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© Project SOUND

Out of the Wilds and Into Your Garden

Gardening with California Native Plants in Western L.A. County Project SOUND – 2013 (our 9th year)

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© Project SOUND

Warfare in the Garden how plants protect themselves

from pests and invasions

C.M. Vadheim and T. Drake

CSUDH & Madrona Marsh Preserve

Madrona Marsh Preserve

March 2 & 5, 2013

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Why consider plant defenses?

Plants – and everything about them – are inherently interesting

Understanding how plants interact with other living things may improve your gardening

Plants and animals are more similar than we think – at least at the cellular level

May suggest novel medicines, pesticides and other useful prodcucts

© Project SOUND

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Plants are primary producers

That means they are ‘food’ to many organisms © Project SOUND

http://www.glogster.com/beckeyy/food-web/g-6mp96eehhgdfvco22h8bna0 http://www.bostonbakesforbreastcancer.org/summer-sun-radiation-and-chemo/

Photosynthesis:

stored energy,

other (biomass)

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But plants aren’t merely generous benefactors

or faithful servants….

© Project SOUND

http://thebillfold.com/2012/04/reader-mail-how-to-be-a-generous-person/

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After all, plants have to live too…

Capturing energy needed for life (photosynthesis)

Obtaining water: roots

Obtaining nutrient chemicals (primarily through the roots)

Reproducing: seed or vegetative

Protecting themselves from anything that impacts the above:

Abiotic factors: temperature, weather, soils etc.

Biotic factors: living things

© Project SOUND

CA Goldenrod - Solidago californica

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Plants are far more

complex than most

of us realize

They interact with many types of organisms – for better or worse

They are at least as complex as higher animals

They were not set on this planet for our use alone

They often behave more like plant warriors than like shrinking violets

© Project SOUND

http://img.ehowcdn.com/article-

new/ehow/images/a08/4f/it/avoid-leggy-seedling-

800x800.jpg

http://gorillaartfare.com/character-design/two-little-kittens/

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Types of defenses

Physical barriers (preformed or induced) Waxy cuticle

Trichomes/leaf hairs

Tough epidermis

Sticky gums & resins

Prickles, barbs and thorns

Dense growth habit

Hard covering to protect seeds

Etc.

Defense chemicals Preformed: always ready

Induced: produced only when needed (usually when stimulated by an attack)

© Project SOUND

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Phytochemicals: the basis of plant chemical warfare

Phytochemicals: non-nutritive plant metabolites that are essential for the survival and proper functioning of growth and reproduction in plants

Often involved in protection against herbivores, pests and micro-organisms (or other environmental stresses)

Sometimes used by animals that eat them: As defense chemicals

As human plant-based medicines, flavorings and other uses

© Project SOUND

http://naturallyjodi.blogspot.com/2012/08/medical-news-

2012.html#!/2012/08/medical-news-2012.html

Phytochemicals are sometimes

called secondary metabolites

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Phytochemicals

© Project SOUND

The distribution of phytochemicals within plants is often tissue/organ specific

These molecules tend to be concentrated in outer cell layers of plant organs, suggesting that they may indeed act as deterrents to pathogens and pests.

These compounds are of two types:

Constitutive chemicals: made during normal growth and development (preformed antimicrobial compounds, or “phytoanticipins”)

Induced chemicals: absent from healthy plants, accumulating only in response to pathogen attack or stress (‘phytoalexins’)

Whether a given compound has a defensive function is the

subject of much current interest & research

http://plantpathology.uark.edu/4844.htm

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Competition between plants: it’s a fact of life,

particularly in our mediterranean climate

Light

Water

Soil nutrients

Access to services of beneficial organisms

© Project SOUND

http://primarybestsc.blogspot.com/2012/10/plants-competition.html

Plants sometimes have to ‘fight

dirty’ to best their competitors:

allelopathy

http://the-gist.org/2012/09/allelopathy-when-plants-attack/

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© Project SOUND

Southern CA Walnut – Juglans californica

http://biology.csusb.edu/PlantGuideFolder/JuglansCalif/JuglansCalifPage.htm

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© Project SOUND

S. CA Walnut: not for

every yard

Proper location: consider

Size: moderate for tree Light: full sun/part shade Soils: clay soils best

Water regime:

Tolerates seasonal flooding No or very occasional deep water

in summer (hot gardens)

Allelopathy:

Leaves produce chemicals toxic to other plants

Can’t grow plants under walnuts

http://biology.csusb.edu/PlantGuideFolder/JuglansCalif/JuglansCalifPage.htm

http://www.phytoimages.siu.edu/imgs/paraman1/r/Juglandaceae_Juglans_

nigra_4178.html

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Allelopathy: one type of chemical warfare

Term from allelon ("of each other“) and pathos ("to suffer“).

Refers to the chemical inhibition of one species by another.

Allelopathy has generally come to mean the deleterious effect that one plant has on another through the production of chemical retardants

The "inhibitory" chemical is released into the environment where it affects development and growth of neighboring plants.

Process is often more complex:

Allelopathic plants are also capable of stimulatory effects

The chemical producing plant may also inhibit itself with the same chemicals that inhibit its neighbors

The process may involve other organisms [soil microbes]

© Project SOUND

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Plants release allelochemicals in several

different ways

Above ground

Leaves release volatiles

Leaching from leaves

Leaching from plant litter or on decomposition

Below ground

From above-ground leachates

Root exudates

Decomposing roots

© Project SOUND http://pubs.ext.vt.edu/430/430-021/430-021.html

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Often responsible for colored barks, root barks and heartwoods

Example: Juglone (C.I. Natural Brown 7)

In leaves, roots, husks, and bark of plants in the Juglandaceae family

Is toxic or growth-stunting to many types of plants and insect herbivores - inhibits key enzymes needed for metabolic function.

