scholarly journals Priming of Resistance-Related Phenolics: A Study of Plant-Associated Bacteria and Hymenoscyphus fraxineus

2021 ◽  
Vol 9 (12) ◽  
pp. 2504
Author(s):  
Greta Striganavičiūtė ◽  
Jonas Žiauka ◽  
Vaida Sirgedaitė-Šėžienė ◽  
Dorotėja Vaitiekūnaitė

European ash (Fraxinus excelsior) is highly affected by the pathogenic fungus Hymenoscyphus fraxineus in all of Europe. Increases in plant’s secondary metabolite (SM) production is often linked tol enhanced resistance to stress, both biotic and abiotic. Moreover, plant-associated bacteria have been shown to enhance SM production in inoculated plants. Thus, our hypothesis is that bacteria may boost ash SM production, hence priming the tree’s metabolism and facilitating higher levels of resilience to H. fraxineus. We tested three different ash genotypes and used Paenibacillus sp. and Pseudomonas sp. for inoculation in vitro. Total phenol (TPC), total flavonoid (TFC) and carotenoid contents were measured, as well as the chlorophyll a/b ratio and morphometric growth parameters, in a two-stage trial, whereby seedlings were inoculated with the bacteria during the first stage and with H. fraxineus during the second stage. While the tested bacteria did not positively affect the morphometric growth parameters of ash seedlings, they had a statistically significant effect on TPC, TFC, the chlorophyll a/b ratio and carotenoid content in both stages, thus confirming our hypothesis. Specifically, in ash genotype 64, both bacteria elicited an increase in carotenoid content, TPC and TFC during both stages. Additionally, Pseudomonas sp. inoculated seedlings demonstrated an increase in phenolics after infection with the fungus in both genotypes 64 and 87. Our results indicate that next to genetic selection of the most resilient planting material for ash reforestation, plant-associated bacteria could also be used to boost ash SM production.

2021 ◽  
Vol 9 (9) ◽  
pp. 1901
Author(s):  
Greta Striganavičiūtė ◽  
Jonas Žiauka ◽  
Vaida Sirgedaitė-Šėžienė ◽  
Dorotėja Vaitiekūnaitė

Aspens (Populus tremula and its hybrids), economically and ecologically important fast-growing trees, are often damaged by Phellinus tremulae, a rot-causing fungus. Plant-associated bacteria can be used to increase plant growth and resistance; however, no systematic studies relating the activity of symbiotic bacteria to aspen resistance against Phellinus tremulae have been conducted so far. The present pioneer study investigated the responses of two Populus tremula and two P. tremula × P. tremuloides genotypes to in vitro inoculations with, first, either Pseudomonas sp. or Paenibacillus sp. bacteria (isolated originally from hybrid aspen tissue cultures and being most closely related to Pseudomonas oryzihabitans and Paenibacillus tundrae, respectively) and, in the subsequent stage, with Phellinus tremulae. Both morphological parameters of in vitro-grown plants and biochemical content of their leaves, including photosynthesis pigments and secondary metabolites, were analyzed. It was found that both Populus tremula × P. tremuloides genotypes, whose development in vitro was significantly damaged by Phellinus tremulae, were characterized by certain responses to the studied bacteria: decreased shoot development by both Paenibacillus sp. and Pseudomonas sp. and increased phenol content by Pseudomonas sp. In turn, these responses were lacking in both Populus tremula genotypes that showed in vitro resistance to the fungus. Moreover, these genotypes showed positive long-term growth responses to bacterial inoculation, even synergistic with the subsequent fungal inoculation. Hence, the studied bacteria were demonstrated as a potential tool for the improved in vitro propagation of fungus-resistant aspen genotypes.


2019 ◽  
pp. 38-48
Author(s):  
L.R. Khakimova ◽  
A.M. Lavina ◽  
L.R. Karimova ◽  
V.V. Fedyaev ◽  
An.Kh. Baymiev ◽  
...  

A Pseudomonas sp. 102 strain, which is highly resistant to toxic effects of cadmium and has plant growth-promoting activity, can significantly increase growth parameters and biomass of tomato plants, including those observed under toxic effects of cadmium. The greatest positive effect was observed in plants transformed with the bacterial adhesin gene rapA1, the product of which is important for colonization of plant roots by bacteria. It was also shown that shoots of transgenic tomato plants accumulated the greatest amount of cadmium during inoculation with Pseudomonas sp. 102. The ability to extract high concentrations of cadmium and accumulate a large biomass under stress opens up prospects for the further use of associative interactions between tomato and Pseudomonas for phytoremediation. phytoremediation, cadmium, tomato, Pseudomonas, inoculation, agglutinins, This study was carried out using the equipment of the Biomika Centre for Collective Use of the Institute of Biochemistry and Genetics (Ufa Federal Research Centre, Russian Academy of Sciences) as part of the government task (project no. AAAA-A16-1160203500284). This study was supported by the Russian Foundation for Basic Research (project nos. 18-34-20004 and 18-34-00033) and 18-344-0033 mol_a_ved and 34-00033 mol_a).


