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- W2584803980 abstract "In this thesis we study the roles of microtubules at the plasma membrane and the cellulose microfibrils in the cell wall and how they are organized. This topic is introduces in chapter 1. In chapter 2 we study the formation of the transverse cortical microtubule array that is characteristic for elongating plant cells. We found that the cortical microtubule array starts ordered, and that the first direction of microtubule order is not transverse to the axis of cell elongation but have a diagonal bias. Quantification of the orientation of microtubule nucleations revealed a significant diagonal bias, which we confirmed by simulations to be sufficient to explain the initial diagonal order. We found that during disassembly the microtubules also showed a diagonal bias and a significant amount of early microtubule nucleations were not generated from γ-TuRC microtubule nucleating complexes. This led to the idea that a proportion of the initial nucleations stem from small microtubule fragments of preexisting microtubules that remained at the cell cortex during cytokinesis or drug induced microtubule disassembly. We showed with simulations that this type of nucleation has the capacity to increase the speed with which the cortical microtubule array is reformed. In chapter 3 we investigate the trafficking of cellulose synthase complexes from assembly in the Golgi system to their insertion into the plasma membrane. We find that the actin cytoskeleton is important for the global distribution of Golgi bodies, which in turn is important for the global distribution of cellulose synthase complexes in the plasma membrane. Cellulose synthase complexes were inserted into the membrane preferentially at locations where cortical microtubules were present. We showed that osmotic stress and a number of cellulose synthesis inhibitors blocked cellulose synthase insertion into the plasma membrane. The cellulose synthase complex containing compartments were seemingly still being delivered to the cortical microtubules where they accumulated. These compartments tracked depolymerizing microtubule ends. When the osmotic stress was relieved, cellulose sythase complex insertion was resumed from these compartments. Rapid movement of proteins, organelles and metabolites in the cytoplasm of plant cells depends on the actin cytoskeleton, whereas microtubules are important in regulating the location of proteins and cellular processes. In chapter 4 we found physical interactions between cortical microtubules and actin. We also found that the formation of the actin cytoskeleton after washing out the actin depolymerizing drug latrunculin B was dependent on the presence of microtubules. In the presence of cortical microtubules, new actin filaments initiated on and in the direction of cortical microtubules. In chapter 5 we investigate the mechanism reorientation of the cortical microtubule array from transverse to longitudinal in response to light signaling. We found that cortical microtubule array reorientation in dark grown hypocotyl cells was regulated by phototropin a blue light photoreceptor. We found that microtubule reorientation was delayed in phot1 phot2 mutants. We also found that ktn1-1, a null mutant of KATANIN P60, and spr3, a GCP2 allele with impaired function, severely retarded microtubule array reorientation in response to light. spry has altered angles of microtubule nucleation relative to the mother polymer, and ktn1-1 abolishes liberation of microtubules form their nucleation complexes to yield treadmilling polymers and microtubule severing at microtubule crossovers. We found that in response to blue light, the proportion of microtubule nucleations branching at 40 degrees from the mother microtubule to nucleation at 0 degrees from the mother microtubule was higher in wild type plant than in the phot1 phot2 mutant. We also found that the chance of microtubule severing at microtubule crossovers was significanlty higher in wild type than in the phot1 phot2 mutant. We propose that upregulation of the branching nucleations is needed to create a number of longitudinally oriented microtubules. These microtubules make a large number of crossovers with the existing transverse array and have an increased chance of being severed. Severing events that result in a stable new tip contribute to the increase in longitudinal microtubule order and ultimately lead to complete reorientation from transverse to longitudinal. The spatial organization of cortical microtubules and cellulose microfibrils are essential for plant morphogenesis, but the mechanism by which is unclear. Chapter 6 discusses the process of cell elongation and offers possible additional roles for cortical microtubules beyond guiding cellulose microfibril deposition in this process." @default.
- W2584803980 created "2017-02-10" @default.
- W2584803980 creator A5032212672 @default.
- W2584803980 date "2012-01-01" @default.
- W2584803980 modified "2023-09-27" @default.
- W2584803980 title "Pattern formation of cortical microtubules and cellulose microfibrils" @default.
- W2584803980 cites W112473830 @default.
- W2584803980 cites W1491459594 @default.
- W2584803980 cites W1511214901 @default.
- W2584803980 cites W1560179018 @default.
