Plasmodesmata dynamics in bryophyte model organisms: secondary formation and developmental modifications of structure and function

• DOI: 10.1007/s00425-024-04476-1
• Publication Date: 2024-07-04T18:01:59Z
• Authors: Linus Wegner; Katrin Ehlers
• Keywords: Plasmodesma; Bryophyte; Sporophyte; Gemma; plant evolution; Physcomitrella patens; Marchantia polymorpha

Abstract Main conclusion Developing bryophytes differentially modify their plasmodesmata structure and function. Secondary formation via twinning appears to be an ancestral trait. Plasmodesmata networks in hornwort sporophyte meristems resemble those of angiosperms. All land-plant taxa use (PD) cell connections for symplasmic communication. In angiosperm development, PD undergo extensive remodeling by structural functional modifications, postcytokinetic additional secondary (secPD). Since comparable information on dynamics is scarce the embryophyte sister groups, we investigated maturating tissues Anthoceros agrestis (hornwort), Physcomitrium patens (moss ) , Marchantia polymorpha (liverwort). As angiosperms, quantitative electron microscopy revealed secPD gametophytes all model bryophytes, which gives rise laterally adjacent pairs or complex branched PD. This finding suggests that ancient evolutionary mechanism adjust numbers during wall expansion. Moreover, bryophyte existing taxon-specific strategies resembling Development type II-like morphotypes with enlarged diameters pit might required maintain transport rates thickening. Similar leaves, fluorescence redistribution after photobleaching a considerable reduction permeability P. phyllids. contrast previous reports monoplex single initials, observed targeted multi-initial basal A. sporophytes. Their share typical features meristems, may hint at putative homologous origin. We also discuss require distinct types networks, without formation, control maintenance initial identity positional signaling.