Analysis Of Resistant Function Of ShWRKY6 In Tomato

Adverse environmental conditions such as high or low temperature, drought, high salt and other important factors seriously affected tomato production and quality, discovering resistance related genes and its function in wild tomato, it opens up more direct, easier and effective way for tomato stress resistance breeding. The WRKY gene could be induced by the external environment, and involved in various physiological activities of plants. At present, the majority of reported WRKY genes were in the model plant such as rice or Arabidopsis thaliana, whereas the reported WRKY genes also small in tomato. In this study, we cloned a WRKY transcription factor Sh WRKY6 from S.habrochaites LA1777, constructed overexpression vector and genetic transformation, and researched stress resistance function of transgenic plants. The main conclusions are as follows:1. Sh WRKY6 is in Class IIb WRKY type proten which encods 163 amino acids and contain a tipical WRKY domains. There are several amino acids changes and amino acids insertion or deletion compared with cultivated tomato in Sh WRKY6 sequence.2. ShWRKY6 is constitutively expressed in different tissues of LA1777, the expression of highest in leaves and lowest in fruit. Sh WRKY6 was strongly induced by drought, high salt, ABA, MV and other abiotic stress.3. We constructed Sh WRKY6 overexpression vector and transferred into a cultivated tomato A57, and successful obtained overexpressing transgenic plant.4. The seedlings of the transgenic plants were did defense responses experiments, we found that the resistant to drought, high salt and low temperature were significantly enhanced in transgenic plants. The overexpressing lines growth significantly better than the control plants under drought stress, remained normal growth, and MDA content was significantly lower than the control, the osmolyte of proline and soluble sugar were higher than that in control, stomatal smaller, drought-related genes were significantly increased expression such as CAT,SOD, APX,Sl TIP2, Msr B2, and a higher survival rate after rehydration than control. Transgenic plants antioxidant capacity increased. Under salt stress, the chlorophyll content of leaves in control decreased more quickly than overexpressing lines, while proline and soluble sugar content of overexpressing lines significantly higher than the control. Leaves of transgenic plants relative conductivity and MDA were significantly lower than Control under cold stress.5. We obtained candidate several proteins which could be interacted with Sh WRKY6 via Yeast Two-Hybrid, Membrane protein, Ferredoxin I, Calcium- dependent protein kinase 2, point to point validation experiment indicated they did not interacted with Sh WRKY6.