Genetic Transformation Of Rice And Screening And Identification Of Its Dwarf Line

Rice?Oryza sativa L.?is an important cereal crop and is also one of the staple food crops in China.Plant height is an important agronomic trait that affects the yield in rice.Plant that is extremely high will be susceptible to lodging and also reduce crop yield in rice.A suitable dwarf plays a crucial role in improving the capability of rice to resist lodging and withstand fertilizer,so as to increase the yield of rice.By agrobacteium conversion,10 genes of DOF transcription factor family and 11 genes of GATA transcription factor family have been transferred derived from corn?Zea mays L.?into Nipponbare.A dwarf line of dof34 is screened from the transgenic plants,and its agronomic straits and photosynthetic efficiency are tested,so as to preliminarily explore the dwarf mechanism,provide material and technique for the breeding of dwarf rice.The results were as follows:1.10 genes of DOF family of 11genes of GATA family are successfully constructed into over-expression vectors using recombinant cloning technology.2.423 transgenic plantlets with DOF family genes and GATA family genes are obtained.A stable dwarf line of dof34 is finally screened from the T0 and T1 generations.3.The agronomic traits of dof34 are investigated,and the results show that the photosynthetic efficiency,transpiration rate,stomatal conductance and intercellular CO₂ concentration are significantly higher than those of wild type.There is no significant difference in 100-grain weight,effective tiller number,and seed setting rate.The plant height and the biomass decrease,compared with the wild type.4.The expression levels of four key enzyme genes,KAO,KS1,CPS1 and GA20ox1 in the gibberellin synthesis pathway,are analyzed based on Quantitative PCR.It is found that the expression level of CPS1,the first key enzyme gene in the gibberellin synthesis pathway and encoding coba pyrophosphate synthase,decrease in the study,resulting in a low level of gibberellin synthesis.It is speculated that Dof34 gene may play a negative regulatory role in gibberellin anabolism in rice.