Cloning and identification of a differentially expressed RING E3 ubiquitin-protein ligase gene responding to Jasmonic acid signaling pathway in rubber tree (Hevea brasiliensis)

In order to understand the key metabolic pathways and key genes involved in the latex biosynthesis process in rubber tree, we studied the differential gene expression between latex and leaves of rubber tree by cDNA microarray. The significant analysis of microarray (SAM) method was used, and genes that were differentially expressed in the latex and leaves of rubber tree were selected and subjected to various analyses of KEGG metabolic pathway, clustering, and gene ontology based biological pathways. The results indicated that many differentially expression genes mainly distribute in transcription factor activity, zinc ion binding, transferase activity, ubiquitin-protein ligase activity. One of the zinc finger protein encoded genes, named HbRBX1, which involves in transcription factor activity, zinc ion binding, ubiquitin-protein ligase activity, was cloned and further confirmed the expression patterns in rubber tree latex and rubber tree leaves by Semi-quantitative RT PCR. In order to understand whether the HbRBX1 involve in latex biosynthesis or not, the HbRBX1 expression patterns were also analyzed in response to exogenous jasmonic acid and ethylene, the two types of phytohormone have been proved to involve in latex biosynthesis in rubber tree, the results showed that HbRBX1 can respond to exogenous jasmonic acid while cannot respond to exogenous ethylene, suggested that HbRBX1 maybe participate in the latex biosynthesis through the jasmonic acid pathway.