Transformation Of TaPDR1 Gene Into Common Wheat And Genetic Analysis Of Fusarium Head Blight Susceptibility Of Mutant NAUH102 From Wangshuibai

Wheat scab not only reduces crop yield and grain quality, but also contaminates seeds with mycotoxin such as deoxinivalenol (DON), which is toxic to animals and humans. Identification of DON-responsive genes is very important to understand the genetic mechanism of FHB resistance. According to geneChip analysis, Shang (2009) identified an EST encoding an ABC (ATP-Binding Cassette) transporter that was up-regulated by the induction of DON in a wheat landrace Wangshuibai. The whole length cDNA clone of TaPDR1 was obtained and physically mapped on chromosome 5A using the Nulli-tetrasomic lines of Chinese Spring. Expression patterns of TaPDR1 were different in wildtype Wangshuibai and the FHB-susceptible mutant, indicating that TaPDRl may be related to FHB resistance. In order to identify the function of TaPDR1 in the response of FHB resistance, TaPDRl gene was transformed into common wheat by genegun bombardment to obtain transgenic plants. In this research, the inheritance mechanism of the FHB susceptibility of a Wangshuibai FHB susceptible mutant NAUH102 was also characterized. By molecular marker analysis, it was found that TaPDRl homologous gene on chromosome 5D (TaPDR1-5D) was found to be deleted in NAUH102. The main results obtained are as follows:1. TaPDR1 full-length cDNA was constructed into PBI220 and the over-expression vector was transformed into Yangmai 158 (FHB mid-susceptible wheat landrace) by genegun bombardment. To all,54 To regeneration plants were obtained. PCR analysis indicated 8 of them were positive transgenic plants. FHB resistance evaluation for the transgenic plants showed that only 3 of the 8 plants showed significant difference of FHB resistance compared with the untransformed Yangmai 158, and the other plants didn't. As TaPDR1 was up-regulated induced by DON, whether it involved in DON resistance remains to be characterized.2. Primer pairs SH49S/SH49A, designed by Shang (2009) according to the cDNA sequence of TaPDRl, were used for amplification of the genomic DNA from Wangshuibai and NAUH102, a Wangshuibai FHB susceptible mutant. Failure amplification of the 5D-specific bands of the primer pair of in NAUH102 indicated that the 5D homologous gene of TaPDRl in NAUH102 was deleted. For further verification of the relationship of the deletion on chromosome 5D in NAUH102 and its susceptibility to FHB, SH49S/SH49A, which could differentiate the 5D fragment deletion (designated as 5D-) in NAUH102 and the intact 5D (designated as 5D+) in Wangshuibai, was used for amplification using the genomic DNA of the (Wangshuibai×NAUH 117) F2 individuals. The results showed that all 5D+plants were FHB resistant and all 5D-were susceptible, suggesting that increased susceptibility in NAUH102 may due to the deletion of a chromosome fragment of chromosome 5D containing the TaPDR1-5D.3. TaPDRl homologous gene TaPDR1-5D was cloned by homology cloning technology, and this laid the foundation for further study the relationship between the gene and FHB resistance of Wangshuibai.