The Relationship between Rubisco Activity and Photosynthesis in Apple Leaves with Different Nitrogen Content
Year: 1997
Type: article
Abstract: Based on the curvilinear relationship between carboxylation efficiency and leaf N in apple leaves, we hypothesized that deactivation of Rubisco accounts for the lack of response of photosynthesis to increasing leaf N under high N supply. A wide range of leaf N content (from 1.0 to 5.0 g·m –2 ) was achieved by fertigating bench-grafted Fuji/M26 apple trees for 6 weeks with different N concentrations using a modified Hoagland solution. Analysis of photosynthesis in response to intercellular CO 2 under both 21% and 2% O 2 indicated that photosynthesis at ambient CO 2 was mainly determined by the activity of Rubisco. Measurements of Rubisco activity revealed that initial Rubisco activity increased with leaf N up to 3.0 g·m –2 , then leveled off with further rise in leaf N, whereas total Rubisco activity increased linearly with increasing leaf N throughout the leaf N range. As a result, Rubisco activation state decreased with increasing leaf N. Photosynthesis at ambient CO 2 and carboxylation efficiency were both linearly correlated with initial Rubisco activity, but showed curvilinear relationships with total Rubisco activity and leaf N. As leaf N increased, photosynthetic nitrogen use efficiency declined with decreasing Rubisco activation state.
Source: HortScience
Authors: Lailiang Cheng, Leslie H. Fuchigami
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2554937870