Extracellular niche establishment by plant pathogens.

The plant extracellular space, referred to as the apoplast, is inhabited by a variety of microorganisms. Reflecting the crucial nature of this compartment, both plants and microorganisms seek to control, exploit and respond to its composition. Upon sensing the apoplastic environment, pathogens activate virulence programmes, including the delivery of effectors with well-established roles in suppressing plant immunity.

Protein phosphatase 2A: a high-value target of virulence factors.

Pathogen-encoded virulence factors perturb host physiology and immune function to promote infection. Reinforcing the concept that protein phosphatase 2A (PP2A) is convergently targeted by virulence factors from diverse pathogens, Li et al. demonstrate that PP2A is coopted by members of a modular family of effector proteins from a plant-pathogenic oomycete.

A method for quantitation of apoplast hydration in Arabidopsis leaves reveals water-soaking activity of effectors of Pseudomonas syringae during biotrophy.

The plant apoplast has a crucial role in photosynthesis and respiration due to its vital function in gas exchange and transpiration. The apoplast is also a dynamic environment that participates in many ion and nutrient transport processes via plasma membrane-localized proteins. Furthermore, diverse microbes colonize the plant apoplast, including the hemibiotrophic bacterial pathogen, Pseudomonas syringae pv.