lect 1 plant bio intro

8/11/2019 Lect 1 Plant Bio Intro

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We could not live without plants

Plants produce most of theoxygen we breathe.

Plants produce most of the

chemically stored energy weconsume as food and burn for

fuel.

Plants produce an amazingassortment of useful

chemicals.


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2013 American Society of Plant Biologists

Plants are primary producers: Energy enters

the biosphere mainly through photosynthesis

by plants

TERRESTRIAL

BIOSPHERE

MARINE

BIOSPHERE

Some energy isintroduced by the

action of

chemotrophsCOAL, OIL

AND GAS

RESERVES

Field, C.B., Behrenfeld, M.J., Randerson, J.T. and Falkowski, P. (1998). Primary production of the biosphere: Integrating terrestrial and oceanic components. Science. 281: 237-240.
http://www.sciencemag.org/content/281/5374/237.abstracthttp://www.sciencemag.org/content/281/5374/237.abstracthttp://www.sciencemag.org/content/281/5374/237.abstracthttp://www.sciencemag.org/content/281/5374/237.abstract


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Plants fix carbon dioxide into energy- rich

molecules we animals can use as food

CO2

Plants are autotrophs:they convert CO2gas

into sugars and other

organic molecules

through the process of

photosynthesis.

O2is a waste productof photosynthesis that

we need to survive

O2

Organic

molecules


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You are what you eat? Plants, food,

and human health

What we get from food

Macronutrients, micronutrients and

phytonutrients, minerals

How diet affects human health

Dietary deficiencies

Diet and chronic diseases

Image courtesy CDC and Mary Anne Fenley (number 13053)
http://phil.cdc.gov/PHIL_Images/13053/13053.tifhttp://phil.cdc.gov/PHIL_Images/13053/13053.tif


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Macronutrients

Carbohydrates (C-H2O)

Mikael Hggstrm

Carbohydratesare sugars and

starches

(polymers of

sugars)

They are primarily

metabolized as

energy sources
http://en.wikipedia.org/wiki/File:Glucose_metabolism.svghttp://en.wikipedia.org/wiki/File:Glucose_metabolism.svg


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Macronutrients - Proteins have many

roles enzymes, muscle, etc.

Muscle meat, milk and

eggs are concentrated

sources of animal protein

widely used as food, butevery animal and plant

cell contains protein.

Legume seeds are

particularly protein rich


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Macronutrients

Lipids: fats and oilsLipids are hydrocarbons, energy-richcompounds. Like gasoline, lipids

release energy when oxidized. Plants

and animals store energy as lipids, and

lipids are also normal components of

every cell and the basis of the cell

membranes. At room temperature, fatsare solid and oils are liquid, but both

are lipidsMany animal-derived

foods are high in fat

Oils are lipids

extracted from plant

seeds or fruits


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Micronutrients vitamins are

essential small molecules

Vitamins are essentialnutrients that we need to

eat because we cannot

synthesize them

Vitamin A

Vitamin B1,

thiamineVitamin B3,

niacine

Vitamin B9,

folate

Vitamin C,

ascorbic acid

Vitamin E


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Several dietary minerals are

essential for human healthIron(Fe) is assimilated

as heme (from animals)

and non-heme (from

plants) forms; non-

heme iron, are less

efficiently assimilated.Leafy greens and beans

are sources of non-

heme iron

Brazil nuts are anunusually good source of

selenium(Se). The Se

content of foods depends

largely on soil content

Potassium (K+) helps

maintain osmotic balance

and is abundant in fruits,

beans, potatoes

Calcium (Ca2+) is

abundant in milk-

products and green

leafy vegetables

Zinc (Zn2+) isfound in animal-

derived foods,

beans and nuts


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The world population grows and grows ...

The world population is

expected to triple between

1950 (2.5 billion) and 2020

(7.5 billion), and grow to 9billion by 2050.


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Population growth has followed advances in agriculture

including recent mechanization, chemical fertilizer, and

science-based breeding and production practices (sanitation

and medicine are also important recent contributors)


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The world population grows and grows ...

