Ribosomal protein L27a is required for growth and patterning in Arabidopsis thaliana.

This work adds to a growing body of evidence supporting roles for translational regulation of basic developmental processes in plants. Although a number of mechanisms for patterning in plants have been described at the molecular level, how these are coordinated with basic synthetic growth processes remains largely unclear. Several lines of evidence have highlighted the potential significance of regulation involving components of translational machinery, including examples of RNA-induced silencing complex (RISC)-mediated RNA silencing, and differential regulation of ribosomal protein genes in response to developmental and environmental inputs. The paper by Szakonyi and Byrne provides a further example, showing that the ribosomal protein gene RPL27aC contributes to dorso-ventral patterning of the leaf. Like three other similarly acting ribosomal protein genes, PIGGYBACK 1, 2 and 3, RPL27aC was identified as a modifier of the dorso-ventral patterning mutant as1. While the exact mechanism by which RPL27aC contributes to patterning processes remains unclear, experiments presented in the current study implicate changes in the expression of STM, a homeodomain transcription factor that is normally a target of AS1-mediated regulation, as well as an altered distribution of auxin.