The quantification of root exudation by an in-situ method based on root morphology over three incubation periods

作者：Chengfu Zhang, Yinmei Cai, Qingxia Zhao, Tengbing He, Tianxu Mao, Tao Zhang, Limin Zhang, Weici Su · 发表于：Frontiers in Plant Science · 年份：2024 · DOI：10.3389/fpls.2024.1423703 · 被引用次数：4 · 研究领域：Soil Carbon and Nitrogen Dynamics、Plant nutrient uptake and metabolism、Clay minerals and soil interactions

Investigating the quantity and spatiotemporal dynamics of metabolite release from plant roots is essential if we are to understand the ecological significance of root exudates in the rhizosphere; however, this is difficult to quantify. In the present study, we quantified in situ root exudation rates during three incubation periods (0–24, 24–48, and 48–72 h) and fine roots within four diameter ranges (<0.8, 0.8–1.0, 1.0–1.2, and 1.2–2.0 mm), and also measured nine morphological traits in the fine roots of Pinus massoniana . Higher root carbon (C) exudation rates were detected during the 0–24 h period. During the 0–24 h and 24–48 h periods, nitrogen (N) uptake rates were higher than N exudation rates, while during the 48–72 h period, N exudation rates exceeded uptake rates. As C exudation increased during 0–48h incubation period, the uptake of N tended to level out. We concluded that the 24–48 h incubation period was the most suitable for capturing root exudates from P. massoniana. The exudation of C from the roots was positively associated with root mass, length, surface area, volume, the number of root tips, and the root tissue density, when incubated for 0–24 h and 24–48 h. Furthermore, length-specific C exudation rates, along with N exudation and uptake rates, all increased as the diameter of the fine roots increased. The release of root exudates could be efficiently predicted by the fine root morphological traits, although the accuracy of prediction depended on the ...