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Rubisco expression in rice leaves is related to genotypic variation of photosynthesis under elevated growth CO 2 and temperature
Author(s) -
GESCH R. W.,
KANG I.H.,
GALLOMEAGHER M.,
VU J. C. V.,
BOOTE K. J.,
H. ALLEN L.,
BOWES G.
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.1365-3040.2003.01110.x
Subject(s) - rubisco , photosynthesis , oryza sativa , cultivar , photosystem ii , japonica , biology , japonica rice , horticulture , genotype , carboxylation , botany , chemistry , zoology , gene , biochemistry , catalysis
Genetic modifications of agronomic crops will likely be necessary to cope with global climate change. This study tested the hypotheses that genotypic differences in rice ( Oryza sativa L.) leaf photosynthesis at elevated [CO 2 ] and temperature are related to protein and gene expression of Rubisco, and that high growth temperatures under elevated [CO 2 ] negatively affect photosystem II (PSII) photochemical efficiency. Two rice cultivars representing an indica (cv. IR72) and japonica type (cv. M103) were grown in 350 (ambient) and 700 (elevated) µ mol CO 2 mol −1 at 28/18, 34/24 and 40/30 °C sinusoidal maximum/minimum, day/night temperatures in outdoor, sunlit, environment‐controlled chambers. Leaf photosynthesis of IR72 favoured higher growth temperatures more than M103. Rubisco total activity and protein content were negatively affected in both genotypes by high temperatures and elevated CO 2 . However, at moderate to high growth temperatures, IR72 leaves averaged 71 and 39% more rbcS transcripts than M103 under ambient and elevated CO 2 , respectively, and likewise had greater Rubisco activity and protein content. Expression of psbA (D1 protein of PSII) in IR72 leaves increased with temperature, whereas it remained constant for M103, except for a 20% decline at 40/30 °C under elevated CO 2 . Even at the highest growth temperatures, PSII photochemical efficiency was not impaired in either genotype grown under either ambient or elevated CO 2 . Genotypic differences exist in rice for carboxylation responses to elevated CO 2 and high temperatures, which may be useful in developing genotypes suited to cope with global climate changes.