Zhang Chengfu, Cai Yinmei, Zhao Qingxia, He Tengbing, Mao Tianxu, Zhang Tao, Zhang Limin, Su Weici
Guizhou Institute of Mountain Resources, Guizhou Academy of Sciences, Guiyang, Guizhou, China.
College of Agriculture, Guizhou University, Guiyang, Guizhou, China.
Front Plant Sci. 2024 Aug 16;15:1423703. doi: 10.3389/fpls.2024.1423703. eCollection 2024.
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 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 . 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 incubation period. Higher values for fine root morphological traits were generally indicative of higher nutrient requirements and tissue investment, as well as higher C exudation rates.
如果我们想要了解根际中根系分泌物的生态意义，那么研究植物根系代谢物释放的数量及时空动态至关重要；然而，这很难进行量化。在本研究中，我们对三个培养期（0 - 24小时、24 - 48小时和48 - 72小时）以及四个直径范围（<0.8毫米、0.8 - 1.0毫米、1.0 - 1.2毫米和1.2 - 2.0毫米）内的细根的根系分泌物速率进行了量化，并且还测量了[具体植物]细根的九个形态特征。在0 - 24小时期间检测到较高的根系碳（C）分泌速率。在0 - 24小时和24 - 48小时期间，氮（N）吸收速率高于N分泌速率，而在48 - 72小时期间，N分泌速率超过吸收速率。在0 - 48小时培养期内，随着C分泌增加，N的吸收趋于稳定。我们得出结论，24 - 48小时的培养期最适合收集马尾松的根系分泌物。当培养0 - 24小时和24 - 48小时时，根系C的分泌与根质量、长度、表面积、体积、根尖数量和根组织密度呈正相关。此外，随着细根直径的增加，单位长度C分泌速率以及N分泌和吸收速率均增加。尽管预测的准确性取决于培养期，但细根形态特征能够有效地预测根系分泌物的释放。细根形态特征值较高通常表明对养分的需求和组织投入较高，以及C分泌速率较高。
