Genetic Transformation And Functional Verification Of Proline Synthase Gene In Maize

Corn is an important industrial raw material forgrain,food and feed in China,which plays an important role in China's agricultural production.Corn is sensitive to drought,which can reduce corn yield and quality.Improving the drought resistance of maize varieties has become an important goal in breeding.Conventional breeding has a long and difficult time to improve maize drought resistance.Transgenic technology can quickly and accurately increase maize resistance.Therefore,it is a convenient and effective method to improve corn by using transgenic technology to improve the drought resistance,salt-alkali resistance,and disease and insect resistance of corn.Proline is an osmotic regulator,which can regulate the osmotic pressure in the plant under stress,maintain the stability of the cell structure in the plant,reduce the damage caused by stress to the plant,and improve the drought resistance and stress resistance of the plant.Therefore,transgenic technology is used to transfer the proline gene into maize plants to improve the drought resistance of plants and provide germplasm resources for drought-resistant breeding.In this experiment,the overexpression vector and RNAi vector of the preline synthase gene constructed by the predecessors were introduced into 16 maize backbone inbred lines through the pollen tube channel method and ultrasound.The morphological index and physiological and biochemical index were measured to verify the function of the target gene,The test results are as follows:1 The pollen tube channel method and ultrasonic method were used to introduce the vector plasmid containing the target gene into 16 maize receptors.After herbicide screening and PCR detection,5 strains of W107 T1 overexpression plants were obtained,and the transformation rate was 6.09%.W107 Four T1 generation interfered plants had a transformation rate of 4.54%.Receptor B T1 generation overexpressed plants had a transformation rate of 5.12%.Three T1 generation interfered plants had a transformation rate of 4.54%.Receptor W107 T2 generation over-expressed 6 plants,W107 T2 generation interfered with 5 plants,Receptor B T2 generation over-expressed 7 plants,T2 generation interfered with 7 plants.2 Southern hybridization results of the T2 generation showed that the positive plants of both receptors had hybridization signals,and the target gene was integrated into the maize genome in the form of single copy and double copy with different integration positions.3 Fluorescence quantitative detection of T2 generation plants with signal showing Southern hybridization,The results showed that the target gene was expressed in the roots,stems and leaves of both receptors.At the same time,the expression of the leaves was the largest,the stem was the smallest,and the roots were in between.The expression level of the target gene in overexpressed plants in different parts> untransformed plants> interfering plants.4 The positive plants were subjected to stress treatment.It was found that there was no change between overexpressed plants,untransformed plants and interfering plants at 0 days of stress.After 10 days of water dehydration and 6 days of rewatering,it was found that both overexpressed plants and untransformed plants The yellow and wilted plants were over-expressed to a lesser extent than the untransformed plants,the interference-expressing plants were short,and the leaves yellowed and wilted.5 The measurement of physiological and biochemical indicators of positive plants found that there was no change between overexpressing plants,untransformed recipient plants and interfering plants at 0 days of stress,After 10 days of water cutoff and 6 days of rewatering,the values of proline,SOD,POD,chlorophyll and relative leaf water content of the plants were all overexpressing plants> untransformed recipient plants> interfering plants The value of malondialdehyde for plants is overexpressing plants <untransformed recipient plants<interfering plants.6 The morphological indexes of the plants after 6 days of rehydration were measured.The results showed that the overexpressed plants had fresh root weight,aboveground fresh weight,root dry weight,aboveground dry weight,root length and other indicators> untransformed recipient plants> interference Plant.