Vascular patterning of superoxide in bursting grapevine buds

Plants regulate cellular oxygen partial pressures (pO2), together with reduction/oxidation (redox) state in order to manage rapid developmental transitions such as bud burst after a period of quiescence. However, our understanding of pO2 regulation in complex meristematic organs such as buds is incomplete and, in particular, lacks spatial resolution.

Respiratory CO2 production during grapevine bud burst.
Respiratory CO2 production during grapevine bud burst. Image from Meitha et al. 2015

Meitha et al. investigate tissue oxygen and redox patterning during bud burst in grapevene (Vitis vinifera), and find that the latent bud complex is hypoxic (<5 kPa pO2) and that superoxide shifts from the apical meristem to the provascular tissue during bud burst. They conclude that spatial and temporal control of the tissue oxygen environment occurs within quiescent buds, and the transition from quiescence to bud burst is accompanied by a regulated relaxation of the hypoxic state and accumulation of reactive oxygen species (ROS) within the developing cambium and vascular tissues of the heterotrophic grapevine buds.

This article appears in the special issue ROS and NO Reactions in Plants.