Limits...
Overexpression of TaNAC2D Displays Opposite Responses to Abiotic Stresses between Seedling and Mature Stage of Transgenic Arabidopsis

View Article: PubMed Central - PubMed

ABSTRACT

Environmental stresses frequently affect plant growth and development, and many genes have been found to be induced by unfavorable environmental conditions. Here, we reported the biological functions of TaNAC2D, a stress-related NAC (NAM, ATAF, and CUC) gene from wheat. TaNAC2D showed transcriptional activator activity in yeast. TaNAC2D-GFP fusion protein was localized in the nucleus of wheat mesophyll protoplasts. TaNAC2D transcript abundance was significantly induced by NaCl, PEG6000, and abscisic acid (ABA) at seedling stage, and repressed by NaCl and PEG6000 at mature plant stage. When TaNAC2D was introduced into Arabidopsis, the 35-day-old soil-grown TaNAC2D-overexpression (TaNAC2D-OX) plants displayed slower stomatal closure, higher water loss rate, and more sensitivity to salt and drought stresses compared with WT plants. In contrast, TaNAC2D-OX seedlings, grown on 1/2 MS medium supplemented with different concentrations of NaCl, Mannitol, and MV, had enhanced tolerances to salt, osmotic and oxidative stresses during seed germination and post-germination periods. The opposite stress-responsive phenotypes of transgenic Arabidopsis were consistent with the expression patterns of TaNAC2D in wheat. Moreover, under high salinity and dehydration conditions, three marker genes, including NCED3, RD29A, and RD29B, were down-regulated in 35-day-old TaNAC2D-OX plants grown in soil and up-regulated in 14-day-old TaNAC2D-OX seedlings grown on 1/2 MS medium. Our results suggest that the change in growth stages and environmental conditions may regulate TaNAC2D’s function.

No MeSH data available.


Related in: MedlinePlus

Response of TaNAC2D-OX plants to dehydration and ABA-mediated stomatal closure.(A) Phenotypes of leaves under dehydration stress for 0, 2, and 3 h. (B) Water loss rate of WT, EV, and OXs. Data are means ± SE of three independent experiments (n = 10). (C) Guard cells of 35-day-old soil-grown WT and OXs treated with or without 30 μM ABA for 1 h. Scale bars = 30 μm. (D) Quantitative analysis of the size of stomatal aperture. Data are means ± SE (n = 50). Asterisks indicate significant differences from WT (∗P < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120104&req=5

Figure 5: Response of TaNAC2D-OX plants to dehydration and ABA-mediated stomatal closure.(A) Phenotypes of leaves under dehydration stress for 0, 2, and 3 h. (B) Water loss rate of WT, EV, and OXs. Data are means ± SE of three independent experiments (n = 10). (C) Guard cells of 35-day-old soil-grown WT and OXs treated with or without 30 μM ABA for 1 h. Scale bars = 30 μm. (D) Quantitative analysis of the size of stomatal aperture. Data are means ± SE (n = 50). Asterisks indicate significant differences from WT (∗P < 0.05).

Mentions: To further investigate the drought-sensitive phenotype of transgenic lines, detached rosette leaves of the 35-day-old soil-grown plants were sampled for dehydration and ABA-mediated stomatal closure. After 2 or 3 h of air drying, the leaves of OX1 and OX8 were severely curled, whereas the effect of dehydration process on WT and EV plants was slightly (Figure 5A). Additionally, TaNAC2D-OX lines showed higher water loss rate compared with control plants (Figure 5B), indicating that overexpression of TaNAC2D in Arabidopsis had a decreased water retention capacity.


Overexpression of TaNAC2D Displays Opposite Responses to Abiotic Stresses between Seedling and Mature Stage of Transgenic Arabidopsis
Response of TaNAC2D-OX plants to dehydration and ABA-mediated stomatal closure.(A) Phenotypes of leaves under dehydration stress for 0, 2, and 3 h. (B) Water loss rate of WT, EV, and OXs. Data are means ± SE of three independent experiments (n = 10). (C) Guard cells of 35-day-old soil-grown WT and OXs treated with or without 30 μM ABA for 1 h. Scale bars = 30 μm. (D) Quantitative analysis of the size of stomatal aperture. Data are means ± SE (n = 50). Asterisks indicate significant differences from WT (∗P < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120104&req=5

Figure 5: Response of TaNAC2D-OX plants to dehydration and ABA-mediated stomatal closure.(A) Phenotypes of leaves under dehydration stress for 0, 2, and 3 h. (B) Water loss rate of WT, EV, and OXs. Data are means ± SE of three independent experiments (n = 10). (C) Guard cells of 35-day-old soil-grown WT and OXs treated with or without 30 μM ABA for 1 h. Scale bars = 30 μm. (D) Quantitative analysis of the size of stomatal aperture. Data are means ± SE (n = 50). Asterisks indicate significant differences from WT (∗P < 0.05).
Mentions: To further investigate the drought-sensitive phenotype of transgenic lines, detached rosette leaves of the 35-day-old soil-grown plants were sampled for dehydration and ABA-mediated stomatal closure. After 2 or 3 h of air drying, the leaves of OX1 and OX8 were severely curled, whereas the effect of dehydration process on WT and EV plants was slightly (Figure 5A). Additionally, TaNAC2D-OX lines showed higher water loss rate compared with control plants (Figure 5B), indicating that overexpression of TaNAC2D in Arabidopsis had a decreased water retention capacity.

View Article: PubMed Central - PubMed

ABSTRACT

Environmental stresses frequently affect plant growth and development, and many genes have been found to be induced by unfavorable environmental conditions. Here, we reported the biological functions of TaNAC2D, a stress-related NAC (NAM, ATAF, and CUC) gene from wheat. TaNAC2D showed transcriptional activator activity in yeast. TaNAC2D-GFP fusion protein was localized in the nucleus of wheat mesophyll protoplasts. TaNAC2D transcript abundance was significantly induced by NaCl, PEG6000, and abscisic acid (ABA) at seedling stage, and repressed by NaCl and PEG6000 at mature plant stage. When TaNAC2D was introduced into Arabidopsis, the 35-day-old soil-grown TaNAC2D-overexpression (TaNAC2D-OX) plants displayed slower stomatal closure, higher water loss rate, and more sensitivity to salt and drought stresses compared with WT plants. In contrast, TaNAC2D-OX seedlings, grown on 1/2 MS medium supplemented with different concentrations of NaCl, Mannitol, and MV, had enhanced tolerances to salt, osmotic and oxidative stresses during seed germination and post-germination periods. The opposite stress-responsive phenotypes of transgenic Arabidopsis were consistent with the expression patterns of TaNAC2D in wheat. Moreover, under high salinity and dehydration conditions, three marker genes, including NCED3, RD29A, and RD29B, were down-regulated in 35-day-old TaNAC2D-OX plants grown in soil and up-regulated in 14-day-old TaNAC2D-OX seedlings grown on 1/2 MS medium. Our results suggest that the change in growth stages and environmental conditions may regulate TaNAC2D&rsquo;s function.

No MeSH data available.


Related in: MedlinePlus