Rye (Secale cereale L.) chromatins have been used to introduce agronomically important traits into wheat (Triticum aestivum L.). Wheat-rye translocations in the form of 1RS.1AL, 1RS.1BL, 2BS.2RL have been developed for an important genetic source of disease and pest resistance. The long arm of rye chromosome 2 (2RL) has valuable genes that confer resistance to pests such as biotype L of Hessian fly, powdery mildew, leaf and stem rust. Here, we report the generation and analysis of expressed sequence tags from Hessian fly infested wheat-rye translocation. RNAs were isolated from young seedlings infested by Hessian fly. cDNA library was constructed using Clontech cDNA library construction kit. Random sequencing of candidate clones were performed. The EST clones might be useful to clone target gene sequences and would provide clues on molecular interaction between wheat and Hessian fly.

The Hessian fly, Mayetiola destructor (Say), is known to be one of the major insect herbivores of wheat worldwide. In order to provide molecular events on interactions of the NIL with H21 and larvae of Hessian fly biotype L, the TaCR1 gene, Triticum aestivum cytokinin repressed 1, was isolated through the suppression subtractive hybridization, which was constructed using stems of the NIL with H21 at 6 days after infestation as tester and stems of the recurrent parent Coker797 without H21 at 6 days after infestation as driver. Transcript levels of TaCR1 mRNA in the NIL with H21 were highest at 6 days after infestation but in the Coker797 without H21 until 8 days were similar with those of non-infested plants. Expression of the TaCR1 gene was decreased at early time and then recovered after wounding or H2O 2 treatment as well as 6-BAP treatment. Transcripts levels of the TaCR1 gene was changed after MeJA, SA, ethephone, or ABA treatment. In drought treatment, the TaCRl gene were increased at early stage of stress and then decreased at late stage. Expression of the TaCRl gene was continued to decrease through 24 h in the cold treatment. Although the TaCRl gene is increased through infestation in NIL with H21, further study was required to elucidate a role on resistance against larvae of Hessian fly. However, the TaCR1 gene could be used as marker gene on response of plants against abiotic stresses as well as application of plants with several hormones.