Changes in total leaf nitrogen and partitioning of leaf nitrogen drive photosynthetic acclimation to light in fully developed walnut leaves

Abstract

Comprehensive studies on the processes involved in photosynthetic acclimation after a sudden change in light regime are scarce, particularly for trees. We tested (i) the ability of photosynthetic acclimation in the foliage of walnut trees growing outdoors after low-to-high and high-to-low light transfers made early or late in the vegetation cycle, and (ii) the relative importance of changes in total leaf nitrogen versus changes in the partitioning of leaf nitrogen between the different photosynthetic functions during a 2 month period after transfer. Changes in maximum carboxylation rate, light-saturated electron transport rate, respiration rate, total leaf nitrogen, ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco) and total chlorophylls were surveyed before and after the change in light regime. Respiration rate acclimated fully within 1 week of transfer, and full acclimation was observed 1 month after transfer for the amount of Rubisco. In contrast, total nitrogen and photosynthetic capacity acclimated only partially during the 2 month period. Changes in photosynthetic capacity were driven by changes in both total leaf nitrogen and leaf nitrogen partitioning. The extent of acclimation also depended strongly on leaf age at the time of the change in light regime.

Effect of nitrogen loading on the growth and photosynthetic responses of Japanese larch seedlings grown under different light regimes

“…The latter value approaches that measured in central Europe, of 25.5 kg N ha -1 y -1 , in 2006 (Izuta, 2006;Galloway et al, 2008). Deposited N may act as a fertilizer and alter plant biodiversity (Fangmeier, et al, 1994;Bobbink, et al, 1998;Wang et al, 2009) and photosynthetic function (Frak et al, 2001;Qu et al, 2005;Mao et al, 2014). In a nursery experiment, the addition of 50 kg N ha -1 y -1 promoted the growth and photosynthesis of F 1 hybrid larch (L. gmelinii var.…”

Diversity of water use efficiency among Quercus robur genotypes: contribution of related leaf traits

“…Collaku et al, 2005;Kabanova et al, 2000 for wheat, Hervé et al, 2001 for sunflower), suggesting considerable environmental influence. This might be due to rapid (within days) acclimation to current irradiance, as shown by Frak et al (2001) for Juglans nigra x regia seedlings. Additionally to the specific selection of "N" genotypes, the pedunculate oak saplings in the present study were raised with optimal water supply, which should reduce the stomatal limitation of assimilation rate and thus facilitate the expression of differences in photosynthetic capacity.…”

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.…”

“…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).…”