Sporsheim Bjørnar, Øverby Anders, Bones Atle Magnar
Department of Biology, the Norwegian University of Science and Technology, Høgskoleringen 5, N-7491 Trondheim, Norway.
Int J Mol Sci. 2015 Dec 7;16(12):29134-47. doi: 10.3390/ijms161226154.
Volatile allyl isothiocyanate (AITC) derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP)-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER), vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.
挥发性烯丙基异硫氰酸酯（AITC）源自芥子油苷黑芥子硫苷酸钾的生物降解，并且与包括模式植物拟南芥在内的多种植物的生长抑制有关。然而，在植物中，这一特性潜在的细胞机制仍鲜有研究。在本研究中，我们提供了证据表明AITC可诱导拟南芥中肌动蛋白依赖性的细胞内运输受到抑制。利用一个表达黄色荧光蛋白（YFP）标记的肌动蛋白丝的拟南芥转基因系，来展示AITC对肌动蛋白丝运动的减弱作用。这种减弱以时间和剂量依赖性的方式逐渐出现，并导致肌动蛋白丝几乎静止不动。此外，我们使用了四个带有YFP融合蛋白标记高尔基体、内质网（ER）、液泡和过氧化物酶体的转基因系，来证明AITC诱导这些结构中肌动蛋白依赖性的细胞内运输受到抑制，这与肌动蛋白丝运动的减弱一致。此外，在暴露于AITC后，肌动蛋白丝、内质网和液泡的形态出现异常。然而，在不含AITC的环境中过夜培养后，所有测试的转基因系经AITC处理的幼苗显示出与相应未处理和对照处理的植物相似的形态和细胞内运动，这表明AITC诱导的肌动蛋白相关运动的减弱是一个可逆过程。这些发现为植物细胞暴露于AITC后的细胞事件提供了新的见解，这可能进一步揭示芥子油苷-黑芥子酶系统的生理意义的线索。
