SOYBEAN CHLOROPLAST TRANSFORMATION WITH CHLAMYDOMONAS RUBISCO GENES

Authors: Zhang, Xing Hai; WIDHOLM, JACK - CROP SCINECES UOFI URBANA; PORTIS JR, ARCHIE

Submitted to: Biennial Conference on Molecular and Cellular Biology of the Soybean
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Rubisco is the key enzyme that determines the rate of photosynthesis. Compared with some other species, soybean Rubisco has a low efficiency of net photosynthesis under current atmospheric CO2 conditions, and the relative efficiency will be even lower in the increased CO2 levels projected in near future. One way to improve the photosynthetic efficiency and thus increase the production of soybean is to replace the soybean Rubisco proteins with a "better" enzyme from another species. We are trying to genetically modify soybean by chloroplast transformation, replacing the soybean Rubisco with the one from the alga, Chlamydomonas reinhardtii. The successful transformation of the soybean chloroplasts could potentially increase the photosynthesis rate by 7 to 21 percent, and result in a significant increase in soybean yield. We have completed several transgene constructs for chloroplast transformation, containing the coding sequences of a selection gene conferring resistance to spectinomycin, Chlamydomonas Rubisco sequences fused with soybean rbcL promoter. Soybean (Glycine max L., cv. Jack) embryogenic tissues from suspension culture were bombarded with gold particles coated with the DNA of these constructs, cultivated in a medium containing spectinomycin, and resistant embryos were selected. Preliminary PCR analysis showed the presence of Chlamydomonas Rubisco coding sequences in the putative transformed embryos. We are now continuing the selection of transformed embryos and attempting regeneration of the putative transformants for further analysis.