Function Analysis Of Phosphate Transporter GmPHT4;10 Gene In Soybean

Soybean is an important food crop.Phosphorus deficiency and drought will reduce soybean yield.Therefore,improving plant phosphorus utilization、clarifying soybean phosphorus metabolism and drought tolerance mechanisms、cultivating high-yield and high-quality soybean varieties have become the current research hotspots.The PHT4 family of plant phosphate transporters are responsible for the transportation and distribution of phosphorus in plant green tissues.In this study,12 soybean PHT4 family members were screened through the transcriptome.Among them,GmPHT4;3 and GmPHT4;10 genes were significantly up-regulated by low phosphorus at 12 and 24 h.Analysis of the promoter elements of these two genes showed that the promoter region of the GmPHT4;10 gene contains both the phosphorus-related element P1 BS and the drought-related element MBS.Therefore,this paper selected GmPHT4;10 of PHT4 family in soybean for further research.The aim of this study was to clarify the biological characteristics of soybean GmPHT4;10 in response to low phosphorus and drought stress,and to clarify the relationship between phosphate transport and photosynthesis.The specific research results of this research are as follows:1.The results of bioinformatics analysis showed that GmPHT4;10 is a member of the PHT4 family of phosphate transporters.It is a hydrophobic transmembrane protein.It is orthologous to At PHT4;5 in Arabidopsis thaliana.2.The results of qPCR analysis showed that the gene expression was the highest in the leaves at the flowering stage in soybean.Compared with that at 0.5 m M phosphate concentration,the expression level of GmPHT4;10 increased significantly at 0.01 m M phosphorus concentration.It indicated that the gene was induced by low phosphate.GmPHT4;10 showed a rhythmic law in response to light.The gene expression was up-regulated under drought condition and reached the maximum at 48 h.3.The homozygous lines of GmPHT4;10 overexpression and GmPHT4;10 complementation atpht4;5 mutant was obtained by dipping flowers.The growth,phosphate content and photosynthesis among wild type、atpht4;5 mutant、GmPHT4;10 overexpression and GmPHT4;10 complementation atpht4;5 mutant were compared.The results showed that GmPHT4;10 complementation atpht4;5 mutant had a significantly larger rosette leaf diameter than atpht4;5 mutant.In addition,the phosphate content and photosynthesis of chloroplasts and rosette leaves were also significantly improved.The diameter and photosynthetic capacity of the leaves of GmPHT4;10 overexpression lines were the largest.These results indicate that GmPHT4;10 has the ability of phosphate transport and affects leaf photosynthesis by affecting leaf area.4.Under drought stress,the proline content and catalase(CAT)activity of overexpression of GmPHT4;10 lines were the highest,while malondialdehyde(MDA)content was the lowest;those indexes of complementation lines were also significantly higher than those of atph4;5 mutant.This indicated that the damage degree of these plants was overexpression < wild type< supplement < atpht4;5.Although all the plants were damaged under drought stress,GmPHT4;10 gene transfer can alleviate the damage caused by drought to a certain extent.The results showed that although the plants were damaged under drought stress,gmpht4;10 gene transfer could alleviate the damage caused by drought to a certain extent.5.After cloning the promoter of GmPHT4;10,a 1689 bp promoter sequence and a 1500 bp promoter fragment without drought response element MBS and 5 ’-UTR were obtained.We constructed vectors P4;10-1::GUS and P4;10-2::GUS,and finally obtained two transgenic Arabidopsis thaliana for GUS quantitative detection,and analyzed the expression of GmPHT4;10 gene.The results showed that the expression of GUS gene regulated by promoter with MBS element was significantly higher than that regulated by promoter without MBS element under drought condition.These results indicate that MBS element in promoter region may be an important factor in GmPHT4;10 response to drought stress.