Function Of Phosphorus Transporter TaPHT1;9 Mediating Phosphorus Absorption And Utilization In Wheat

Phosphorus is one of the essential nutrients for crops and is the main nutrient limiting factor for yield and quality formation.At present,the utilization efficiency of phosphorus fertilizer in wheat is only 19% in the current season,and the problem of low efficiency of phosphorus fertilizer is extremely prominent.It has become a key limiting factor for wheat nutrient efficiency.Exploring phosphorus efficient genes is of great significance for improving wheat phosphorus utilization efficiency.In the early stage,the research team excavated a high affinity phosphorus transporter TaPHT1;9 through i TRAQ(Isobaric Tag for Relative Absolute Quantitation,i TRAQ)proteomics and targeted protein quantitative technology,and then proved that TaPHT1;9 played an important role in wheat phosphorus absorption and transport through yeast mutants,virus induced gene transient silencing(VIGS),genome editing and other technologies.On the basis of the above,this study further proved that TaPHT1;9 plays an important role in phosphorus absorption and transport and belongs to a phosphorus efficient gene by detecting the changes in phosphorus absorption and transport of TaPHT1;9 genome editing wheat plants and TaPHT1;9 heterologous expression rice transgenic plants under soil culture conditions.In addition,it was found that auxin mediated the phosphorus absorption function of TaPHT1;9.The main conclusions are as follows:1.Under soil culture conditions,the phosphorus absorption and utilization capacity of TaPHT1;9 genome editing wheat plants significantly decreasedThrough soil culture experiments to verify the function of TaPHT1;9,it was found that TaPHT1;9 can participate in the process of phosphorus absorption and utilization in wheat,and the editing of TaPHT1;9 significantly limits the yield per plant and yield factor indicators of wheat.Compared with the wild type,in the soil culture experiment under three different phosphorus application levels(P0: 0 mg Pi/kg soil;P5: 5 mg Pi/kg soil;P20: 20 mg Pi/kg soil),the number of grains per ear of genome editing plants significantly decreased by 8.77%,6.04% and 7.67%,the1000 grain weight significantly decreased by 3.80%,5.58% and 4.33%,and the yield per plant significantly decreased by 13.12%,12.41% and 11.02%,respectively,The accumulation of phosphorus per plant significantly decreased by 17.76% and 9.77% under the conditions of applying5 mg/kg and 20 mg/kg of phosphorus,respectively.It can be seen that after editing TaPHT1;9,it hindered the absorption and transport of phosphorus within wheat,reducing the grain yield per plant of wheat.2.Under soil culture conditions,the heterologous expression of TaPHT1;9 significantly increases the phosphorus absorption and utilization ability of rice plantsFurther evaluate the phosphorus absorption and utilization function of TaPHT1;9 heterologous expression rice.In the soil culture experiment,compared with wild-type rice,TaPHT1;9heterologous expression transgenic rice plants significantly increased the number of grains per panicle by 6.47% and 6.10%,respectively.The 1000-kernal weight significantly increased by 10.55%and 10.41%,and the grain yield per plant also significantly increased by 16.45% and 9.58% under the conditions of no phosphorus fertilizer(NP)and low phosphorus fertilizer(LP),respectively.The phosphorus absorption and transportation ability of transgenic plants was significantly improved under lower phosphorus conditions.Under low phosphorus(LP)and medium phosphorus(MP)application conditions,the phosphorus absorption efficiency significantly increased by 35.70% and15.94%.Under the NP and LP conditions,phosphorus utilization efficiency significantly increased by 16.02% and 11.75%.It can be seen that the heterologous expression of TaPHT1;9 promotes the absorption and utilization of phosphorus by transgenic rice plants under lower phosphorus conditions,and also increases the grain yield per plant.3.Auxin mediates the phosphorus absorption and transport process of TaPHT1;9The mechanism of phosphorus absorption involved in TaPHT1;9 was explored through hydroponic experiments.The results indicate that under normal phosphorus(CK: 200 μmol/L)and low phosphorus(LP: 5 μmol/L),compared with WT plants,the root morphology of genome editing plants changed significantly.At the same time,it was found that the auxin content in the roots of genome editing plants significantly increased under different phosphorus concentrations,which may be related to the significant up regulation of auxin synthesis and transport related genes in the roots of genome editing plants.Further investigation of TaPHT1;9 promoter elements were analyzed and found that there were auxin response elements,and exogenous auxin significantly induced TaPHT1;9,indicating that auxin mediates TaPHT1;9 Phosphorus absorption and utilization process.