The cortical microtubule arrays of higher plants are organized without centrosomes and feature treadmilling polymers that dynamic at both ends. control polymer end stability is fundamental for the assembly organization cytoskeletal arrays, yet relatively little understood about how minus ends controlled in acentrosomal no factors have been identified act plants. Here, we identify Arabidopsis thaliana SPIRAL2 (SPR2) as a protein tracks protects them against subunit loss. SPR2 function...

Central to the building and reorganizing cytoskeletal arrays is creation of new polymers. Although nucleation has been major focus study for microtubule generation, severing proposed as an alternative mechanism create polymers, a recently shown drive reorientation cortical higher plants in response blue light perception. Severing produces plus ends behind stabilizing GTP-cap. An important unanswered question how these are stabilized vivo promote net generation. Here we identify conserved...

Abstract Many plant cell functions, including morphogenesis and anisotropic growth, rely on the self-organisation of cortical microtubules into aligned arrays with correct orientation. An important ongoing debate is how geometry, wall mechanical stresses, other internal external cues are integrated to determine orientation array. Here, we demonstrate that microtubule-based nucleation can markedly shift balance between these often competing forces. For this, developed a novel, more realistic...

Abstract The development of the water transporting xylem tissue in plants involves an intricate interplay Rho-of-Plants (ROP) proteins and cortical microtubules to generate highly functional secondary cell wall patterns, such as ringed or spiral patterns early-developing protoxylem. We study requirements protoxylem microtubule band formation with simulations CorticalSim, extended include finite persistence length a novel algorithm for microtubule-based nucleation. find that flexibility...

Abstract The development of the water transporting xylem tissue in plants involves an intricate interplay Rho-of-Plants (ROP) proteins and cortical microtubules to generate highly functional secondary cell wall patterns, such as ringed or spiral patterns early-developing protoxylem. We study requirements protoxylem microtubule band formation with simulations CorticalSim, extended include finite persistence length a novel algorithm for microtubule-based nucleation. find that flexibility is...

Abstract Mirror-image flowers (enantiostyly) involve a form of sexual asymmetry in which flower’s style is deflected either to the left or right side, with pollinating anther orientated opposite direction. This curious floral polymorphism, was known but not studied by Charles Darwin, occurs at least 11 unrelated angiosperm families and represents striking example adaptive convergence function associated cross-pollination insects. In several lineages, dimorphic enantiostyly (one stylar...

The cortical microtubule array of dark-grown hypocotyl cells plant seedlings undergoes a striking, and developmentally significant, reorientation on exposure to light. This process is driven by the exponential amplification population longitudinal microtubules, created severing events localized at crossovers with microtubules pre-existing transverse array. We present dynamic one-dimensional model for through this type templated severing. focus role probability immediate...

The light-induced reorientation of the cortical microtubule array in dark-grown Arabidopsis thaliana hypocotyl cells is a striking example dynamical plasticity cytoskeleton. A consensus model, based on katanin-mediated severing at crossovers, has been developed that successfully describes onset observed switch between transverse and longitudinal orientation. However, we currently lack an understanding why newly populated direction remains stable for longer times re-equilibration effects...

The interaction between actin filaments and microtubules is crucial for many eukaryotic cellular processes, such as, among others, cell polarization, motility wound healing. importance of this has long been recognized, yet very little understood about both the underlying mechanisms consequences spatial (re)organization cytoskeleton. At same time, understanding causes different biomolecular components are key questions in vitro research involving reconstituted systems, especially light...

ABSTRACT Many animals and plants show left-right (LR) asymmetry. In some animal systems, handedness has a simple genetic basis, which allowed identifying how is determined at the molecular level, even if its functional relevance remains unclear. Mirror-image flowers represent an example of LR asymmetry clear significance, with reciprocal placement male female organs in left-versus right-handed promoting cross-pollination. Here, we use South African geophyte Cyanella alba to study...

Abstract Central to building and reorganizing cytoskeletal arrays is the creation of new polymers. While nucleation has been major focus study for microtubule generation, severing proposed as an alternative mechanism create polymers, a recently shown drive reorientation cortical higher plants in response blue light perception. As produces plus ends behind stabilizing GTP-cap, important unanswered question how these are stabilized vivo promote net generation. Here we identify conserved...

Most animals undergo ontogentic niche shifts during their life. Yet, standard ecological theory builds on models that ignore this complexity. Here, we study how complex life cycles, where juvenile and adult individuals each feed different sets of resources, affect community richness. Two modes assembly are considered: gradual adaptive evolution immigration new species with randomly selected phenotypes. We find under cycles can lead to both higher lower richness when compared a model simple...

Abstract Mirror-image flowers (enantiostyly) involve a form of sexual asymmetry in which flower’s style is deflected either to the left or right side, with pollinating anther orientated opposite direction. This curious floral polymorphism, was known but not studied by Charles Darwin, occurs at least 11 unrelated angiosperm families and represents striking example adaptive convergence function associated cross-pollination insects. In several lineages, dimorphic enantiostyly (one stylar...

The light-induced reorientation of the cortical microtubule array in dark-grown A. thaliana hypocotyl cells is a striking example dynamical plasticity cytoskeleton. A consensus model, based on katanin -mediated severing at crossovers, has been developed that successfully describes onset observed switch between transverse and longitudinal orientation. However, we currently lack an understanding why newly-populated direction remains stable for longer times re-equilibration effects would tend...

The interaction between actin filaments and microtubules is crucial for many eukaryotic cellular processes, such as, among others, cell polarization, motility wound healing. importance of this has long been recognised, yet very little understood about both the underlying mechanisms consequences spatial (re)organization cytoskeleton. At same time, understanding causes different biomolecular components are key questions \emph{in vitro} research involving reconstituted systems, especially in...

Abstract Complex life-cycles – that is, organismal development unfolds across ecological niches are pervasive in nature. In this work we set out to investigate the effects of complex on potential for diversification via evolutionary branching. We did by analyzing a mathematical model consumer with two life-stages, each which is characterized specific feeding efficiency trait undergoes change response conditions such as resource competition. find (i) life-cycle complexity can favor when...

Most animals undergo ontogentic niche shifts during their life. Yet, standard ecological theory builds on models that ignore this complexity. Here, we study how complex life cycles, where juvenile and adult individuals each feed different sets of resources, affect community richness. Two modes assembly are considered: gradual adaptive evolution immigration new species with randomly selected phenotypes. We find under cycles can lead to both higher lower richness when compared a model simple...