Abstract

Transcription factors of AP2/ERF superfamily are generally involved in defense responses of plants to biotic and abiotic stresses. Although, defense proteins are present in abundance in laticifers of rubber tree, little is known about their transcriptional regulation. In this study, a full length cDNA, referred to asHbEREBP2 was characterized by means of bioinformatic analysis and quantitative real-time RT-PCR. The HbEREBP2 was 786-bp in length and contained a 480-bp open reading frame (ORF) encoding a protein of 159 amino acid residues. Bioinformatic analysis showed that the deduced amino acid sequence of HbEREBP2 had a specific domain of AP2 superfamily and shared relative high identity with members of CBF/DREB subfamily from different plant species. Quantitative real-time RT-PCR revealed that methyl jasmonate was more effective than ethylene and rapidly than mechanical wounding on up-regulating HbEREBP2expression. The results suggest that HbEREBP2 may be involved in the regulation of jasmonate-mediated defense responses in laticifers of rubber tree.

Key words: Hevea brasiliensis, Laticifer, defense proteins, AP2/ERF transcription factor, Methyl jasmonates, Ethephon, mechanical wounding.

Abbreviation

AP2, APETALA2; CRT, C-repeat; CBF/DREB, dehydration-responsive element; EREBP, ethylene-responsive element binging protein; ERE, ethylene-response elements; ERF, ethylene-response factors; EST, expressed sequence tag; ET, ethylene; JA, jasmonic acid; Me-JA, methyl jasmonate; SA,salicylic acid; ORF, open reading frame; PCR, polymerase chain reaction; RACE,rapid amplification of cDNA ends; RT-PCR, reverse transcriptase polymerase chain reaction; UTR, untranslated region.