摘要
在富集低磷逆境的根系cDNA差减文库中,获得了与小麦磷转运蛋白基因TaPT2具有相同序列的表达序列标签(EST)。TaPT2的表达呈根系特异性,对外界低磷逆境呈明显应答,表明该基因在小麦抵御外界低磷逆境中可能发挥重要作用。采用基因组行走技术,克隆了长度为1 300 bp的TaPT2启动子,该启动子含有保守TATA盒、CAAT盒,以及应答低磷逆境的Pho-like元件和其他3个组织特异元件,表明上述元件在调控TaPT2的表达中施加重要影响。用TaPT2启动子驱动报告基因GUS的实验证实,该启动子在烟草中驱动GUS的表达特征与TaPT2在小麦中的表达特征一致,表现为呈根系特异表达且在外界低磷逆境下的GUS活性较正常供磷水平明显增强。因此,TaPT2的表达与其启动子中含有的应答低磷逆境元件和组织特异表达元件密切相关。根系特异表达且呈表达低磷胁迫诱导特征表明,TaPT2在改善小麦植株在低磷下磷素的吸收中可能发挥重要功能。
In a root subtrative cDNA library that enriched the low-Pi induced differential expressed genes,a expressed tag（EST） being identical to TaPT2,a wheat phosphate transporter gene was obtained.TaPT2 was detetcted to be expressed specifically in roots and to be responded dramatically to the external low-Pi stress.Based on genome walking approach,the TaPT2 promoter with a 1 300 bp in length was cloned.The putative promoter contains the conserved elements such as TATA box and CAAT box,as well as a low-Pi responding cis-regulatory elements Pho-like,and three other elements to determine the expression with tissue specific pattern.These regulatory elements are possibly involved in regulation of TaPT2 expression patterns in wheat.The transgenic tobacco plants in which the reporter gene GUS was under the control of TaPT2 promoter was integrated.GUS activities of the transgenic tobacco plants under various Pi supply conditions suggests that TaPT2 promoter directs GUS expression to be root specific and to be induced by low-Pi,in consistent to the expression patterns of TaPT2 in wheat plants.Taken together,it is suggested that the expression patterns of TaPT2 are transcriptional regulated by the distinct cis-regulatory elements located at the promoter.In the meantime,it has been implicated that TaPT2 plays possibly important roles on adaptation to the deficiency of Pi in plants.
出处
《河北农业大学学报》
CAS
CSCD
北大核心
2011年第2期6-12,共7页
Journal of Hebei Agricultural University
基金
国家自然科学基金项目(30971773)
关键词
小麦
磷转运蛋白基因
表达
转录调控
wheat
phosphate transporter
expression
transcriptional regulation
