Transformation Of Ppdk Of Maize To Indica Rice And The Effect On Photosynthetic Traits

Rice is classified as C3 plants that its low photosynthetic performance become the majoy intrinsic limit factor of elevation biology yield. Newly, spikelet fertility become the mainstream of rice breeding target,as a result,the storage become biger and biger and the source become shorter and shorter,source become the main limit to improve yield potential.Due to it,s high photosynthetic performance,low CO2 expiation point, scarcely any photorespiration, As a consequence, the transfer of C4 traits to C3 plants rice is one strategy being adopted for improving the relationship between storage and source. The enzyme pyruvate, orthophosphate dikinase (PPDK) is the key enzyme of C4 photosynthesis pathway in C4 plants, in catalyse the regeneration of the primary CO2 acceptor PEP.Hang NO.1 developed by the Institute of Rice Science of Fujian Academy of Agricultural Sciences,is a restorer line with big spikelet, it has sufficient storage but shortage source .The C4-ppdk gene encoding the C4 enzyme pyruvate, orthophosphate dikinase (PPDK) of maize (Zea mays) containing its own promoter and terminator sequences and exon/intron structure was introduced into Plant expression vectors pC1380 and transfered to the restorer line Hang NO.1 by Agrobacterium tumefaciens. Afterwards, photosynthetic physiology analysis of the transgenic plant was carried out.The results were as follows:1. 273 embryogenic callus of Hang NO.1 were infected by Agrobacterium tumefaciens which containing plasmid pC1380-ppdk with complete maize ppdk gene and it's primal promoter, 46 resistant callus were got from 273 embryogenic callus and 13 regenerated rice plants from 5 individual hangl callis.The transformation efficiency was 16.8%,and plants regeneration efficiency was 10.9%.2. Results of PCR and spot hybridization indicated that the maize ppdk gene had been successfully transformed into the transgenic restorer lines rice Hang NO.1.3. Photosynthetic and other physiological analysis on 7 transgenic plants of indica Hang NO.1 demonstrated:its net photosynthesis rate, water-use efficiency of transgenic plant 5-2 has increased by 44.98%, 26.53% accordingly to non-transformants,because of its good performance,it show a bright future for application.In one word,this study has established foundation for studing the applicational value of PPDK on improving the relationship between storage and source of C3 plants,and for breeding new Hang NO.1,which is more harmonized between storage and source.