The core metabolome and root exudation dynamics of three phylogenetically distinct plant species

Root exudates are plant-derived, exported metabolites likely shaping root-associated microbiomes by acting as nutrients and signals. However, root exudation dynamics are unclear and thus also, if changes in exudation are reflected in changes in microbiome structure. Here, we assess commonalities and differences between exudates of different plant species, diurnal exudation dynamics, as well as the accompanying methodological aspects of exudate sampling. We find that exudates should be collected for hours rather than days as many metabolite abundances saturate over time. Plant growth in sterile, nonsterile, or sugar-supplemented environments significantly alters exudate profiles. A comparison of Arabidopsis thaliana, Brachypodium distachyon, and Medicago truncatula shoot, root, and root exudate metabolite profiles reveals clear differences between these species, but also a core metabolome for tissues and exudates. Exudate profiles also exhibit a diurnal signature. These findings add to the methodological and conceptual groundwork for future exudate studies to improve understanding of plant-microbe interactions

The core metabolome and root exudation dynamics of three phylogenetically distinct plant species

Root exudates are plant-derived, exported metabolites likely shaping root-associated microbiomes by acting as nutrients and signals. However, root exudation dynamics are unclear and thus also, if changes in exudation are reflected in changes in microbiome structure. Here, we assess commonalities and differences between exudates of different plant species, diurnal exudation dynamics, as well as the accompanying methodological aspects of exudate sampling. We find that exudates should be collected for hours rather than days as many metabolite abundances saturate over time. Plant growth in sterile, nonsterile, or sugar-supplemented environments significantly alters exudate profiles. A comparison of Arabidopsis thaliana, Brachypodium distachyon, and Medicago truncatula shoot, root, and root exudate metabolite profiles reveals clear differences between these species, but also a core metabolome for tissues and exudates. Exudate profiles also exhibit a diurnal signature. These findings add to the methodological and conceptual groundwork for future exudate studies to improve understanding of plant-microbe interactions

Tunnelivadelman kirvatorjunnan tehostaminen Anthocoris nemoralis -petoluteen avulla

Tunneli suojaa vadelmakasvustoa monilta kasvitaudeilta ja tuholaisilta, mutta tunneliin päästessään esimerkiksi kirvat lisääntyvät nopeasti, eivätkä biologiset torjuntaeliöt aina torju kirvoja riittävän tehokkaasti. Tunnelivadelmalla esiintyy isovattukirvaa sekä pikkuvattukirvaa. Kirvatorjun-nan tehostamiseen lähdettiin hakemaan apua kenttäkokeella, jossa kirvatorjuntaan käytettiin tyrninokkaludetta (Anthocoris nemoralis). Toimeksiantajana opinnäytetyössä oli biologinen torjuntafirma Biotus Oy. Koe suoritettiin uusimaalaisella tilalla kahdessa vadelmatunnelissa kesän 2017 aikana. Tunneleihin levitettiin kolmen viikon välein hyötyeliöitä. Hyötyeliöinä kokeessa käytettiin vainokaisia, kirvasääskiä sekä tyrninokkaluteita. Kirvojen määrä tunneleista laskettiin joka viikko ja samalla havainnoitiin hyötyeliöiden sekä tuhoeliöiden esiintyvyyttä tunneleissa. Ensimmäiset kirvahavainnot tunneleissa tehtiin heinäkuussa. Suurin osa havaituista kirvoista oli pikkuvattukirvan siivetöntä muotoa. BerryProtect -putkilo oli toimiva ennakkotorjunnassa. Kirvasääski torjui tehokkaammin toisessa tunnelissa, kun taas toisessa tyrninokkalude oli tehokkaampi. Näillä levitysstrategioilla saatiin kuitenkin Wennborgin tilan kannalta toimiva lopputulos

Conservation of beneficial microbes between the rhizosphere and the cyanosphere

Biocrusts are phototroph-driven communities inhabiting arid soil surfaces. Like plants, most photoautotrophs (largely cyanobacteria) in biocrusts are thought to exchange fixed carbon for essential nutrients like nitrogen with cyanosphere bacteria. Here, we aim to compare beneficial interactions in rhizosphere and cyanosphere environments, including finding growth-promoting strains for hosts from both environments. To examine this, we performed a retrospective analysis of 16S rRNA gene sequencing datasets, host-microbe co-culture experiments between biocrust communities/biocrust isolates and a model grass (Brachypodium distachyon) or a dominant biocrust cyanobacterium (Microcoleus vaginatus), and metabolomic analysis. All 18 microbial phyla in the cyanosphere were also present in the rhizosphere, with additional 17 phyla uniquely found in the rhizosphere. The biocrust microbes promoted the growth of the model grass, and three biocrust isolates (Bosea sp._L1B56, Pseudarthrobacter sp._L1D14 and Pseudarthrobacter picheli_L1D33) significantly promoted the growth of both hosts. Moreover, pantothenic acid was produced by Pseudarthrobacter sp._L1D14 when grown on B. distachyon exudates, and supplementation of plant growth medium with this metabolite increased B. distachyon biomass by over 60%. These findings suggest that cyanobacteria and other diverse photoautotrophic hosts can be a source for new plant growth-promoting microbes and metabolites

ANTI-CORROSION COATING OF MILD STEEL USING TERNARY Zn-ZnO-Y2O3 ELECTRO-DEPOSITON

Mild steel has found many engineering applications due to its great formability, availability, low cost and good mechanical properties among others. However its functionality and durability is subject of concern due to corrosion deterioration. Based on these, Yttria is selected as reinforcing particles using electroplating process to enhance the corrosion and wear behaviors. Bath formulation of Zinc- Yttria was prepared at moderated temperature and pH, to coat the sample. Corrosion and wear behaviour were analyzed using electrochemical potentiostat and abrasive test rig. The composition and microstructure of coated samples were investigated using standard method. The microstructure of the deposited sample obtained at 10 % Yttria, revealed fine-grains deposit of the Yttria on the mild steel surface. The results showed that adding of Yttria particles, improved wear behaviour and corrosion resistance in sodium chloride solution. Microhardness of the coated samples showed increases hardness values before and after heat treatment. This work established that elecrodeposition of mild steel with Yttria is promising in increasing the wear and corrosion resistanc