Effects of nitrogen form on growth, CO2 assimilation, chlorophyll fluorescence, and photosynthetic electron allocation in cucumber and rice plants
Cucumber and rice plants with varying ammonium (NH4+) sensitivities were used to examine the effects of different nitrogen (N) sources on gas exchange, chlorophyll (Chl) fluorescence quenching, and photosynthetic electron allocation. Compared to nitrate (NO3-)-grown plants, cucumber plants grown und...
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Published in | Journal of Zhejiang University. B. Science Vol. 12; no. 2; pp. 126 - 134 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Heidelberg
SP Zhejiang University Press
01.02.2011
Springer Nature B.V Zhejiang University Press |
Subjects | |
Online Access | Get full text |
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Summary: | Cucumber and rice plants with varying ammonium (NH4+) sensitivities were used to examine the effects of different nitrogen (N) sources on gas exchange, chlorophyll (Chl) fluorescence quenching, and photosynthetic electron allocation. Compared to nitrate (NO3-)-grown plants, cucumber plants grown under NH4+-nutrition showed decreased plant growth, net photosynthetic rate, stomatal conductance, intercellular carbon dioxide (CO2) level, transpiration rate, maximum photochemical efficiency of photosystem II, and O2-independent alternative electron flux, and increased O2-dependent alternative electron flux. However, the N source had little effect on gas exchange, Chl a fluorescence parameters, and photosynthetic electron allocation in rice plants, except that NH4+-grown plants had a higher O2-independent alternative electron flux than NO3--grown plants. NO3- reduction activity was rarely detected in leaves of NH4*-grown cucumber plants, but was high in NH4+-grown rice plants. These results demonstrate that significant amounts of photosynthetic electron transport were coupled to NO3- assimilation, an effect more significant in NO3-- grown plants than in NH4+-grown plants. Meanwhile, NH4*-tolerant plants exhibited a higher demand for the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) for NO3- reduction, regardless of the N form supplied, while NH4+-sensitive plants had a high water-water cycle activity when NH4+ was supplied as the sole N source. |
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Bibliography: | 33-1356/Q S143.1 Nitrogen form, Photosynthetic electron allocation, Alternative electron flux, Nitrate reductase ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 1673-1581 1862-1783 |
DOI: | 10.1631/jzus.B1000059 |