Study On Transfer Of RAR1 Gene Of Plant Disease Resistance Signal Path Into Wheat(Triticum Aestivum L.)

The deseases of wheat powerdery mildew,stripe rust and sharp eye spot have been the main factor causing the production decreasing of wheat in recent years.So,it's important to research emphasis on disease resistance mechanism.The resistance of wheat powerdery mildew,stripe rust is controled by mono-gene which interacts with Avr gene in terms of hypothesis of gene for gene.RAR1 is the fistly identified componets required in resistance mediated by R gene Mla-12 in barly. Later studies also showed that RAR1 widly exsisted in plant,and played an important role in signal pathway. RAR1 gene encodes 25.5 kDa protein, reveals two about 60-amino acid domains,CHORD â… , â…¡ ,two Zn²⁺-binding domains,and shows highly homology with that of barly,rice and Thinopyrum interedium.RAR1 gene is also a required signal molecule in plant disease resistance against kinds of pathogens and virus.In order to understand the role of RAR1 gene in wheat against of different diseases, we isolated a RAR1 gene from a wheat wild-relative Thinopyrum intermedium with multi resistance to various wheat pathogens. Then, we constructed expression vector pURAR1 using RAR1 gene instead of GUS gene of pAHC25, which contained the RAR1 gene and BAR gene respectively under control of the maize ubiquitin promoter.The vector plasmid pURAR1 was bombarded to 3044 immature embryos of an elite wheat variety 'Yangmai 12' by biolistic particle made in BIO-RAD corporation. After regeneration and resistance selection by Bialaphos, 265 resistant plants were grown in plots. Out of them, 23 positive transgenic individuals were identified by PCR assay in the T₀ generation with the transformation frequency of 0.76%.23 positive transgenic individuals were identified by PCR assay in the T₁ generation with segregation rate of 2.6:1.The results of Southern blotting and RT-PCR assay also showed that the transgene RAR1 could be inheritable from T₀ generation to T₁ generation, and could transcript in T₁ plants. The resistance test was performed by inoculating the mixed spore of powerdery mildew,and showed that the RAR1 transgenic individuals in T₁...