Expression profiling of shoot apices of 35S::WOX1:GR seedlings transiently treated with DEX. Arabidopsis thaliana

The WOX1 transcription factor is a multifunctional regulator of lateral-organ development that acts as a transcriptional repressor. WOX1 promotes lamina growth, controls marginal tissue differentiation and is involved in establishment and maintenance of the adaxial-abaxial pattern from the middle domain of leaf primordia. To identify the WOX1 downstream genes, we performed a microarray analysis of shoot apices of transgenic Arabidopsis thaliana lines harboring 35S::WOX1:glucocorticoid receptor (GR) in which the WOX1 function was temporarily enhanced by dexamethasone (DEX). Overall design: The effects of transient enhancement of WOX1 function on shoot apices of seedlings were analyzed by using GR-DEX system. Plants were grown on solid medium contains 0.5x Murashige and Skoog (MS) salts, 1% sucrose, 0.05% MES-KOH (w/v) pH 5.7, 1.2 % purified agar for 6 days and transfer to liquid medium containing 0.5x MS salts, 1% sucrose and 0.05% MES-KOH (w/v) pH 5.7 with or without 10 µM DEX, 10 µM cycloheximide (CHX) and 20 µM IAA. Samples were treated with DEX, CHX and IAA treatments for 6 hours, 6 hours and 3 hours, respectively, before collection. RNA samples were extracted from shoot apices, including leaf primordia, of 6-day post sowing seedlings by using Plant RNeasy Mini Kit (QIAGEN). For analysis of 35S::WOX1:GR plants treated with or without DEX and/or CHX, sampling was performed twice in two independent lines. For analysis of 35S::GFP:GR and of a combined application of DEX and IAA, sampling was performed from two independent lines.