Transcript Jan 20
Plan A Standard lecture course Plan B Standard lecture course, except: 1.Last lectures will be chosen by you -> electives 2.Last 4 labs will be an independent research project 3.20% of grade will be “elective” • Paper • Talk • Research proposal • Poster • Exam Plan C We will pick a problem in plant biology and see where it takes us. 1. Phytoremediation 2. Plant products 3. Biofuels 4. Climate/CO2 change 5. Stress responses/stress avoidance 6. Improving food production 7. Biotechnology 8. Plant movements 9. Plant signaling (including neurobiology) 10. Flowering? 11. Something else? Plan C 1.Pick a problem 2.Pick some plants to study 3.Design some experiments 4.See where they lead us Plan C Grading? Combination of papers and presentations •First presentation: 5 points •Research presentation: 10 points •Final presentation: 15 points •Assignments: 5 points each •Poster: 10 points •Intermediate report 10 points •Final report: 30 points ALTERNATIVES •Paper(s) instead of 1 or two presentations •Research proposal instead of a presentation •One or two exams? •Scavenger hunts? Vegetative Plants 3 Parts 1. Leaf 2. Stem 3. Root Vegetative Plants 3 tissue types 1. Dermal 2. Ground 3. Vascular • Plant Development Cell division = growth • • Plant Development Cell division = growth Determination = what cell can become • • • Plant Development Cell division = growth Determination = what cell can become Differentiation = cells become specific types • • • • Plant Development Cell division = growth Determination = what cell can become Differentiation = cells become specific types Pattern formation: developing specific structures in specific locations • • • • • Plant Development Cell division = growth Determination = what cell can become Differentiation = cells become specific types Pattern formation Morphogenesis: organization into tissues & organs Plant Development umbrella term for many processes • embryogenesis Plant Development umbrella term for many processes • Embryogenesis • Seed dormancy and germination Plant Development umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis Plant Development umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis • Transition to flowering, fruit and seed formation Plant Development umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis • Transition to flowering, fruit and seed formation Many responses to environment Plant Development Umbrella term for many processes Unique features of plant development • Cell walls: can’t move: Plant Development Umbrella term for many processes Unique features of plant development • Cell walls: can’t move: Must grow towards/away from signals Plant Development Umbrella term for many processes Unique features of plant development • Cell walls: cells can’t move: must grow instead • Plasticity: plants develop in response to environment Unique features of plant development • Cell walls: cells can’t move • Plasticity: plants develop in response to environment • Totipotency: most plant cells can form an entire new plant given the correct signals • • • • Unique features of plant development Cell walls: cells can’t move Plasticity: plants develop in response to environment Totipotency: most plant cells can form an entire new plant given the correct signals Meristems: plants have perpetually embryonic regions, and can form new ones • • • • Unique features of plant development Cell walls: cells can’t move Plasticity: plants develop in response to environment Totipotency: most plant cells can form an entire new plant given the correct signals Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line! Unique features of plant development Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line! Cells at apical meristem become flowers: allows Lamarckian evolution! Unique features of plant development Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line! Cells at apical meristem become flowers: allows Lamarckian evolution! • Different parts of the same 2000 year old tree have different DNA & form different gametes Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first • mainly cellulose • Can stretch! Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first • mainly cellulose • Can stretch! 2˚ wall made after growth stops Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first • mainly cellulose • Can stretch! 2˚ wall made after growth stops • Lignins make it tough Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first • mainly cellulose • Can stretch! 2˚ wall made after growth stops • Lignins make it tough Cell walls 1˚ wall made first 2˚ wall made after growth stops • Lignins make it tough • Problem for "cellulosic Ethanol" from whole plants Middle lamella = space between 2 cells Cell walls 1˚ wall made first 2˚ wall made after growth stops Middle lamella = space between 2 cells Plasmodesmata = gaps in walls that link cells Cell Walls Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane Cell Walls Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane • Desmotubule joins ER of both cells Cell Walls Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane • Desmotubule joins ER of both cells • Exclude objects > 1000 Dalton, yet viruses move through them! Types of Organelles 1) Endomembrane System 2) Putative endosymbionts Endomembrane system Common features • derived from ER Endomembrane system Common features • derived from ER • transport is in vesicles Endomembrane system Common features • derived from ER • transport is in vesicles • proteins & lipids are glycosylated Endomembrane system Organelles derived from the ER 1) ER 2) Golgi 3) Vacuoles 4) Plasma Membrane 5) Nuclear Envelope 6) Endosome 7) Oleosomes ER Network of membranes t/out cell 2 types: SER & RER SER tubules that lack ribosomes fns: 1) Lipid syn 2) Steroid syn 3) drug detox 4) storing Ca2+ 5) Glycogen catabolism RER Flattened membranes studded with ribosomes 1˚ fn = protein synthesis -> ribosomes are making proteins ER SER & RER make new membrane! GOLGI COMPLEX Flattened stacks of membranes made from ER GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack Makes most cell wall carbohydrates! GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack Makes most cell wall carbohydrates! Protein’s address is built in VACUOLES Derived from Golgi; Fns: 1)digestion a) Organelles b) food particles VACUOLES Derived from Golgi; Fns: 1)digestion a) Organelles b) food particles 2) storage VACUOLES Derived from Golgi; Fns: 1) digestion a) Organelles b) food particles 2) storage 3) turgor: push plasma membrane against cell wall VACUOLES Vacuoles are subdivided: lytic vacuoles are distinct from storage vacuoles! Endomembrane system Organelles derived from the ER 1) ER 2) Golgi 3) Vacuoles 4) Plasma Membrane Regulates transport in/out of cell Endomembrane system Organelles derived from the ER 1) ER 2) Golgi 3) Vacuoles 4) Plasma Membrane Regulates transport in/out of cell Lipids form barrier Proteins transport objects & info Endomembrane System 5) Nuclear envelope: regulates transport in/out of nucleus Continuous with ER Endomembrane System 5) Nuclear envelope:regulates transport in/out of nucleus Continuous with ER Transport is only through nuclear pores Endomembrane System 5) Nuclear envelope:regulates transport in/out of nucleus Continuous with ER Transport is only through nuclear pores Need correct signal & receptor for import Endomembrane System 5) Nuclear envelope: regulates transport in/out of nucleus Continuous with ER Transport is only through nuclear pores Need correct signal & receptor for import new one for export Endomembrane System Nucleus: spherical organelle bounded by 2 membranes and filled with chromatin = mix of DNA and protein Endomembrane System Nucleus: spherical organelle bounded by 2 membranes and filled with chromatin fns = information storage & retrieval Ribosome assembly (in nucleolus) Endomembrane System Endosomes: vesicles derived from Golgi or Plasma membrane Fn: sorting materials & recycling receptors Endomembrane System Oleosomes: oil storage bodies derived from SER Surrounded by lipid monolayer! Endomembrane System Oleosomes: oil storage bodies derived from SER Surrounded by lipid monolayer! • filled with lipids: no internal hydrophobic effect!