The Study Of Antisense Expression Vectors Construction Of Tobacco Disease-Resistant Defense Genes SGT1,RAR1and Functions

Partial hypersensitive reactions could produce some kinds of signal molecules, whenplants are infected by virus or pathogen. The entire plant could resist more virus andpathogen, because defense reaction of the plant could be induceded by the signalmolecules. RAR1and SGT1were early reported as the plant defense signal protein.The signal transmission function of RAR1/SGT1was found in the course of plantdisease-resistance. Tobacco is a kind of very important economic crop. Tobacco couldbe damaged by many kinds of bacterial diseases. People look for some methods ofcontrolling tobacco disease by study in the defense signal components.Two antisense expression vectors of RAR1and SGT1are constituted at the sduty.Tobacco is transducted by two antisense expression vectors, and transgenic tobaccoplants were obtained. As a result, the resistance of TMV and red star disease wereidentified.The primary research methods and results were as follows:1. As full length of RAR1,SGT1by published at GenBank, PCR amplification primershave been designed as segmental and specific sequence. The segmental sequences ofRAR1(273bp) and SGT1(497bp) have been amplified. After be identified byrestriction endonuclease reaction sequencing, it showed that the sequences wereinserted between the promoter and terminator of PupTn, and the antisense expressionvectors have been builded successfully.2. Tobacco YongDing400and HongHuaDaJinYuan have been transformed byDordrecht method. The first generation of genetically modified tobaccos has beenobtained by testing marker genes,GUS and by RT-PCR, therefore12TobaccoYong-Ding400plants transformed with RAR1,10Tobacco HongHuaDaJinYuanplants transformed with RAR1were obtained,14Tobacco YongDing400plantstransformed with SGT1,12Tobacco HongHuaDaJinYuan plants transformed withSGT1.3. Tobacco plants have been infected by TMV or red star disease. It showed that thefirst generation of genetically modified tobaccos what has inserted segmental sequences of RAR1and SGT1could resist TMV well, but red star diseaseindistinctively.