| Title: | Tomato E8 Encodes a C-27 Hydroxylase in Metabolic Detoxification of alpha-Tomatine during Fruit Ripening |
| Author(s): | Akiyama R; Nakayasu M; Umemoto N; Kato J; Kobayashi M; Lee HJ; Sugimoto Y; Iijima Y; Saito K; Muranaka T; Mizutani M; |
| Address: | "Graduate School of Agricultural Science, Kobe University, Rokkodai 1-1, Nada-ku, Kobe, Hyogo, 657-8501 Japan. Laboratory of Plant Gene Expression, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 Japan. Department of Nutrition and Life Science, Kanagawa Institute of Technology, 1030 Shimo-ogino, Atsugi, Kanagawa, 243-0292 Japan. RIKEN Center for Sustainable Resource Science, Suehiro-cho 1-7-22, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan. Plant Molecular Science Center, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675 Japan. Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871 Japan" |
| ISSN/ISBN: | 1471-9053 (Electronic) 0032-0781 (Linking) |
| Abstract: | "Tomato (Solanum lycopersicum) contains alpha-tomatine, a steroidal glycoalkaloid that contributes to the plant defense against pathogens and herbivores through its bitter taste and toxicity. It accumulates at high levels in all the plant tissues, especially in leaves and immature green fruits, whereas it decreases during fruit ripening through metabolic conversion to the nontoxic esculeoside A, which accumulates in the mature red fruit. This study aimed to identify the gene encoding a C-27 hydroxylase that is a key enzyme in the metabolic conversion of alpha-tomatine to esculeoside A. The E8 gene, encoding a 2-oxoglutalate-dependent dioxygenase, is well known as an inducible gene in response to ethylene during fruit ripening. The recombinant E8 was found to catalyze the C-27 hydroxylation of lycoperoside C to produce prosapogenin A and is designated as Sl27DOX. The ripe fruit of E8/Sl27DOX-silenced transgenic tomato plants accumulated lycoperoside C and exhibited decreased esculeoside A levels compared with the wild-type (WT) plants. Furthermore, E8/Sl27DOX deletion in tomato accessions resulted in higher lycoperoside C levels in ripe fruits than in WT plants. Thus, E8/Sl27DOX functions as a C-27 hydroxylase of lycoperoside C in the metabolic detoxification of alpha-tomatine during tomato fruit ripening, and the efficient detoxification by E8/27DOX may provide an advantage in the domestication of cultivated tomatoes" |
| Keywords: | "Fruit/growth & development/*metabolism Solanum lycopersicum/genetics/growth & development/*metabolism Mixed Function Oxygenases/genetics/*metabolism Phylogeny Plant Proteins/genetics/*metabolism Plants, Genetically Modified Recombinant Proteins/genetics/m;" |
| Notes: | "MedlineAkiyama, Ryota Nakayasu, Masaru Umemoto, Naoyuki Kato, Junpei Kobayashi, Midori Lee, Hyoung Jae Sugimoto, Yukihiro Iijima, Yoko Saito, Kazuki Muranaka, Toshiya Mizutani, Masaharu eng 13J02443/Japan Society for the Promotion of Science/ Japan 2021/06/09 Plant Cell Physiol. 2021 Oct 1; 62(5):775-783. doi: 10.1093/pcp/pcab080" |
