Cloning and function analysis of JAZ1 gene from Nicotiana tabacum

JAZ (Jasmonate ZIM-domain) protein, as a target protein of E3 ubiquitin ligase degradation SCF^COI1 complex receptor, is a key component in jasmonic acid signal transduction pathway. To identify the function and regulation mechanism of JAZ gene in tobacco, NtJAZ1 was cloned by homologous cloning strategy, and NtJAZ1 function was analyzed by bioinformatics and gene expression patterns. The results showed that NtJAZ1 encoded 239 amino acids with the cDNA sequence of 720 bp. NtJAZ1 protein contained two conserved domains:TIFY and CCT-2 (also known as Jas domain). The secondary structure of NtJAZ1 consisted of α-helix, extended chain and random coil, and its tertiary structure had the structural characteristics of TIFY superfamily protein. Phylogenetic analysis indicated that NtJAZ1 and SlJAZ1 belonged to the same branch and had a close genetic relationship. The expression level of NtJAZ1 was the highest in root treated by Phytophthora parasitica var. nicotianae, followed by stem and leaf. It was speculated that the high expression of NtJAZ1 inhibited the expression of JA response genes, which resulted in the occurrence of tobacco black shank.