Plants have evolved complex signalling networks in order to respond to the plethora of environmental and developmental stimuli to which they are exposed. Within these networks, a diverse range of signals are integrated, allowing the plant to formulate an appropriate response to the prevailing conditions. An important feature of signalling pathways into networks is the potential for pathways to interact with each other, thereby influencing the responses observed. This is known as crosstalk. Signalling networks act through a hub and spoke model where the hub is a key determinant of the pathways that will crosstalk with one another. Reactive oxygen species (ROS) are an example of such a signalling hub that play an intrinsic role in crosstalk within plant stress signalling networks. ROS are of particular interest due to their ability to have positive or negative effects, depending on their abundance within the cell.