Cloning and Expression Analysis of A Glutathione-S-transferase Gene in The Latex of Hevea brasiliensis(para rubber tree)

【Objcetive】The objective of this study is to clone the cDNA and genomic clone of a glutathione-S-transferase(GST) from rubber tree,and characterize its structural and phylogenetic characteristics,investigate its expression patterns under various abiotic stresses and hormone treatments.【Method】Combined with the latex EST database,RT-PCR and PCR were used to clone the full length cDNA and genomic DNA of a Hevea GST,respectively.On-line bioinformatics tools were used to predict the conserved functional domains and subcellular localization.Clustal X was used to construct the phylogenetic tree.Real-time RT-PCR(qRT-PCR) was used to characterize the expression patterns of the Hevea GST gene under various treatments(tapping,wounding,chilling,hormone and tapping panel dryness).【Result】The full-length cDNA(793 bp) encoding a 25.4 kD(219 aa) Tau GST protein was firstly cloned from the latex of H.brasiliensis,named HbGSTU1 and deposited in GenBank(JF729318).The genomic DNA(1 313 bp) of HbGSTU1 was also cloned,which contains one intron(520 bp) and two exons.HbGSTU1 protein contained the Tau GST-specific N-terminal domain(G site) and the C-terminal domain(H site).HbGSTU1 was predicted to be a cytoplasmic protein,which shared the highest amino acid identity(85%) with a GST from Ricinus communis.The qRT-PCR results show that HbGSTU1 expression was regulated by tapping,wounding,4℃ chilling,2,4-D and Ethrel,but not by the three hormones JA,SA and ABA.【Conclusion】HbGSTU1 is a typical Tau GST protein,and is implicated in stress-responses in Hevea tree,which may serve as a target gene for Hevea molecular breeding.