COURSE OVERVIEW 1) Understanding how plants work. 2) Understanding how plant biologists work. Method Technology

We will pick a problem in plant physiology and see where it takes us. Plan C We will pick a problem in plant physiology and see where it takes us. Biofuels Climate/CO2 change Stress responses/stress avoidance Plant products Improving food production Biotechnology Phytoremediation Plant movements Plant signaling (including neurobiology) Something else?

Plan C Pick a problem Pick some plants to study Design some experiments See where they lead us

Plan C Grading? Combination of papers and presentations First presentation:10 points Research presentation: 10 points Final presentation: 15 points Assignments: 5 points each Poster: 10 points Intermediate report 10 points Final report: 30 points Scavenger hunts?

Vegetative Plants 3 Parts Leaf Stem Root

Vegetative Plants 3 tissue types Dermal Ground 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: cells 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

Why are cells so small? 1) many things move inside cells by diffusion 2) surface/volume ratio surface area increases more slowly than volume exchange occurs only at surface eventually have insufficient exchange for survival

Plant Cells Cell walls Carbohydrate barrier surrounding cell

Plant Cells Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape

Plant Cells Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first mainly cellulose

Plant Cells Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first mainly cellulose Can stretch!

Plant Cells Cell walls Carbohydrate barrier surrounding cell Protects & gives cell shape 1˚ wall made first mainly cellulose Can stretch! 2˚ wall made after growth stops

Plant Cells 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

Plant Cells 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 Problem for "cellulosic Ethanol" from whole plants

Plant Cells 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

Plant 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

Plant Cells Plasmodesmata = gaps in walls that link cells Lined with plasma membrane

Plant Cells Plasmodesmata = gaps in walls that link cells Lined with plasma membrane Desmotubule joins ER of both cells

Plant Cells 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: Lipid syn Steroid syn drug detox storing Ca2+ 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