Study On The Transformation Of Yield Related Gene ZmAPO1-9 Into Maize

With the development of science and technology,the growth of the population and the deterioration of the natural environment,food production that is essential for human survival has become a global issue we need to solve urgently.At present,the world's population is growing faster than food production.As one of the main food crops,the improvement of the yield and quality of maize has become our focus.APO1gene is a gene that may be related to yield in maize.Therefore,the over-expression vector and CRISPR vector of Zm APO1-9 were transformed into maize genome in this study,and their functions were verified by analyzing the agronomic characters of maize offspring.The following results were obtained through research:?1?In the induction stage of immature embryo callus,the most suitable callus material was selected as maize inbred line GSH9901 through the culture of different materials,and the most suitable culture conditions were determined through optimization experiments.That was to say,the length of immature embryo was between 1.6-2.0mm;the cold storage time at 4?before embryo inoculation was1day;the concentration of glyphosate was 10mg/ml;the concentration of bacteriostatic antibiotic was 250mg/ml;the concentration of 2,4-D was 0.25mg/ml;the concentration of proline was 0.8mg/ml;the concentration of folate was 0.5mg/ml.?2?Through agrobacterium tumefaciens transformation,the over-expression vector and CRISPR vector of Zm APO1-9 were respectively transformed into the genome of maize inbred line GSH9901,five PCR positive transformed plants with T₃ generation overexpression and CRISPR were obtained,respectively.?3?Southern imprinting of the T₂ and T₃ generation positive plants showed that the target gene was randomly integrated into the maize genome in the form of single or multiple copies.It was detected by fluorescent quantitative PCR,and the results showed that the expression level of Zm APO1-9 gene in the over-expressing plants was significantly higher than that in the control group,and the expression levels in different organs were different.The gene was not detected in any CRISPR plant.?4?Gene sequencing of CRISPR positive plants showed that a variety of mutants were generated after gene editing,making the Zm APO1-9 gene unable to express normally.?5?Identification of physiological and biochemical indexes of T₃ generation maize plants.Itwas found that zmapo1-9 gene could reduce the relative conductivity and malondialdehyde content of maize leaves,and increase the proline content and peroxidase activity.?6?The agronomic traits of T₃ generation maize plants were determined,and the phenotypic data were analyzed.The results showed that the 100-kernel weight of the Zm APO1-9 gene over-expressing plants was significantly higher than that of the control group,and the CRISPR plants were significantly lower than the control.?7?The quality and character of T₃ generation maize plants were determined,and the results showed that the expression of Zm APO1-9 gene could significantly reduce the starch and protein content of maize,but had no significant effect on the fat content.