[Molecular marker analysis of wheat-Roegneria ciliaris additions lines.].

A total of 135 EST, 27 STS, and 253 SSR primer pairs located in 7 homoeologous groups of wheat and barly were used for amplification of 24 possible Wheat-R. ciliaris disomic addition lines. Fifty-five primer pairs could amplified polymorphic bands between common wheat variety "Inayama Komugi" and the Inayama Komugi- R. ciliaris amphiploid, and 31 of the 55 could amplify the specific bands of R. ciliaris in the addition lines. According to the PCR (polymerase Chain Reaction) results, the added R. ciliaris chromosomes in lines 07K02, 07K06, 07K39, 07K201, 07K202, 07K255, and 07K256 belong to homoeologous group 1 of wheat; the added R. ciliaris chromosomes in lines 07K07, 07K08, 07K09, 07K11, 07K14, and 07K17 belong to homoeologous group 2 of wheat; the added R. ciliaris chromosomes in lines 07K15, 07K16, 07K21, and 07K47 belong to homoeologous group 6 of wheat.

Plastidial glutathione reductase from Haynaldia villosa is an enhancer of powdery mildew resistance in wheat (Triticum aestivum).

A full-length cDNA (Hv-GR) whose transcript accumulation increased in response to infection by Blumeria graminis DC.f.sp. tritici (Bgt) was isolated from Haynaldia villosa. Southern analysis revealed a single copy of Hv-GR present in H. villosa. This gene encodes a glutathione reductase (GR) with high similarity to chloroplastic GRs from other plant species. Chloroplastic localization of Hv-GR was confirmed by targeting of the green fluorescent protein (GFP)-Hv-GR fusion protein to chloroplasts of epidermal guard cells. Following inoculation with Bgt, transcript accumulation of Hv-GR increased in a resistant line of wheat, but no significant change was observed in a susceptible line. In vivo function of Hv-GR in converting oxidized glutathione (GSSG) to the reduced form (GSH) was verified through heterologous expression of Hv-GR in a yeast GR-deficient mutant. As expected, overexpression of this gene resulted in increased resistance of the mutant to H(2)O(2), indicating a critical role for Hv-GR in protecting cells against oxidative stress. Moreover, overexpression of Hv-GR in a susceptible wheat variety, Triticum aestivum cv. Yangmai 158, enhanced resistance to powdery mildew and induced transcript accumulation of other pathogenesis-related genes, PR-1a and PR-5, through increasing the foliar GSH/GSSG ratio. Therefore, we concluded that a high ratio of GSH to GSSG is required for wheat defense against Bgt, and that chloroplastic GR enzymes might serve as a redox mediator for NPR1 activation.

[Discrimination of the Triticum aestivum-T. timopheevii introgression lines using PCR-based molecular markers].

In order to determine the fragment size of Triticum timopheevii chromosome segments introduced into wheat background and physically map the Pm6 gene, a total of 72 primers (including SSR and STS primers) were used to analyze the eight introduced introgression lines containing Pm6 gene. Referring to the available mapping information of the analyzed markers on chromosome 2B, Pm6 was physically located in distal part of the long arm of chromosome 2B at the region of Bin 2BL-6. The introgressed fragment sizes of the chromosome 2G in different introgression lines was determined to be as follow (from short to long): IGV1-465