水稻铁氧化酶基因OsLPR5对拟南芥根系发育和养分利用的影响

Effects of rice ferroxidase gene OsLPR5 on root growth and nutrient utilization in Arabidopsis plants

[目的]本文旨在研究水稻铁氧化酶基因OsLPR5对拟南芥根系发育和养分利用的影响,从而解析其作用。[方法]通过蛋白表达、纯化及酶活性测定,确定OsLPR5蛋白具有铁氧化酶活性;利用农杆菌介导花序侵染法创制OsLPR5转化拟南芥atlpr1突变体的转基因材料,通过根系形态鉴定和多种养分含量测定,研究OsLPR5对转基因植株根系发育及养分利用的影响。[结果]p GS-21a-OsLPR5融合蛋白酶活性明显高于对照;低磷条件下,与突变体相比,OsLPR5转化株主根变短,根系总磷、氮、钾、钠、铁、铜和锌等多种养分含量降低,趋于野生型; OsLPR5的表达显著回补了At LPR1基因的突变对主根表型和养分含量的影响,表明OsLPR5在植株根系构型和多种养分利用方面起到重要作用。[结论]OsLPR5蛋白具有铁氧化酶活性,在拟南芥转基因植株中参与低磷条件下根系构型和养分利用等重要过程。

[Objectives]This work is aimed at confirming the effects of rice ferroxidase gene OsLPR 5 on root growth and nutrient utilization in Arabidopsis plants,so as to investigated its function.[Methods]We analysed the ferroxidase activity of OsLPR5 protein expressed in bacteria by specific activity analysis.We obtained transgenic Arabidopsis plants overexpressing OsLPR 5 in the atlpr 1 background using the Agrobacterium-mediated floral dip method,and examined the impact of OsLPR 5 overexpression on root morphology and nutrient utilization known to be related to phosphorous nutrition or its regulation.[Results]Ferroxidase activity of pGS-21a-OsLPR 5 protein was significantly higher than the control.Under the condition of low phosphorus,the primary roots of OsLPR 5 transformed lines became shorter,and the contents of total phosphorus,nitrogen,potassium,sodium,iron,copper and zinc decreased,which tended to wild type.The expression of OsLPR 5 significantly compensated for the effect of AtLPR 1 mutation on primary root phenotype and nutrient content,indicating that OsLPR 5 plays an important role in root architecture and nutrient utilization.[Conclusions]The results confirm that OsLPR5 protein probably has ferroxidase activity,and indicate that OsLPR 5 is probably involved in processes,including root morpholog and nutrient utilization to environmental phosphorus stress.