Leaf anatomy as a constraint for photosynthetic acclimation: differential responses in leaf anatomy to increasing growth irradiance among three deciduous trees

Abstract

Interspecific variation in the response to transfer from low to high growth irradiance with respect to anatomical and photosynthetic characteristics was studied in mature leaves of three tree species, Betula ermanii Cham., Acer rufinerve Sieb. et Zucc. and Fagus crenata Blume, which occur in different successional stages in temperate deciduous forests. Transfer from low to high irradiance increased the light-saturated rate of photosynthesis per unit leaf area ( P max ) significantly in B. ermanii and A. rufinerve , but not in F. crenata . Leaves of B. ermanii grown at low irradiance were relatively thick and had vacant spaces along the mesophyll cell surfaces which was not occupied by chloroplasts or other organelles. After transfer to high irradiance, chloroplasts enlarged to fill the space along with P max without an increase in leaf thickness. Leaves of A. rufinerve were plastic in mesophyll cell surface area and in leaf thickness, both of which increased after the transfer to high irradiance, along with an increase in the amount of chloroplasts and in P max . On the other hand, F. crenata had little mesophyll cell surface unoccupied by chloroplasts and leaf anatomy was not changed after the transfer. In all species, P max was strongly correlated with chloroplast surface area adjacent to the exposed mesophyll surface across different growth irradiances. An increase in P max was observed only when chloroplast volume also increased. We conclude that light acclimation potential is primarily determined by the availability of unoccupied cell surface into which chloroplasts expand, as well as by the plasticity of the mesophyll that allows an increase in its surface area.Key-words : acclimation potential; chloroplasts; leaf anatomy; leaf nitrogen; mature leaves; photosynthetic capacity; sun/ shade acclimation; transfer experiment.

From ecophysiology to phenomics: some implications of photoprotection and shade–sun acclimation in situ for dynamics of thylakoids in vitro

“…This commonly observed structural constraint [70] has been examined in detail by Oguchi et al [71], who found that although chloroplasts in mature leaves of low-light-grown Chenopodium album increased in size and occupied a higher proportion of cell walls adjacent to air spaces, leaf thickness did not increase. Moreover, leaves of deciduous woody plants showed at least three versions of these forms of anatomical constraints on the capacity to acclimate to light intensity [72]. Distinctions have been drawn previously between chloroplast and leaf level components of acclimation [73] and that in the long run, thylakoid dynamics may also be determined by these higher level constraints of space and time.…”

Adaptações estruturais de sete espécies ciófitas arbustivas de Floresta Ombrófila Densa

“…Apesar desta constatação ser mais amplamente reportada às plantas pioneiras (heliófitas) (Poorter et al 2010), existem registros tão contundentes quanto que espécies não pioneiras têm potencial plástico para se ajustar à variação da luminosidade em função de características interespecíficas (Oguchi et al 2005).…”

Photosynthetic acclimation within individual Typha latifolia leaf segments

“…These changes may include adjustments in partitioning among carboxylation, electron transport and light harvesting, chloroplast ultrastructure, volume, and orientation (Sebaa et al, 1987;De la Torre and Burkey, 1990a;Sailaja and Rama Das, 1995;Frank et al, 2001;Oguchi et al, 2003Oguchi et al, , 2005. The high N content of shaded segments should not be viewed as wasteful.…”

“…Lower case letters indicate significant differences between treatments for a sampling period; a lack of letters indicates insignificant differences at p ≤ 0.05. Naidu and De Lucia, 1998;Oguchi et al, 2005). Typha leaf segments that were continuously exposed to high light showed a slow A full sun decline.…”

“…The local light environment influences the morphological development of leaves in many species, resulting in comparatively thick leaves in bright locations Hikosaka, 1996;Niinemets, 2007). Fully expanded leaves have a limited capacity for morphological change (Sims and Pearcy, 1992;Evans and Porter, 2001;, and acclimation by these leaves requires biochemical changes in carboxylation, electron transport, and light harvesting, as well as modifications to chloroplast structure and orientation (Sebaa et al, 1987;De la Torre and Burkey, 1990a, b;Avalos and Mulkey, 1999;Frank et al, 2001;Murchie et al, 2002;Oguchi et al, 2003Oguchi et al, , 2005Walters, 2005).…”