1. Construction of transgenic Ipomoea obscura that exhibits new reddish leaf and flower colors due to introduction of β-carotene ketolase and hydroxylase genes.
- Author
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Otani M, Kitayama K, Ishikuro H, Hattan JI, Maoka T, Harada H, Shiotani Y, Eguchi A, Nitasaka E, and Misawa N
- Abstract
Ipomoea obscura , small white morning glory, is an ornamental plant belonging to the family Convolvulaceae, and cultivated worldwide. I. obscura generates white petals including a pale-yellow colored star-shaped center (flower vein). Its fully opened flowers were known to accumulate trace amounts of carotenoids such as β-carotene. In the present study, the embryogenic calli of I. obscura , were successfully produced through its immature embryo culture, and co-cultured with Agrobacterium tumefaciens carrying the β-carotene 4,4'-ketolase ( crtW ) and β-carotene 3,3'-hydroxylase ( crtZ ) genes for astaxanthin biosynthesis in addition to the isopentenyl diphosphate isomerase ( idi ) and hygromycin resistance genes. Transgenic plants, in which these four genes were introduced, were regenerated from the infected calli. They generated bronze (reddish green) leaves and novel petals that exhibited a color change from pale-yellow to pale-orange in the star-shaped center part. Especially, the color of their withered leaves changed drastically. HPLC-PDA-MS analysis showed that the expanded leaves of a transgenic line (T
0 ) produced astaxanthin (5.2% of total carotenoids), adonirubin (3.9%), canthaxanthin (3.8%), and 3-hydroxyechinenone (3.6%), which indicated that these ketocarotenoids corresponded to 16.5% of the total carotenoids produced there (530 µg g-1 fresh weight). Furthermore, the altered traits of the transgenic plants were found to be inherited to their progenies by self-crossing., Competing Interests: Disclosure of potential conflicts of interestThe authors declare that they have no conflicts of interest., (© 2021 Japanese Society for Plant Biotechnology.)- Published
- 2021
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