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Auxin regulates SNARE-dependent vacuolar morphology restricting cell size.

Löfke C, Dünser K, Scheuring D, Kleine-Vehn J - Elife (2015)

Bottom Line: Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole.Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation.Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria.

ABSTRACT
The control of cellular growth is central to multicellular patterning. In plants, the encapsulating cell wall literally binds neighbouring cells to each other and limits cellular sliding/migration. In contrast to its developmental importance, growth regulation is poorly understood in plants. Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole. TIR1/AFBs-dependent auxin signalling posttranslationally controls the protein abundance of vacuolar SNARE components. Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation. Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition. Our data suggests that the adaptation of SNARE-dependent vacuolar morphogenesis allows auxin to limit cellular expansion, contributing to root organ growth rates.

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Auxin effect on vacuolar morphology increases in time.Auxin (250 nM NAA) induced changes in vacuolar morphology over time. Error bars represent s.e.m. For statistical analysis DMSO and NAA treatments were compared. n = 50 cells in 10 individual seedlings for each time point. Student´s t-test p-values: ***p < 0.001.DOI:http://dx.doi.org/10.7554/eLife.05868.007
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fig2s1: Auxin effect on vacuolar morphology increases in time.Auxin (250 nM NAA) induced changes in vacuolar morphology over time. Error bars represent s.e.m. For statistical analysis DMSO and NAA treatments were compared. n = 50 cells in 10 individual seedlings for each time point. Student´s t-test p-values: ***p < 0.001.DOI:http://dx.doi.org/10.7554/eLife.05868.007

Mentions: Next we investigated the auxin effect on vacuoles in the course of time. As the auxin effect on vacuoles was most pronounced in atrichoblasts, we focused our analysis (from here onwards) mainly on this cell-type. Notably, auxin imposed in time steadily increasing effects on vacuolar appearance (Figure 2—figure supplement 1). Auxin induced detectable changes in vacuolar morphology already after 15–30 min (Figure 2A). On the other hand the auxin effect on late meristematic cell size was slightly later starting to be significantly affected around 45 min (Figure 2B).10.7554/eLife.05868.006Figure 2.Auxin effect on vacuoles precedes cell size regulation.


Auxin regulates SNARE-dependent vacuolar morphology restricting cell size.

Löfke C, Dünser K, Scheuring D, Kleine-Vehn J - Elife (2015)

Auxin effect on vacuolar morphology increases in time.Auxin (250 nM NAA) induced changes in vacuolar morphology over time. Error bars represent s.e.m. For statistical analysis DMSO and NAA treatments were compared. n = 50 cells in 10 individual seedlings for each time point. Student´s t-test p-values: ***p < 0.001.DOI:http://dx.doi.org/10.7554/eLife.05868.007
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384535&req=5

fig2s1: Auxin effect on vacuolar morphology increases in time.Auxin (250 nM NAA) induced changes in vacuolar morphology over time. Error bars represent s.e.m. For statistical analysis DMSO and NAA treatments were compared. n = 50 cells in 10 individual seedlings for each time point. Student´s t-test p-values: ***p < 0.001.DOI:http://dx.doi.org/10.7554/eLife.05868.007
Mentions: Next we investigated the auxin effect on vacuoles in the course of time. As the auxin effect on vacuoles was most pronounced in atrichoblasts, we focused our analysis (from here onwards) mainly on this cell-type. Notably, auxin imposed in time steadily increasing effects on vacuolar appearance (Figure 2—figure supplement 1). Auxin induced detectable changes in vacuolar morphology already after 15–30 min (Figure 2A). On the other hand the auxin effect on late meristematic cell size was slightly later starting to be significantly affected around 45 min (Figure 2B).10.7554/eLife.05868.006Figure 2.Auxin effect on vacuoles precedes cell size regulation.

Bottom Line: Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole.Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation.Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria.

ABSTRACT
The control of cellular growth is central to multicellular patterning. In plants, the encapsulating cell wall literally binds neighbouring cells to each other and limits cellular sliding/migration. In contrast to its developmental importance, growth regulation is poorly understood in plants. Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole. TIR1/AFBs-dependent auxin signalling posttranslationally controls the protein abundance of vacuolar SNARE components. Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation. Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition. Our data suggests that the adaptation of SNARE-dependent vacuolar morphogenesis allows auxin to limit cellular expansion, contributing to root organ growth rates.

Show MeSH