Abstract
Upon submergence, a heterophyllous aquatic plant of Ludwigia arcuata produce narrow submerged-type leaves, with a reduction of the number of epidermal cells in transverse direction. Such reduction has been ascribed to the effect of ethylene.
In this study, we examined at what extent ethylene affects the orientation of the division planes in developing leaves, whereby developmental plasticity was considered in the third young leaves. Two days after addition of ethylene, divided cells, in which division planes were parallel to the leaf long axis decreased in a whole leaf level. Furthermore, the ratio of division planes transverse to the leaf long axis increased in the basal portion of the third young leaves, while division plane parallel to the leaf long axis decreased near the central region. These outcomes indicate that ethylene actually affected the direction of division planes, resulting in changing leaf shape.
