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The electrical signals in plant's physiological processes are of great interest in biology, biohybrid robotics, and sensors for interfacing the living organisms with an electronic readout and control. This paper reports on the application of conformable, self‐adhering surface electrodes for the measurement and bidirectional stimulation of electrical signals in plants. The inkjet‐printed poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate based electrodes are <3 µm thick, light‐weight, soft and flexible, and can be easily and non‐invasively transferred onto plant's outer organs for surface potential recordings due to their realization on tattoo transfer paper. The devices prove to be extremely versatile for analyzing electrical signals in Dionaea muscipula, Arabidopsis thaliana, and Codariocalyx motorius and for stimulating mechanical responses in D. muscipula. A benefit over traditional electrodes is the van der Waals self‐adherence of the thin electrodes, their intrinsic flexibility and adaptation also on small leaves while providing excellent readout. The same electrode allows long‐term multicycle measurements over at least 10 days and, moreover, straightforward recordings on fast‐moving organs such as snapping fly traps and endogenously oscillating leaflets. The results confirm that self‐adhering soft organic electronics are particularly suitable for plant electrical signal analysis when easy‐application, self‐adaptation, and long‐term performance are required in plant science, biohybrid robotics, and biohybrid sensors. [ABSTRACT FROM AUTHOR]

Background and Aims: Plants affect the soil environment via litter inputs and changes in biotic communities, which feed back to subsequent plant growth. Here we investigated the individual contributions of litter and biotic communities to soil feedback effects, and plant ability to respond to spatial heterogeneity in soil legacy.Methods: We tested for localised and systemic responses of Trifolium repens to soil biotic and root litter legacy of seven grassland species by exposing half of a root system to control soil and the other half to specific inoculum or root litter.Results: Soil inoculation triggered a localised reduction in root length while litter locally increased root biomass independent of inoculum or litter species identity. Nodule formation was locally suppressed in response to soil conditioned by another legume (Vicia cracca) and showed a trend towards systemic reduction in response to conspecific soil. V. cracca litter also caused a systemic response with thinner roots produced in the part of the root system not directly exposed to the litter.Conclusions: Spatial heterogeneity in root litter distribution and soil communities generate distinct local and systemic responses in root morphology and nodulation. These responses can influence plant-mutualist interactions and nutrient cycling, and should be included in plant co-existence models. [ABSTRACT FROM AUTHOR]

Plant genetic diversity can affect ecosystem functioning by enhancing productivity, litter decomposition and resistance to natural enemies. However, the mechanisms underlying these effects remain poorly understood. We hypothesized that genetic diversity may influence ecosystem processes by eliciting functional plasticity among individuals encountering kin or genetically diverse neighbourhoods., We used soil conditioned by groups of closely related (siblings) and diverse genotypes of Deschampsia cespitosa - a species known to exhibit kin recognition via root exudation - to investigate the consequences of kin interactions for root litter decomposition and negative feedback between plants and soil biota., Genetically diverse groups produced root litter that had higher nitrogen (N) content, decomposed faster and resulted in greater N uptake by the next generation of seedlings compared with litter produced by sibling groups. However, a similar degree of negative soil feedback on plant productivity was observed in soil conditioned by siblings and genetically diverse groups. This suggests that characteristics of roots produced by sibling groups slow down N cycling but moderate the expected negative impact of soil pathogens in low-diversity stands., These findings highlight interactions between neighbouring genotypes as an overlooked mechanism by which genetic diversity can affect biotic soil feedback and nutrient cycling. [ABSTRACT FROM AUTHOR]

