Data from: Specialized roots of Velloziaceae weather quartzite rock while mobilizing phosphorus using carboxylates

1.Campos rupestres is an extremely phosphorus (P)‐impoverished rocky
ecosystem in Brazil. Velloziaceae is an important plant family in this
environment, and some species colonize exposed quartzite rock. However, we
know virtually nothing about their root development and nutrient
acquisition within the rock outcrops and their possible role in rock
weathering and landscape formation. 2.We tested the hypothesis that
Velloziaceae dissolve P from the rock, enhancing rock‐weathering. The
study was carried out with two Barbacenia species (Velloziaceae) that
colonize quartzite rocks. We assessed the root specializations and
exudates, and determined the mineralogical composition of the rocks. 3.The
quartzite rocks contained a low concentration of total P in a matrix
composed predominantly of silica. Using transmission electron microscopy,
we show root growth perpendicular to the rock‐bedding planes. A micro‐XRF
setup at the XRF beamline of a synchrotron evidenced root‐associated rock
dissolution. 4.The investigated roots show novel morphological and
physiological specializations, coined vellozioid roots, which are highly
effective at P acquisition. These carboxylate‐releasing roots function
like others specialized roots in nutrient‐depleted soils. The rocks
represent a barrier for most species, but due to their chemical and
physical actions inside the rocks, vellozioid roots play a pivotal role in
rock weathering, contributing to shaping the campos rupestres landscapes.