Data from: Local adaptation is associated with zinc tolerance in Pseudomonas endophytes of the metal-hyperaccumulator plant Noccaea caerulescens

Metal hyperaccumulating plants, which are hypothesised to use metals for
defence against pests and pathogens, provide a unique context in which to
study plant–pathogen co-evolution. Previously, we demonstrated that the
high concentrations of zinc found in leaves of the hyperaccumulator
Noccaea caerulescens provide protection against bacterial pathogens, with
a potential trade-off between metal-based and pathogen-induced defences.
We speculated that an evolutionary arms race between zinc-based defences
in N. caerulescens and zinc tolerance in pathogens might have driven the
development of the hyperaccumulation phenotype. Here, we investigate the
possibility of local adaptation by bacteria to the zinc-rich environment
of N. caerulescens leaves and show that leaves sampled from the
contaminated surroundings of a former mine site harboured endophytes with
greater zinc tolerance than those within plants of an artificially created
hyperaccumulating population. Experimental manipulation of zinc
concentrations in plants of this artificial population influenced the zinc
tolerance of recovered endophytes. In laboratory experiments, only
endophytic bacteria isolated from plants of the natural population were
able to grow to high population densities in any N. caerulescens plants.
These findings suggest that long-term co-existence with zinc
hyperaccumulating plants leads to local adaptation by endophytic bacteria
to the environment within their leaves.