Awareness of walnut toxicity dates back at least to Roman times

Used as: an herbicide

a dye for cloth and inks

a coloring agent for foods and cosmetics (hair dyes).

Folk medicine – ground/extract green hulls

© Project SOUND

Naphthoquinones

http://kremerpigments.com/shopus/index.php?cat=0104&lang=EN

G&product=37300&sidFEE4B14F27014E7795A5F1BD0DD62743=

63e5300d98a56f6479a23d579380ca6a

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Juglone is an effective toxin because it affects

basic processes required for life

The active agent inhibiting growth of other plants was suggested by Massey in 1925; confirmed by Davis in 1928.

Juglone disrupts oxygen and food use in both plants and animals, a respiration poison. Juglone is like cyanide in its effect on people, animals, and plants

Juglone is so toxic only minute amounts can sicken, sedate, or kill people and animals. The concentration difference of juglone between that needed for sedation, and that causing death, is small.

© Project SOUND

http://www.bgshoppingmall.com/Brand-Names/abbyson-

living.php

So how do walnut

trees survive?

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The toxin is stored in a non-toxic form (so

it doesn’t harm the walnut tree)

Juglone exists within wlanut tree cells in a non-toxic form called hydrojuglone.

Hydrojuglone is colorless and generally nontoxic, but is immediately converted to juglone by oxidation.

Upon continual contact with oxidative conditions, or tissue drying, juglone is tied up and decomposed.

When you cut open a green walnut husk, it quickly turns brown when exposed to air. This is caused by the clear, non-toxic hydrojuglone being quickly converted into the toxic, dark brown juglone in the presence of oxygen.

© Project SOUND

http://www.biologie.uni-hamburg.de/b-online/ge20/02b.gif

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Allelochemicals: many modes of action

Allelopathic chemicals can be present in any part of the plant - leaves, flowers, roots, fruits, or stems.

They can also be found in the surrounding soil.

Target species are affected by these toxins in many different ways:

Inhibited shoot/root growth

Inhibited nutrient uptake

Altered symbiotic relationship [mycorrhyzae] - destroying the plant's usable source of a nutrient.

© Project SOUND

http://www.sustland.umn.edu/implement/images/trees_turf_4.gif

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Why do Juglans species make juglone? At

least part of the story involves seedlings

Juglone in the husk protect the seed from being eaten. The juglone also leaches into the surrounding soil

If juglone leaks back into a walnut root, it is quickly made non-toxic again and stored.

Annual plants, garden vegetables, fruit trees, and some broad-leaf perennials can be severely damaged when juglone is in the soil. These are a seedling’s biggest competitors

Most grasses seem immune from juglone problems.

Select mycorrhizal fungi and soil microbes have been shown to be highly adapted to walnut tree control zones and the presence of juglone.

© Project SOUND

http://www.hiltonpond.org/images/WalnutBlackS

eedling01.jpg

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Other native trees/large shrubs with

allelopathic properties

Oaks – Quercus spp. Cottonwoods – Populus spp.

Manzanitas – Arctostaphylos spp.

CA Sycamore – Platanus racemosa

CA Bay Laurel - Umbellularia californica

False Indigo - Amorpha fruticosa

Eucalyptus

Tree of Heaven

© Project SOUND

http://farm1.static.flickr.com/29/101896704_625b8ccece.jpg

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Dealing with allelopathy in the garden

Rake up leaves & other parts containing the chemicals(s)

Leaves, twigs, fruit husks, and wood chips from walnut trees should be well aged or completely composted before adding to a garden or landscape, if at all

Walnut stumps should be ground-down or removed from a site

Plant tolerant species under/near: Solanaceae, annuals are particularly susceptible

Grasses are usually not

Soil microorganisms ingest allelochemicals as energy sources, and metabolic decomposition can render the chemicals non-toxic to plants. When soils are well drained and aerated, a healthy population of aerobic microorganisms can accelerate this progress.

© Project SOUND

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But making Juglone is expensive: is

allelopathy the only explantion?

Juglone precursors appear to be translocated from older tissue to younger tissue over time.

The immediate precursors of juglone are found in high concentrations within buds, flowers, fruit, and in the phloem (vascular system).

Juglone is also effective for protection from leaf, root and stem pests, like insects, diseases, nematodes, and grazing animals.

© Project SOUND

http://enhancedbc.tfrec.wsu.edu/CA_walnut.html

http://www.graftedwalnuts.co.uk/pest.ihtml

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Pros/cons of preformed defense

chemicals (or precursor forms of them)

Positive Always ready

Mechanism often involves basic mechanisms – effective against a wide range of living things

Negative May not ever be needed – a waste of

energy & other resources

Not specific – so may not work as well against some threats

May be deleterious to the plant itself

© Project SOUND

http://c0365781.cdn2.cloudfiles.rackspacecloud.com/datas/5598254/

original/799px-155mmMustardGasShells.jpg

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© Project SOUND

Southern Goldenrod – Solidago spectabilis var. confinis

http://www.jcsemple.uwaterloo.ca/goldenrod_figs.htm

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© Project SOUND

Other good native Goldenrods

Solidago californica Euthamia (Solidago) occidentalis

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© Project SOUND

The genus Solidago: the Goldenrods

~ 100 perennial species

Most grow in meadows, pastures, along roads & ditches in North America

Unfairly blamed for hay fever in late summer/fall - Ragweed (Ambrosia sp.), blooming at the same time but wind-pollinated, is the usual culprit.

