摘要
【目的】在克隆小麦锌指蛋白基因TaZAT6的基础上,深入研究该基因的分子特征和在不同磷水平下的表达特性。【方法】通过对富集石新828不同低磷胁迫时间点特异表达基因的cDNA差减文库克隆测序,获得1锌指蛋白型转录因子基因EST。利用RT-PCR技术,在低磷处理24h的石新828和冀7369根系中克隆了该锌指蛋白基因TaZAT6,并采用该技术进一步研究该基因应答介质中Pi的特征。【结果】TaZAT6开放阅读框为717bp,编码238个氨基酸残基,编码的蛋白质中含有1个保守的核定位区、2个C2H2锌指蛋白域和1个DLN保守盒。系统进化分析表明,TaZAT6可能与另外2个小麦锌指蛋白基因ZAT22和ZAT23具有共同的祖先。TaZAT6的表达表现为明显的低磷诱导特性,恢复至正常磷水平下其表达降低至磷胁迫前水平。与磷低效品种冀7369相比,石新828根叶中TaZAT6具有更强应答低磷胁迫能力。小麦高亲和磷转运蛋白基因TaPT2对生长介质中Pi的响应特点与TaZAT6相似,表明TaZAT6可能参与了对TaPT2的转录调节。【结论】低磷胁迫条件下,石新828中TaZAT6具有较强应答Pi能力,由此进一步调控下游基因表达,可能与该品种在低磷下表现磷高效具有密切联系。
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 pattems of TaZAT6 under various Pi conditions were analyzed with RT-PCR method. [Result] With an open reading flame 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 eultivar 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.
出处
《中国农业科学》
CAS
CSCD
北大核心
2009年第9期3339-3345,共7页
Scientia Agricultura Sinica
基金
国家"973"计划前期研究专项(2007CB116209)
河北省重点基础研究项目(08965525D)
