Functional analysis of LSH3 and LSH4 which are direct targets of CUC1 transcription factor controlling boundary formation

Abstract

Plants produce organs from meristem throughout their life. One of the important events during organ formation is to generate boundary that separates meristem and organs. CUC1, CUC2 and CUC3 encode transcription factors with NAC domain and are involved in organ boundary formation. To understand how boundary formation is regulated, we identified CUC1 direct target genes by microarray and in situ expression analysis. One target, LIGHT-DEPENDENT SHORT HYPOCOTYLS 4 (LSH4), encodes a nuclear-localized protein. LSH4 is expressed at boundary region in a similar pattern with CUC1. Interestingly, overexpression of LSH4 results in formation of aberrant leave shape and production of extra floral organs. LSH3, a closest homolog of LSH4 in Arabidopsis, is also expressed at boundary region under the control of CUC1. We will present functional analysis of LSH3 and LSH4 genes.