Phenolic profile within the fine-root branching orders of an evergreen species highlights a disconnect in root tissue quality predicted by elemental- and molecular-level carbon composition.
Phenolic profile within the fine-root branching orders of an evergreen species highlights a disconnect in root tissue quality predicted by elemental- and molecular-level carbon composition.
复制标题
DOI：
10.1111/nph.13385
复制
发表时间：
2015-06
期刊：
影响因子：
--
通讯作者：
Jun-Jian Wang;N. Tharayil;A. Chow;V. Suseela;Hui Zeng
中科院分区：
文献类型：
--
作者：
Jun-Jian Wang;N. Tharayil;A. Chow;V. Suseela;Hui Zeng
细根是陆地生态系统中植物生产力和凋落物周转的重要来源，但人们对细根结构中酚类化合物的数量和质量分布知之甚少，这些酚类化合物可以调节植物根系对土壤有机质库的潜在贡献。为了了解传统的根的宏观元素和形态特征与其分子水平碳化学之间的联系，我们分析了西洋参细根(远端五级)和叶片中游离酚、结合酚和木质素酚单体产量的季节变化。细根中结合酚的浓度是叶的两倍，木质素酚的浓度是叶的三倍。在细根中，游离酚和结合酚的浓度随根序的增加而降低，且低位根中酚类物质的季节变化比高位根更明显。根的形态和宏观元素性状与酚类化合物的数量、组成和组织结合是分离的，揭示了这些传统参数可能无法捕捉到细根构型内以及细根和叶片之间酚碳的分子同一性。我们的结果突出了细根构型中酚碳组成的分子水平的异质性，并暗示捕捉到根构型的分子同一性的特征可能更好地预测细根级内的分解动力学。
Fine roots constitute a significant source of plant productivity and litter turnover across terrestrial ecosystems, but less is known about the quantitative and qualitative profile of phenolic compounds within the fine-root architecture, which could regulate the potential contribution of plant roots to the soil organic matter pool. To understand the linkage between traditional macro-elemental and morphological traits of roots and their molecular-level carbon chemistry, we analyzed seasonal variations in monomeric yields of the free, bound, and lignin phenols in fine roots (distal five orders) and leaves of Ardisia quinquegona. Fine roots contained two-fold higher concentrations of bound phenols and three-fold higher concentrations of lignin phenols than leaves. Within fine roots, the concentrations of free and bound phenols decreased with increasing root order, and seasonal variation in the phenolic profile was more evident in lower order than in higher order roots. The morphological and macro-elemental root traits were decoupled from the quantity, composition and tissue association of phenolic compounds, revealing the potential inability of these traditional parameters to capture the molecular identity of phenolic carbon within the fine-root architecture and between fine roots and leaves. Our results highlight the molecular-level heterogeneity in phenolic carbon composition within the fine-root architecture, and imply that traits that capture the molecular identity of the root construct might better predict the decomposition dynamics within fine-root orders.