PHYSIOLOGY AND GENETICS OF PLANT ARCHITECTURE

Plant architecture results from developmental processes occurring throughout the plant life span. In the current article, the processes responsible for the formation of aerial organs and their organization at the whole plant scale, i.e. primary and secondary growth, branching, and flowering are considered, whereas the below-ground plant organization is not included. This article focuses on the advances made on the comprehension of the physiologic and genetic base of plant architecture initially elucidated in plant models, and which are progressively being deciphered in a large range of species. The current knowledge allows comparisons of the processes among groups and to examine their conservation versus their major differences. However, numerous questions remain especially when regularities in plant structure are observed at coarse scales of plant organization such as annual shoots, axes, or branching systems. Moreover, the overlap of numerous gene functions over several processes leads to pleiotropic effects that make the genetic effects complex to interpret. The evidence of such overlaps opens evo-devo perspectives.