Where does Münch flow begin? Sucrose transport in the pre-phloem path.
Curr Opin Plant Biol
; 43: 101-107, 2018 06.
Article
em En
| MEDLINE
| ID: mdl-29704829
ABSTRACT
Current conceptions of sucrose export largely neglect the effect of transpiration-induced water potential gradients within leaf mesophyll, even as the mix of convection and diffusion in the pre-phloem path remains uncertain. It is also generally held that the relative importance of convection and diffusion in the pre-phloem path is controlled by the ratio of their respective mass transfer coefficients. Here, we consider pre-phloem sucrose transport in the presence of adverse water potential gradients, finding that whether convection impedes or aids sucrose delivery to the phloem is independent of the permeability of the plasmodesmata to bulk flow, and depends only on assimilation rate, path-length, and the diffusivity. For most tissues subject to transpiration, convection through plasmodesmata pushes sugar away from the phloem.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plantas
/
Sacarose
Idioma:
En
Revista:
Curr Opin Plant Biol
Ano de publicação:
2018
Tipo de documento:
Article