Mining the Brassica oleracea Genome for Q-type C2H2 Zinc Finger Transcription Factor Genes

Abstract

Q-type zinc finger proteins have been studied in several plant species and have been associated with response to stress. A whole genome analysis of Arabidopsis identified 176 putative C2H2 transcription factors (TF). Q-type C2H2 TFs containing the QALGGH motif and are a subset of these. In Arabidopsis, 18 have been described that contain two zinc finger motifs per protein, and several of these have been associated with a response to abiotic stress. The zinc fingers bind to the promoters of genes and negatively regulate transcription via the ethylene-responsive element-binding factor-associated amphiphilic repression (EAR) motif. Previously, we have identified StZFP2 from potato as induced upon infestation by insect pests. Interest in finding similar proteins in the newly annotated cabbage genome (Brassica oleracea var. capitata) led to the discovery of 25 proteins with 2-Q-type zinc finger domains. Examination of several transcriptome studies of B. oleracea submitted to the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA) confirms the expression of all of these genes in at least one tissue type. Identification of the nearest homologs of these proteins in Arabidopsis and comparison of the map positions of both Arabidopsis and B. oleracea genes supports both the synteny between the genetic maps of these related species and the triplication event in Brassica species hypothesized to occur prior to the split from the ancestral progenitor of Arabidopsis and B. oleracea.