Cloning and Functional Analysis of a WRKY28-like Gene in Soybean

Abstract

WRKY transcription factors play important roles in regulating plant growth and development, and participate in plant response to abiotic and biotic stresses. Arabidopsis WRKY28 is an essential transcription factor for plant response to necrotrophic pathogen and abiotic stress. To explore the function of the homologues gene of AtWRKY28 in soybean, we cloned GmWRKY28- like (Glyma.14G028900) and performed bioinformatics analysis. Its sub-cellular localization and tissue expression patterns were further investigated. We also analyzed the expression levels of GmWRKY28-like under ABA, PEG, and NaCl stress treatments. Our results showed that the coding DNA sequence (CDS) of GmWRKY28-like gene is 1008 bp in length, encoding 335 amino acids. GmWRKY28-like contains a conserved WRKY domain with 22 serine, one threonine and two tyrosine, without any trans- membrane domain or signal peptide. Phylogenetic analysis showed that the WRKY28 from Phaseolus vulgaris was most similar to GmWRKY28-like. GmWRKY28-like was verified to be located in the nucleus. This gene expressed at low levels in root and seed while high levels in true leaf, flower and shoot apical meristem. The 1500 bp upstream region of GmWRKY28-like contains a