Growth and biomechanics of shoot organs.

Plant organs arise through complex interactions between biological and physical factors that control morphogenesis. While there has been tremendous progress in the understanding of the genetics behind development, we know much less about how mechanical forces control growth in plants. In recent years, new multidisciplinary research combining genetics, live-imaging, physics, and computational modeling has begun to fill this gap by revealing the crucial role of biomechanics in the establishment of plant organs. In this review, we provide an overview of our current understanding of growth during initiation, patterning, and expansion of shoot lateral organs. We discuss how growth is controlled by physical forces, and how mechanical stresses generated during growth can control morphogenesis at the level of both cells and tissues. Understanding the mechanical basis of growth and morphogenesis in plants is in its early days, and many puzzling facts are yet to be deciphered.