Articles
TRANSPIRATION RATE AND AMINO ACID DISTRIBUTION IN WATER STRESSED MEDICAGO TRUNCATULA PLANTS
Article number
846_39
Pages
339 – 344
Language
English
Abstract
Nitrogen fixation (NF) is very sensitive to a wide range of environmental stresses such as drought.
Despite much research effort in the area, the mechanisms influencing NF response to limited soil water are not well understood.
Accumulating evidences indicate that genotypic differences in sensitivity to drought may be associated with levels of nitrogen compounds in leaves or nodules of N2-fixing plants.
The aim of the present work was to study the relationship between transpiration rate and total amino acid accumulation in water stressed plants to unravel its possible role in NF regulation. Medicago truncatula cv.
Jemalong A17 plants inoculated with Sinorhizobium meliloti strain 2011 were grown in a split-root system (SRS). Twelve-week-old plants were separated randomly into three sets.
Controls were supplied daily with nutrient solution to achieve field capacity to both sides of the SRS whereas drought treatment was achieved by withholding water/nutrients from both sides.
Partial drought plants were irrigated to field capacity to one side of the SRS whilst water/nutrients were withheld from the other side.
Plants were harvested at day 7 after the onset of the drought treatment.
Transpiration rate (ET) and NF were determined in intact plants and afterwards, nodules and roots were harvested for amino acid determination.
Transpiration and nitrogen compound accumulation will be discussed in relation to the NF inhibition in water stressed plants, differentiating between local and systemic responses.
Despite much research effort in the area, the mechanisms influencing NF response to limited soil water are not well understood.
Accumulating evidences indicate that genotypic differences in sensitivity to drought may be associated with levels of nitrogen compounds in leaves or nodules of N2-fixing plants.
The aim of the present work was to study the relationship between transpiration rate and total amino acid accumulation in water stressed plants to unravel its possible role in NF regulation. Medicago truncatula cv.
Jemalong A17 plants inoculated with Sinorhizobium meliloti strain 2011 were grown in a split-root system (SRS). Twelve-week-old plants were separated randomly into three sets.
Controls were supplied daily with nutrient solution to achieve field capacity to both sides of the SRS whereas drought treatment was achieved by withholding water/nutrients from both sides.
Partial drought plants were irrigated to field capacity to one side of the SRS whilst water/nutrients were withheld from the other side.
Plants were harvested at day 7 after the onset of the drought treatment.
Transpiration rate (ET) and NF were determined in intact plants and afterwards, nodules and roots were harvested for amino acid determination.
Transpiration and nitrogen compound accumulation will be discussed in relation to the NF inhibition in water stressed plants, differentiating between local and systemic responses.
Publication
Authors
E. Gil-Quintana, J. Aldasoro, R. Ladrera, C. Arrese-Igor, E.M. González
Keywords
nitrogen compounds, drought, nitrogen fixation, nodule, evapotranspiration
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