Why are plants long and thin

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A playful introduction to anisotropic cell growth in plants and how this is regulated by the microtubule cytoskeleton.

Transcript of Why are plants long and thin

Bela Mulder - Why are plants long and thin08/08/2012 [1]

Waarom zijn planten lang en dun

Why are plants long and thin ?

Bela MulderTheory of Biomolecular Matter

Bela Mulder - Why are plants long and thin

Individual plant cell become elongated with age

08/08/2012 [2]

Laskowski et al. Plos Biology(2008)

youngold

Bela Mulder - Why are plants long and thin

Plant cells grow by stretching

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yield

resist

turgor pressure

Bela Mulder - Why are plants long and thin

Plant cell wall: a fiber reinforced structure

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Cellulose microfibrils

Bela Mulder - Why are plants long and thin

Fiber direction is crucial for growth

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Unfavorable

Favorable

Bela Mulder - Why are plants long and thin

Guiding the motion of cellulose synthases

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Cellulose microfibril

“Fiber factory” = protein-complex

Bela Mulder - Why are plants long and thin

The “rail complex” of the growing cell

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Microscopiy:Pankaj Dhonukse, UvA

Bela Mulder: NTVB Schoorl Meeting

Microtubule “Dynamic instability”

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ShrinkingGrowing

length (mm)

time (min)

catastrophe

rescue

15.2 μm

231 s

Anna Akhmanova, EMC

Bela Mulder: NTVB Schoorl Meeting

Cortical microtubule “collision dynamics”

25/05/2012 [9]

zippering

induced catastrophe

cross-over

R. Dixit & R. Cyr, Plant Cell (2004)

Bela Mulder - Why are plants long and thin

Microtubule “scattering cross-sections”

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Data: Dixit & Cyr (2004) Tobacco BY-2 cells

zippering cross-over

induced catastrophe

zipperingcross-over

induced catastrophe

Bela Mulder - Why are plants long and thin

Analytical dynamical model

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growing

shrinking

inactive

rescue catastrophe

induced catastrophe zippering growth

rescue catastrophe

induced catastrophe shrinkagereactivation

zippering reactivation

Bela Mulder - Why are plants long and thin

Spontaneous alignment predicted

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isotropic

fully ordered no zippering

strong zippering

Critical interaction strength

Bela Mulder - Why are plants long and thin

Survival of the aligned

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experience fewer collisions and hence become longer

is likely to undergo catastrophic collision

is likely to shrink back to zero length

can be renucleated in a more favourable direction

Bela Mulder - Why are plants long and thin

Computer simulations

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Bela Mulder - Why are plants long and thin

Aan het werk

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Bela Mulder - Why are plants long and thin

Results are close to reality

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in silico

in vivo

Microscopy: Jan Vos, WUR

Bela Mulder - Why are plants long and thin

Not just curiosity

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From which source should we get our biofuels?

Bela Mulder - Why are plants long and thin

Lots of (unused) cell wall available

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5% of the earth’s biomass is in cell walls !

Only ruminants are able to digest cellulose

Bela Mulder - Why are plants long and thin

Acknowledgements

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The grey materialists

RhodaHawkins

AMOLF → Paris → Bristol → Sheffield

EvaDeinum

AMOLF → AMOLF+WUR

Jelmer Lindeboom

AMOLF → WUR → Stanford

Simon Tindemans

AMOLF → Imperial College

The €’s

EU- NoE “Active Biomics”

Computational Life Science

EU- NEST “CASPIC”

Jan Vos WUR

Annemie Emons WUR/AMOLF

Dave Ehrhardt Stanford

The green fingers

Pankaj DhonuksheUtrecht

Ben ScheresUtrecht

Bela Mulder - Why are plants long and thin

Het corset van de cel: de celwand

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Bela Mulder - Why are plants long and thin

Het corset is hard nodig

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Aan Uit

Bela Mulder - Why are plants long and thin

Constructie van de celwand

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Cellulose microvezelsBaleinen

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Bela Mulder - Why are plants long and thin

Met de voeten in de modder en het hoofdje in de zon

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Bela Mulder - Why are plants long and thin

Microtubules: the (dynamical) Lego™ of life

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zippering

induced catastrophe

cross-over

Microscopy: Anna Akhmanova, UMR