Wu Shiqi, Nakagawa Wakutaka, Mori Yuki, Azhari Saman, Méhes Gábor, Nishina Yuta, Kawano Tomonori, Miyake Takeo
Graduate School of Information, Production and Systems, Waseda University, Kitakyushu, 808-0135, Japan.
Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu, 808-0135, Japan.
Biosens Bioelectron. 2025 Nov 1;287:117674. doi: 10.1016/j.bios.2025.117674. Epub 2025 Jun 8.
Monitoring sucrose transport in plants is essential for understanding plant physiology and improving agricultural practices, yet effective sensors for continuous and real-time in-vivo monitoring are lacking. In this study, we developed a plant-insertable sucrose sensor capable of real-time sucrose concentration monitoring and demonstrated its application as a useful tool for plant research by monitoring the sugar-translocating path from leaves to the lower portion of plants through the stem in living plants. The biosensor consists of a bilirubin oxidase-based biocathode and a needle-type bioanode integrating glucose oxidase, invertase, and mutarotase, with the two electrodes separated by an agarose gel for ionic connection. The sensor exhibits a sensitivity of 6.22 μA mM cm, a limit of detection of 100 μM, a detection range up to 60 mM, and a response time of 90 s at 100 μM sucrose. Additionally, the sensor retained 86 % of its initial signal after 72 h of continuous measurement. Day-night monitoring from the biosensor inserted in strawberry guava (Psidium cattleianum) showed higher sucrose transport activity at night, following well the redistribution of photosynthetically produced sugars. In addition, by monitoring the forced translocation of sucrose dissolved in the stable isotopically labeled water, we demonstrated that a young seedling of Japanese cedar known as Sugi (Cryptomeria japonica) can absorb and transport both water and sucrose through light-dependently opened stomata, which is the recently revealed path for liquid uptake by higher plants. These findings highlight the potential of our sensor for studying dynamic plant processes and its applicability in real-time monitoring of sugar transport under diverse environmental conditions.
监测植物中的蔗糖运输对于理解植物生理学和改进农业实践至关重要，但目前缺乏用于连续实时体内监测的有效传感器。在本研究中，我们开发了一种可插入植物的蔗糖传感器，能够实时监测蔗糖浓度，并通过监测活体植物中从叶片经茎到植物下部的糖分转运路径，证明了其作为植物研究有用工具的应用。该生物传感器由基于胆红素氧化酶的生物阴极和集成葡萄糖氧化酶、转化酶和变旋酶的针型生物阳极组成，两个电极由琼脂糖凝胶隔开以进行离子连接。该传感器在100 μM蔗糖时表现出6.22 μA mM cm的灵敏度、100 μM的检测限、高达60 mM的检测范围和90 s的响应时间。此外，在连续测量72小时后，该传感器保留了其初始信号的86%。对插入草莓番石榴（番樱桃）中的生物传感器进行昼夜监测表明夜间蔗糖运输活性较高，与光合产生的糖分重新分配情况良好相符。此外，通过监测溶解在稳定同位素标记水中的蔗糖的强制转运，我们证明了日本柳杉（Cryptomeria japonica）的幼苗可以通过光依赖打开的气孔吸收和运输水和蔗糖，这是高等植物最近揭示的液体吸收途径。这些发现突出了我们的传感器在研究动态植物过程方面的潜力及其在不同环境条件下实时监测糖分运输的适用性。
