Support searching mechanism in Pea plants by potential perceptual completion of divided supports

Pea plants, as climbing plants, require support to sustain growth and optimise proximity to an adequate light source. In nature, however, the complete perception of potential supports could be hindered by several above- and below-ground elements. In such circumstances, plants need to perform some sort of perceptual “completion” to produce a unified perception of their target elements. The present thesis aims to investigate the possible existence of perceptual completion process in pea plants by analyzing their approach behavior using three-dimensional (3D) kinematic analysis. To do this, pea plants were tested in the presence of a support divided into two parts located in opposite positions of the pot they were planted in. One part was grounded and only perceived by the root system. The other part was raised from the ground so that only the aerial part was accessible. A control condition in which plants were tested in the presence of an undivided support was considered. The results showed that the plants integrated the information coming from the two parts of the supports to clasp it properly. Overall the results suggest capability of perceptual completion and integration of information coming from different parts of the plant. Crosstalk and continuous information flow across plant modules via diverse signalling networks like hormones, and/or electric signals may enable the completion process to take place. Future research could explore the mechanisms of these networks and provide further insight into detection, exploration, and clasping processes. Ecological observation could reveal whether these findings are applicable to pea plants in natural conditions.