title: 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.
abstract: 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.
authors: The Belle W. Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA.|Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China.
authors: Jun-Jian
authors: JJ
authors: Wang
authors: School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA.
authors: Nishanth
authors: N
authors: Tharayil
authors: The Belle W. Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA.
authors: Alex T
authors: AT
authors: Chow
authors: School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA.
authors: Vidya
authors: V
authors: Suseela
authors: Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China.|College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
authors: Hui
authors: H
authors: Zeng
mesh_terms: D002244:Carbon / Q000378:metabolism*; D002681:China; D015999:Multivariate Analysis; D009584:Nitrogen / Q000378:metabolism; D010636:Phenols / Q000378:metabolism*; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism*; D025341:Principal Component Analysis; D012621:Seasons; D013045:Species Specificity
chemical_list: D010636:Phenols; D002244:Carbon; D009584:Nitrogen
keywords: decomposition; fine roots; lignin; lignin indices; organic matter; phenolics