| Phosphorus is one of the essential and abundant elements for plant growth and development,as well as a constraint for sustainable agriculture.Since the effective phosphorus content of soils is often insufficient to support the needs of rapid crop growth,phosphorus fertilizers are often applied in large quantities in agricultural production to maintain crop yields.However,the fixation of soil results in only 20% of the in-season utilization efficiency of phosphorus fertilizer applied in agriculture,which not only increases the production cost of agriculture,but also makes the unused phosphorus fertilizer cause environmental pollution with soil erosion.Therefore,it is important to improve the efficiency of crop use of phosphorus fertilizer to achieve sustainable agricultural development.Studies have shown that there is a strong link between plants and soil microbial communities,and plants can influence the composition and function of rhizosphere soil microbial communities through root secretions,thus improving the rhizosphere microenvironment and promoting crop growth.Rice purple acid phosphatase10c(OsPAP10c)is the most important acid phosphatase secreted by rice roots,and overexpression of OsPAP10 c can improve the availability of organic phosphorus in rice roots,thus promoting rice growth and yield per plant.However,current studies on root secretion of acid phosphatase have mainly used hydroponic systems,and the ecological effects on rhizosphere soil physicochemical properties and bacterial communities are not clear.Therefore,in this study,based on the previous study,pot experiments were conducted using natural paddy soil to analyze the changes of rhizosphere soil physicochemical properties and bacterial community succession under different phosphorus fertilizer application conditions in wild type,OsPAP10 c mutant(pap10c)and overexpression material(OE-PAP10c),and the main findings were as follows:1.By analyzing the growth phenotypes of each genotype under different developmental stages,we found that overexpression of OsPAP10 c could promote rice growth and significantly increase rice plant height and yield.The accumulation of potassium nutrients in rice plants did not differ significantly among genotypes,but the accumulation of nitrogen and phosphorus nutrients in plants at tillering and elongation stages without phosphorus application was significantly affected by genotype and showed higher accumulation of nutrients in the overexpressed material than in the wild type and mutant,indicating that the expression of OsPAP10 c facilitate the uptake of nitrogen and phosphorus under the conditions of no phosphorus application.2.The phosphorus content and related extracellular enzyme activities of the rhizosphere soil of each genotype were measured under different phosphorus application conditions,and the results showed that the phosphorus content in the rhizosphere soil did not differ significantly among the genotypes,but the acid phosphatase(ACP)activity in the rhizosphere soil of OE-PAP10 c was significantly higher than that of WT and pap10 c,and the ACP activity of pap10 c was lower.Phosphorus fertilizer application increased the activity of alkaline phosphatase(ALP)in the rhizosphere soil during late plant growth,while the activity of phytase in the soil was mainly influenced by the combination of genotype and phosphorus application at the elongation and maturity stages.3.The developmental stage had the greatest effect on the diversity of the rhizosphere soil bacterial community.Changes in OsPAP10 c expression did not significantly affect bacterial α-diversity,but there was a significant effect on β-diversity.db-RDA analysis based on soil physicochemical indicators and bacterial community composition showed that phytase and phosphatase activities,and Olsen-P levels significantly affected the composition of the bacterial community.4.The relative abundance of rhizosphere soil microbial communities of rice was compared among genotypes at the phylum level,and the results showed that the composition of rhizosphere soil bacterial communities differed significantly among genotypes of rice.Although the dominant bacterial phylum enriched in rhizosphere soil was consistent across the four stages for different genotypes,their abundance differed significantly in some bacterial phylums.Further linear discriminant analysis effect size(LEf Se)analysis at the genus level revealed that different bacterial phyla were enriched in the rhizosphere soil of each rice material under different conditions and facilitated the maintenance of rhizosphere function,and that OsPAP10 c expression contributed to the recruitment of phosphorus solubilizing bacteria(PSB)during the filling period.5.Tax4Fun2 predictions were used to assess how OsPAP10 c,phosphorus application level and developmental stage affect the phosphorus cycling function of bacterial communities.Analysis showed that developmental period had the greatest effect on the relative abundance of genes involved in phosphorus transformation in soil bacteria(P<0.001),that no phosphorus fertilizer application increased the relative abundance of genes regulating phosphorus starvation responses during early growth,and that plant genotype had no significant effect on predicted gene abundance.However,there was an interaction between genotype×phosphorus application level×developmental stage and the total abundance of genes involved in phosphorus uptake and transport systems,suggesting that the root-secreted acid phosphatase OsPAP10 c affects the ability of rhizosphere soil bacteria to participate in phosphorus cycling and transformationIn conclusion,this study used the genetic material of rice OsPAP10 c to demonstrate that root-secreted acid phosphatase OsPAP10 c can significantly influence the spatial and temporal changes of the inter-root microbial community,which in turn changes the solubilization and mineralization capacity of soil phosphorus by rhizosphere microorganisms,and ultimately affects the ability of rice to utilize rhizosphere nutrients and growth and development. |