Easily recognized by their golden flowering stalks with hundreds of small flowers; plants & flowers make nice yellow & green dyes.

Their alternate leaves are linear to lanceolate. Their margins are usually finely to sharply serrated.

CA Goldenrod - Solidago californica

Goldenrods have been used in British gardens for > 200 years

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© Project SOUND

Southern Goldenrod is an herbaceous perennial

Size: 2-3 ft tall

2+ ft wide, spreading

Growth form: Stout looking herbaceous

perennial

Fall/winter deciduous; dies back to basal rosette

Foliage: Leaves lance-shaped – mostly

basal

Leaves fleshy, bright to pale green

Roots: spreads via rhizomes

© 2003 Christopher L. Christie

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© Project SOUND

The genus Solidago: the Goldenrods

Propagation by wind-disseminated seed or underground rhizomes (form patches that are vegetative clones of a single plant).

Goldenrod is a companion plant, playing host to beneficial insects, repelling some pests

Goldenrods are important habitat plants for a wide range of native insects, butterflies, birds, etc.

CA Goldenrod - Solidago californica

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© Project SOUND

Outside of their native range, Goldenrods

can be invasive. Why?

http://www.calflora.net/bloomingplants/southerngoldenrod.html

http://www.calflora.net/bloomingplants/southerngoldenrod.html

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Teasing out whether the effect is due to allelopathy:

can be difficult Competing processes: competition for

Light

Water

Nutrients

Associated animal species may be the culprit: Pollinators, mycorrhyzae, other

beneficial species

Above or below-ground pests – Solidago may be tolerant

Vast number of chemicals produced; many not toxic (at least to other plants)

Nature of the chemicals themselves: highly changeable (oxygen; pH; exposure to other chemicals)

© Project SOUND © 2003 Christopher L. Christie

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Bioassays often used to test for allelopathy

Example: testing the effects of plant tissue extracts (or specific chemicals) on the germination of seeds.

Issues in relating laboratory bioassays to allelopathic interactions in the field; allelopathy in the laboratory is not always demonstrated in the field – and vice versa

© Project SOUND

http://www.biosci.ohio-state.edu/~plantbio/osu_pcmb/pcmb_lab_resources/images/pcmb300lamb/allelopathyExperiment.jpg

http://plantecology.dbs.umt.edu/People/collaborators.html

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Why are U.S. Goldenrods so invasive in

China? Could it be due to allelpathy?

Extracts were made from 12.5 g of dried leaf tissue placed in 500 ml of distilled water.

Dilutions of each extract, ranging from 0% to 100% in 10% increments were made.

Filter paper was placed in 90 mm petri plates with 20 seeds of the target species (lettuce & radish).

Five trials were run for each dilution for each goldenrod species tested.

© Project SOUND

http://posieinthevase.blogspot.com/

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The answer is not exactly straightforward

Solidgo canadensis does influence soil levels of possible allelochemicals (total phenolics, total flavones and total saponins)

The chemical content and possible allelopathic effects were greater in S. canadensis from China than those from the USA as demonstrated in a field survey and a common garden experiment.

Suggests that S. canadensis has evolved to be more competitive – and possibly more allelopathic - in the introduced range

Allelopathy might significantly increase competitiveness for this invasive species.

© Project SOUND

But is the effect direct?

http://www.sciencedirect.com/science/article/pii/S0929139311000849

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Plants have complex relationships with

other living things

© Project SOUND

http://www.sciencedirect.com/science/article/pii/S1360138510001007

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Roots and the rhizosphere: life within the soil

© Project SOUND

http://ars.els-cdn.com/content/image/1-s2.0-S1360138512000799-gr2.jpg

http://www.cottoncrc.org.au/industry/Tools/Symptoms_Identification_Tool/Cotton_Symptoms/Allelopathy

Beneficial effect

of mycorrhyzae

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Goldenrods brought ‘novel weapons’ with them

S. canadensis altered the indigenous mycorrhizal fungal spore composition and reduced the mycorrhizal colonization of native plants one year after invasion.

The alien Goldenrod inhibited the colonization of native species and changed the indigenous mycorrhizal fungi by exuding allelochemicals.

Experimental results suggest that invasive S. canadensis may acquire spreading advantage in non-native habitat by using “novel weapons” to inhibit not only local plants but also soilborne pathogens and beneficial microbes.

© Project SOUND

http://openi.nlm.nih.gov/detailedresult.php?img=2972720_pone.0015418.g001&query=the

&fields=all&favor=none&it=none&sub=none&uniq=0&sp=none&req=4&simCollection=305

8081_1471-5945-11-5-6&npos=74&prt=3

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A novel, non-native plant species (like Goldenrod)

can have many effects on the environment

© Project SOUND http://www.sciencedirect.com/science/article/pii/S016953471000145X

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You may have noticed that the Sunflower

family is pretty successful

The Sunflower family (Asteraceae) is one of the most diverse families in California.

Largest plant family worldwide: contains ~ 1550 genera and 24,000 species.

Almost 200 pages of the Jepson Manual are dedicated to describing the California species alone.

© Project SOUND

http://www.wildflowers-and-weeds.com/Plant_Families/Asteraceae_pics/Asteraceae.jpg

Why are they so successful?

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Possible reasons for Sunflower success

Ability to adapt well to variety of environments Plasticity: changes in phenotype

Ability to evolve quickly – change in the genes in the population

Make lots of seeds

Work well with wide range of pollinators and other beneficial species

?? Good defenses

© Project SOUND

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What types of invaders/competitors do

plants need to worry about?

Other plants (compete for water, light, nutrients)

Large herbivores

Insect herbivores

Other herbivores: mollusks

Pathogens

Fungal

Bacterial

Viral

© Project SOUND

http://www.sciencedirect.com/science/article/pii/S1360138509003008

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Young leaves and other tissues are

attractive food

© Project SOUND

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Why do plants make the chemicals found

in ‘essential oils’?

A wide range of reasons, many related to communication:

To attract pollinators – or the spreaders of seed (usually in flowers, fruits)

To repel herbivores – insect or other; either cue or toxin

As breakdown products from compounds used for other purposes

As protection against fungi, bacteria and viruses

To prevent other plants from growing too close ?

To communicate with other plants – via soil water or air

© Project SOUND

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The ‘Double-whammy’ of injury

Tissue damage (from physical injury or herbivory) Vascular tissue: must seal off

quickly, then re-grow or re-attach if possible Water – Xylem tissue

Nutrients + other - Phloem tissue

Support tissue

Other

Secondary infection Bacterial

Fungal

Viral

© Project SOUND

http://www.tantebazar.com/gardening_histology_of_plant_part_2.php

http://ipm.ncsu.edu/corn/diseases/cornfg18.gif

http://ericwongmma.com/wp-

content/uploads/2013/01/double-

whammy.jpg

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Insects are known to be selective in their

use of plants in the sunflower family

© Project SOUND

http://ipmworld.umn.edu/chapters/charlet2.htm

Sunflower Bud Moth Long-horned Beetle

This suggests that Asteraceae may selectively deter some pest species

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Certain plant compounds are effective

against insect herbivores

The most important of these are alkaloids, terpenoids, steroids, phenols, saponins and tannins

These may be an alternative source of insect control agents

© Project SOUND

http://michellebiology.blogspot.com/2012/02/54-pesticide-and-biological-control.html

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The most cost effective strategy is often

to prevent/limit herbivory

Has a pleasant odor similar to pennyroyal, peppermint and camphor.

Is used in flavoring agents, in perfumery, and in aromatherapy

Insect repellant; less toxic to animals/humans than other insect repellants

© Project SOUND

Pulegone

Plants in both the Sunflower

and Mint families make a range

of chemicals to prevent/limit

herbivory

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Mint family insecticidals: mostly terpenoids

Most common : monoterpenes (1,8-cineole, thujone, camphor, pulegone, menthone, others)

Plant-derived insecticides may represent alternative pest control strategies. They may degrade more rapidly than the

synthetic insecticides

May be more specific in their action

Have no genotoxicity.

Mint oil is already used as an environmentally-friendly insecticide for some common pests like wasps, hornets, ants and cockroaches

Mints also repel some birds & other large herbivores – terpenoid’s smells repel

© Project SOUND

http://www.safesolutionsinc.com/TweetMint_Gallon.jpg

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Diterpenes: another class of bioactive

terpenoids

They have 20 carbon atoms

Produced by plants and fungi; often play active role as hormones (Gibberelins)

Found in resins, gummy exudates, and in the resinous high-boiling fractions remaining after distillation of essential oils.

Diterpenes display a broad range of activities against insects

Important defense chemicals in Asteraceae, Salvia, many others

© Project SOUND

http://ars.els-cdn.com/content/image/1-s2.0-

S0367326X02001703-gr1.gif

http://www.cyberlipid.org/images/pict295.gif

monoterpenes

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How do plant insecticidal chemicals work?

Feeding deterrants: Render plants unattractive or unpalatable;

Usually small chemicals; may be aromatic

Often bitter or strong tasting/smelling

Examples: alkeloids, terpenopids;

Direct toxicity: Kill insects outright; or stun them

significantly so that they are eaten by their predators

Usually function as neurotoxins

Examples:

Other, more subtle methods:

© Project SOUND

http://www.gov.mb.ca/agriculture/crops/ins

ects/images/fae02s00a.jpg

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How do plant insecticidal chemicals work?

A few more subtle means

Modifying plant food absorption Modify either the food itself, the gut wall or gut flora

Often larger size

Example: Tannins – make food undigestable

Disrupting the endocrinologic balance of insects Affects reproduction

Acting as insect growth regulators, disrupting the normal process of morphogenesis May ultimately kill

Usually affects reproduction

Behaviour modifying agents Usually influence the feeding and ovipositing (egg-laying) behavior

of insects © Project SOUND

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California/Big Gum Plant Grindelia camporum var. bracteosa

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CA Gum Plant

Erect herbaceous perennial to 4 ft tall by 4 ft wide

Grows in clay or sandy soil:

Dry stream banks, washes

Rocky fields & plains

Sandy or alkali bottomlands

Along road sides

Grows where it gets full sun

Is stress deciduous – looses leaves during dry periods

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Asteraceae species do much to protect

their young leaves & flowers

© Project SOUND

3/11/2013

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Gumplants make an interesting array of chemicals

Active compounds: resin flavanoids and diterpenes of the grindelane type.

The resin produced in multicellular glands on the surfaces of stems, leaves, and involucres - density of resin glands highest on the immature involucre bracts and lowest on the stems.

The resin is composed of grindelic acid and several of its derivatives. These labdane diterpenes are similar to the resin acids that constitute rosin, a principal product of the naval stores industry

© Project SOUND

http://www.ag.arizona.edu/~spmcl/Research/newcrops.htm

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Protecting developing leaves and flowers

Grindelia species are used as food plants by the larvae of some Lepidoptera species including Flower Moths, other herbivores

Grindelane diterpenoids make up most of the resin (to 20% of the dry weight). Grindelic acid, camporic acid,

17-carboxygrindelic acid

many other diterpenoids

The diterpenoids appear to have insect repellant/insecticidal & antibiotic activity

Used as a traditional medicine (until 1960) wide range of ailments: asthma, bronchitis;

antispasmodic , urinary tract disinfectant; topical preparations to soothe burns, insect bites, skin rashes, poison ivy rash.

© Project SOUND

Balsamic scent – fairly strong

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Labdane terpinoids: typical preformed

compounds affecting a wide range of pests

Stored where likely to be needed Resin ducts of trichomes of leaves

In special plastids in epidermal or other near-surface cells

A variety of biological activities: Antibacterial, antifungal, antiprotozoal

Anti-inflammatory activities and modulation of immune cell functions – may induce long-term immunity

Significant effects on basic cell processes: Interfere with biochemical pathways of cell

death and the cell cycle phases

May explain why they affect wide range of cell types in pests (insects, microbes) and in humans

© Project SOUND

Found in many plant

parts (above/below-

ground)

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Have you ever noticed how birds know

when the fruits are ripe?

© Project SOUND

http://www.gardenguides.com/633-barren-bushes-treat-

hungry-birds.html

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Many fruit-berry plants use critters to

spread their seeds

Berries attract the critter

Critter eats the fruit –yum!

Critter moves around while seeds pass through the digestive tract

Seed are deposited – with a load of fertilizer – in a new place away from the parent plant

How do the birds know the fruits are ripe?

© Project SOUND

http://www.ibabuzz.com/garybogue/2009/04/15/cedar-waxwings-they-will-eat-no-toyon-berry-

before-its-time/

Cedar Waxwing gobbling up Toyon fruits

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Toyon/California Christmas Berry –

Heteromeles arbutifolia

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Toyon in nature

Formerly common in the South Bay: Semi-dry slopes Back dune areas (old sand)/

coastal prairie Canyons sides

Likes some seasonal moisture Found on sandy or rocky soils Strong branching root

system Re-sprouts after a fire

This is the “red-berried

shrub” that you see on native hillsides everywhere in winter

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But it’s the berries that made it famous

Formed in late summer

Turn bright red in Nov.

Beloved by birds – this is a great plant to attract Doves Cedar Waxwings Songbirds

Squirrels also like them

Makes nice holiday decorations

Berries toxic if many are eaten (particularly the unripe, uncooked berries)

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Rose’s dirty little secret…poison

The highly cyanogenic nature of rosaceous stone fruits (e.g. almonds, peaches, cherries) has long been known.

The fleshy portions of the ripe fruits are basically innocuous – so we eat them

The seeds, which accumulate the cyanogenic disaccharide (R)-amygdalin, have been responsible for numerous cases of acute cyanide poisoning of humans and domesticated and wild animals

© Project SOUND http://barefootintheorchard.blogspot.com/2011/07/fridays-photos-stone-fruit.html

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Yikes, cyanide?

Cyanogenic glycosides are hydrolyzed by enzymes (b-glycosidases) with the release of hydrogen cyanide.

Cyanide is one of the quickest acting poisons – stops production of energy, so heart, nervous system, breathing stop

Why aren’t the plants killed?

The glycosides are stored in vacuoles within plant cells, while the hydrolytic enzymes are found in the cytosol – fine until something injures the cells

Plants also have a way to produce the energy molecules (ATP) even when exposed to cyanide

© Project SOUND

http://www.ag.ndsu.edu/publications/landing-

pages/livestock/cyanide-poisoning-v-1150

http://leavingbio.net/cell%20structure_files/Cell%20Structure_files/image007.jpg

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Plants use several strategies to protect

themselves against their own toxins

Enzymes to quickly break down the toxins

Other ways around the toxic effects

Sequestration of toxic chemicals – lock away in a safe place

Storage as non-toxic precursor chemicals – that can be readily formed into toxins as needed

Compartmentalization Storing precursors and enzymes in separate compartments –

only released with cell/tissue damage

Storing precursors and enzymes in separate tissues -

© Project SOUND

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Heteromeles – just a rose by another name?

The cyanogenic glycoside content of Toyon - as well as its resultant toxicity to insects and other herbivores - is well described.

The cyanogenic potential is highest in the newly developing leaves.

The cyanic glycosides in the pulp of immature fruits protect them from premature bird predation

During the long seed maturation process, cyanogenic glucosides are gradually shifted from pulp to seed, while pulp carbohydrates increase and fruits turn from green to red.

The birds read the cues and eat the fruit

Subsequent seed predation is prevented by the localization of cyanogenic glycosides in the seeds. It can be used (as needed) or converted to other Nitrogen compounds.

© Project SOUND

Toyon is the ‘pome’ branch of the

Rose Family along with quince, pear,

apple hawthorn, pyracantha,

cotoneaster, pomegranate, and others

http://curls-eyelashes.blogspot.com/2012/12/why-coat-apple-fruits.html

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Cyanide: some herbivores more vulnerable

Substantial evidence that cyanogenic glycosides are primarily involved in defence against generalist herbivores including mammals, insects and molluscs

Rumen microorganisms produce the hydrolysis enzymes. Ruminants are therefore more susceptible to the toxic effects of cyanide

Most larger animals can detoxify in limited amounts

Heat releases HCN – cooking and dyeing

© Project SOUND

http://www.urbanoutdoorskills.com/NEWS/2011_ToyonJam.jpg

http://sunnysavagedesigns.com/wp-content/uploads/2012/11/medicinal-

clothing-sunny-savage-designs-natural-dye-toyon-hollywood-bioregional-

slow-fashion-eco.jpg

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Leaves of some Chaparral plants are

indigestible as well as water-conserving

Most woody chaparral plants allocate significant energy resources to forming chemical compounds that deter herbivores or pathogens from feeding.