2017 ◽  
Vol 27 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Lidiia Samarina ◽  
Valentina Malyarovskaya ◽  
Yulija Abilfazova ◽  
Natalia Platonova ◽  
Kristina Klemeshova ◽  
...  

Structural and physiological responses of chrysanthemum to repeated osmotic stress were studied. Plants were cultured for 2 weeks (for each stress1 and stress 2) on half MS supplemented with mannitol 100 mM (Treatment I) and 200 mM (Treatment II). First stress inhibited growth parameters stronger than second stress in treatment I. In treatment II both stress events strongly inhibited growth parameters of micro‐shoots. Proline content exceeded control 6 ‐ 8 times after 1st stress, and 2 ‐ 5 times after the 2nd stress in treatments I and II, respectively. Soluble protein was accumulated in leaves during both stress exposures, and 2 ‐ 2.5 times exceeded control after the 2nd stress. Relative water content in both treatments increased after the 2nd stress exposure. In treatment II chlorophyll а and carotenoids contents were 8.78 and 4.62 mg/g comparing to control (4.21 and 2.25 mg/g, respectively) after the 1st stress. But after the 2nd stress there was no difference with control.Plant Tissue Cult. & Biotech. 27(2): 161-169, 2017 (December)


1997 ◽  
Vol 25 (3) ◽  
pp. 303-309
Author(s):  
Václav Mandys ◽  
Katerina Jirsová ◽  
Jirí Vrana

The neurotoxic effects of seven selected Multicenter Evaluation of In Vitro Cytotoxicity programme chemicals (methanol, ethanol, isopropanol, sodium chloride, potassium chloride, iron [II] sulphate and chloroform) were evaluated in organotypic cultures of chick embryonic dorsal root ganglia (DRG), maintained in a soft agar culture medium. Two growth parameters of neurite outgrowth from the ganglia — the mean radial length of neurites and the area of neurite outgrowth — were used to evaluate the toxicities of the chemicals. Dose-dependent decreases of both parameters were observed in all experiments. IC50 values (the concentration causing 50% inhibition of growth) were calculated from the dose-response curves established at three time-points during culture, i.e. 24, 48 and 72 hours. The lowest toxic effect was observed in cultures exposed to methanol (the IC50 ranging from 580mM to 1020mM). The highest toxic effect was observed in cultures exposed to iron (II) sulphate (the IC50 ranging from 1.2mM to 1.7mM). The results of other recent experiments suggest that organotypic cultures of DRG can be used during in vitro studies on target organ toxicity within the peripheral nervous system. Moreover, these cultures preserve the internal organisation of the tissue, maintain intercellular contacts, and thus reflect the in vitro situation, more precisely than other cell cultures.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tongda Li ◽  
Ross Mann ◽  
Jatinder Kaur ◽  
German Spangenberg ◽  
Timothy Sawbridge

AbstractPaenibacillus species are Gram-positive bacteria that have been isolated from a diverse array of plant species and soils, with some species exhibiting plant growth-promoting (PGP) activities. Here we report two strains (S02 and S25) of a novel Paenibacillus sp. that were isolated from perennial ryegrass (Lolium perenne) seeds. Comparative genomics analyses showed this novel species was closely related to P. polymyxa. Genomic analyses revealed that strains S02 and S25 possess PGP genes associated with biological nitrogen fixation, phosphate solubilisation and assimilation, as well as auxin production and transportation. Moreover, secondary metabolite gene cluster analyses identified 13 clusters that are shared by both strains and three clusters unique to S25. In vitro assays demonstrated strong bioprotection activity against phytopathogens (Colletotrichum graminicola and Fusarium verticillioides), particularly for strain S02. A transcriptomics analysis evaluating nitrogen fixation activity showed both strains carry an expressed nif operon, but strain S02 was more active than strain S25 in nitrogen-free media. Another transcriptomics analysis evaluating the interaction of strains with F. verticillioides showed strain S02 had increased expression of core genes of secondary metabolite clusters (fusaricidin, paenilan, tridecaptin and polymyxin) when F. verticillioides was present and absent, compared to S25. Such bioactivities make strain S02 a promising candidate to be developed as a combined biofertiliser/bioprotectant.


