Clone And Expression Analysis Of Transciption Factor Gene TaWRKY Induced By Stripe Rust Fungus In Wheat

Wheat is one of the most important food crops in the world, and is the second largest food crop planted in China. Stripe rust is one of the most harmful diseases against wheat production. On pandemic years, it could significantly grain yield and end-use quality. Currently, the main methods to defense the stripe rust are fostering and promoting varieties resistant to stripe rust, supplemented with drug prevention and culture controling, in which gaining and popularized good metarial is the main way, for its safety and effectivity. Among this, resistant gene has to be discovered and used as an imporant basis.During the defense between the pathogens and plants, series of signal transducton are involved, and in which transcription factors play an important role. WRKY is a transcription factor families found in plants recent years and classified as zinc finger transcription factor families. WRKY is found to bind with W-box locating in the promoter region of disease resistant gene.Then regulate expression of downstream genes and open the plant defense response system.Now, in many plants such as Arabidopsis thaliana and tabacum, various of WRKY factors are confirmed to work during the defent process. For example, transcription factor TaWRKY34 has been reported to be related to the powdery mildew resistance in Triticum aestivum. However, until now, there is no report about the participating in the stripe rust resistance of WRKY factor in wheat.1. In this study, Chinese Spring and Chinese Spring-Agropyron elongatum 3E addition line were used as materials. A fragment length of 813bp was obtained by RT-PCR after extracting total RNA, with primers of HvWRKY9 reported in barley WRKY research paper. This fragment encodes 270 amino acid residues which includes the conserved WRKY domain WRKYGQK, and is named TaWRKY. The similarity between TaWRKY and HvWRKY9 is about 93%. Until now there is no related sequence been reported in wheat. By sequences analysis and comparison, this transciption facter TaWRKY can be speculated as a member of group II WRKY family.2. After inducing by the stripe rust fungus, we found that expression levels of TaWRKY increased in both the Chinese Spring and Chinese Spring-Agropyron elongatum 3E addition lines through real time q-PCR. In Chinese Spring, the expression reached a maximum at 24h after being induced, about 6 times more than the initial level. While in Chinese Spring-Agropyron elongatum 3E addition line, the expression reached a small peak at 36h and increased sharply at 96h by about 10 and 40 times than the initial level respectively.We can speculate that the transcription factor TaWRKY may participate the defense reaction to stripe rust in wheat based on the result above.3. From the research of the stripe rust resistance in both two materials, we found that the expression of TaWRKY was different.The expression of TaWRKY in Chinese Spring-Agropyron elongatum 3E addition line was about 2,1.5,10,3,40 times more than that in Chinese Spring at 12 h,24h,36h,72 h,96h after inducing. All above may lead to a result that TaWRKY gene may involve in resistance to stripe rust response and its expression increase by the addition of Agropyron elongatum chromosome 3E in Chinese Spring background.