Cloning of PPDK gene from Red Amaranand transformation of Alfalfa.

Background: Cloning valuable genes can provide useful objectives for plant engineering. Pyruvate orthophosphate dikinase (PPDK), the limited enzyme in C4 photosynthesis and crassulacean acid metabolism (CAM).Some research indicated that over-express the gene encoding PPDK could improve the photosynthesis rate and the production. In this study, the C4 type-PPDK gene in Red amaran was cloned and transformed into alfalfa. Results: The gene encoding C4 type-PPDK in Red amaran has been cloned; it showed that the PPDK cDNA was 3.4 kb, including an ORF of 2871 bp, which encoding of 957 AA of 107kD. By comparing, there is a highest similarity with wheatgrass of 84%. Plant expression vector containing the full length of C4-type PPDK gene was constructed and transgenic alfalfa plants were obtained. A sequence about 600 bp in the upstream of the C4 type-PPDK cDNA was cloned, it contains TATA-box, CAAT-box, GT1-motif and sp1, some was transformed into tobacco, and the result showed that there was a transient expression in it. Conclusion: PPDK gene of type C4 plants will improve the photosynthetic efficiency of C3 plants. [ABSTRACT FROM AUTHOR]