• Plant roots are specialized belowground organs that spatiotemporally shape their development in function of varying soil conditions. This root plasticity relies on intricate molecular networks driven by phytohormones, such as auxin and jasmonate (JA). Loss‐of‐function of the NOVEL INTERACTOR OF JAZ (NINJA), a core component of the JA signaling pathway, leads to enhanced triterpene biosynthesis, in particular of the thalianol gene cluster, in Arabidopsis thaliana roots.
• We have investigated the biological role of thalianol and its derivatives by focusing on Thalianol Synthase (THAS) and Thalianol Acyltransferase 2 (THAA2), two thalianol cluster genes that are upregulated in the roots of ninja mutant plants. THAS and THAA2 activity was investigated in yeast, and metabolite and phenotype profiling of thas and thaa2 loss‐of‐function plants was carried out.
• THAA2 was shown to be responsible for the acetylation of thalianol and its derivatives, both in yeast and in planta. In addition, THAS and THAA2 activity was shown to modulate root development.
• Our results indicate that the thalianol pathway is not only controlled by phytohormonal cues, but also may modulate phytohormonal action itself, thereby affecting root development and interaction with the environment.

中文翻译：

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特化三萜调节拟南芥根系生长

• 植物根系是专门的地下器官，它们在时空上根据不同的土壤条件塑造它们的发育。这种根系可塑性依赖于由植物激素驱动的复杂分子网络，例如生长素和茉莉酸 (JA)。NOVEL INTERACTOR OF JAZ ( NINJA ) 是 JA 信号通路的核心成分，其功能丧失导致拟南芥根中三萜生物合成的增强，尤其是噻烷醇基因簇的合成。
• 我们通过关注酞醇合成酶( THAS ) 和酞醇酰基转移酶 2 ( THAA2 ) 这两个在忍者突变植物的根中上调的酞醇簇基因，研究了酞醇及其衍生物的生物学作用。研究了酵母中的 THAS 和 THAA2 活性，并对thas和thaa2功能丧失植物进行了代谢物和表型分析。
• THAA2 被证明负责酵母和植物中的thalianol 及其衍生物的乙酰化。此外，已显示 THAS 和 THAA2 活性可调节根发育。
• 我们的研究结果表明，thalianol 途径不仅受植物激素信号的控制，还可能调节植物激素本身的作用，从而影响根系发育和与环境的相互作用。