The world population is expected

to triple between 1950 (2.5 billion)and 2020 (7.5 billion), and grow to 9

billion by 2050.

A major objective of plant science

is to increase food production;

current estimates indicate that we

need to increase production by 70%

in the next 40 years.


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More than one billion people are chronically

hungry, and more than two billion people do not

get adequate vitamins or minerals in their diet

www.wfp.org


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Plants can produce an amazing

assortment of chemicals

vitamin A

vitamin C

vanillin

caffeine

morphine

CO2

O2

Organicmolecules


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Herbal

medicines

have beenused for

millennia

1000s of

plants have

medicinal

uses

More people in the world

depend on herbal medicinesthan pharmaceutical

medicines

More than half of

the 150 most-

prescribedmedicines have at

least one compound

derived from plants

Credits: WHOphoto by D. Henrioud; Mycelium101
http://ihm.nlm.nih.gov/luna/servlet/detail/NLMNLM~1~1~101437071~140711http://en.wikipedia.org/wiki/File:Inyanga_in_Ndumba.jpghttp://en.wikipedia.org/wiki/File:Inyanga_in_Ndumba.jpghttp://ihm.nlm.nih.gov/luna/servlet/detail/NLMNLM~1~1~101437071~140711


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Written records of medicinal plants

date back 4000 years

NIHImages from the history of medicine; Beijing Digital Museum of TCM;

Sumerian and Egyptian

texts from more than 3500

years ago describe the use

of medicinal plants

The use of herbal medicines

in China and India date back

at least 4000 years

These ancient texts mention hundreds of

plants including aloe, peppermint, opium,

willow, wormwood and many more
http://ihm.nlm.nih.gov/luna/servlet/view/search?q=B029804http://en.tcm-china.info/materia/theories/75645_3.shtmlhttp://en.tcm-china.info/materia/theories/75645_3.shtmlhttp://ihm.nlm.nih.gov/luna/servlet/view/search?q=B029804


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From 1800 to the present: Quest for

active compounds

Taxus breviola,

Pacific yew

1966 - Taxol purified from

Pacific yew (Taxus breviola)

1820Quinine

purified from

Cinchona tree

(Cinchonaspp)

1820s - Salicinwas isolated

from willow

bark

eventually to

become

aspirin

1805Morphinepurified from opium

poppy

(Papaver

somniferum)


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Plant cell walls provide important

durable materials

Wood isprimarily

composed of

plant cell

walls.

Photo credit: tom donald
http://www.clearwood.co.uk/http://www.clearwood.co.uk/


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Wood and fibers are everywhere

Rembrandt van Rijn 1631)

Clothing made

from plant fibers

(cotton, linen)

Plant fibers are usedfor making paper, and

before that papyrus.

Wood is used forbuildings and

furniture.

Painting

canvas is madefrom flax or

hemp fibers.


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Plants provide fibers for

paper and fabric

Cotton is being bred for increased pest

resistance and better fiber production.

Photo credits: Chen Lab; IFPC
http://cottongenomics.biosci.utexas.edu/http://www.cottonpromotion.org/http://www.cottonpromotion.org/http://cottongenomics.biosci.utexas.edu/


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Plants can be a source of biofuels

Energy

from

sunlight

Image source: Genome Management Information System, Oak Ridge National Laboratory

Sugars, starches andcellulose can be

fermented into ethanol

Biodiesel produced

from rape, algae and

soybeans are replacingpetroleum-derived

diesel.
http://genomicsgtl.energy.gov/biofuels/placemat.shtmlhttp://genomicsgtl.energy.gov/biofuels/placemat.shtml


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What are Plants? Plants are multicellular,

terrestrial and photosynthetic (Streptophytes)

Multicellular: Different cells can

have various functions, but they

must integrate their activities

Terrestrial: Plant ancestors were

aquatic, but terrestrial plants

have to cope with very dry air

Photosynthetic: Plants and manyother organisms can convert solar

energy to chemical energy

Leaf cross section image from Bouton, J.H., et al., (1986). Photosynthesis, leaf anatomy, and morphology of progeny from hybrids between C3and C3/C4PanicumSpecies. Plant Physiol. 80: 487-492.
http://www.plantphysiol.org/content/80/2/487.full.pdf+htmhttp://www.plantphysiol.org/content/80/2/487.full.pdf+htmhttp://www.plantphysiol.org/content/80/2/487.full.pdf+htmhttp://www.plantphysiol.org/content/80/2/487.full.pdf+htm


