Identifying microbiota community patterns important for plant protection using synthetic communities and machine learning.

Plant-associated microbiomes contribute to important ecosystem functions such as host resistance to biotic and abiotic stresses. The factors that determine such community outcomes are inherently difficult to identify under complex environmental conditions. In this study, we present an experimental and analytical approach to explore microbiota properties relevant for a microbiota-conferred host phenotype, here plant protection, in a reductionist system.

Salt- and Osmo-Responsive Sensor Histidine Kinases Activate the General Stress Response to Initiate Functional Symbiosis.

The general stress response (GSR) enables bacteria to sense and overcome a variety of environmental stresses. In alphaproteobacteria, stress-perceiving histidine kinases of the HWE and HisKA_2 families trigger a signaling cascade that leads to phosphorylation of the response regulator PhyR and, consequently, to activation of the GSR σ factor σ. In the nitrogen-fixing bacterium , PhyR and σ are crucial for tolerance against a variety of stresses under free-living conditions and also for efficient infection of its symbiotic host soybean.

A general non-self response as part of plant immunity.

Plants, like other multicellular lifeforms, are colonized by microorganisms. How plants respond to their microbiota is currently not well understood. We used a phylogenetically diverse set of 39 endogenous bacterial strains from Arabidopsis thaliana leaves to assess host transcriptional and metabolic adaptations to bacterial encounters.

Bradyrhizobium diazoefficiens Requires Chemical Chaperones To Cope with Osmotic Stress during Soybean Infection.

When engaging in symbiosis with legume hosts, rhizobia are confronted with environmental changes, including nutrient availability and stress exposure. Genetic circuits allow responding to these environmental stimuli to optimize physiological adaptations during the switch from the free-living to the symbiotic life style. A pivotal regulatory system of the nitrogen-fixing soybean endosymbiont for efficient symbiosis is the general stress response (GSR), which relies on the alternative sigma factor σ However, the GSR-controlled process required for symbiosis has not been identified.

Independently specified Atoh1 domains define novel developmental compartments in rhombomere 1.

The rhombic lip gives rise to neuronal populations that contribute to cerebellar, proprioceptive and interoceptive networks. Cell production depends on the expression of the basic helix-loop-helix (bHLH) transcription factor Atoh1. In rhombomere 1, Atoh1-positive cells give rise to both cerebellar neurons and extra-cerebellar nuclei in ventral hindbrain.