Selection of a subspecies-specific diterpene gene cluster implicated in rice disease resistance

• Published in: Nature plants Vol. 6; no. 12; pp. 1447 - 1454
• Main Authors: Zhan, Chuansong, Lei, Long, Liu, Zixin, Zhou, Shen, Yang, Chenkun, Zhu, Xitong, Guo, Hao, Zhang, Feng, Peng, Meng, Zhang, Meng, Li, Yufei, Yang, Zixin, Sun, Yangyang, Shi, Yuheng, Li, Kang, Liu, Ling, Shen, Shuangqian, Wang, Xuyang, Shao, Jiawen, Jing, Xinyu, Wang, Zixuan, Li, Yi, Czechowski, Tomasz, Hasegawa, Morifumi, Graham, Ian, Tohge, Takayuki, Qu, Lianghuan, Liu, Xianqing, Fernie, Alisdair R., Chen, Ling-Ling, Yuan, Meng, Luo, Jie
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2020; Nature Publishing Group
• Subjects: 631/208/8; 631/449/1870; 631/449/2667; Antiinfectives and antibacterials; Arrays; Biomedical and Life Sciences; Biosynthesis; Blight; China; Chromosome 7; Crops, Agricultural - genetics; Crops, Agricultural - metabolism; Disease resistance; Disease Resistance - genetics; Disease Resistance - physiology; Diterpenes; Diterpenes - metabolism; Domestication; Enzymes; Epigenetics; Gene Expression Regulation, Plant; Letter; Life Sciences; Methyl jasmonate; Multigene Family; Natural products; Oryza; Oryza - genetics; Oryza - metabolism; Oryza rufipogon; Oryza sativa japonica; Phytoalexins; Plant Sciences; Rice; Rice blast; China
• ISSN: 2055-0278; 2055-0278
• DOI: 10.1038/s41477-020-00816-7

Diterpenoids are the major group of antimicrobial phytoalexins in rice 1 , 2 . Here, we report the discovery of a rice diterpenoid gene cluster on chromosome 7 ( DGC7 ) encoding the entire biosynthetic pathway to 5,10-diketo-casbene, a member of the monocyclic casbene-derived diterpenoids. We revealed that DGC7 is regulated directly by JMJ705 through methyl jasmonate-mediated epigenetic control 3 . Functional characterization of pathway genes revealed OsCYP71Z21 to encode a casbene C10 oxidase, sought after for the biosynthesis of an array of medicinally important diterpenoids. We further show that DGC7 arose relatively recently in the Oryza genus, and that it was partly formed in Oryza rufipogon and positively selected for in japonica during domestication. Casbene-synthesizing enzymes that are functionally equivalent to OsTPS28 are present in several species of Euphorbiaceae but gene tree analysis shows that these and other casbene-modifying enzymes have evolved independently. As such, combining casbene-modifying enzymes from these different families of plants may prove effective in producing a diverse array of bioactive diterpenoid natural products. A rice diterpenoid gene cluster is reported that controls the biosynthesis of 5,10-diketo-casbene, a phytoalexin that confers resistance to rice bacterial blight and blast fungus. It recently evolved in the japonica subspecies under artificial selection.