Cloning and characterization of HbJAZ1 from the laticifer cells in rubber tree (Hevea brasiliensis Muell. Arg.)

摘要

Although jasmonate (JA) signaling has recently been well elucidated in Arabidopsis thaliana, the JASMONATE ZIM domain proteins (JAZs) are suggested to have an important role in regulating specific JA responses in plants, not much is known about how the specific JA responses are regulated in plants. Laticifer is the sole site of natural rubber biosynthesis in rubber tree. Here, the full-length cDNA and promoter region of HbJAZ1 gene were cloned and characterized from the laticifer cells in rubber tree by a combination of molecular techniques and bioinformatic analyses. The cDNA was 1,442-bp long containing an 852-bp open reading frame (ORF) encoding a putative protein of 284 amino acids. The predicted HbJAZ1 protein possessed the conservative ZIM and Jas domains, and was homologous to the JAZ members from Arabidopsis and the JAZ homologs from other plant species. The 976-bp promoter region of HbJAZ1 was isolated using PCR-based DNA Walking. TATA box and other core configurations as well as some special cis-acting elements involving in gibberellin-, jasmonic acid- and wound-responsiveness were found within this region. Transcription pattern analysis revealed that HbJAZ expression was strongly up-regulated by tapping and mechanical wounding, but not by ethrel application. Characterization of HbJAZ1 will attribute to understand JA signaling in laticifers, a specialized tissue for natural rubber biosynthesis in rubber trees.