| Soybeans need a lot of phosphorus to meet their own growth metabolism and material accumulation.However,limited by the non-renewable phosphate rock and the limited ability of plants to absorb phosphorus,low phosphorus stress has always been an important factor affecting soybean yield and quality.Screening phosphorus-efficient soybean varieties and improving soybean’s ability to adapt to low phosphorus stress are effective ways to solve this problem.Studies have shown that the phosphorus transporter family plays an important role in promoting the absorption and transport of phosphorus by plants.It is divided into six categories: PHT1,PHT2,PHT3,PHT4,PHT5 and PHO1.They have different functions due to their different structures and positions.Currently,only the PHT1 family has been studied in soybeans.It is important to clarify the composition of the soybean phosphorus transporter family and reveal its function.In order to study the expression of genes involved in inorganic phosphorus transport under low phosphorus stress,this experiment carried out transcriptome sequencing of soybean roots and leaves treated with long-term and short-term low phosphorus stress,and obtained a large number of differentially expressed genes and transcription factors related to phosphorus transport.At the same time,combined with bioinformatics analysis,soybean PT family members were obtained from soybean database based on Arabidopsis thaliana and rice PHT amino acid sequences and cluster analysis was performed.Analysis of the cis-acting element of the PT gene promoter revealed that part of the gene contained the drought response element MBS in addition to the low-phosphorus response element P1 BS.In order to further analyze the function of these genes,the expression of genes in soybean roots and leaves treated with low-phosphorus drought was determined by qPCR method,and the correlation between expression level and phosphorus content was analyzed,and genes responding to low-phosphorus drought were identified.Finally,the key genes were cloned and functional analysis.The specific research results are as follows:1.Through agronomic traits,physiological indicators,yield factors,phytic acid content reduction rate and other indicators,Changnong 26,Yanyu 3,Suinong 28 and other phosphorus efficient varieties were screened from 193 soybean varieties widely planted in Northeast China.2.Transcriptome sequencing analysis of differential expression of genes in soybean roots and leaves under long-term low phosphorus and short-term low phosphorus stress,a large number of genes and transcription factors that respond to low phosphorus were obtained.In order to clarify the classification and membership of the soybean phosphorus transporter family,a total of 57 genes of soybean PHT1,PHT2,PHT3,PHT4,PHT5 and PHO1 families were obtained by bioinformatics and transcriptome data analysis.Analysis of promoter elements of these genes revealed 13 genes containing both the low-phosphorus response element P1 BS and the drought response element MBS.3.The expression levels of 13 target genes under low phosphorus and drought stress were analyzed by qPCR method.The correlation between gene expression level and phosphorus content was analyzed by combining phosphorus content data.And further identified key genes are GmPHT1;1,GmPHT1;7,GmPHT4;7,GmPHT4;8,GmPHT4;10,GmPHO1;4,GmPHO1;5,GmPHO1;7.4.The key gene GmPHT4;10 was successfully cloned.Subcellular localization results indicate that the gene is localized to the chloroplast.The gene expression assay showed that the gene was expressed in the leaves with high expression,which responded to short-term low phosphorus and drought stress and increased the phosphorus content of the leaves. |