2021 ◽  
Vol 11 (13) ◽  
pp. 5902
Author(s):  
Rafael Nguenha ◽  
Maral Seidi Damyeh ◽  
Anh D. T. Phan ◽  
Hung T. Hong ◽  
Mridusmita Chaliha ◽  
...  

Mycotoxins are naturally occurring toxins produced by certain types of fungi that contaminate food and feed, posing serious health risks to human and livestock. This study evaluated the combination of blue light with curcumin to inactivate Aspergillus flavus spores, its effect on aflatoxin B1 (AFB1) production and maintaining carotenoid content in three maize varieties. The study was first conducted in vitro, and the spore suspensions (104 CFU·mL−1) were treated with four curcumin concentrations (25 and 50 µM in ethanol, 1000 and 1250 µM in propylene glycol) and illuminated at different light doses from 0 to 130.3 J·cm−2. The photoinactivation efficiency was light-dose dependent with the highest photoinactivation of 2.3 log CFU·mL−1 achieved using 1000 µM curcumin at 104.2 J·cm−2. Scanning electron microscopy revealed cell wall deformations as well as less density in photosensitized cells. Photosensitization of maize kernels gave rise to a complete reduction in the viability of A. flavus and therefore inhibition of AFB1 production, while no significant (p > 0.05) effect was observed using either light or curcumin. Moreover, photosensitization did not affect the carotenoids in all the studied maize varieties. The results suggest that photosensitization is a green alternative preservation technique to decontaminate maize kernels and reduce consumer exposure to AFB1 without any effect on carotenoid content.


Author(s):  
Maria-Dimitra Tsolakidou ◽  
Ioannis A Stringlis ◽  
Natalia Fanega-Sleziak ◽  
Stella Papageorgiou ◽  
Antria Tsalakou ◽  
...  

Abstract Composts represent a sustainable way to suppress diseases and improve plant growth. Identification of compost-derived microbial communities enriched in the rhizosphere of plants and characterization of their traits, could facilitate the design of microbial synthetic communities (SynComs) that upon soil inoculation could yield consistent beneficial effects towards plants. Here, we characterized a collection of compost-derived bacteria, previously isolated from tomato rhizosphere, for in vitro antifungal activity against soil-borne fungal pathogens and for their potential to change growth parameters in Arabidopsis. We further assessed root-competitive traits in the dominant rhizospheric genus Bacillus. Certain isolated rhizobacteria displayed antifungal activity against the tested pathogens and affected growth of Arabidopsis, and Bacilli members possessed several enzymatic activities. Subsequently, we designed two SynComs with different composition and tested their effect on Arabidopsis and tomato growth and health. SynCom1, consisting of different bacterial genera, displayed negative effect on Arabidopsis in vitro, but promoted tomato growth in pots. SynCom2, consisting of Bacilli, didn't affect Arabidopsis growth, enhanced tomato growth and suppressed Fusarium wilt symptoms. Overall, we found selection of compost-derived microbes with beneficial properties in the rhizosphere of tomato plants, and observed that application of SynComs on poor substrates can yield reproducible plant phenotypes.


Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4170 ◽  
Author(s):  
Olumide Owolabi Omoboye ◽  
Niels Geudens ◽  
Matthieu Duban ◽  
Mickaël Chevalier ◽  
Christophe Flahaut ◽  
...  

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.


2013 ◽  
Vol 23 ◽  
pp. 83-90
Author(s):  
Seung Han Oh ◽  
In Young Na ◽  
Kyoung Hee Choi

Although titanium dioxide (TiO2) is an implantable biomaterial with its antibacterial activity, infection on TiO2 surfaces remains a problem for medical settings. According to our previous studies, curcumin, the main component of turmeric (Curcuma longa), partially hindered the attachment of Streptococcus mutans to human tooth surfaces. Therefore, it was examined whether several implant device-associated bacteria were able to adhere to nanosized TiO2 surfaces. In addition, the effect of curcumin on the bacterial adhesion was investigated. Bacterial strains were cultured on pure Ti and TiO2 surfaces with various nanotube sizes in the absence or presence of curcumin and observed by scanning electron microscopy. Consequently, most bacteria adhered to Ti and TiO2 surfaces. However, curcumin increased the adhesion of bacteria including S. mutans. The results suggest that bacterial adhesion to implant titanium surfaces can be augmented via curcumin ingestion.


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