Abstract
The Arabidopsis ACL5 gene, whose inactivation causes a severe defect in the stem elongation, encodes a polyamine biosynthetic enzyme, spermine synthase. Although polyamines are recognized as being necessary for cell proliferation, how they control the plant development remains to be understood. To elucidate the mechanism, we have focused on suppressor mutants of acl5-1 (sac51-d-54-d). In this study, we performed cDNA microarray analysis with RNAs extracted from acl5-1, sac51-d acl5-1, and wild-type seedlings. To better view the expression profiles, genes were grouped based on their expression pattern. We identified a large number of genes whose transcript levels were increased in acl5-1, but not in sac51-d acl5-1. They include genes involved in vascular differentiation. In addition, we found that a hAT-like transposase gene was expressed at lower levels in both acl5-1 and sac51-d acl5-1 than in the wild type, and that AtMRU1 and At5g35480 transcripts were significantly increased by the sac51-d mutation.
