Evaporation-driven internal hydraulic redistribution alleviates root drought stress: Mechanisms and modeling.
Plant Physiol
; 193(2): 1058-1072, 2023 09 22.
Article
en En
| MEDLINE
| ID: mdl-37350505
ABSTRACT
Many tree species have developed extensive root systems that allow them to survive in arid environments by obtaining water from a large soil volume. These root systems can transport and redistribute soil water during drought by hydraulic redistribution (HR). A recent study revealed the phenomenon of evaporation-driven hydraulic redistribution (EDHR), which is driven by evaporative demand (transpiration). In this study, we confirmed the occurrence of EDHR in Chinese white poplar (Populus tomentosa) through root sap flow measurements. We utilized microcomputed tomography technology to reconstruct the xylem network of woody lateral roots and proposed conceptual models to verify EDHR from a physical perspective. Our results indicated that EDHR is driven by the internal water potential gradient within the plant xylem network, which requires 3 conditions high evaporative demand, soil water potential gradient, and special xylem structure of the root junction. The simulations demonstrated that during periods of extreme drought, EDHR could replenish water to dry roots and improve root water potential up to 38.9% to 41.6%. This highlights the crucial eco-physiological importance of EDHR in drought tolerance. Our proposed models provide insights into the complex structure of root junctions and their impact on water movement, thus enhancing our understanding of the relationship between xylem structure and plant hydraulics.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Populus
/
Sequías
Idioma:
En
Revista:
Plant Physiol
Año:
2023
Tipo del documento:
Article
País de afiliación:
China