Localized measurements of water potential reveal large loss of conductance in living tissues of maize leaves.
Plant Physiol
; 194(4): 2288-2300, 2024 Mar 29.
Article
em En
| MEDLINE
| ID: mdl-38128552
ABSTRACT
The water status of the living tissue in leaves between the xylem and stomata (outside xylem zone (OXZ) plays a critical role in plant function and global mass and energy balance but has remained largely inaccessible. We resolve the local water relations of OXZ tissue using a nanogel reporter of water potential (ψ), AquaDust, that enables an in situ, nondestructive measurement of both ψ of xylem and highly localized ψ at the terminus of transpiration in the OXZ. Working in maize (Zea mays L.), these localized measurements reveal gradients in the OXZ that are several folds larger than those based on conventional methods and values of ψ in the mesophyll apoplast well below the macroscopic turgor loss potential. We find a strong loss of hydraulic conductance in both the bundle sheath and the mesophyll with decreasing xylem potential but not with evaporative demand. Our measurements suggest the OXZ plays an active role in regulating the transpiration path, and our methods provide the means to study this phenomenon.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Água
/
Zea mays
Idioma:
En
Revista:
Plant Physiol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos