Preliminarily Analysis Of Sucrose Transporter Genes Responses To Phosphate In Rice

Rice(Oryza sativa L.)is one of the most important staple crops that provide food for more than half of the world’s population.Phosphorus(P)is essential for plant growth and development due to its involvement in the processes of energy metabolism and synthesis of nucleic acids and membranes.However,the low availability of soil P is a major constraint for crop production in many agricultural systems worldwide.Sucrose is the major carbohydrate transported through the phloem in most plant species.Sucrose signal is important to regulate plant growth and metabolism.In recent years,many studies show that sugar signal may be related to the mechanism that plants response to phosphorus deficiency.In this thesis,we take the sucrose transporter in rice as the main object of study.In order to understand the function of sucrose transporter,the OsSUT1 over-expression and ossut3 mutant plant were generated.Bioinformatics and qRT-PCR were employed to identify the gene expression.The main results were as follows:1、Amino acid sequence homology share more than 50%.Analyses of promoter found that OsSUT2 and OsSUT3 promoter within P1BS,so we speculate that the two genes may be associated with responding to phosphorus deficiency.2、Analyses of RT-PCR indicated that OsSUTl-4 were expressed in leaves.And the transcript levels of the four genes were significantly enhanced by Pi-starvation in the leaves.3、The seeds’ length of OsSUT1 over-expression were obviously longer than that of WT,which suggested that OsSUT1 may be involved in development of caryopsis.4、The analyses of ossut3 mutant showed that the ovary was shorter than that of WT.Compared with WT,ossut3 seed-setting rate reduced approximately 30%.Seed germination experiment showed that ossut3 primary roots was shorter than that of WT.These results suggested that OsSUT3 was involved in development of caryopsis and seed germination.The mutant total Pi content of flag leaf was lower than that of WT,which indicated that OsSUT3 responses to Pi deficiency.5、Promoter::GUS and CRISPR/Cas9 knockout of OsSUT1 and OsSUT3 plants were successfully generated through transgenic manipulation.