Evidence for the plant recruitment of beneficial microbes to suppress soil‐borne pathogens

Endophytes associated with halophytes may contribute to the host’s adaptation to adverse environmental conditions through improving their stress tolerance and protecting them from various soil-borne pathogens. In this study, the diversity and antifungal activity of endophytic bacteria associated with halophytic samples growing on the shore of the western Aral Sea in Uzbekistan were investigated. The endophytic bacteria were isolated from the nine halophytic samples by using the culture-dependent method and identified according to their 16S rRNA gene sequences. The screening of endophytic bacterial isolates with the ability to inhibit pathogenic fungi was completed by the plate confrontation method. A total of 289 endophytic bacterial isolates were isolated from the nine halophytes, and they belong to Firmicutes, Actinobacteria, and Proteobacteria. The predominant genera of the isolated endophytic bacteria were Bacillus, Staphylococcus, and Streptomyces, accounting for 38.5%, 24.7%, and 12.5% of the total number of isolates, respectively. The comparative analysis indicated that the isolation effect was better for the sample S8, with the highest diversity and richness indices. The diversity index of the sample S7 was the lowest, while the richness index of samples S5 and S6 was the lowest. By comparing the isolation effect of 12 different media, it was found that the M7 medium had the best performance for isolating endophytic bacteria associated with halophytes in the western Aral Sea Basin. In addition, the results showed that only a few isolates have the ability to produce ex-enzymes, and eight and four endophytic bacterial isolates exhibited significant inhibition to the growth of Valsa mali and Verticillium dahlia, respectively. The results of this study indicated that halophytes are an important source for the selection of microbes that may protect plant from soil-borne pathogens.

Download Full-text

Supplementation of Lactobacillus early in life alters attention bias to threat in piglets

Scientific Reports ◽

10.1038/s41598-021-89560-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Else Verbeek ◽

Johan Dicksved ◽

Linda Keeling

Keyword(s):

Lactobacillus Plantarum ◽

Lactobacillus Reuteri ◽

Attention Bias ◽

Control Group ◽

Emotional States ◽

Beneficial Microbes ◽

Gut Microbes ◽

Suitable Tool ◽

Vigilance Behaviour

AbstractGut microbes play an important role in regulating brain processes and influence behaviour, cognition and emotional states in humans and rodents. Nevertheless, it is not known how ingestion of beneficial microbes modulates emotional states in piglets and whether it can improve welfare. Here we use an attention bias task to assess the effects of Lactobacillus reuteri ATCC-PTA-6475 and Lactobacillus plantarum L1-6 supplementation early in life on emotional states in 33 piglets compared to 31 placebo supplemented piglets. We hypothesized that Lactobacillus supplementation would reduce vigilance behaviour (head at shoulder height or higher) and attention (head oriented towards the threat) in response to an auditory threat. The results showed that the control group increased vigilance behaviour in response to the threat, but there was no increase in the probiotics group. Despite the increased vigilance, the control group paid less attention to the threat. One explanation may be that control piglets avoided looking in the direction of the threat just because they perceived it as more threatening, but further research is necessary to confirm this. In conclusion, Lactobacillus supplementation may be a suitable tool to reduce anxiety, promote a more appropriate response to a challenge and so improve welfare.

Download Full-text

Interrogating Plant-Microbe Interactions with Chemical Tools: Click Chemistry Reagents for Metabolic Labeling and Activity-Based Probes

Molecules ◽

10.3390/molecules26010243 ◽

2021 ◽

Vol 26 (1) ◽

pp. 243

Author(s):

Vivian S. Lin

Keyword(s):

Plant Growth ◽

Immune Responses ◽

Click Chemistry ◽

Chemical Biology ◽

Molecular Mechanisms ◽

Metabolic Labeling ◽

Beneficial Microbes ◽

Plant Hosts ◽

Microbe Interactions ◽

Growth Metabolism

Continued expansion of the chemical biology toolbox presents many new and diverse opportunities to interrogate the fundamental molecular mechanisms driving complex plant–microbe interactions. This review will examine metabolic labeling with click chemistry reagents and activity-based probes for investigating the impacts of plant-associated microbes on plant growth, metabolism, and immune responses. While the majority of the studies reviewed here used chemical biology approaches to examine the effects of pathogens on plants, chemical biology will also be invaluable in future efforts to investigate mutualistic associations between beneficial microbes and their plant hosts.

Download Full-text

Freezing temperatures restrict woody plant recruitment and restoration efforts in abandoned montane pastures

Global Ecology and Conservation ◽

10.1016/j.gecco.2021.e01462 ◽

2021 ◽

Vol 26 ◽

pp. e01462

Author(s):

Evan M. Rehm ◽

Stephanie Yelenik ◽

Carla D’Antonio

Keyword(s):

Woody Plant ◽

Plant Recruitment ◽

Freezing Temperatures

Download Full-text

Can repeated soil amendment with biogas digestates increase soil suppressiveness toward non-specific soil-borne pathogens in agricultural lands?

Renewable Agriculture and Food Systems ◽

10.1017/s1742170520000393 ◽

2020 ◽

pp. 1-12

Author(s):

L. M. Manici ◽

F. Caputo ◽

G. A. Cappelli ◽

E. Ceotto

Keyword(s):

Plant Growth ◽

Biomass Production ◽

Soil Amendment ◽

Plant Biomass ◽

Amended Soils ◽

Soil Suppressiveness ◽

Soil Microbial ◽

Soil Borne Pathogens ◽

The Impact ◽

Plant Biomass Production

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).

Download Full-text