The Role Of Sucrose Transporter Gene OsSUT1 On Growth And Phosphorus Nutrition In Rice

Phosphorus is one of the necessary nutrients for plant growth and development,and plays an important role in metabolic pathways.Although the content of total phosphorus in soil is rich,the phosphorus that can be directly used by plants is much lower than the growth and development of plants.Sucrose is not only the main form of long-distance transport of photosynthetic products in higher plants,but also the material basis for the growth and development of seeds and other "library" organs.It has been found that sucrose can be used as a signaling molecule to participate in the regulation of plant responsing to phosphorus deficiency mechanisms.In this paper,the rice sucrose transporter gene OsSUT1 was used as the research object,and the rice model variety Nipponbare was used as experimental material.The expression characteristics of OsSUT1 were identified through bioinformatics and expression pattern analysis.The function of OsSUT1 in rice growth and phosphorus uptake and utilization is studied using CRISPR/Cas9 mutant materials and overexpression materials.Main fundings of this study are:By quantitatively analyzing PCR results and OsSUTlpro::GUS material staining results,it was found that OsSUT1 is expressed in roots,stems,leaves,floral organs,and caryopsis of rice,and it is more strongly expressed in flower organs and developing caryopsis.The observation of OsSUT1pro::YFP material showed that OsSUTl was expressed in the seed coat,aleurone layer and embryo of caryopsis at the filling stage.OsSUT1 plays an important role in the growth and development of rice during mature period.Normal phosphorus supply and deficient phosphorus were applied to rice at seedling stage.No significant difference in the length of shoot and root of OsSUT1 overexpression material is found compared with wild type.At the mature period,compared with the wild type,the number of tillers,seed length and width of the overexpressing material increased significantly,and the filling material of the mutant material was delayed and severely insufficient.The number of tillers and seed setting rate were significantly decreased,The spike length,the number of spikes and sucrose content in the caryopsis after the removal of endosperm increased significantly.OsSUT1 is involved in the absorption and utilization of phosphorus in rice.Quantitative PCR result show that OsSUT1 is induced by phosphorus deficiency in rice roots.At the seedling stage,compared with the wild type,under the normal phosphorus supply condition,the phosphorus content in the overexpression tissues increased significantly,and the phosphorus content in the roots increased.However,under the condition of deficient phosphorus,the phosphorus content in shoots and roots was not significantly higher than that in the wild type.Compared with the wild type,the content of phosphorus in all parts of the OsSUTl overexpression material increased significantly during the mature period.In summary,our research on the rice sucrose transporter gene OsSUT1 showed that OsSUT1 mainly plays a role in the later stage of rice growth and development.OsSUT1 is not only closely related to the development of rice pollen and caryopsis,but also involved in the absorption and utilization of phosphorus in rice.Combined with the transport characteristics of SUT protein,our research can help to clarify the physiological role and detailed mechanism of OsSUT1 in rice growth and phosphorus nutrition,and provide a theoretical basis for the cultivation of rice varieties with high quality and high yield.