Modification of Paraburkholderia TALE-Like Protein to Activate Transcription of Target Genes in Plant

The technology of transcription activator-like effector (TALE) is based on designing and synthesizing DNA binding protein as a molecular tool for specific targeting of any desired gene. TALE-like proteins were originally identified in bacteria including two plant pathogenic bacteria and one fungal symbiotic bacteria (namely Paraburkholderia rhizoxinica). Plant transcription activator protein can be customly designed based on the information of the original Paraburkholderia TALE-like protein (BAT). In the present study, we designed a new protein in order to reorder the repeat domain to specifically target the minimal BS3 promoter. This modified BAT sequence was fused to nuclear localization signal (NLS) at the 5` end and Herpes simplex virus VP16 activation domain at the 3` end, then designed protein sequence was reverse translated, de novo synthesized and cloned in a plant expression system. Nicotiana benthamiana plants were co-transformed via agro-infiltration method with the expression cassette with the modified BAT sequence to target the effector binding element (EBE) of the minimal BS3 promoter that drives GUS gene of the mBS3::GUS cassette. Two days post inoculation, plant leaves were GUS-stained and strong signal was detected as indicator for GUS gene activation by the modified BAT sequence. This data suggests that the synthesized BAT protein could be used as a custom transcription activator of any desired genes in plant.