Limits...
Overexpression of the PP2A regulatory subunit Tap46 leads to enhanced plant growth through stimulation of the TOR signalling pathway.

Ahn CS, Ahn HK, Pai HS - J. Exp. Bot. (2014)

Bottom Line: DEX-induced Tap46 overexpression and Tap46 RNAi resulted in increased and decreased phosphorylation of S6 kinase (S6K), respectively, which is a sensitive indicator of endogenous TOR activity, and Tap46 interacted with S6K in planta based on bimolecular fluorescence complementation and co-immunoprecipitation.Furthermore, inactivation of TOR by estradiol-inducible RNAi or rapamycin treatment decreased Tap46 protein levels, but increased PP2A catalytic subunit levels.These findings suggest that Tap46 modulates plant growth as a positive effector of the TOR signalling pathway and Tap46/PP2Ac protein abundance is regulated by TOR activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Systems Biology, Yonsei University, Seoul 120-749, Korea.

No MeSH data available.


Related in: MedlinePlus

Analysis of seed enlargement in Tap46 overexpression lines. (A) Mature seeds of WT, OE-5, and OE-10 plants. Scale bars, 500 µm. (B) Average seed length (n = 500). (C) Average seed mass per 1000 seeds (n = 3). (D) Average seed number per silique (n = 30). (E) Tetrazolium staining to determine seed viability. WT, OE-5, and OE-10 seeds were incubated under accelerated ageing conditions for 0–48 hours. Viable seeds are stained red (and appear here as the darker seeds). (F) Germination rate (%) of WT, OE-5, and OE-10 seeds after accelerated ageing treatment for 0–48 hours (n = 100). This figure is available in colour at JXB online.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4321543&req=5

Figure 3: Analysis of seed enlargement in Tap46 overexpression lines. (A) Mature seeds of WT, OE-5, and OE-10 plants. Scale bars, 500 µm. (B) Average seed length (n = 500). (C) Average seed mass per 1000 seeds (n = 3). (D) Average seed number per silique (n = 30). (E) Tetrazolium staining to determine seed viability. WT, OE-5, and OE-10 seeds were incubated under accelerated ageing conditions for 0–48 hours. Viable seeds are stained red (and appear here as the darker seeds). (F) Germination rate (%) of WT, OE-5, and OE-10 seeds after accelerated ageing treatment for 0–48 hours (n = 100). This figure is available in colour at JXB online.

Mentions: To investigate the effect of Tap46 overexpression on seed development, we determined the average length and mass of mature dry seeds from WT, OE-5, and OE-10 plants that had been grown in soil under the same conditions. OE-5 and OE-10 seeds were longer and heavier than WT seeds (Fig. 3A–C), although the seed number per silique was slightly reduced in Tap46 overexpression plants (Fig. 3D). To test seed quality, seed viability was monitored under accelerated-aging conditions (Fig. 3E, F). Seeds were incubated under high temperature (43°C) and high humidity (100% relative humidity) for 0–72 hours. Tetrazolium uptake assays were performed to determine seed viability. Upon incubation with the tetrazolium solution, viable seeds are stained red, while seeds with low viability remain white (Oge et al., 2008; Seo et al., 2011). OE-5 and OE-10 seeds survived and germinated at a higher frequency after 24 or 48 hours of treatment, compared with WT seeds (Fig. 3E, F). None of the WT or Tap46 overexpression seeds survived after 72 hours of treatment. Thus, Tap46 overexpression seeds appeared to be more resistant to environmental stresses that reduce seed viability.


Overexpression of the PP2A regulatory subunit Tap46 leads to enhanced plant growth through stimulation of the TOR signalling pathway.

Ahn CS, Ahn HK, Pai HS - J. Exp. Bot. (2014)

Analysis of seed enlargement in Tap46 overexpression lines. (A) Mature seeds of WT, OE-5, and OE-10 plants. Scale bars, 500 µm. (B) Average seed length (n = 500). (C) Average seed mass per 1000 seeds (n = 3). (D) Average seed number per silique (n = 30). (E) Tetrazolium staining to determine seed viability. WT, OE-5, and OE-10 seeds were incubated under accelerated ageing conditions for 0–48 hours. Viable seeds are stained red (and appear here as the darker seeds). (F) Germination rate (%) of WT, OE-5, and OE-10 seeds after accelerated ageing treatment for 0–48 hours (n = 100). This figure is available in colour at JXB online.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4321543&req=5

Figure 3: Analysis of seed enlargement in Tap46 overexpression lines. (A) Mature seeds of WT, OE-5, and OE-10 plants. Scale bars, 500 µm. (B) Average seed length (n = 500). (C) Average seed mass per 1000 seeds (n = 3). (D) Average seed number per silique (n = 30). (E) Tetrazolium staining to determine seed viability. WT, OE-5, and OE-10 seeds were incubated under accelerated ageing conditions for 0–48 hours. Viable seeds are stained red (and appear here as the darker seeds). (F) Germination rate (%) of WT, OE-5, and OE-10 seeds after accelerated ageing treatment for 0–48 hours (n = 100). This figure is available in colour at JXB online.
Mentions: To investigate the effect of Tap46 overexpression on seed development, we determined the average length and mass of mature dry seeds from WT, OE-5, and OE-10 plants that had been grown in soil under the same conditions. OE-5 and OE-10 seeds were longer and heavier than WT seeds (Fig. 3A–C), although the seed number per silique was slightly reduced in Tap46 overexpression plants (Fig. 3D). To test seed quality, seed viability was monitored under accelerated-aging conditions (Fig. 3E, F). Seeds were incubated under high temperature (43°C) and high humidity (100% relative humidity) for 0–72 hours. Tetrazolium uptake assays were performed to determine seed viability. Upon incubation with the tetrazolium solution, viable seeds are stained red, while seeds with low viability remain white (Oge et al., 2008; Seo et al., 2011). OE-5 and OE-10 seeds survived and germinated at a higher frequency after 24 or 48 hours of treatment, compared with WT seeds (Fig. 3E, F). None of the WT or Tap46 overexpression seeds survived after 72 hours of treatment. Thus, Tap46 overexpression seeds appeared to be more resistant to environmental stresses that reduce seed viability.

Bottom Line: DEX-induced Tap46 overexpression and Tap46 RNAi resulted in increased and decreased phosphorylation of S6 kinase (S6K), respectively, which is a sensitive indicator of endogenous TOR activity, and Tap46 interacted with S6K in planta based on bimolecular fluorescence complementation and co-immunoprecipitation.Furthermore, inactivation of TOR by estradiol-inducible RNAi or rapamycin treatment decreased Tap46 protein levels, but increased PP2A catalytic subunit levels.These findings suggest that Tap46 modulates plant growth as a positive effector of the TOR signalling pathway and Tap46/PP2Ac protein abundance is regulated by TOR activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Systems Biology, Yonsei University, Seoul 120-749, Korea.

No MeSH data available.


Related in: MedlinePlus