD gene cluster. This strain also harbors a partial vanG-like gene cluster. The presence of vanD- and vanG-containing anaerobic bacteria in the human bowel flora suggests that these bacteria may serve as a reservoir for the vanD and vanG vancomycin resistance genes.



Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 822
Author(s):  
María Hernández-Fernández ◽  
Gustavo Cordero-Bueso ◽  
Marina Ruiz-Muñoz ◽  
Jesús M. Cantoral

The extensive use of synthetic fertilizers and pesticides has negative consequences in terms of soil microbial biodiversity and environmental contamination. Faced with this growing concern, a proposed alternative agricultural method is the use of microorganisms as biofertilizers. Many works have been focused on bacteria, but the limited literature on yeasts and their potential ability to safely promote plant growth is gaining particular attention in recent years. Thus, the objective of this review is to highlight the application of yeasts as biological agents in different sectors of sustainable agricultural practices through direct or indirect mechanisms of action. Direct mechanisms include the ability of yeasts to provide soluble nutrients to plants, produce organic acids and phytohormones (indole-3-acetic acid). Indirect mechanisms involve the ability for yeasts to act as biocontrol agents through their high antifungal activity and lower insecticidal and herbicidal activity, and as soil bioremediating agents. They also act as protective agents against extreme environmental factors by activating defense mechanisms. It is evident that all the aspects that yeasts offer could be useful in the creation of quality biofertilizers and biopesticides. Hence, extensive research on yeasts could be promising and potentially provide an environmentally friendly solution to the increased crop production that will be required with a growing population.



Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 892
Author(s):  
Massimo Ferrara ◽  
Antonia Gallo ◽  
Carla Cervini ◽  
Lucia Gambacorta ◽  
Michele Solfrizzo ◽  
...  

Ochratoxin A (OTA) is a well-known mycotoxin with wide distribution in food and feed. Fungal genome sequencing has great utility for identifying secondary metabolites gene clusters for known and novel compounds. A comparative analysis of the OTA-biosynthetic cluster in A. steynii, A. westerdijkiae, A. niger, A. carbonarius, and P. nordicum has revealed a high synteny in OTA cluster organization in five structural genes (otaA, otaB, ota, otaR1, and otaD). Moreover, a recent detailed comparative genome analysis of Aspergilli OTA producers led to the identification of a cyclase gene, otaY, located in the OTA cluster between the otaA and otaB genes, encoding for a predicted protein with high similarity to SnoaLs domain. These proteins have been shown to catalyze ring closure steps in the biosynthesis of polyketide antibiotics produced in Streptomyces. In the present study, we demonstrated an upregulation of the cyclase gene in A. carbonarius under OTA permissive conditions, consistent with the expression trends of the other OTA cluster genes and their role in OTA biosynthesis by complete gene deletion. Our results pointed out the involvement of a cyclase gene in OTA biosynthetic pathway for the first time. They represent a step forward in the understanding of the molecular basis of OTA biosynthesis in A. carbonarius.



2020 ◽  
Author(s):  
Armand Chatard ◽  
Margaux Renoux ◽  
Jean Monéger ◽  
Leila Selimbegovic

Research indicates that individuals often deal with mortality salience by affirming beliefs in national or cultural superiority (worldview defense). Because worldview defense may be associated with negative consequences (discrimination), it is important to identify alternative means to deal with death-related thoughts. In line with an embodied terror management perspective, we evaluate for the first time the role of physical warmth in reducing defensive reaction to mortality salience. We predicted that, like social affiliation (social warmth), physical warmth could reduce worldview defense when mortality is salient. In this exploratory (preregistered) study, 202 French participants were primed with death-related thoughts, or an aversive control topic, in a heated room or a non-heated room. The main outcome was worldview defense (ethnocentric bias). We found no main effect of mortality salience on worldview defense. However, physical warmth reduced worldview defense when mortality was salient. Implications for an embodied terror management perspective are discussed.



2016 ◽  
Vol 3 (3) ◽  
Author(s):  
R. S. Suman

The highest yield (420 kg/ha) was recorded in the year 2011-12. In Front-Line Demonstration, it was 27.27 percent more over the farmers practice (320 kg/ha), however, the lowest yield (350 kg/ha) was recorded in the year 2010-11 under Front-Line Demonstration and 310 kg/ha in farmers' practice. Increase in the yield (27.27%) under Front-Line Demonstration over farmers practice was obtained during the year 2011-12. The variation in the percent increase in the yield was found due to variation in agro climate parameter under rainfed condition. Under sustainable agricultural practices, with this study it is concluded that the Front- LineDemonstration programme was effective in changing attitude, skill and knowledge of improved / recommended practices of High Yielding Varieties of peas included adoption. This also improved the relationship between farmers and scientist and built confidence between them.



2016 ◽  
Vol 3 (3) ◽  
Author(s):  
DHANANJAI SINGH ◽  
A.K. PATEL ◽  
S.K. SINGH ◽  
M.S. BAGHEL

Krishi Vigyan Kendra laid down Front Line Demonstration in the year 2010-11 and 2011-12 introducing new, high yielding and scented variety “Pusa Sugandha-3” and applying scientific practices in their cultivation. The FLDs were carried out in village “Dainiha” of Sidhi district in supervision of KVK scientist. The productivity and economic returns of paddy in improved technologies were calculated and compared with the corresponding farmer's practices (local check). Improved practices recorded higher yield as compared to farmer's practices. The improved technology recorded higher yield of 30.83 q/ha and 32.65 q/ha in the year 2010-11 and 2011-12, respectively than 22.13 and 24.21 q/ha. The average yield increase was observed 37.15 per cent. In spite of increase in yield of paddy, technology gap, extension gap and technology index existed. The improved technology gave higher gross return (37020 and 39180 Rs./ha), net return (16820 and 18920 Rs./ha) with higher benefit cost ratio (1.83 and 1.93) as compared to farmer's practices. The variation in per cent increase in the yield was found due to the poor management practices, lack of knowledge and poor socio economic condition. Under sustainable agricultural practices, with this study it is concluded that the FLDs programmes were effective in changing attitude, skill and knowledge of improved package and practices of HYV of paddy adoption.



2021 ◽  
Author(s):  
Xuhua Mo ◽  
Tobias A. M. Gulder

Over 30 biosynthetic gene clusters for natural tetramate have been identified. This highlight reviews the biosynthetic strategies for formation of tetramic acid unit for the first time, discussing the individual molecular mechanism in detail.



Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.



2009 ◽  
Vol 191 (10) ◽  
pp. 3415-3419 ◽  
Author(s):  
Hyun Sook Lee ◽  
Yun Jae Kim ◽  
Jung-Hyun Lee ◽  
Sung Gyun Kang

ABSTRACT Two hypothetical genes were functionally verified to be a pyrophosphatase and a PAP phosphatase in Thermococcus onnurineus NA1. This is the first report of the pyrophosphatases and the PAP phosphatases being organized in the gene clusters of the sulfate activation system only in T. onnurineus NA1 and “Pyrococcus abyssi.”



Sign in / Sign up

Export Citation Format

Share Document