Fig 1.
Carotenoid biosynthetic pathway.
Possible pathways leading to the formation of the ketocarotenoids canthaxanthin and astaxanthin, which can be formed from β-carotene through reactions catalyzed by ketolase and hydroxylase enzymes. The crtB gene encodes a phytoene synthase enzyme that catalyzes the formation of phytoene. A “*” indicates a β-carotene ketolase, such as the ketolases encoded by the crtW or bkt1 genes used in this study. This enzyme can use different substrates, so its final products depend on the substrates available.
Fig 2.
Schematic representations of transformation constructs.
See Plasmid Construction for construct details. Abbreviations used: hph, hygromycin resistance gene; Bcon, β-conglycinin; StUbi, Solanum tuberosum ubiquitin; kanR, kanamycin resistance.
Fig 3.
Soybean seeds from events producing canthaxanthin.
The top row in each panel is of wild-type (WT) soybean cultivar Jack. The second row is of carotene-accumulating seeds resulting from transformation with crtB. The third row is of seeds containing canthaxanthin after transformation with pCEH1B+bkt (left panel) or pCEH1B+crtW (right panel). The cotyledons from one seed have been separated in each case.
Fig 4.
RT-PCR analysis of carotenoid biosynthetic pathway RNA from transgenic soybean seeds.
Panel A shows RT-PCR products for crtB, crtW, and bkt1. Lower panel (B) shows reactions without reverse transcriptase. Cv. Jack NT is a non-transgenic control sample. NTC stands for no template control.
Table 1.
Amounts of compounds from the carotenoid biosynthetic pathway detected by HPLC in transgenic T1 soybean seeds resulting from transformation with pCEH1B+crtW.
Table 2.
Amounts of compounds from the carotenoid biosynthetic pathway detected by HPLC in transgenic T1 soybean seeds resulting from transformation with pCEH1B+bkt.
Table 3.
Amounts of compounds from the carotenoid biosynthetic pathway detected in transgenic T1 soybean seeds resulting from transformation with pCEH1B+crtW based on HPLC analysis by Craft Technologies.
Table 4.
Amounts of compounds from the carotenoid biosynthetic pathway detected in T2 transgenic soybean seeds from an event resulting from transformation with pCEH1B+crtW.
Table 5.
Amounts of compounds from the carotenoid biosynthetic pathway detected in T3 transgenic soybean seeds from an event resulting from transformation with pCEH1B+bkt.
Table 6.
Amounts of compounds from the carotenoid biosynthetic pathway detected in transgenic T1 soybean seeds resulting from transformation with pCEH1B+crtW and pCEH1B+bkt.
Fig 5.
Soybean somatic embryo accumulating carotenoids.
From left to right: non-transformed Jack somatic embryo, somatic embryo from Jack transformed with pCEH1B+crtW. The embryos in this picture were imaged approximately 5 months after bombardment.