Function Analysis Of (phyA2) Gene Express In Root Of Transgenic Maize Plant

Phosphorus is an essential nutrient for plant growth and development. The productivity of a large proportion of the world's agricultural crops is limited by the availability of soil phosphorus. How to develop and utilize the resources of phosphorus in soil is wide paid attention.To find plant potential of hydrolyzed and utilized soil organic phosphorus with plant intrinsic characteristics and use bioengineering method have been a hot spot.As a large proportion of soil P occurs in organic forms, phytate more and more be paid attention. How to utilize phytate as P resources is an important research issue.In this study, phytase gene (phyA2) with a secretion signal peptide sequence was constructed phytase gene expression vector pGA1611EAO and transformed into genome of maize rataria. The main work is about: production of transgenic plants, screen homozygosis transgenic maize plant, molecule detection of phyA2 which inserted into maize genome and express in maize plant, assay of phytase activity secrete from maize plant root and analysis the location that phytase localized in root use histochemical method.The major results are as follows:1. On the ground of our laboratory works, we grow transgenic maize plant in the deficiency phosphorus soil,we obained T3 transgenic phyA2 lines that could grow in the deficiency phosphorus soil.2. We checked transgenic gene by PCR method and phytase acticity assay screening high activity phytase maize seeds.Transgenic maize was cultivated from generation T2 to T7.3. Analysis of genetic background, we gained homozygosis transgenic maize plant seeds at T5 generation.4. RT-PCR reactions analysis of phyA2 transcripts showed that the presence of phyA2 transcripts in transgenic maize leaf, stem and root5. Western-blot analysis of phyA2 proteins in transgenic maize plant, and showed that phytase has been expressed in maize leaf, stem and root, we also found the phytase size have difference.6. The transgenic maize was further detected by southern blotting assay, the result showed that phyA2 has been inserded into maize genome, and contains two copies of the transgene.7. Transgenic maize and wild-type maize grow in the nutrient solution, phytase activity in leaves and roots of transgenic plant was approximately eleven times and twenty times higher than that of wild-tape plants.8. Collection of root exudates and measurement of phytase activity, extracellular phytase activity of transgenic plant was approximately thirty times higher than that of wild-type plants.9. Assay of phosphorus content, plant biomass and plant growth state showed that transgenic maize extracellular phytase utilization of phytate for plant growth and development.10. Make transgenic maize root sections of different growth periods, analysis the location of phytase localized in maize root used histochemical method. The result indicated that phytase activity was consistently found in the pericycle, epidermis, cortex endodermis and root hair.All of that results indicated that phyA2 gene was expressed in transgenic maize plant and the roots secretion phytase hydrolyzed and utilized phytate as phosphorus resources for plant growth.