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Increases of chlorophyll a / b ratios during acclimation of tropical woody seedlings to nitrogen limitation and high light
Author(s) -
KITAJIMA K.,
HOGAN K. P.
Publication year - 2003
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 - 10.1046/j.1365-3040.2003.01017.x
Subject(s) - photosynthesis , acclimatization , nitrogen , chlorophyll , botany , photosynthetic capacity , biology , chlorophyll a , rubisco , specific leaf area , horticulture , chemistry , organic chemistry
According to the theory of optimal nitrogen partitioning within a leaf, the chlorophyll (Chl) a / b ratio is expected to increase when leaf N content decreases. Here, we report the first empirical support for this prediction. The Chl a / b ratio increased while Chl content decreased in response to N limitation in photosynthetic cotyledons and leaves of seedlings of four tropical woody species in the Bignoniaceae. The responses of all four species were in the same direction, but differed in magnitude. For Tabebuia rosea , the species that exhibited the greatest increase in Chl a / b ratios (up to values of 5.9), detailed photosynthetic characteristics were also examined. Light and N availability were positively correlated with the light‐ and CO 2 ‐saturated photosynthetic O 2 evolution rate, as well as with leaf carboxylation capacity ( V cmax ) and electron transport rate ( V j ). Severe N limitation and high light did not cause chronic photo‐inhibition (i.e. no change in quantum yield or in dark‐acclimated F v / F m ). The observed change in the ratio of V cmax to leaf N in response to N availability was consistent with likely functional reasons for change in the Chl a / b ratio. Adjustment of the Chl a / b ratio was apparently an integral feature of acclimation to high light conditions and low N availability.