Coordinated modifications in mesophyll conductance, photosynthetic potentials and leaf nitrogen contribute to explain the large variation in foliage net assimilation rates across Quercus ilex provenances.

Autor: Peguero-Pina JJ; Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda Montañana 930, 50059 Zaragoza, Spain.; Instituto Agroalimentario de Aragón-IA2 (CITA-Universidad de Zaragoza), 50013 Zaragoza, Spain., Sisó S; Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda Montañana 930, 50059 Zaragoza, Spain., Flexas J; Research Group on Plant Biology under Mediterranean conditions, Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa, 07122 Palma de Mallorca, Spain., Galmés J; Research Group on Plant Biology under Mediterranean conditions, Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa, 07122 Palma de Mallorca, Spain., Niinemets Ü; Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia., Sancho-Knapik D; Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda Montañana 930, 50059 Zaragoza, Spain.; Instituto Agroalimentario de Aragón-IA2 (CITA-Universidad de Zaragoza), 50013 Zaragoza, Spain., Gil-Pelegrín E; Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda Montañana 930, 50059 Zaragoza, Spain.; Instituto Agroalimentario de Aragón-IA2 (CITA-Universidad de Zaragoza), 50013 Zaragoza, Spain.
Jazyk: angličtina
Zdroj: Tree physiology [Tree Physiol] 2017 Aug 01; Vol. 37 (8), pp. 1084-1094.
DOI: 10.1093/treephys/tpx057
Abstrakt: Leaf dry mass per unit area (LMA) has been suggested to negatively affect the mesophyll conductance to CO2 (gm), the most limiting factor for photosynthesis per unit leaf area (AN) in many evergreens. Several anatomical traits (i.e., greater leaf thickness and thicker cell walls) constraining gm could explain the negative scaling of gm and AN with LMA across species. However, the Mediterranean sclerophyll Quercus ilex L. shows a major within-species variation in functional traits (greater LMA associated with higher nitrogen content and AN) that might contrast the worldwide trends. The objective of this study was to elucidate the existence of variations in other leaf anatomical parameters determining gm and/or biochemical traits improving the capacity of carboxylation (Vc,max) that could modulate the relationship of AN with LMA across this species. The results revealed that gm was the most limiting factor for AN in all the studied Q. ilex provenances from Spain and Italy. The within-species differences in gm can be partly attributed to the variation in several leaf anatomical traits, mainly cell-wall thickness (Tcw), chloroplast thickness (Tchl) and chloroplast exposed surface area facing intercellular air spaces (Sc/S). A positive scaling of gm and AN with Vc,max was also found, associated with an increased nitrogen content per area. A strong correlation of maximum photosynthetic electron transport (Jmax) with AN further indicated a coordination between the carboxylase activity and the electron transport chain. In conclusion, we have confirmed the strong ecotypic variation in the photosynthetic performance of individual provenances of Q. ilex. Thus, the within-species increases found in AN for Q. ilex with increasing foliage robustness can be explained by a synergistic effect among anatomical (at the subcellular and cellular level) and biochemical traits, which markedly improved gm and Vc,max.
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Databáze: MEDLINE
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