Despite the agronomic importance of sugar beet (Beta vulgaris L.), the early‐stage development of its taproot has only been poorly investigated. Thus, the mechanisms that determine growth and sugar accumulation in sugar beet are largely unknown. In the presented study, a physiological characterization of early‐stage sugar beet taproot development was conducted. Activities were analyzed for fourteen key enzymes of carbohydrate metabolism in developing taproots over the first 80 days after sowing. In addition, we performed in situ localizations of selected carbohydrate‐metabolic enzyme activities, anatomical investigations, and quantifications of soluble carbohydrates, hexose phosphates, and phytohormones. Based on the accumulation dynamics of biomass and sucrose, as well as on anatomical parameters, the early phase of taproot development could be subdivided into three stages—prestorage, transition, secondary growth and sucrose accumulation stage—each of which was characterized by distinct metabolic and phytohormonal signatures. The enzyme activity signatures corresponding to these stages were also shown to be robustly reproducible in experiments conducted in two additional locations. The results from this physiological phenotyping approach contribute to the identification of the key regulators of sugar beet taproot development and open up new perspectives for sugar beet crop improvement concerning both physiological marker‐based breeding and biotechnological approaches.

中文翻译：

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早期甜菜主根发育的特点是三个不同的生理阶段。


尽管甜菜（ Beta vulgaris L.）具有农艺重要性，但其主根的早期发育却很少被研究。因此，决定甜菜生长和糖积累的机制在很大程度上是未知的。在本研究中，对早期甜菜主根发育的生理特征进行了研究。分析了播种后 80 天内主根发育过程中碳水化合物代谢的 14 种关键酶的活性。此外，我们还对选定的碳水化合物代谢酶活性进行了原位定位、解剖学研究以及可溶性碳水化合物、磷酸己糖和植物激素的定量。根据生物量和蔗糖的积累动态以及解剖参数，主根发育的早期阶段可分为三个阶段：预贮期、过渡期、次生生长和蔗糖积累阶段，每个阶段都具有不同的代谢和代谢特征。植物激素特征。在另外两个地点进行的实验中，与这些阶段相对应的酶活性特征也被证明具有很强的可重复性。这种生理表型分析方法的结果有助于确定甜菜主根发育的关键调节因子，并为基于生理标记的育种和生物技术方法的甜菜作物改良开辟了新的视角。