A FLOE-related protein regulates the two-dimensional to three-dimensional growth transition in the moss Physcomitrium patens

This is the authors' abstract. We don't add key points for this paper.

The colonization of the land by plants coincided with the evolution of three-dimensional (3D) growth: the acquisition of apical cells with the capacity to rotate the plane of cell division. The moss Physcomitrium patens has recently been developed as a model system in which to dissect the genetic basis of 3D growth, a unifying feature of all land plants. The cytokinin-unresponsive nog1-R mutant incorrectly orients division planes in developing buds and thus fails to make the transition to 3D growth. To reveal the genetic interactors of the NOG1 gene, which encodes a protein with a C-terminal UBA domain, we performed a screen and identified the suppressor of nog1a (snog1a) mutant. We have mapped the causative mutation to a gene that encodes a protein related to FLOE2/3 from Arabidopsis and demonstrated that the mutant phenotypes observed in both a nog1 disruptant mutant (nog1dis) and snog1a can be attributed to changes in cytokinin perception. We present a revised model in which NOG1 operates independently of the APB transcription factors to promote 3D growth initiation.