Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress
Flavones, one of the largest classes of flavonoids in plants, have a variety of bioactivities and participate in the resistance response of plants to biotic and abiotic stresses. However, flavone synthase (FNS), the key enzyme for flavone biosynthesis, has not yet been characterized in mulberry. In...
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| Format: | Article |
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MDPI AG
2020-02-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/9/2/215 |
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| author | Han Li Dong Li Zhen Yang Qiwei Zeng Yiwei Luo Ningjia He |
| author_facet | Han Li Dong Li Zhen Yang Qiwei Zeng Yiwei Luo Ningjia He |
| author_sort | Han Li |
| collection | DOAJ |
| description | Flavones, one of the largest classes of flavonoids in plants, have a variety of bioactivities and participate in the resistance response of plants to biotic and abiotic stresses. However, flavone synthase (FNS), the key enzyme for flavone biosynthesis, has not yet been characterized in mulberry. In this study, we report that the leaves of certain mulberry cultivars, namely BJ7, PS2, and G14, are rich in flavones. We identified a Fe<sup>2+</sup>/2-oxoglutarate-dependent dioxygenase from <i>Morus notabilis</i> (MnFNSI) that shows the typical enzymatic activity of a FNSI-type enzyme, and directly converts eriodictyol and naringenin into their corresponding flavones. Overexpression of <i>MnFNSI</i> in tobacco increased the flavones contents in leaves and enhanced the tolerance of tobacco to ultraviolet-B (UV-B) stress. We found that mulberry cultivars with higher flavones contents exhibit less UV-B induced damage after a UV-B treatment. Accordingly, our findings demonstrate that MnFNSI, a FNSI-type enzyme, is involved in the biosynthesis of flavones, which provide protection against UV-B radiation. These results lay the foundation for obtaining mulberry germplasm resources that are more tolerant to UV-B stress and richer in their nutritional value. |
| first_indexed | 2024-04-11T18:24:53Z |
| format | Article |
| id | doaj.art-0135677cffb944b2a326708f11c15ccd |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-04-11T18:24:53Z |
| publishDate | 2020-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-0135677cffb944b2a326708f11c15ccd2022-12-22T04:09:39ZengMDPI AGPlants2223-77472020-02-019221510.3390/plants9020215plants9020215Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B StressHan Li0Dong Li1Zhen Yang2Qiwei Zeng3Yiwei Luo4Ningjia He5State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaState Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaState Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaState Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaState Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaState Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, ChinaFlavones, one of the largest classes of flavonoids in plants, have a variety of bioactivities and participate in the resistance response of plants to biotic and abiotic stresses. However, flavone synthase (FNS), the key enzyme for flavone biosynthesis, has not yet been characterized in mulberry. In this study, we report that the leaves of certain mulberry cultivars, namely BJ7, PS2, and G14, are rich in flavones. We identified a Fe<sup>2+</sup>/2-oxoglutarate-dependent dioxygenase from <i>Morus notabilis</i> (MnFNSI) that shows the typical enzymatic activity of a FNSI-type enzyme, and directly converts eriodictyol and naringenin into their corresponding flavones. Overexpression of <i>MnFNSI</i> in tobacco increased the flavones contents in leaves and enhanced the tolerance of tobacco to ultraviolet-B (UV-B) stress. We found that mulberry cultivars with higher flavones contents exhibit less UV-B induced damage after a UV-B treatment. Accordingly, our findings demonstrate that MnFNSI, a FNSI-type enzyme, is involved in the biosynthesis of flavones, which provide protection against UV-B radiation. These results lay the foundation for obtaining mulberry germplasm resources that are more tolerant to UV-B stress and richer in their nutritional value.https://www.mdpi.com/2223-7747/9/2/215flavone synthaseflavoneuv-b radiationdna damagemulberry |
| spellingShingle | Han Li Dong Li Zhen Yang Qiwei Zeng Yiwei Luo Ningjia He Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress Plants flavone synthase flavone uv-b radiation dna damage mulberry |
| title | Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress |
| title_full | Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress |
| title_fullStr | Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress |
| title_full_unstemmed | Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress |
| title_short | Flavones Produced by Mulberry Flavone Synthase Type I Constitute a Defense Line against the Ultraviolet-B Stress |
| title_sort | flavones produced by mulberry flavone synthase type i constitute a defense line against the ultraviolet b stress |
| topic | flavone synthase flavone uv-b radiation dna damage mulberry |
| url | https://www.mdpi.com/2223-7747/9/2/215 |
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