Developmental analyses of divarications in leaves of an aquatic fern Microsorum pteropus and its varieties

Abstract

Plant leaves occur in diverse shapes. Divarication patterns that develop during early growths are one of key factors that determine leaf shapes. We utilized leaves of Microsorum pteropus, a semi-aquatic fern, and closely related varieties to analyze a variation in the divarication patterns. The leaves exhibited three major types of divarication: no lobes, bifurcation, and trifurcation (i.e., monopodial branching). Our investigation of their developmental processes, using time-lapse imaging, revealed localized growths and dissections of blades near each leaf apex. Restricted cell divisions responsible for the apical growths were confirmed using a pulse-chase strategy for EdU labeling assays.

Theoretical models for branch formation in plants

“…That is, a system that can select coexisting or independent modes is important for the formation of such branches. In leaves, the two different modes can be observed in closely related fern species (Miyoshi et al 2019) (Fig. 5a, d).…”

“…1, 4, and 5. The mode differences are observed in both two-or three-dimensional branches in leaves (Miyoshi et al 2019) or body plans (Harrison 2017) (Fig. 5).…”