Drought stress increases total C released from roots

作者：Danielle Ulrich, Kelsey N. Flathers, Hannah Goemann, Rebecca Mueller, Brent Peyton · 发表于：Annals of Botany · 年份：2026 · DOI：10.1093/aob/mcag007 · 被引用次数：1 · 研究领域：Soil Carbon and Nitrogen Dynamics、Plant nutrient uptake and metabolism、Plant Water Relations and Carbon Dynamics

BACKGROUND AND AIMS: Root exudation and rhizodeposition are critical pathways for plant carbon (C) allocation to soil, influencing soil organic C stability and ecosystem functioning under changing climates. However, the effects of drought stress on these below-ground processes remain poorly understood. We provide an updated and comprehensive assessment of the current state of knowledge on how drought stress affects root-derived C fluxes (root exudates, rhizodeposition) across diverse functional types and experimental setups to direct future research. METHODS: We conducted a meta-analysis to quantify how drought stress affects total C and other compound classes in root exudation and rhizodeposition. KEY RESULTS: Our analysis included 40 data points spanning diverse functional types, ecosystems, sampling methods and experimental conditions. We observed that root-released total C significantly increased in response to drought stress. Among compound classes, carbohydrates and organic acids also increased in response to drought stress, suggesting these compound classes may underlie total C responses in root exudation and rhizodeposition. The variables that explained the most variance in total C response ratio were ecosystem, flowering type, cotyledon type, functional type and drought intensity. CONCLUSIONS: To direct future research, our analysis identified knowledge gaps, particularly the need for studies to examine trees and shrubs, field-based research, broader drought intensit...