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What are (not) plants? Plants are

photosynthetic eukaryotes

ALL LIFEPHOTOSYNTHETIC

ORGANISMS

CYANOBACTERIA +

DESCENDANTS

EUKARYOTES WITH

CYANOBACTERIA-DERIVED

CHLOROPLASTS

Non-

photosynthetic

bacteria

Archaea

Fungi

Animals

You are here

Green

sulfur

bacteria

Purple

sulfur

bacteria

Other

bacteria

Cyanobacteria

DiatomsRed algae

Brown

algae

PLANTS

GREEN ALGAE ANDDESCEDANTS

(Circ les no t

drawn to

scale)


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Plants descended from a eukaryotic ancestor &

a cyanobacteria The first prokaryotes arose >3.5 byain the seas, and were heterotrophs.

Photosynthesis evolved in bacteriashortly after, and flourished as

energy-rich organic molecules were

depleted

Eukaryotes arose through endo-

symbiosis ~2.0 bya (mitochondria)and 1.5 bya (chloroplasts)

Toxic oxygen was first absorbed by

iron, but began to accumulate in the

atmosphere ~2.5 bya and reached

modern levels ~550 myaThis lead to ozone layer ~450 mya

and allowed life to survive closer to

the water surface and on the shores

Adapted from Govindjee and Shevela, D. (2011). Adventures with cyanobacteria: a personal perspective. Frontiers in Plant Science. 2: 28.
http://www.frontiersin.org/plant_physiology/10.3389/fpls.2011.00028/pdf/fullhttp://www.frontiersin.org/plant_physiology/10.3389/fpls.2011.00028/pdf/full


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The terrestrial environment is challenging:Too heavy, dry, hot and cold and bright

Aquatic environment:

Buoyancy

Abundant water

Moderate temperatures

Filtered light

Terresrial environment:

No buoyancy

Scarce water

Extreme temperatures

Excess light including UV

waxy cuticle, stomata, protected spores, vascular tissues, lignified cell

walls, roots, stems, leaves, and protected embryos (seeds), etc., are allevolutionary traits for movement onto land and into the air.

F il t Pl t l & d t ti f


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Family tree: Plants, green algae, & adaptations for

the transition from water to land & air

Adapted from Hay, A. and Tsiantis, M. (2010). KNOX genes: versatile regulators of plant development and diversity. Development. 137: 3153-3165and Prigge,

M.J. and Bezanilla, M. (2010). Evolutionary crossroads in developmental b iology:Physcomitrella patens. Development. 137: 3535-3543.

1200?

450

400

360

300

Chlorophytes

Charophytes

Bryophytes

Lycophytes

Ferns

Gymnosperms

Angiosperms

Green algae Plants

Terrestrialization

Stomata

Vascular tissues

Seeds

Flowers
http://dev.biologists.org/content/137/19/3153.abstracthttp://dev.biologists.org/content/137/21/3535.abstracthttp://dev.biologists.org/content/137/21/3535.abstracthttp://dev.biologists.org/content/137/21/3535.abstracthttp://dev.biologists.org/content/137/21/3535.abstracthttp://dev.biologists.org/content/137/19/3153.abstracthttp://dev.biologists.org/content/137/19/3153.abstracthttp://dev.biologists.org/content/137/19/3153.abstract


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Among land plants, the root system

serves to anchor the plant in the ground

& collect water & minerals from the soil

The stem raises the photosyntheticparts of the plant up toward the sun

The leaves are highly specialized

photosynthetic organs

Roots stems and leaves areconnected by a complicated and

efficient vascular system for the

transport of food and water.

Collectively, the roots make up the root system, and

the stems and leaves together make up the shoot

system. Stems are divided into nodes and internodes.

The node is the part of the stem at which one or more

leaves are attached, and the internode is the part of

the stem between two successive nodes

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