Nutritional quality of most maize varieties is very low due to the lack of lysine and tryptophan and extremely low provitamin A carotenoids including β-carotene, α-carotene, and β cryptoxanthin. | Turkish Journal of Biology Research Article Turk J Biol (2017) 41: 1003-1010 © TÜBİTAK doi: Overexpression of the IbOr gene from sweet potato (Ipomea batatas ‘Hoang Long’) in maize increases total carotenoid and β-carotene contents Thi-Luong TRAN, Thi-Huong HO, Duc-Thanh NGUYEN* Plant Cell Genetics Laboratory, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam Received: Accepted/Published Online: Final Version: Abstract: Nutritional quality of most maize varieties is very low due to the lack of lysine and tryptophan and extremely low provitamin A carotenoids including β-carotene, α-carotene, and β-cryptoxanthin. In this study, we report the successful overexpression of the IbOr gene in H145 and H95 inbred maize lines under the control of maize seed-specific promoter globulin 1 (Glo1) for the purpose of improving β-carotene in maize. The results showed that the total carotenoid and β-carotene content of all analyzed transgenic maize plants were significantly higher than those of wild-type lines. For H145-IbOr transgenic maize, in the best line (), the total carotenoid and β-carotene contents were increased up to and , respectively, compared to the wild type (H145-WT). In the case of H95-IbOr transgenic plants, increase in total carotenoid and increase in β-carotene were achieved in the line compared to nontransgenic plants (H95-WT). In all the transgenic plants derived from the wild-type maize line with less carotenoid content (H145-WT), the content of both total carotenoid and β-carotene was higher than in transgenic plants derived from the wild-type maize line having more carotenoid content (H95-WT). Our research is the first in successful overexpression of IbOr gene in maize. Key words: β-Carotene, carotenoid content, IbOr gene, maize, sweet potato 1. Introduction Maize is
