title: Effects of stomatal density and leaf water content on the ¹⁸O enrichment of leaf water.
abstract: Leaf water isotopic composition is imprinted in several biomarkers of interest and it is imperative that we understand the isotopic enrichment of leaf water. Here, we test the effect of stomatal density and leaf water content on the oxygen isotopic composition of leaf water in transgenic Arabidopsis plants expressing different stomatal densities, and several other species showing a range of stomatal density. We grew Arabidopsis plants hydroponically and collected other species in the field. Stomatal density and leaf water content were determined for each plant. We measured transpiration and extracted leaf water for isotopic determination. Using these measurements and the current leaf water isotope model, we calculated several of the parameters related to leaf water isotopic enrichment. High stomatal density promoted leaf water isotope enrichment. No conclusion, however, can be drawn regarding the effect of leaf water content on leaf water isotope enrichment. Factors such as transpiration might mask the effect of stomatal density on leaf water isotopic enrichment. We propose a method by which stomatal density can be incorporated in the current Peclet model of leaf water isotope enrichment. These findings have important applications in the use of plant-based metabolic proxies in paleoclimate studies.
authors.affiliation: Programa de Pós Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
authors.forename: Leticia
authors.initials: L
authors.lastname: Larcher
authors.affiliation: Graduate School of Science, Department of Botany, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hara-Nishimura
authors.affiliation: Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33124, USA.
authors.forename: Leonel
authors.initials: L
authors.lastname: Sternberg
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010103:Oxygen Isotopes / Q000032:analysis; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000378:metabolism; D054046:Plant Stomata / Q000033:anatomy & histology* / Q000378:metabolism; D018526:Plant Transpiration; D014867:Water / Q000378:metabolism*
chemical_list: D010103:Oxygen Isotopes; D014867:Water; D010100:Oxygen
keywords: Arabidopsis; leaf water; leaf water content; oxygen isotope ratios; stomatal density