Leaf water 18 O and 2 H maps show directional enrichment discrepancy in Colocasia esculenta.
Plant Cell Environ
; 40(10): 2095-2108, 2017 Oct.
Article
em En
| MEDLINE
| ID: mdl-28658718
ABSTRACT
Spatial patterns of leaf water isotopes are challenging to predict because of the intricate link between vein and lamina water. Many models have attempted to predict these patterns, but to date, most have focused on monocots with parallel veins. These provide a simple system to study, but do not represent the majority of plant species. Here, a new protocol is developed using a Picarro induction module coupled to a cavity ringdown spectrometer to obtain maps of the leaf water isotopes (18 O and 2 H). The technique is applied to Colocasia esculenta leaves. The results are compared with isotope ratio mass spectrometry. In C. esculenta, a large enrichment in the radial direction is observed, but not in the longitudinal direction. The string-of-lakes model fails to predict the observed patterns, while the Farquhar-Gan model is more successful, especially when enrichment is accounted for along the radial direction. Our results show that reticulate-veined leaves experience a larger enrichment along the axis of the secondary veins than along the midrib. We hypothesize that this is due to the lower major/minor vein ratio that leads to longer pathways between major veins and sites of evaporation.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Isótopos de Oxigênio
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Folhas de Planta
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Colocasia
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Deutério
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article