CYP722C from Gossypium arboreum catalyzes the conversion of carlactonoic acid to 5-deoxystrigol
CYP722C from Gossypium arboreum catalyzes the conversion of carlactonoic acid to 5-deoxystrigol
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DOI：
10.1007/s00425-020-03390-6
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发表时间：
2020-04-18
期刊：
影响因子：
4.3
通讯作者：
Sugimoto, Yukihiro
中科院分区：
文献类型：
--
作者：
Wakabayashi, Takatoshi;Shida, Kasumi;Sugimoto, Yukihiro
主要结论来自棉花的CYP 722 C是参与豇豆和番茄中列当醇合成的酶的同源物，催化carlactonoic acid转化为5-deoxystrigol。独脚金内酯（Strigolactones，SL）是一类重要的植物激素，对植物的生长发育具有重要的调节作用。这些化合物还通过与有益的丛枝菌根真菌和有害的根寄生植物相互作用而在根际中充当信号分子。典型的SL，如5-脱氧独脚金醇（5DS），由一个三环内酯环（ABC-环）连接到一个甲基丁烯二醇（D-环）组成。虽然已知5DS生物合成始于源自β-胡萝卜素的carlactonoic acid（CLA），但催化CLA转化的酶仍然难以捉摸。最近，我们鉴定了细胞色素P450（CYP 722 C）作为在豇豆和番茄中催化CLA直接转化为列当醇的酶（Wakabayashi等人，Sci Adv 5：eaax9067，2019）。奥罗班醇具有与5DS不同的C环构型。本研究的目的是表征同源基因，命名为GaCYP 722 C，从棉花（亚洲棉），以检查该基因是否参与5 DS的生物合成。磷酸盐饥饿，这是一个SL生产条件下的GaCYP 722 C的表达上调。重组GaCYP 722 C在杆状病毒-昆虫细胞表达系统中表达，发现其催化CLA转化为5DS，但不催化转化为4-deoxyorobanchol。这些结果有力地表明，棉花的GaCYP 722 C是一个5DS合酶，CYP 722 C是参与典型SL生成的关键性的CYP 145亚家族，而与不同的C-环构型无关。
Main conclusion CYP722C from cotton, a homolog of the enzyme involved in orobanchol synthesis in cowpea and tomato, catalyzes the conversion of carlactonoic acid to 5-deoxystrigol. Strigolactones (SLs) are important phytohormones with roles in the regulation of plant growth and development. These compounds also function as signaling molecules in the rhizosphere by interacting with beneficial arbuscular mycorrhizal fungi and harmful root parasitic plants. Canonical SLs, such as 5-deoxystrigol (5DS), consist of a tricyclic lactone ring (ABC-ring) connected to a methylbutenolide (D-ring). Although it is known that 5DS biosynthesis begins with carlactonoic acid (CLA) derived from beta-carotene, the enzyme that catalyzes the conversion of CLA remains elusive. Recently, we identified cytochrome P450 (CYP) CYP722C as the enzyme that catalyzes direct conversion of CLA to orobanchol in cowpea and tomato (Wakabayashi et al., Sci Adv 5:eaax9067, 2019). Orobanchol has a different C-ring configuration from that of 5DS. The present study aimed to characterize the homologous gene, designated GaCYP722C, from cotton (Gossypium arboreum) to examine whether this gene is involved in 5DS biosynthesis. Expression of GaCYP722C was upregulated under phosphate starvation, which is an SL-producing condition. Recombinant GaCYP722C was expressed in a baculovirus-insect cell expression system and was found to catalyze the conversion of CLA to 5DS but not to 4-deoxyorobanchol. These results strongly suggest that GaCYP722C from cotton is a 5DS synthase and that CYP722C is the crucial CYP subfamily involved in the generation of canonical SLs, irrespective of the different C-ring configurations.