CAJ | 학술논문

在富集低磷胁迫特异表达基因的小麦根系cDNA差减杂交文库中,鉴定了1个与拟南芥WRKY75同源的小麦WRKY型转录因子基因表达序列标签(EST).依据该EST序列高度同源的小麦WRKY72b序列,克隆了对应基因TaWRKY726-1.TaWRKY72b-1与WRKY72b在cDNA序列上有2个碱基的差异,但编码氨基酸没有改变.TaWRKY72b-1开放阅读框为621 bp,编码206个氨基酸残基,氨基酸组成上含有保守的WRKY基序和C2H2基序.系统进化分析表明,TaWRKY72b-1与小麦WRKY72a和大麦WRKY12可能来自相同的祖先.与对照供磷水平(2 mmol L~(-1)P)相比,低磷处理使根叶中TaWRKY72b-1的转录本数量均明显增多.表明TaWRKY72b-1对低磷胁迫逆境产生了明显的应答作用.TaWRKY726-1在烟草中表达表明,低磷胁迫条件下,高表达TaWRKY72b-1的烟草植株干重、单株磷累积量和磷利用效率均较对照明显增加.因此,TaWRKY72b-1基因在改善低磷胁迫下作物的磷效率中可能具有较重要的应用价值.
재부집저린협박특이표체기인적소맥근계cDNA차감잡교문고중,감정료1개여의남개WRKY75동원적소맥WRKY형전록인자기인표체서렬표첨(EST).의거해EST서렬고도동원적소맥WRKY72b서렬,극륭료대응기인TaWRKY726-1.TaWRKY72b-1여WRKY72b재cDNA서렬상유2개감기적차이,단편마안기산몰유개변.TaWRKY72b-1개방열독광위621 bp,편마206개안기산잔기,안기산조성상함유보수적WRKY기서화C2H2기서.계통진화분석표명,TaWRKY72b-1여소맥WRKY72a화대맥WRKY12가능래자상동적조선.여대조공린수평(2 mmol L~(-1)P)상비,저린처리사근협중TaWRKY72b-1적전록본수량균명현증다.표명TaWRKY72b-1대저린협박역경산생료명현적응답작용.TaWRKY726-1재연초중표체표명,저린협박조건하,고표체TaWRKY72b-1적연초식주간중、단주린루적량화린이용효솔균교대조명현증가.인차,TaWRKY72b-1기인재개선저린협박하작물적린효솔중가능구유교중요적응용개치.
Phosphorus is one of the indispensable elements in plant growth and development, which is the main component for ATP, nucleic acid, and lecithin. Since phosphorus usually exists in the hard-absorption compounds in soil to cause plant suffering from phosphorus deficiency during growing stage. So plant morphological and physiologically develops the adaptation to low phosphorus stress. Transcription regulation plays an important role in responding to deficient-P cue in plants. Several transcription factors mediating the deficient@ signal transduction have been reported in Arabidopsis and rice. But no similar studies have been conducted in wheat by now. In this study, an expressed sequence tag (EST) homologous to Arabidopsis WRKY75 was identified based on sequencing of clones from a subtraetive root cDNA library, in which the differential expressed genes responding to low-P were enriched. The EST gene with high similarity to wheat WRKY72b (GenBank accession No. EF368383), was cloned and referred to TaWRKY72b-1. TaWRKY72b-1 had two base differences with WRKY72b at the cDNA sequence, with an open reading frame (OR.F) of 621 bp and encoding a polypeptide of 206 amino acids. TaWRKY72b-1 contained one of conserved WRKY motif and one of C_2H_2 zinc finger motif. Phylogenetic tree analysis indicated that TaWRKY72b-1, wheat WRKY72a and barley WRKY12 were possibly derived from one ancestor. Compared with those in sufficient-P (2 mmol L~(-1) P) condition, the transcripts of TaWRKY72b-1 in roots and leaves under the defieient-P (20 μmol L~(-1) P) condition were all dramatically increased, suggesting that TaWRKY72b-1 gene was involved in the response to low P stress in the plants. Under deficient-P condition, the expression of TaWRKY72b-1 in transgenic tobacco plants obviously increased plant dry weights, plant accumulative phosphorus amount, and phosphorus utilization efficiency compared with that in CK (empty vector transformed plants). Therefore, the TaWRKY72b-1 gene has possibly a potential use in improving the crop phosphorus use efficiency under low-Pi stress condition.