【目的】以中国春遗传背景的整套B染色体双端体为材料,鉴定磷转运蛋白基因TaPHT2;1,的染色体定位特征。解析不同供磷水平下,上述材料和不同磷利用效率小麦品种该基因的表达特征及其与植株干物质生产能力和磷效率特征的联系。【方法】采用溶液培养法水培中国春(CS)及该品种遗传背景的整套B染色体组双端体和不同磷效率小麦品种材料。以B染色体组供试端体为材料进行TaPHT2;1 PCR扩增,鉴定TaPHT2;1在染色体上的定位。采用半定量RT—PCR及qRT-PCR技术分析B染色体组供试端体和小麦品种TaPHT2;1的表达水平。采用常规分析技术,测定供试材料单株干重和磷吸收参数。【结果】①PCR检测发现,在CS及所有供试B染色体组双端体材料中,除缺失1B长臂的1BS外,其它所有材料均能特异扩增出目标基因TaPHT2;1,表明TaPHT2;1,定位在1B长臂。②丰、缺磷条件下,乃册』在cs及除1BS外双端体根、叶中的表达均表现为叶片优势表达特征,且在叶片中表达受到低磷胁迫的诱导。乃鹏J在根系中的表达不受低磷逆境调控。表明厅职J在介导丰磷下磷素吸收、转运及增强低磷下植株体内磷素再度调运中可能发挥重要功能。③丰磷条件下,与CS相比,1BS的单株干重和全磷含量显著降低;缺磷条件下,1BS的单株干重与CS相比也显著下降,但全磷含量增加。表明位于1B染色体长臂后的磷转运蛋白基因乃职,对丰、缺磷条件下的植株磷素吸收、转运具有较大影响,进一步对不同供磷水平下的植株干重产生重要调控效应。④丰磷条件下,与CS相比,1BS的单株磷累积量显著增加,磷利用效率没有改变;缺磷条件下,与CS相比,1BS的单株磷累积量没有变化,磷利用效率显著降低。不同磷利用效率品种相比,丰磷条件下,随着品种磷利用效率提高,叶片中TaPHT2;1的表达水平、单?
[Objective] In this study, the chromosome localization of TaPHT2;1, a phosphate transporter gene in wheat, was determined by using Chinese spring (CS) and its chromosome-based ditelosimic lines of B genome. Moreover, the expression pattern of TaPHT2;1 as well as its relationship with plant dry matter production and P use efficiency was studied under high- and low-Pi conditions. [ Method ] The cultivar CS together with its chromosome-based ditelosimic lines of B genome as well as wheat cultivars with varied P use efficiencies was hydroponically cultured. The chromosomal localization of TaPHT2;1 was detected by PCR amplification using specific primers with genome DNA of the tested materials as the template. The expression pattems of TaPHT2; 1 in CS, its chromosome-based ditelosimic lines of B genome, and wheat cultivars with different P use efficiencies were determined by semi-quantitative RT-PCR and real time PCR. The plant dry weight and P acquisition parameters of the tested materials were assayed by following the conventional approach. [Result] For the CS and its chromosome-based ditelosimic lines ofB genome, only 1BS that a line lacking the long arm of 1B was failed to detect the transcripts of TaPHT2;1, indicating that TaPHT2;1 is located in the long arm of lB. Under P sufficience and P deprivation, the expression of TaPHT2;1 in roots and leaves of CS and other ditelosimic lines of B genome other than 1BS exhibited to be predominant in leaves and the expression levels were induced by Pi deprivation stress. The expression of TaPHT2;1 in roots was not regulated by Pi deprivation stress. These results suggest that TaPHT2;1 is involved in mediating plant Pi acquisition and cellular Pi translocation under Pi sufficience and in regulating re-transportation of cellular Pi under Pi deprivation. Under P sufficience, the plant dry weight and total Pi content in 1BS were significantly decreased in comparison with those in CS; under Pi deprivation, the plant dry weight of 1BS was also significantly lower than that of