Biological activities of purified harpin(Xoo) and harpin(Xoo) detection in transgenic plants using its polyclonal antibody

Many harpins have been found in plant pathogen bacteria that can elicit disease and insect resistance in plants,and promote plant growth.In this work,we overexpressed and purified Xanthomonas oryzae pv.oryzae harpin,harpin_(Xoo),in Escherichia coli BL21/pGEX-hpal.Harpin_(Xoo) was fused to the C- terminus of glutathione S-transferase (GST) and purified using the Bulk GST purification module and thrombin cleavage capture kit.Purified harpin_(Xoo) protein was sensitive to protease K and stable to heat treatment,and could not induce a hypersensitive response after treatment with various plant metabolic inhibitors;these characteristics were similar to harpin_(Ea) of Erwinia amylovora.The purified harpin_(Xoo) showed a similar ability to induce tobacco mosaic virus resistance in tobacco as harpin_(Ea).Its antibody worked well in detecting the purified harpin_(Xoo).harpin_(Xoo) in the total protein of E.coli BL21/pGEX-hpal and an hpal transgenic rice.