PlWRKY70: a Paeonia lactiflora transcription factor that sensitively responds to low-temperature, salt and waterlogging stresses

The WRKY family is a specific super gene family in plants that plays a significant regulatory role in abiotic stress in plants. In this paper, the PlWRKY70 gene was cloned by RT-PCR from Paeonia lactiflora ‘Da Fugui’ buds (GenBank accession no. KU891819). The open reading frame of the gene was 936 bp in length, encoding 311 amino acids. The PlWRKY70 gene contained a WRKY domain in its coding region that belonged to the group III WRKY family and was evolutionarily the closest to Paeonia suffruticosa. PlWRKY70 was widely expressed and found at an extremely high level in buds. Moreover, the PlWRKY70 protein was mostly detected in the nucleus. The expression of PlWRKY70 was remarkably influenced by different abiotic stresses with completely different patterns. It could be significantly induced by low-temperature and salt stress, rapidly reaching peak levels after the initial 4 or 8 h of the stress treatment, whereas under waterlogging stress, it was considerably suppressed, dramatically dropping to minimum levels after 2 h of treatment. These profiles suggested that PlWRKY70 was sensitive to low-temperature, salt, and waterlogging stresses in P. lactiflora.