Research On Improving Plant Persistence Disease Resistance By Inducible Pathways.

In the coevolution with pathogens , plants have evolved complex , integrated defense mechanisms against pathogens infection.Systemic acquired resistance is an important component of plant disease resistance mechanisms. Recently , a lot of work in systemic acquired resistance and signal transduction pathway has been done using the model plant Arabidopsis.In this report , first step, the promoter of pathogenesis-related protein PR-1a was obtained from the genome of tobacco by PCR;the promoter of systemic acquired resistance gene SAR8.2b was also obtained from the genome of tobacco by PCR. Both of promoter we cloned could induced by pathogens or salicylic acid . Arabidopsis thaliana and Arabidopsis Pumila NPR1 gene was amplified by RT--PCR method. NPR1 gene was the key gene in plant SAR, which could actived by salicylic acid and regulate downstreams pathogenesis-related proteins expression.We use promoter PR-1a active NPR1, promoter SAR8.2b active HRAP gene which could intensify and accelerate the intensity and speed of plant hypersensitive response. We constructed the constitulive expression and inducible expression vector to test the anti-disease ability of transgenic plant.The recombinant plasmids pBI121-HRAP,pBI121-PR1a,pBI121-SAR,pBin438-NPR1,pBin438-XNPR1,2300-SAR-HRAP,2301-PR1A-XNPR1,2300 binary vector were transferred into Agrobacterium tumefaciens EHA105 or GV3101. Using leaf discs method, the gene were transferred into tobacco cell. Transferred leafs were selected on solid medium containing Kanamycin. Transgenic tobacco plants were found containing purpose gene by PCR. We used RT-PCR methold to test the purpose gene transcription level. These transgenic tobacco inoculate the TMV virus to testify the anti- disease ability.This research not only laied a foundation for researching on function of NPR1 and HRAP, but also provided a new way for anti-disease genetic engineering, presented theorical significance and applicative prospect.