Abstract:

【Objective】 Based on the cloning of wheat zinc finger protein gene TaZAT6, the molecular characterization and the expression patterns under various Pi levels of this gene were studied. 【Method】 After sequencing of clones in a subtractive suppression cDNA library constructed from cv. Shixin828, in which the differential expressed genes in various deficient-Pi time points were enriched, a new EST of zinc finger protein type transcription factor was identified. The gene, TaZAT6, corresponding to this EST, was cloned using RT-PCR approach from cv. Shixin828 and Ji7369. Similarly, the expression patterns of TaZAT6 under various Pi conditions were analyzed with RT-PCR method. 【Result】 With an open reading frame of 717 bp, TaZAT6 encoded 238 amino acids, in which containing one conserved nuclear location signal (NLS), two C2H2 zinc-finger domains, and one conserved DLN box. Phylogenetic analysis suggested that TaZAT6 derived from same ancestor with other two zinc-finger protein gene ZAT22 and ZAT23 in wheat. The expression of TaZAT6 was shown to be Pi-deprivation inducible, and reduced to the level of pre-initiation of low-Pi treatment when resupply of normal phosphorus (2 mmol?L-1 Pi). Compared to those of Ji7369, a cultivar of low-P use efficiency, TaZAT6 in Shixin828 had much stronger capability of responding to the deficient-Pi treatment. TaPT2, one high-affinity phosphate transporters, displayed similar expression patterns with TaZAT6 when treated with low Pi, suggesting that its expression was partly regulated by TaZAT6 at the transcription level. 【Conclusion】 The stronger responding capability of TaZAT6 to low-Pi and its further transcriptional regulation of corresponding downstream genes, is possibly related to the high-P use efficiency of Shixin828 under deficient-Pi condition.

Key words: wheat (Triticum aestivum L.)')">wheat (Triticum aestivum L.), trancription factor, zinc-finger protein gene, cloning, expression