Living plants can enhance litter decomposition rates via a priming effect by releasing root exudates which provide energy to saprotrophic microbes and thereby enable them to degrade litter faster. The strength of this effect, however, is expected to be dependent on the litter properties. To test whether the presence of a growing plant affects the decomposition rate of dead roots with different traits, we used dead roots of seven species (3 grasses, 3 legumes, 1 forb) as litter and quantified litter mass loss after eight weeks of incubation in soil with or without a growing white clover ( Trifolium repens ) plant. We expected root decomposition to be faster in the presence of T. repens , especially for roots with high C:N ratio. We found that the presence of T. repens slowed down the decomposition of grass and forb roots (negative priming), while it did not significantly affect the decomposition of legume roots. Our results show that root decomposition can be slowed down in the presence of a living plant and that this effect depends on the properties of the decomposing roots, with a pronounced reduction in root litter poor in N and P, but not in the relatively nutrient-rich legume root litters. Negative priming effect of legume plants on non-legume litter decomposition may have resulted from preferential substrate utilisation by soil microbes. [ABSTRACT FROM AUTHOR]

Some plant species are able to distinguish between neighbours of different genetic identity and attempt to pre-empt resources through root proliferation in the presence of unrelated competitors, but avoid competition with kin. However, studies on neighbour recognition have met with some scepticism because the mechanisms by which plants identify their neighbours have remained unclear., In order to test whether root exudates could mediate neighbour recognition in plants, we performed a glasshouse experiment in which plants of Deschampsia caespitosa were subjected to root exudates collected from potential neighbours of different genetic identities, including siblings and individuals belonging to the same or a different population or species., Our results show that root exudates can carry specific information about the genetic relatedness, population origin and species identity of neighbours, and trigger different responses at the whole root system level and at the level of individual roots in direct contact with locally applied exudates. Increased root density was mainly achieved through changes in morphology rather than biomass allocation, suggesting that plants are able to limit the energetic cost of selfish behaviour., This study reveals a new level of complexity in the ability of plants to interpret and react to their surroundings. [ABSTRACT FROM AUTHOR]

Organic Electronics: Ultraconformable, Self-Adhering Surface Electrodes for Measuring Electrical Signals in Plants (Adv. Biohybrid robotics and sensors, electrophysiology, organic electronics, plant's electrical signals, soft electronics Utilizable to record and bidirectionally stimulate electrophysiological signals in different plant species, the devices are relevant for plant science and plant-hybrid robotics and -sensors. [Extracted from the article]

Plant populations can exhibit local adaptation to their abiotic environment, such as climate and soil properties, as well as biotic components such as the chemical signatures of dominant plant species and mutualistic and pathogenic microbial populations. While patterns of local adaptation in individual species are widely recorded, the importance of microevolutionary processes for plant community assembly and function is poorly understood.Here, we examined how a history of long‐term co‐existence, and thus potential for local co‐adaptation, influenced the process of plant community assembly. Soil inocula and seeds of eight plant species were collected from three calcareous grasslands with a long history of grazing within a single geographical region. Mesocosm communities were established using local genotypes from a single site or an artificial mixture of genotypes from two different sites. To investigate the role of root exudates and local ('home') and non‐local ('away') soil biota as mediators of plant species co‐existence, the population origin treatment was combined with the addition of activated carbon, which is known to adsorb exudates from soil, and sterilization of soil inocula. Individual‐, species‐ and mesocosm‐level responses were measured over the course of three growing seasons.We found that root exudates promoted seedling survival, species co‐existence and productivity in assemblages of genotypes originating from the same community but had a weak impact in mixed, novel communities. Soil biota promoted the growth of subordinate forbs and restrained the growth of dominant graminoids, particularly in communities composed of local genotypes. The effects of population origin were significant in the first 2 years of the experiment but were not detectable in the third year when interbreeding and new seedling establishment took place. Plant genotypes coupled with 'home' microbial inoculum experienced a stronger reduction in growth compared with genotypes exposed to 'away' inoculum, indicating that plants experienced home‐field disadvantage in interactions with soil biota.Synthesis. Our study demonstrates that the mechanisms of initial grassland community assembly depend on community history, with below‐ground chemical interactions and plant interactions with soil biota becoming stronger drivers of dynamics in established and potentially co‐evolved communities. [ABSTRACT FROM AUTHOR]