Breeding Of Anti-taedr1 Transgenic Wheat For Powdery Mildew Resistance

Powdery mildew caused by Blumeria graminis (DC.) E. O. Speer f. sp. tritici (Bgt), is one of the most serious diseases of common wheat(Triticum aestivum L.) in China and many countries of the world. With the molecular biology study on plant disease resistance mechanism, cloning of powdery mildew resistance related genes progress rapidly. To research wheat disease resistance molecular mechanism, understand the disease resistance signal pathways and explore the key signaling genes will provide theoretical and material basis for transgenic wheat disease resistance breeding. Referenced disease resistance molecular mechanism of Arabidopsis, a putative negative regulator of wheat disease resistance gene TaEDR1 was cloned by RACE. Using inhibiting gene expression technology, a target gene fregmant was reversly inserted into a binary expression vector, and then transfored it into high-yield wheat'Zhoumai 18'. Some powdery mildew resistant transgenic plants were obtained.1,Cloning and characterization of TaEDR1: RACE technique was successfully used to amplify of a cDNA from leaves of wheat-rye 1BL/1RS translocation line 22/2439 induced with Bgt. A full-length cDNA clone obtained is highly homologous to barley EDR1 gene. It was named as TaEDR1(GenBank accession AY743662). TaEDR1 gene cDNA is 3 050 bp, encoding a 959 amino acid constituted peptide. The nucleotide sequence and deduced amino acid sequence of TaEDR1 were homologous to HvEDR1 by 96 % and 92 % identity respectively. Expression analysis in different organs in wheat of TaEDR1gene was carried out by Semi-QRT-PCR. The transcribing of TaEDR1 in leaves was enhanced slightly by the pathogen infection. TaEDR1 gene was expressed in leaf, spike, stem and root.2,Plant expression vector construction of TaEDR1 gene: An expression vector of pAHC25-anti2-TaEDR1 for plant was constructed using pAHC25. The PCR result of pCAMBIA-1301/220U-TaEDR1 with primers TaEDR1-R-F and TaEDR1-R-R, which adding a pair of restriction sites. TaEDR1 gene and pAHC25 vector fragments were received by digestion amplified products and pAHC25 vector, then the fragment of TaEDR1 gene was inserted directionally into downstream of Ubi promoter and the upstream of nos3' terminator in the monocotyledon expression vector pAHC25, constituting an expression system independently. The plant high-expression vector of pAHC25-anti2-TaEDR1 was constructed, and transformed in the E. coli DH5α.3,The pAHC25-anti2-TaEDR1 vector was transformed into a new high yield wheat cultivar'Zhoumai 18'by pollen-tuber pathway. Some T0 transgenic plants were obtained. Total 9 T0 transgenic plants with transgene and nos terminator were obtained by PPT resistance screening and PCR amplification. 36 powdery mildew resistance enhanced plants were obtained by field assessment, including 23 molecular positive plants.