Identification and Functional Evaluation of Three Polyubiquitin Promoters from Hevea brasiliensis

Hevea brasiliensis is an economically important tree species that provides the only commercial source of natural rubber. The replacement CaMV35S promoter by endogenous polyubiquitin promoters may be a viable way to improve genetic transformation this species. However, no in have been reported yet. Here, we identified three genes HbUBI10.1, HbUBI10.2 and HbUBI10.3, which encode ubiquitin monomers having nearly identical amino acid sequences AtUBQ10. genomic fragments upstream these HbUBI genes, including signature leading introns, were amplified as putative promoters. In silico analysis showed number cis-acting elements are conserved within strong constitutive presented Transcriptomic data revealed HbUBI10.1 had expression plants. Semi-quantitative RT-PCR expressed higher than GUS gene driven transgenic leaves. All exhibited capability direct GFP both transient stable assays, although they produced lower protoplast efficiencies promoter. These will expand availability for driving transgene engineering.