Evaluating a new method to estimate the rate of leaf respiration in the light by analysis of combined gas exchange and chlorophyll fluorescence measurements

• Published in: Journal of experimental botany 2011-06, Vol.62 (10), p.3489-3499
• Main Authors: Yin, Xinyou, Sun, Zhouping, Struik, Paul C., Gu, Junfei
• Format: Article
• Language: English
• Subjects: (co2)-c-12 emission; biochemical-model; Biological and medical sciences; c-3 photosynthesis; Carbon Dioxide - metabolism; Cell Respiration - physiology; Chlorophyll - metabolism; Corn; dark respiration; Data ranges; elevated co2 concentration; Estimation methods; Fluorescence; Fundamental and applied biological sciences. Psychology; Irradiance; Leaves; Linear regression; mesophyll conductance; Photosynthesis; Photosynthesis - physiology; photosynthetic electron-transport; Plant Leaves - metabolism; Plant physiology and development; Plants; quantum yield; RESEARCH PAPER; Research Papers; Respiration; ribulose-1,5-bisphosphate carboxylase oxygenase; xanthium-strumarium
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/err038

Day respiration (R d ) is an important parameter in leaf ecophysiology. It is difficult to measure directly and is indirectly estimated from gas exchange (GE) measurements of the net photosynthetic rate (A), commonly using the Laisk method or the Kok method. Recently a new method was proposed to estimate R d indirectly from combined GE and chlorophyll fluorescence (CF) measurements across a range of low irradiances. Here this method is tested for estimating R d in five C 3 and one C 4 crop species. Values estimated by this new method agreed with those by the Laisk method for the C 3 species. The Laisk method, however, is only valid for C 3 species and requires measurements at very low CO 2 levels. In contrast, the new method can be applied to both C 3 and C 4 plants and at any CO 2 level. The R d estimates by the new method were consistently somewhat higher than those by the Kok method, because using CF data corrects for errors due to any non-linearity between A and irradiance of the used data range. Like the Kok and Laisk methods, the new method is based on the assumption that R d varies little with light intensity, which is still subject to debate. Theoretically, the new method, like the Kok method, works best for non-photorespiratory conditions. As CF information is required, data for the new method are usually collected using a small leaf chamber, whereas the Kok and Laisk methods use only GE data, allowing the use of a larger chamber to reduce the noise-to-signal ratio of GE measurements.