Abstract:

In this study，the AgERF4 gene was cloned from celery variety‘Liuhehuangxinqin’.
Sequence analysis indicated that the length of AgERF4 gene was 597 bp，which encoded 198 amino acids.
It is predicted that the molecular mass of its protein was 21.43 kD，and pI was 8.51. Phylogenetic analysis
indicated that the ERF4 showed high evolutionary conservation among celery and other species. The
AgERF4 belongs to hydrophilic protein. Yeast one-hybrid and β-galactosidase activity assays confirmed
the GCC box-binding activities of AgERF4 factor. RT-qPCR analysis demonstrated that the AgERF4 gene
was mainly expressed in leaf blade. The expression profiles of the AgERF4 gene in root and petiole have
no significant difference. When exposed to high or low temperature treatments，the expression level of
AgERF4 gene showed an increased trend at first，followed by a reduction. Under salt treatments，the
transcription of AgERF4 was higher than that of the control. The results suggested that AgERF4 factor
may play important roles in the defense response to abiotic stress in celery.

Key words: Apium graveolens, ERF protein, yeast one-hybrid, abiotic stress, gene expression