Xylem and phloem in petioles are coordinated with leaf gas exchange in oaks with contrasting anatomical strategies depending on leaf habit

Martín Sánchez, RubénSancho Knapik, DomingoFerrio Díaz, Juan PedroAlonso Forn, DavidLosada, Juan ManuelPeguero Pina, José JavierMencuccini, MaurizioGil Pelegrín, Eustaquio2024-08-272024-08-272024Martín-Sánchez, R., Sancho-Knapik, D., Ferrio, J. P., Alonso-Forn, D., Losada, J. M., Peguero-Pina, J. J., Mencuccini, M., & Gil-Pelegrín, E. (2024). Xylem and phloem in petioles are coordinated with leaf gas exchange in oaks with contrasting anatomical strategies depending on leaf habit. ESS Open Archive. August 24, 2024.http://hdl.handle.net/10532/7218As the single link between leaves and the rest of the plant, petioles must develop conductive tissues according to the water influx and sugar outflow of the leaf lamina. A scaling relationship between leaf area and anatomical traits of xylem and phloem is expected to improve the efficiency of these tissues. However, the different constraints compromising the functionality of both tissues (e.g., risk of cavitation) must not be disregarded. Additionally, plants present two main leaf habits (deciduous and evergreen) that may have different strategies to produce and package their petiole conduits to cope with environmental restrictions. In this study, we explore, in a diverse group of 33 oak species, the relationships between petiole anatomical traits, leaf area, stomatal conductance and photosynthesis rate. Results showed allometric scaling between anatomical structure of xylem and phloem with leaf area. We also found how photosynthesis and stomatal conductance at leaf-level are correlated with anatomical traits in the petiole. Nonetheless, the main novelty is how oaks present a different strategy depending on the leaf habit. Deciduous species tend to increase their diameters to achieve a greater leaf-specific conductivity. By contrast, evergreen oaks develop larger xylem conductive areas for a given leaf area than deciduous ones. This trade-off between safety-efficiency in petioles has never been attributed to the leaf habit of the species.enCreative Commons Attribution-NonCommercial-NoDerivs 4.0 SpainBosques de frondosas caducasConductancia EstomáticaFloemaQuercusTejidos VegetalesXilemaXylem and phloem in petioles are coordinated with leaf gas exchange in oaks with contrasting anatomical strategies depending on leaf habitJournal Contribution2024-08-27QuercusTejidos vegetalesXilemaFloemaConductancia estomáticaBosques de frondosas caducas