One of the most important such compounds is tannin. Up to twenty percent of the dry weight of leaf tissues in some shrubs may be composed of tannins.

Oak, manzanita and toyon have tannin-rich leaf tissues.

Mechanism of action: binds proteins to form non-biodegradable products – that’s why the leaves don’t degrade very quickly

© Project SOUND

‘What doesn’t kill

me will starve me’

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© Project SOUND

Silver Bush Lupine – Lupinus albifrons

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© Project SOUND

Flowers that glow in

the silvery light Blooms:

Spring; usually Mar-Apr or even May our area

Long bloom season

Flowers: Typical lupine/pea shape

On stalks above the foliage

Often appear almost an iridescent blue/purple – in part due to contrast with silvery foliage

Banner spot turns from white to pink when pollinated

Seeds: pods explode (dehisc) flinging the seeds from parent plant

http://www.manhattanbeachbotanicalgarden.org/springbloomerspage2manhattanbeachbotanical

garden.html

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© Project SOUND http://norenes5percent.blogspot.com/2006_03_01_archive.html

http://farm4.static.flickr.com/3175/2673277265_678df36ea6.jpg

Silvery Dune Lupine makes a

nice mid-size shrub

Nice as a smaller foundation plant

Floral fragrance – plant where you can enjoy

Quite hardy – fine for parking strips, roadways

Nice addition to rock garden Wonderful for the ‘evening

garden’ with its silvery foliage

Not the best of plants for eating

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Many herbivores avoid Silver Bush lupine

Plant produces bitter-tasting toxins – the nitrogen-containing Quinolizidine alkaloids

These toxins can negatively affect livestock, causing birth defects and decreasing weight especially in young, unexperienced cattle, sheep, horses

Deer and rabbits avoid it

Deter insects leaf herbivores: aphids, beetles, thrips

The larva of the federally-endangered mission blue butterfly feed on Lupinus albifrons, becoming toxic and giving it a bitter taste to deter predators [similar to Monarch & Milkweeds].

© Project SOUND

http://www.nps.gov/goga/images/20

080328170300.jpg

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Like Toyon, Lupines also protect their

seeds with chemical poisons

Aklaoids : found in a wide variety of plants, animals, and

fungi

Many have medicinal and toxic properties.

Quinolizidine alkaloids (QAs) are known as lupine alkaloids because they mainly occur in lupinus species. Example: lupinine

Produced in green tissues; transported via phloem, stored in all organs of the plant, but particularly in reproductive organs/ seeds

Defense against pathogens and predators

© Project SOUND

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Quinolizidine alkaloids (QAs) protect

lupines throughout life

Available pre-formed in seeds – protect seeds from insect herbivory

Released into the rhizosphere at germination – protect roots of young seedlings from fungal and bacterial pathogens

Induced by biotic stresses in older plants – mobilized in times/places where needed

© Project SOUND http://www.unine.ch/bota/lamun/ang/pictures/projects/logoface.jpg

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© Project SOUND http://urbanext.illinois.edu/soil/SoilBiology/images/A-3.jpg

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Wavy-leaf Soap Plant - Chlorogalum

pomeridianum var. pomeridianum

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Wavy-leaf Soap Plant - Chlorogalum

pomeridianum var. pomeridianum

West coast from S. OR to N. Baja

In southern CA commonly found: Grasslands Open hillsides Sheltered places in coastal

sage scrub, chaparral

Member of the Lily family

http://www.swsbm.com/Maps/Chlorogalum.gif

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The Lily Family (Liliaceae)

Strap-like leaves with parallel veins (grass-like)

Flowers in ‘3’s

Bulb-forming

Includes many edible native plants (onions, wild hyacinths (brodeas), Mariposa Lilys)

http://www.wcosf.org/php/d1f.php?sci_name=Chlorogalum%20pomeridianuml

http://www.vernalpools.org/Mather/list/pages/chlpom.htm

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Soap Plant

requirements

Light: full sun to part-shade

Soils: any local (well-drained best)

Water: tolerates average

to low watering Requires dry period

in late summer/fall

Nutrients: benefits from organic mulch

http://www.pacificbulbsociety.org/pbswiki/index.php/Chlorogalum

http://plants.montara.com/ListPages/FamPages/Lilia2.html

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The Amole bulb:

useful organ, indeed

For the plant Storage organ for plant Reproductive organ for plant

Potential food source for animals

Many uses for humans:

Edible: must slow bake to remove bitter saponins

Makes good shampoo/soap; can even dry for stored soap

Medicinal: for cramps and rheumatism; an antiseptic rub for treating wounds, infections and sores; and an internal remedy for treating stomachache and gas.

To stun fish

Hairy covering makes good brush

Baked ‘juice’ used as glue

http://plants.montara.com/ListPages/FamPages/Lilia2.html

Saponins are responsible for

some of these uses

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Saponins: a group of

related chemicals

High-molecular-weight compounds with a fat-soluble nucleus (either a steroid or triterpenoid structure) and one or more side chains of water-soluble sugars

Despite their fairly large structural diversity these compounds share some unique biological properties:

The ability to lyse cells (erythrocytes)

To ability foam when agitated in water

Triterpene saponins are more widely distributed in nature, primarily in dicots; steroidal saponins are less common and usually found in monocots, particularly among members of such families as Liliaceae, Dioscoreaceae, Agavaceae, Alliums

© Project SOUND

Saponins are glucosides (or

glycosides): plant compounds

containing glucose (or another

sugar) combined with other non-

sugar molecules.

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Saponins: why do they foam?

