Exploring movements in pea plants: decision-making in support selection

Choosing a support is a crucial aspect of the life journey of climbing plants. Those that can find a suitable support exhibit higher performance and fitness. While numerous studies on climbing plants have provided insights into the mechanistic details of support-searching behaviors, few have explored the purposeful nature of these movements and the decision-making processes involved. One crucial factor influencing plants’ decisions is the diameter of the support. Once it exceeds a certain point, climbing plants struggle to maintain tensional forces and detach from the support. In this connection, the present study focuses on the decision-making processes underlying support-searching in pea plants (Pisum sativum L.). The plants were grown in two conditions: a single-support setting and an environment to choose between two supports of different diameters. As they developed, their movements were analyzed using time-lapse photography and 3D motion analysis. Consistently with previous research suggesting a preference for supports with smaller diameters, the results show an inclination among plants to choose the thinner support. The statistical analyses revealed disparities in the kinematic properties depending on the growth condition and the grasped support type. Plants that chose a thicker support differed significantly in their movement patterns from plants that grasped a thin support. Similarly, plants grown in the single-support condition varied from those in the decision-making condition. The current study elucidates the decision-making process of climbing plants in their search for support and presents evidence that plants adopt different plastic responses, choosing the one that optimally corresponds to environmental conditions.