The shaping of plant axes and crowns by tropisms and elasticity (and the resulting balance between genetic control and environmental plasticity)

The study of the development of plant architecture has revealed a set of typical patterns of axes traits inside the crown, at the specific (architectural unit) or supra-specific (architectural model) levels. These patterns are mostly heritable. However, plant architectural development also displays a very high level of phenotypical plasticity. Understanding the bases of this duality at both the scale of the axis and that of the crown is still a challenge. Here I will show how the biophysical study of i) tropisms in axes and ii) the shaping of the crown in isolated trees is bringing new insights on this long-standing topic. I will discuss how the driving of the growth directions through the biological sensing of external physical signals can account for the interplay between developmental genetic heritability and environmental plasticity in shoot and crown shapes in land angiosperms.