The ability of a saponin to foam is caused by the combination of the non-polar sapogenin and the water soluble side chain present on the molecule.

The foams tend to be stable and have been used in fire extinguishers as the foaming agent.

They are also used to produce foam in beer and are responsible for the natural foam in root beer.

They have been used as the foaming agent in toothpaste and are employed by local people where the plants occur as a shampoo and laundry detergent.

© Project SOUND

http://www.instructables.com/id/A-Homemade-

Organic-Herbal-Shampoo/step6/Blend/

Yucca root soap

http://www.indianweaving.com/wool.html

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Saponins: use by plants not entirely understood

Location in plant suggests protection against herbivores and/or microbial agents

Stored in healthy plant cells as ‘preformed’ inactive precursors - readily converted into biologically active compounds in response to pathogen attack, particularly fungal.

But plant saponin content (levels/types) also seems to be dynamic, responding to many external factors:

Stimuli connected to herbivory/ attack/ pathogenic infection

Stimuli involved in plant mutualistic symbioses with rhizobial bacteria and mycorrhizal fungi.

© Project SOUND

http://www.chemicalbook.com/CAS%5CGIF%5C76296-72-

5.gif

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Affect of saponins on membranes may explain

part of their effectiveness against microbes

Interact with fats (sterols) in membranes

This is followed by pore formation and loss of membrane integrity

Cell function becomes completely disrupted

© Project SOUND

Affect on spores of soil fungi

http://archive.bio.ed.ac.uk/jdeacon/microbes/saponins.htm

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Saponin effects

on fish Fish take in saponins directly into

their bloodstream through their gills.

The toxin acts on the respiratory organs of the fish without affecting their edibility. Saponins also cause the breakdown of red blood cells that help the toxin to spread quickly.

Even though the effects of the poison are powerful, they are not usually fatal. The fishermen gather the stunned fish quickly as they floated to the surface.

Fish that are washed away into untainted water revive, and can return to their pre-toxic condition.

© Project SOUND

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Saponins: appear to affect cellular function

Antibacterial:

Attaches to membranes & form pores; cause cell membrane to leak

May work in concert with other chemicals (natural antibiotics)

Antifungal:

Complexes with cell membranes

Antiviral:

? Interfere with replication

]

© Project SOUND

Normal fungal spore

Fungal spores treated with a saponin

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Saponins: complex mechanisms of action

Herbivory: Bitter taste (anti-feedant) – large herbivores

Cell damage may release chemicals that break down saponin precursors into more active forms

Insecticidal effects: strong insecticidals against broad range of insect types – wide range of mechanisms Anti-feedant – decreased intake

Decreased movement of food through insect gut

Blockage of sterol uptake in insect gut – insects cannot make own (need for insect hormones)

Cellular toxicity – effect on membranes

Some saponins are toxic to cold-blooded organisms and insects at particular concentrations. There is a need for further research to define the roles of these natural products in their host organisms, which have been described as "poorly understood" to date.

© Project SOUND

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Saponins may provide a source of new

medicines and other products

Saponins exert a wide range of pharmacological activities including expectorant, antiinflammatory, vasoprotective, hypocholesterolemic, immunomodulatory, hypoglycaemic, molluscicidal, antifungal, antiparasitic and many others

Used as adjuvants in the production of vaccines

Many pet foods and "kitty litter" products now contain yucca extract to reduce these noxious odors.

Anti-protozoals in animals

Humans generally do not suffer severe poisoning from saponins. Our cholesterin inactivates them so that only our mucus membranes are affected. Because of this, saponins have been used in sneezing powders, emetics, and cough syrups to facilitate expectoration.

© Project SOUND

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© Project SOUND

Peninsula Onion – Allium peninsulare

©2005 Victoria Marshall

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Genus Allium Many places: Europe, N. America, N. Africa and Asia

Includes the various edible perennials onions, garlics, chives, and leeks; usually both leaves & bulbs are edible

The word "allium" derived from the Greek phrase "to leap out," thereby suggesting a strong interaction between the crop and its consumer.

Has played a pivotal role in cooking worldwide; raw or cooked in many ways, produce a large variety of flavors and textures. Nutritious & tastely!

Also used as ornamentals, medicines.

Estimates of the number of species have been as low as 260, and as high as 860 – likely ~ 600

© Project SOUND

http://www.efloras.org/object_page.aspx?object_id=41473&flora_id=1

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Foothills: coast & SW CA, Sierra

Locally: Catalina Isl, San Clemente Isl, Santa Monica Mtns, San Gabriels

Summer dry slopes, flats often in clay soils

Usually in Valley Grassland, Foothill Woodland, and Coastal Chaparral

© Project SOUND

Peninsula Onion – Allium peninsulare

var. franciscanum

var. peninsulare

http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242102162

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© Project SOUND

Peninsula Onion:

few leaves Size:

~ 1 ft tall

~ 1 ft wide

Growth form: Perennial from a true bulb

Summer/fall dormant – dies back to bulb after setting seed

Foliage: One of few leaves

Linear; channel-like (C-shape)

Medium green to blue-green

Dies back before flowering

Roots: Roots from a true bulb

©2010 Barry Breckling

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© Project SOUND

Flowers are fantastic

Blooms: in spring – usually April-May in our area; one of the later-blooming onions

Flowers: Tepals (petals/sepals) mostly

fused

Color: usually brilliant magenta; sometimes lighter and even white

In open, rather flat umbel-like clusters

©2010 Barry Breckling

©2011 Steven Perry http://en.wikipedia.org/wiki/File:Alliumpeninsulare.jpg

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Propagation

Seeds: Pretty easy

May take a few rainstorms to get them to germinate – be patient

Vegetative reproduction: Bulb offsets

Bulbils – above-ground

http://farm9.staticflickr.com/8024/7390488038_d032d

f3d13_z.jpg

©2011 Steven Perry

http://www.hazmac.biz/080303/080303AlliumPeninsulare.html

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© Project SOUND

Plant Requirements Soils:

