Microarray analysis of gene expression during tissue-reunion in the Arabidopsis cut stem.

Abstract

We have previously shown that the cortex of cut hypocotyls completely united in 7 days, and that gibberellin (GA) is required for this process in cucumber and tomato seedlings. To better understand how the tissue-reunion takes place, hisotchemical and gene expression analyses were performed using Arabidopsis cut flowering stem. The lowest internode of the main flowering stem was cut in half of its diameter with micro-surgical knife, and observed the reunion process. As in cucumber and tomato hypocotyls, cell division was initially observed three days after the cut, and the tissue-reunion completed in seven days in Arabidopsis stems. DNA microarray analysis showed that genes involved in cell division and cell wall modification were up regulated during the reunion process, and that some of those genes were previously determined to be GA- responsive.