Growing Roots and their Searching Behaviour

František Baluška

IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany

Title: Growing Roots and their Searching Behaviour

Abstract

Plant roots perform complex movements (tropisms) in order to navigate successfully in the soil. In order to provide plants with nutrition, they need to search for water- and nutrition-rich soil patches and avoid dangerous dry or toxic patches. This exploratory root behaviour is crucial for healthy plant growth and it constitutes a major key to successful agriculture. Sensory events are located at the very tip of the root, in the root cap, whereas the motoric (bending) processes are located basally, in the elongation region. In-between the root cap and the elongation zone, lies the apical meristem and the adjoining transition zone. This transition zone plays crucial role in the initiation of root tropisms. Moreover, similarly to the root cap, the transition zone has sensory modalities, especially for light, gravity and mechano-stimulation. As the sensory-motoric circuit in gravitropism is very rapid and effective, both chemical and electric cell-cell communications are likely to be involved. Our current understanding of the sensory-motoric circuits of roots is limited. Recent data implicate synaptic-like secretory polar auxin transport behind of these root sensory-motoric circuits. In roots, the most active electric signalling has been reported for the transition zone, which is also the most active one with respect to polar auxin transport and endocytic vesicle recycling.

Contribution to the Workshop “Smart Solution from the Plant Kingdom”