The family Brassicaceae is a source of important crop species, including Brassica napus (oilseed rape), Brassica oleracea, and B. rapa, that is used globally for oil production or as a food source (e.g., pak choi or turnip). However, despite advances in recent years, including genome sequencing, a lack of established tools tailored to the study of Brassica crop species has impeded efforts to understand their molecular processes in greater detail. Here, we describe the use of a simple Agrobacterium‐mediated transient expression system adapted to B. rapa and B. napus that could facilitate study of molecular and biochemical events in these species. We also demonstrate the use of this method to characterize the N‐degron pathway of protein degradation in B. rapa. The N‐degron pathway is a subset of the ubiquitin‐proteasome system and represents a mechanism through which proteins may be targeted for degradation based on the identity of their N‐terminal amino acid residue. Interestingly, N‐degron‐mediated processes in plants have been implicated in the regulation of traits with potential agronomic importance, including the responses to pathogens and to abiotic stresses such as flooding tolerance. The stability of transiently expressed N‐degron reporter proteins in B. rapa indicates that its N‐degron pathway is highly conserved with that of Arabidopsis thaliana. These findings highlight the utility of Agrobacterium‐mediated transient expression in B. rapa and B. napus and establish a framework to investigate the N‐degron pathway and its roles in regulating agronomical traits in these species.

中文翻译：

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一种简单有效的农杆菌介导的瞬时表达系统，用于剖析油菜和欧洲油菜中的分子过程。

十字花科是重要作物物种的来源，包括欧洲油菜（油菜）、甘蓝和油菜，它们在全球范围内用于石油生产或作为食物来源（例如，小白菜或萝卜）。然而，尽管近年来取得了进展，包括基因组测序，但缺乏专门用于研究芸苔属作物物种的成熟工具阻碍了更详细地了解其分子过程的努力。在这里，我们描述了一种简单的农杆菌介导的瞬时表达系统，适用于油菜和欧洲油菜。这可以促进对这些物种的分子和生化事件的研究。我们还展示了使用这种方法来表征B. rapa中蛋白质降解的 N-degron 途径。N-degron 途径是泛素-蛋白酶体系统的一个子集，代表了一种机制，通过该机制，蛋白质可以根据其 N 端氨基酸残基的特性而被靶向降解。有趣的是，植物中 N-degron 介导的过程与调节具有潜在农艺重要性的性状有关，包括对病原体的反应和对非生物胁迫（如洪水耐受性）的反应。油菜中瞬时表达的 N-degron 报告蛋白的稳定性表明其 N-degron 通路与拟南芥。这些发现突出了农杆菌介导的瞬时表达在油菜和欧洲油菜中的效用，并建立了一个框架来研究 N- degron途径及其在调节这些物种农艺性状中的作用。