Cloning And Stress-related Functional Characterization Of WRKY Transcirpiton Factors Gene In Maize (Zea Mays L.)

WRKY transfactors are involved in responses to biotic and abiotic stresses, and in regulation diverse developmental processes. Three WRKY genes, designated ZmWRKY33, ZmWRKY57and ZmWRKY62, were responsive to stress tolerance and isolated in maize. Their functions in plants were explored preliminarily in this study. The results are summarized as follows:1. ZmWRKY33,ZmWRKY57and ZmWRKY62were all responsive to drought、hight salt and cold stresses.2. Three WRKY genes, ZmWRKY33, ZmWRKY57and ZmWRKY62, were isolated. ZmWRKY33, ZmWRKY57and ZmWRKY62dispartly encode307,311and306amino acid residues, all containing only one conserved WRKY domain with a zinc finger motif of C2H2.3. An overexpression vector for ZmWRKY33was constructed and transformed into rice calli by Agrobacterium-mediated method.20lines of ZmWRKY33-overexpressing T0plants were generated. In the next T₁generation of ZmWRKY33-overexpressing plants, the study of responing to abiotic stresses showed that ZmWRKY33-overexpressing plant showed enhanced drought, hight salt and cold tolerance.4. To determine the subcellular localization of the ZmWRKY33, ZmWRKY57and ZmWRKY62proteins, we generated PRTL2-ZmWRKY33-mGFP, PRTL2-ZmWRKY57-mGFP and PRTL2-ZmWRKY62-mGFP fusion constructs under the control of CaMV35S promoter. Then fusion constructs was bombarded into the onion epidermal cells. The results of this experiment revealed that these fusion proteins are all expressed in the nuclei of the onion epidermal cells. These data thus indicate that the three proteins are all nuclear proteins that may act as a transcription factor to regulate the expression of downstream genes.5. Two overexpression vectors for ZmWRKY57and ZmWRKY62（p-ZmWRKY57（bar+） and p-ZmWRKY62（bar+））were constructed and two double-stranded RNA interfering vectors(p1301（2ZmWRKY57i-bar+） and p1301（2ZmWRKY62i-bar+） were constructed and transformed into Agrobacterium. They may be tansformed into maize.