- W2584803980 cites W1563537805 @default.
- W2584803980 cites W1599211019 @default.
- W2584803980 cites W1636584860 @default.
- W2584803980 cites W1875496156 @default.
- W2584803980 cites W1908201726 @default.
- W2584803980 cites W1921801861 @default.
- W2584803980 cites W1964945634 @default.
- W2584803980 cites W1966975175 @default.
- W2584803980 cites W1968017414 @default.
- W2584803980 cites W1968196561 @default.
- W2584803980 cites W1970185525 @default.
- W2584803980 cites W1970532735 @default.
- W2584803980 cites W1971909620 @default.
- W2584803980 cites W1971985327 @default.
- W2584803980 cites W1973801116 @default.
- W2584803980 cites W1975226153 @default.
- W2584803980 cites W1975238158 @default.
- W2584803980 cites W1977218379 @default.
- W2584803980 cites W1978120848 @default.
- W2584803980 cites W1979261853 @default.
- W2584803980 cites W1980127299 @default.
- W2584803980 cites W1980585989 @default.
- W2584803980 cites W1981819609 @default.
- W2584803980 cites W1982269427 @default.
- W2584803980 cites W1982380255 @default.
- W2584803980 cites W1982728774 @default.
- W2584803980 cites W1984374880 @default.
- W2584803980 cites W1984613650 @default.
- W2584803980 cites W1985501881 @default.
- W2584803980 cites W1986302825 @default.
- W2584803980 cites W1986719961 @default.
- W2584803980 cites W1986950157 @default.
- W2584803980 cites W1988701211 @default.
- W2584803980 cites W1989429542 @default.
- W2584803980 cites W1990022480 @default.
- W2584803980 cites W1992739444 @default.
- W2584803980 cites W1994724896 @default.
- W2584803980 cites W1996701351 @default.
- W2584803980 cites W1998129215 @default.
- W2584803980 cites W2000004737 @default.
- W2584803980 cites W2000639895 @default.
- W2584803980 cites W2001396309 @default.
- W2584803980 cites W2002139565 @default.
- W2584803980 cites W2008921607 @default.
- W2584803980 cites W2010802329 @default.
- W2584803980 cites W2016181161 @default.
- W2584803980 cites W2016776801 @default.
- W2584803980 cites W2017482909 @default.
- W2584803980 cites W2018805958 @default.
- W2584803980 cites W2018841495 @default.
- W2584803980 cites W2020042592 @default.
- W2584803980 cites W2021431752 @default.
- W2584803980 cites W2023849539 @default.
- W2584803980 cites W2024536005 @default.
- W2584803980 cites W2025698994 @default.
- W2584803980 cites W2026258096 @default.
- W2584803980 cites W2028181110 @default.
- W2584803980 cites W2028377541 @default.
- W2584803980 cites W2031540192 @default.
- W2584803980 cites W2035018334 @default.
- W2584803980 cites W2035788016 @default.
- W2584803980 cites W2036312682 @default.
- W2584803980 cites W2036852149 @default.
- W2584803980 cites W2037775595 @default.
- W2584803980 cites W2041062999 @default.
- W2584803980 cites W2041158925 @default.
- W2584803980 cites W2041497876 @default.
- W2584803980 cites W2043009418 @default.
- W2584803980 cites W2048206320 @default.
- W2584803980 cites W2048216898 @default.
- W2584803980 cites W2050796253 @default.
- W2584803980 cites W2055715626 @default.
- W2584803980 cites W2056823846 @default.
- W2584803980 cites W2058427633 @default.
- W2584803980 cites W2058557578 @default.
- W2584803980 cites W2061399999 @default.
- W2584803980 cites W2063456169 @default.
- W2584803980 cites W2067318411 @default.
- W2584803980 cites W2068417946 @default.
- W2584803980 cites W2069719347 @default.
- W2584803980 cites W2073702182 @default.
- W2584803980 cites W2074307550 @default.
- W2584803980 cites W2074403192 @default.
- W2584803980 cites W2077681275 @default.
- W2584803980 cites W2079175432 @default.
- W2584803980 cites W2080326081 @default.
- W2584803980 cites W2082104619 @default.
- W2584803980 cites W2083332910 @default.
- W2584803980 cites W2085292193 @default.
- W2584803980 cites W2085512981 @default.