磷转运蛋白AsPT6对紫云英结瘤及固氮酶活性的影响
Isolation and identification of mutant of symbiotic nitrogen fixation related genes from Sinorhizobium meliloti

采用组织定位、超表达及RNAi等方法对紫云英中的Pht1家族磷转运蛋白AsPT6进行了研究。时空表达结果显示,AsPT6基因在根、茎、叶中均有表达，接种根瘤菌后在根和根瘤中高量表达；化学组织定位分析表明,AsPT6在根和根瘤的维管组织及根和根瘤连接处均有表达，起到向根瘤转运磷的作用；超表达及RNAi结果显示AsPT6能显著影响紫云英的结瘤及固氮酶活性。这些研究结果表明，AsPT6参与根瘤形成和发育过程中磷的转运。
Phosphorus is an important element required for plant growth. The absorption and transportation of Pi are carried out by phosphate transporter in legumes. In this paper,phosphate transporter AsPT6,a new member of pht1 family,was identified in Astragalus sinicus. AsPT6 was expressed in leaves,stems and roots. The expression of AsPT6 was increased significantly in the roots and nodules when inoculated with Mesorhizobium huakuii 7653R. The results of tissue localization showed that AsPT6 was expressed in the vascular tissue of roots,nodules,and the junctions between root and nodule,indicating that AsPT6 may play a role in transporting phosphate from the root to nodule. Overexpression and RNA silence of AsPT6 significantly affected the nodulation and nitrogenase activity of nodules. It is indicated that AsPT6 is involved in the transportation of phosphorus during the formation and development of nodules.