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Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia.

Estrada-Melo AC - Hortic Res (2015)

Bottom Line: The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations.Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development.Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of California Davis , Davis, CA, USA.

ABSTRACT
The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress, the transgenic plants had increased transcripts of NCED mRNA, elevated leaf ABA concentrations, increased concentrations of proline, and a significant increase in drought resistance. The transgenic plants also displayed the expected decreases in stomatal conductance, transpiration, and photosynthesis. After 14 days without water, the control plants were dead, but the transgenic plants, though wilted, recovered fully when re-watered. Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy.

No MeSH data available.


Related in: MedlinePlus

Leaf gas exchange and water potential in LeNCED1-overexpressed petunia. Plants of non-transformed control, transgenic rd29A:LeNCED1 lines 8F, 7D, 3D, and CaMV-35S:LeNCED1-12F line were grown in UC mix soils in greenhouse for 6 weeks under non-stress conditions and were subjected to drought treatment by withholding irrigation for 3 days. CO2 assimilation rate (a), leaf conductance (b), transpiration rate (c), and stem water potential (d) were measured using intact leaves. Error bars represent standard deviation of the mean where n = 6. Different letters denote significant differences at the 0.05 level.
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fig6: Leaf gas exchange and water potential in LeNCED1-overexpressed petunia. Plants of non-transformed control, transgenic rd29A:LeNCED1 lines 8F, 7D, 3D, and CaMV-35S:LeNCED1-12F line were grown in UC mix soils in greenhouse for 6 weeks under non-stress conditions and were subjected to drought treatment by withholding irrigation for 3 days. CO2 assimilation rate (a), leaf conductance (b), transpiration rate (c), and stem water potential (d) were measured using intact leaves. Error bars represent standard deviation of the mean where n = 6. Different letters denote significant differences at the 0.05 level.

Mentions: In well-watered plants, the photosynthesis rate, transpiration rate, stomatal conductance, and stem water potential of control and rd29A:LeNCED1 plants were very similar (Figure 6). In contrast, these parameters were all significantly lower in plants of the CaMV-35S:LeNCED1 line. Drought stress reduced these physiological parameters in all plants. Photosynthesis, stomatal conductance, and transpiration in the stressed transgenic plants were lower than in the stressed non-transformed controls, but stem water potential of the controls was much lower than that in the transgenic lines (Figure 6).


Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia.

Estrada-Melo AC - Hortic Res (2015)

Leaf gas exchange and water potential in LeNCED1-overexpressed petunia. Plants of non-transformed control, transgenic rd29A:LeNCED1 lines 8F, 7D, 3D, and CaMV-35S:LeNCED1-12F line were grown in UC mix soils in greenhouse for 6 weeks under non-stress conditions and were subjected to drought treatment by withholding irrigation for 3 days. CO2 assimilation rate (a), leaf conductance (b), transpiration rate (c), and stem water potential (d) were measured using intact leaves. Error bars represent standard deviation of the mean where n = 6. Different letters denote significant differences at the 0.05 level.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595983&req=5

fig6: Leaf gas exchange and water potential in LeNCED1-overexpressed petunia. Plants of non-transformed control, transgenic rd29A:LeNCED1 lines 8F, 7D, 3D, and CaMV-35S:LeNCED1-12F line were grown in UC mix soils in greenhouse for 6 weeks under non-stress conditions and were subjected to drought treatment by withholding irrigation for 3 days. CO2 assimilation rate (a), leaf conductance (b), transpiration rate (c), and stem water potential (d) were measured using intact leaves. Error bars represent standard deviation of the mean where n = 6. Different letters denote significant differences at the 0.05 level.
Mentions: In well-watered plants, the photosynthesis rate, transpiration rate, stomatal conductance, and stem water potential of control and rd29A:LeNCED1 plants were very similar (Figure 6). In contrast, these parameters were all significantly lower in plants of the CaMV-35S:LeNCED1 line. Drought stress reduced these physiological parameters in all plants. Photosynthesis, stomatal conductance, and transpiration in the stressed transgenic plants were lower than in the stressed non-transformed controls, but stem water potential of the controls was much lower than that in the transgenic lines (Figure 6).

Bottom Line: The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations.Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development.Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of California Davis , Davis, CA, USA.

ABSTRACT
The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress, the transgenic plants had increased transcripts of NCED mRNA, elevated leaf ABA concentrations, increased concentrations of proline, and a significant increase in drought resistance. The transgenic plants also displayed the expected decreases in stomatal conductance, transpiration, and photosynthesis. After 14 days without water, the control plants were dead, but the transgenic plants, though wilted, recovered fully when re-watered. Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy.

No MeSH data available.


Related in: MedlinePlus