Various diterpene synthases have been functionally identified in cultivated rice (Oryza sativa). These are the homologs of ent-copalyl diphosphate (ent-CDP) synthase and ent-kaurene synthase (KS) that are responsible for the biosynthesis of gibberellins, diterpenoid phytohormones. We isolated a cDNA encoding full-length OsKSL12, a previously uncharacterized KS like (KSL) enzyme that consists of a β-domain and an α-domain with an active center, but lacks an N-terminal γ-domain. Functional analysis using a bacterial expression system showed that recombinant OsKSL12 converted ent-CDP into ent-manool or ent-13-epi-manool. Comparative genomics revealed that functional OsKSL12 homologs exist in diverse wild species in the Oryzeae-Oryza nivara (Oryza rufipogon), Oryza coarctata, Oryza granulata, Leersia perrieri, and Leersia tisseranti. KSL12 homologs in O. granulata, L. perrieri, and L. tisseranti preferentially reacted with geranylgeranyl diphosphate rather than ent-CDP, resulting in geranyllinalool rather than ent-manool or ent-13-epi-manool as the main product, meaning that KSL12 functionally diversified during evolution in the Oryzeae.

中文翻译：

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缺乏γ域的功能性贝壳杉烯合酶样二萜合酶广泛存在于稻和相关物种中。

已在栽培稻 (Oryza sativa) 中功能鉴定了多种二萜合酶。这些是 ent-copalyl 二磷酸 (ent-CDP) 合酶和 ent-kaurene 合酶 (KS) 的同源物，它们负责赤霉素、二萜类植物激素的生物合成。我们分离出编码全长 OsKSL12 的 cDNA，这是一种以前未表征的 KS 样 (KSL) 酶，由一个 β 结构域和一个具有活性中心的 α 结构域组成，但缺少 N 端 γ 结构域。使用细菌表达系统的功能分析表明，重组 OsKSL12 将 ent-CDP 转化为 ent-manool 或 ent-13-epi-manool。比较基因组学显示，功能性 OsKSL12 同源物存在于 Oryzeae-Oryza nivara (Oryza rufipogon)、Oryza coarctata、Oryza granulata、Leersia perrieri 和 Leersia tisseranti 的多种野生物种中。