Cloning, expression of harpin gene from a Erwinia amylovora EAKKB29 isolate and studying its effect on wheat (Triticum aestivum L.) seedlings

Harpin, occured naturally, is a bacterial based protein. Harpin, which mobilezes the natural defense mechanism of the plant, has been isolated from bacterial pathogen Erwinia amylovora.This study is about cloning of Erwinia amylovora EAKKB29 hrpN gene, isolation of its gene product and its effects on Triticum aestivum plant. Having defined the base sequencing of 1200 nt gene, which coding hrpN gene, was cloned to pET-28a(+) and pET- 20b (+) vectors. Clones were transformod to E.coli BL21, and expression was performed and Harpin protein was purified. The molecular weight of Harpin protein was determined as 40 kDa, effects of prufied HrpN(Ea)E, HrpN(Ea)E-His, HrpN(Ea)I and HrpN(Ea)I-His proteins on leaf length, root length, dry weight and wet weight of Triticum aestivum shoots were studied. HrpN(Ea)I was found the most effective one. The most effective concentration of it was determined as 300μl (4,5 μg). Over 900 μl (13,5 μg) applications have reducing effects on studied parameters.