The Crossregulation Triggered by Strains Is Strain-Specific and Improves Adaptation to Biotic and Abiotic Stress in Arabidopsis.

Plants are sessile organisms that overcome environmental stress by activating specific metabolic pathways, leading to adaptation and survival. In addition, they recruit beneficial bacterial strains to further improve their performance. As plant-growth-promoting rhizobacteria (PGPR) are able to trigger multiple targets to improve plant fitness, finding effective isolates for this purpose is of paramount importance.

Bacillus G7 improves adaptation to salt stress in Olea europaea L. plantlets, enhancing water use efficiency and preventing oxidative stress.

In addition to genetic adaptative mechanisms, plants retrieve additional help from the surrounding microbiome, especially beneficial bacterial strains (PGPB) that contribute to plant fitness by modulating plant physiology to fine-tune adaptation to environmental changes. The aim of this study was to determine the mechanisms by which the PGPB Bacillus G7 stimulates the adaptive mechanisms of Olea europaea plantlets to high-salinity conditions, exploring changes at the physiological, metabolic and gene expression levels. On the one hand, G7 prevented photosynthetic imbalance under saline stress, increasing the maximum photosynthetic efficiency of photosystem II (Fv/Fm) and energy dissipation (NPQ) and protecting against photooxidative stress.

Modulation of Photosynthesis and ROS Scavenging Response by Beneficial Bacteria in Plantlets under Salt Stress Conditions.

Climate change consequences for agriculture involve an increase of saline soils which results in lower crop yields due to increased oxidative stress in plants. The present study reports the use of Plant Growth Promoting Bacteria (PGPB) as a tool to modulate plant innate mechanisms of adaptation to water stress (salinity and drought) in one year-old olive plantlets var. Arbosana and Arbequina.

H47 triggers metabolism activating DOXP and shikimate pathways simultaneously and modifying leaf extracts' antihypertensive activity.

Improvement of plant adaptation by beneficial bacteria (PGPB) may be achieved by triggering multiple pathways to overcome the environmental stress on plant's growth cycle, activating plant's metabolism. The present work reports the differential ability of three strains to trigger olive tree metabolism, among which, only H47 was outstanding increasing iridoid and flavonol concentration. One-year old olive seedlings grown open air, under harsh conditions of water shortage in saline soils, were root-inoculated with three PGPB strains throughout a 12-month period after which, photosynthesis was determined; photosynthetic pigments and bioactive secondary metabolites (iridoids and flavonols) were analyzed, and a study of gene expression of both pathways involved was undertaken to unravel molecular targets involved in the activation.

Management of Plant Physiology with Beneficial Bacteria to Improve Leaf Bioactive Profiles and Plant Adaptation under Saline Stress in L.

Global climate change has increased warming with a concomitant decrease in water availability and increased soil salinity, factors that compromise agronomic production. On the other hand, new agronomic developments using irrigation systems demand increasing amounts of water to achieve an increase in yields. Therefore, new challenges appear to improve plant fitness and yield, while limiting water supply for specific crops, particularly, olive trees.