The SET domain protein SUVR5 is involved in regulation of hormone responsive genes

Histone methylation is involved epigenetic gene regulation and it’s disruption can result in cancer. The histone methyltransferase SUVAR3-9 from Drosophila melanogaster is homologous to SUVR5 in the plant model species Arabidopsis thaliana. Interestingly, SUVR5 also contains three C2H2 zinc finger motifs (Lindroth et al., 2004). In order to determine SUVR5’s function, the mRNA transcriptome was sequenced in suvr5 mutant lines and changes in transcript abundance were seen in genes involved in hormone regulation, suggesting that SUVR5 is involved in hormone regulation.

To test this hypothesis, suvr5 mutants were exposed to a range of dilutions of different hormones. Changes in growth were observed in suvr5 mutants exposed to auxin.

Furthermore, two reporter lines were generated to monitor SUVR5 expression. A SUVR5 2kb promoter driving uidA, encoding beta-glucuronidase (SUVR5pro-GUS) and SUVR5 2kb promoter followed by the SUVR5 coding sequence fused to uidA (SUVR5-GUS) have been successfully transformed into the parental generation. Two weeks old offspring containing the SUVR5pro-GUS construct showed ubiquitous GUS expression, whereas the GUS expression in seedling of the SUVR5-GUS line was restricted to meristematic tissue and the basal part of young leaves. This indicates that the expression of SUVR5 is regulated post-transcriptionally.

We conclude that SUVR5 is involved in auxin-mediated gene regulation and hope to see changes in SUVR5 expression pattern after hormone treatment in order to gain further information about the biological and molecular functions of SUVR5.