Functional Study On Gmwrky23,Gmspx7 And Gmspx8 Genes Regulating Phosphorus Metabolism And Phosphorus Balance In Soybean（Glycine Max（L.） Merr.）

Phosphorus（P）is an indispensable and important nutrient in plants.It is not only the main component of plant cells,but also participates in a series of physiological and biochemical reactions in cells,such as signal transduction and enzymatic reactions.In nature,plants have evolved a series of adaptive mechanisms in order to adapt to low-phosphorus stress environments,including the regulation of transcription factor transcription levels and post-transcriptional protein regulation.WRKY transcription factors and SPX proteins have been reported in a variety of plants to participate in signal transduction in response to phosphorus starvation.However,there are few studies on WRKY transcription factors and SPX proteins in soybean phosphorus metabolism and phosphorus balance.Therefore,this study first screened the GmWRKY23,GmSPX7 and GmSPX8 genes in soybean responding to low phosphorus stress by qRT-PCR,and then cloned and studied their functions.The main results are as follows:1.Under low phosphorus stress,compared with the wild type Arabidopsis thaliana（WT）,the growth and development of GmWRKY23 overexpression transgenic Arabidopsis thaliana were inhibited,which showed fewer lateral roots,shoots fresh weight,shoots dry weight,roots fresh weight,roots dry weight and the content of inorganic phosphorus（Pi）were significantly reduced;under the condition of total phosphorus,the growth and development of GmWRKY23 overexpression transgenic Arabidopsis thaliana were also inhibited,which showed fewer lateral roots,roots fresh weight and roots dry weight were significantly reduced.Under low phosphorus stress,compared with the pCAMBIA3301-GFP no-load control,the content of total phosphorus（P）and zinc（Zn）in the hairy roots of GmWRKY23 overexpression transgenic soybean was significantly reduced.Under low phosphorus stress,compared with the parent receptor,the growth and development of GmWRKY23 overexpression transgenic soybeans were inhibited,which showed fewer lateral roots,shoots fresh weight,shoots dry weight,roots fresh weight,roots dry weight,the content of Pi in roots and leaves and net photosynthetic rate were significantly reduced,and anthocyanin content was significantly increased,showing traits sensitive to low phosphorus;under the condition of total phosphorus,the growth and development of GmWRKY23 overexpression transgenic soybeans were also inhibited,which showed fewer lateral roots,shoots fresh weight,shoots dry weight and roots dry weight were significantly reduced.The above results indicate that the GmWRKY23 gene may play a negative regulatory role in the soybean regulatory network in response to low phosphorus stress.2.Under low phosphorus stress,compared with the wild type Arabidopsis thaliana,the growth and development of GmSPX7 overexpression transgenic Arabidopsis thaliana were inhibited,which showed fewer lateral roots,shoots fresh weight,shoots dry weight,roots fresh weight,roots dry weight and the content of Pi were significantly reduced;compared with the pCAMBIA3301-GFP no-load control,the content of P in the hairy roots of GmSPX7 overexpression transgenic soybean was significantly reduced.The above results indicate that GmSPX7 gene may play a negative regulatory role in the soybean regulatory network in response to low phosphorus.3.Under low phosphorus stress,compared with the wild type Arabidopsis thaliana,GmSPX8 overexpression transgenic Arabidopsis thaliana has more lateral roots,longer main roots,shoots fresh weight,shoots dry weight,roots fresh weight,roots dry weight,root-shoot ratio and the content of Pi were significantly increased;compared with the pCAMBIA3301-GFP no-load control,the content of P in the hairy roots of GmSPX8 overexpression transgenic soybean was significantly increased.The above results indicate that the GmSPX8 gene may play a positive regulatory role in the soybean regulatory network in response to low phosphorus stress.