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Comparison of the A–C c curve fitting methods in determining maximum ribulose 1·5‐bisphosphate carboxylase/oxygenase carboxylation rate, potential light saturated electron transport rate and leaf dark respiration
Author(s) -
MIAO ZEWEI,
XU MING,
LATHROP RICHARD G.,
WANG YUFEI
Publication year - 2009
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2008.01900.x
Subject(s) - rubisco , ribulose 1,5 bisphosphate , photosynthesis , mathematics , carboxylation , botany , physics , horticulture , chemistry , biology , biochemistry , catalysis
ABSTRACT A review of the literature revealed that a variety of methods are currently used for fitting net assimilation of CO 2 –chloroplastic CO 2 concentration ( A–C c ) curves, resulting in considerable differences in estimating the A–C c parameters [including maximum ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate ( V cmax ), potential light saturated electron transport rate ( J max ), leaf dark respiration in the light ( R d ), mesophyll conductance ( g m ) and triose‐phosphate utilization ( TPU )]. In this paper, we examined the impacts of fitting methods on the estimations of V cmax , J max , TPU , R d and g m using grid search and non‐linear fitting techniques. Our results suggested that the fitting methods significantly affected the predictions of Rubisco‐limited ( A c ), ribulose 1,5‐bisphosphate‐limited ( A j ) and TPU ‐limited ( A p ) curves and leaf photosynthesis velocities because of the inconsistent estimate of V cmax , J max , TPU , R d and g m , but they barely influenced the J max : V cmax , V cmax : R d and J max : TPU ratio. In terms of fitting accuracy, simplicity of fitting procedures and sample size requirement, we recommend to combine grid search and non‐linear techniques to directly and simultaneously fit V cmax , J max , TPU , R d and g m with the whole A–C c curve in contrast to the conventional method, which fits V cmax , R d or g m first and then solves for V cmax , J max and/or TPU with V cmax , R d and/or g m held as constants.