Dynamic architectural responses of morphological traits to emergence time in Abutilon theophrasti  (Malvaceae)

Abstract How plants respond to the complex environmental changes via phenotypic plasticity has not been well documented. Dynamic architectural analysis provides a valuable approach to understanding the strategies of plants in response to variation in emergence time. To investigate how plants respond to emergence time via dynamic architectural plasticity, we conducted a field experiment by sowing plants of Abutilon theophrasti at different dates to make them emerge in different growth periods, and measured a series of mass and morphological traits in different vertical layers of plants at different stages. Plant architecture can vary over time, and branches played a significant role in modifying the distribution of modules long different layers. The layers with greatest total mass went up higher over time, a delay of emergence time caused more upper layers with the greater total layer mass than lower layers. The layers with the greatest total layer mass were mainly ascribed to greater allocation of leaf and reproductive mass. Plants of A. theophrasti tended to allocate greater mass to leaf and reproductive mass in higher layers with later emergence at day 50 and had petiole length decreasing with higher layers day 70. Results suggested plants can avoid the shading of its upper leaves and branches through additional elongation of petioles, and branches play a significant role in modifying the distribution of modules long different layers. Plants are able to optimize the sunlight acquirement though modifying architectural traits over time, and allocating more energy to the leaves and reproductive branches in the top layers is the most efficient strategy for maximizing light acquirement.