Department of Plant & Environmental Sciences

Abstract

Though plants are sessile, and have no brain or nervous system, they survive and thrive in harsh and fluctuating environments, moving by growing. I will discuss how plants capitalize on their changing morphology and passive mechanics in order to negotiate their environment (a form of morphological computation). I start with understanding the interplay between growth-driven movements with passive mechanics, presenting a model complemented by a unique numerical framework. As a case study I recover observations of waving patterns characteristic of roots growing on an inclined substrate. Building on this framework, I shift to a behavioral question, tackling how climbing plants decide whether to twine on a newly found support, based on their mechanical stability. Combining theory with experiment, we find that climbing plants take advantage of large exploratory movements, termed circumnutations, to exert forces on newly encountered supports, and twining occurs after a threshold. These forces provide a readout on resistance (mechanical stability) - akin to whisking movements of rodents and cats