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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

P5CS expression and proline accumulation 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. Relative expression levels of P5CS in petunia leaves at 0 and 3 days after drought treatment were measured by semi-quantitative RT-PCR (a, b). Proline accumulation in the control and rd29A:LeNCED1 petunia intact leaves exposed to 0 and 3 days under drought (c). Mean SD values of three independent experiments are shown. Different letters denote significant differences at the 0.05 level.
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fig7: P5CS expression and proline accumulation 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. Relative expression levels of P5CS in petunia leaves at 0 and 3 days after drought treatment were measured by semi-quantitative RT-PCR (a, b). Proline accumulation in the control and rd29A:LeNCED1 petunia intact leaves exposed to 0 and 3 days under drought (c). Mean SD values of three independent experiments are shown. Different letters denote significant differences at the 0.05 level.

Mentions: Under non-stressed conditions, P5CS transcript abundance was low, but detectable in transgenic rd29A:LeNCED1 and control plants (Figure 7a). Abundance was much higher in the non-stressed CaMV-35S:LeNCED1 plants. After 3 days of drought stress, P5CS transcript abundance had increased substantially in all plants, but much more in the transgenic plants than in the controls (Figure 7b). The proline content of the plants mirrors the transcript abundance (Figure 7c); concentrations were low in non-stressed plants, although somewhat higher in the CaMV-35S:LeNCED1 plants (Figure 7c). Stressed plants all contained much higher concentrations of proline, but concentrations in the transgenic lines were double that in the controls (Figure 7c).


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

Estrada-Melo AC - Hortic Res (2015)

P5CS expression and proline accumulation 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. Relative expression levels of P5CS in petunia leaves at 0 and 3 days after drought treatment were measured by semi-quantitative RT-PCR (a, b). Proline accumulation in the control and rd29A:LeNCED1 petunia intact leaves exposed to 0 and 3 days under drought (c). Mean SD values of three independent experiments are shown. 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

fig7: P5CS expression and proline accumulation 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. Relative expression levels of P5CS in petunia leaves at 0 and 3 days after drought treatment were measured by semi-quantitative RT-PCR (a, b). Proline accumulation in the control and rd29A:LeNCED1 petunia intact leaves exposed to 0 and 3 days under drought (c). Mean SD values of three independent experiments are shown. Different letters denote significant differences at the 0.05 level.
Mentions: Under non-stressed conditions, P5CS transcript abundance was low, but detectable in transgenic rd29A:LeNCED1 and control plants (Figure 7a). Abundance was much higher in the non-stressed CaMV-35S:LeNCED1 plants. After 3 days of drought stress, P5CS transcript abundance had increased substantially in all plants, but much more in the transgenic plants than in the controls (Figure 7b). The proline content of the plants mirrors the transcript abundance (Figure 7c); concentrations were low in non-stressed plants, although somewhat higher in the CaMV-35S:LeNCED1 plants (Figure 7c). Stressed plants all contained much higher concentrations of proline, but concentrations in the transgenic lines were double that in the controls (Figure 7c).

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