Study On Agrobacterium-mediated Transformation Of HAK And PSY Genes Into Maize

Potassium is the necessary mineral elements to the normal growth of plants, thetransport capacity of potassium ion relates to the adaptive capacity of all kinds ofabiotic stress in plant. In this study, the HAK（High affinity K+transporter）gene wastransferred into five different inbred lines of maize including7922、P138、265、238and271by Agrobacterium-mediated transformation. Factors influencingtransformation efficiency were optimized. Progenies of transgenic plants wereacquired by PCR and RT-PCR amplification and were confirmed to resist PPT. Whentreated with either100mmol/L or200mmol/L NaCl, higer K+、proline andchlorophyll content were observed in transgenic leaves than in wild type leaves，butNa+content in transgenic leaves was obviously lower than in wild type leaves. Theseresults proved that HAK gene was integrated into maize genome and transcriptionnormally. Over-expressing of HAK gene enhances the salt tolerance of transgenicmaize.Carotenoids is the essential nutrients as a precursor of vitamin A in human body.Insufficient intakes of carotenoids will directly lead to vitamin A deficiency. Corn isone of the crops most widely cultivated in the world. Improving carotenoids contentof corn with genetic engineering technology has important significance. In this study,the PSY（phytoene synthase）gene was transferred into the shoot meristems of twodifferent maize inbred lines including H00-108and7922by Agrobacterium-mediatedtransformation. Factors influencing transformation efficiency were optimized.Theresults indicated that the optimal transformation condition is infection time withvacuum at20min and co-cultivation time for3days.The transgenic plants wereobtained after selected by200mg/L PPT and6of them were confirmed positive bymolecular detection. RT-PCR and HPLC analysis results showed that PSY gene hadbeen integrated into the maize genome and transcribed normally, the total carotenoidcontent in transgenic maize was increased25%compared to the wild type. Thismethod eliminates the tedious process of tissue culture and proves to be a simple,strong operability transformation method.