Transcriptional profiling of the lectin ArathEULS3 from Arabidopsis thaliana toward abiotic stresses

The family of EUL-related lectins groups all proteins with an Euonymus lectin (EUL) domain, a protein motif which is highly conserved throughout the plant kingdom and occurs as part of many chimeric proteins with different domain architectures. The S3 type EUL lectin from Arabidopsis thaliana (ArathEULS3) has become the model protein within this EUL family. Based on sequence homology to an ABA/NaCl inducible gene from rice and some publicly available high-throughput micro-array data, it was hypothesized that ArathEULS3 is transcriptionally regulated by osmotic stress responses. Here we present a detailed expression analysis of the ArathEULS3 lectin gene. Under normal growth conditions, ArathEULS3 is stably expressed throughout plant development. After ABA, NaCl and methyl jasmonate (MeJA) treatments transcription is upregulated. Furthermore, in silico promoter and co-expression analyses suggested the A. thaliana Homeobox 7 (ATHB-7) as a candidate transcription factor that may regulate ArathEULS3 expression. Taken together, our data confirm that the ArathEULS3 lectin gene indeed shows a stress-inducible expression pattern. We speculate on a role for ArathEULS3 in the plant stress response.