Effects of partial suppression of ribosomal protein S6 on organ formation in Arabidopsis thaliana.

An expression library of Arabidopsis thaliana cDNAs was randomly introduced into A. thaliana. The transformant pool was used to obtain a line, c105, with reduced apical dominance and irregular positioning of leaves and flowers. The inserted DNA was a 3'-fragment of the ribosomal protein S6 gene with antisense orientation. The transcriptional level of the ribosomal protein S6 was lower in c105 than in the wild-type plant. Introduction of the same fragment into the wild-type plant gave phenotypes similar to those of c105, so the phenotypes of c105 were due to the S6 antisense expression. The phenotypes suggest selectively reduced function of specific proteins rather than an overall decrease in protein function caused by defective ribosomal biogenesis.