Abstract
Translational regulation, exerted by the cytosolic ribosome, has been shown to participate in the establishment of abaxial-adaxial polarity in Arabidopsis thaliana: many hypomorphic and null alleles of genes encoding proteins of the cytosolic ribosome enhance the leaf polarity defects of asymmetric leaves1 (as1) and as2 mutants. Here, we report the identification of the SCABRA1 (SCA1) nuclear gene, whose loss-of-function mutations also enhance the polarity defects of the as2 mutants. In striking contrast to other previously known enhancers of the phenotypes caused by the as1 and as2 mutations, we found that SCA1 encodes a plastid-type ribosomal protein that functions as a structural component of the 70S plastid ribosome and, therefore, its role in abaxial-adaxial patterning was not expected.
Highlights
Translational regulation, exerted by the cytosolic ribosome, has been shown to participate in the establishment of abaxial-adaxial polarity in Arabidopsis thaliana: many hypomorphic and null alleles of genes encoding proteins of the cytosolic ribosome enhance the leaf polarity defects of asymmetric leaves[1] and as[2] mutants
The scabra[1] mutant was isolated in a large-scale screen for ethyl methanesulfonate (EMS)-induced mutants with abnormal leaf morphology[8]
The sca[1] mutant exhibits a general reduction in size, which translates into rosettes with significantly reduced projected area when compared with its wild type, Landsberg erecta (Ler) (Fig. 1A,B; Supplementary Figure S1A)
Summary
Translational regulation, exerted by the cytosolic ribosome, has been shown to participate in the establishment of abaxial-adaxial polarity in Arabidopsis thaliana: many hypomorphic and null alleles of genes encoding proteins of the cytosolic ribosome enhance the leaf polarity defects of asymmetric leaves[1] (as1) and as[2] mutants. We describe the identification of the Arabidopsis SCABRA1 (SCA1) gene, whose partial loss-of-function enhances the polarity defects caused by as[2] alleles. Contrary to other previously known as[1] and as[2] enhancers, we found that SCA1 encodes a plastid-type ribosomal protein that functions as a structural component of the 70S plastid ribosome and, its role in abaxial-adaxial patterning was unexpected.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call