Texture: clay or rocky soils in nature; most local soils, except poorly draining

pH: any local

Light: full sun to part-shade

Water: Winter: rains will be enough

in many years; supplement if long dry periods

Summer: best with none (Water Zone 1); more tolerant of a little summer water than most native bulbs

Fertilizer: none; likes poor soils

Other: leave dry leaves attached until fall

©2010 Barry Breckling

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© Project SOUND

An exotic color spot

Excellent container plant – as are all native Alliums and other bulbs

Fronts of summer-dry beds

In mixed meadow/prairie

Tucked into dry places

©2011 Steven Perry

©2011 Steven Perry http://www.flickr.com/photos/xerantheu

m/5684109897/ http://www.theodorepayne.org/mediawiki/

index.php?title=Allium_peninsulare

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Why do Alliums have different shapes?

© Project SOUND

http://paulchong.net/2010/05/16/the-

magic-healing-power-of-onions/

The shape is due to variations in the Allium leaves and leaf bases. In all cases a short, flattened stem is found under these leaf bases.

The bulb is essentially fleshy leaves/leaf bases atop a short, flattened stem. The base of the leaves swell with carbohydrates from photosynthesis. The concentric swollen leaf bases make up the onion bulb.

Similarly, the swollen leaf base and its protective leaf sheath make up the clove of the garlic bulb.

Those alliums that form a pseudostem (leeks), do so because the overlapping leaf bases form a hollow stemlike structure. These leaf bases do not swell but make up the edible portion of the crop

Vegetable alliums consumed for their leaf blades (green onions; chives) typically do not form swollen structures such as bulbs.

http://flashfree.files.wordpress.com/2009/04/dreamstime_446249

2.jpg

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North American

onions

In northwestern North America, numerous Indian tribes (e.g., the Salish of British Columbia) collected and consumed several species of native onions.

Onions were eaten raw, but more often steam-cooked in underground pits overnight or roasted ; some of the strong flavor and smell was lost once properly cooked

Cooked onions were eaten immediately, used as an ingredient to flavor meat and fish meals, or dried in strings for use at a later time.

In California wild onions were eaten raw after soaking in salt water, roasted, or boiled

Raw onions were rubbed on skin as an insect repellent.

© Project SOUND

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What’s the deal with sulfur and plants?

Sulfur is a plant ‘secondary macronutrient’ (nutrients plants need in smaller quantities) along with calcium, silicon, magnesium

Soil sulfur comes from three sources: airborne particles, the weathering of minerals in soils, and microbial activity (decomposing organic materials)

Like all plants, alliums uptake sulfur as sulfate from the soil.

Sulfur is essential for many plant functions. A structural component of protein and peptides

Active in the conversion of inorganic N into protein

A catalyst in chlorophyll production

Promotes nodule formation in legumes

A structural component of various enzymes

© Project SOUND

http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2006/ct_060

6a2.htm

Sulfur-containing compounds

give Alliums their

characteristics flavors

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Why do Alliums make these compounds?

Early Alliums probably evolved in a ‘challenging’ climate – note the storage bulbs which are often advantages in dry/variable climates.

Stored food is necessary to survive into the next season; Alliums store their survival food in bulbs.

Protection of stored food is vital for survival – so Alliums evolved some serious chemical weapons to defend it!

© Project SOUND http://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Allium_textile_drawing.png/210px-

Allium_textile_drawing.png

http://allcityanimaltrapping.blogspot.com/2010/10/gopher-removal-in-la-and-orange-county.html

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What are the Allium defense chemicals

Garlic cloves produce a chemical called allicin, which is responsible for their strong pungency and aroma. Relatively large molecule; acts mainly on direct

contact with the eater, a plant version of hand-to-hand combat.

The flat-leafed Chinese or garlic chives produces a small amount of garlicky allicin, but much more of a different weapon that has a milder, cabbage-like aroma.

Onions, shallots, scallions and leeks produce a sulfur molecule that’s a long-distance weapon - the lachrymatory factor - it makes people’s eyes water.

© Project SOUND

So why do onions smell

mild until they are injured?

Why don’t they just smell

strong all the time?

http://www.capital-cooking.com/blog/?p=969

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How Alliums insure that the compounds

are ready when needed

Sulfate is used to form the allium flavor precursors, known collectively as the alk(en)yl-L-cysteine sulfoxides or ACSOs.

The ACSOs are present in the mesophyll storage cells, inside the cell's cytoplasm.

Each allium crop is characterized by a different number and ratio of these ACSOs, which ultimately determine its flavor.

© Project SOUND

http://www.meritnation.com/ask-answer/question/what-is-mesophyll-cell/nutrition-in-

plants/2216347

Cross-section of a leaf –

much magnified

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How do Alliums insure that the

compounds are ready when needed?

The ACSOs are actually ‘flavor precursors’. They do not impart flavors directly

The chemical reaction begins when the enzyme alliinase, stored in the bundle sheath cells and protected from the ACSOs by a membrane, comes into contact with the ACSOs after tissues are cut.

The scent of an unchopped onion bulb is completely different from after tissues have been chopped; the enzyme reaction changes the ACSOs into thiosulfinates, which are actually responsible for allium flavors.

© Project SOUND

http://plantcellbiology.masters.grkraj.org/html/Plant_Cell_Biochemistry_

And_Metabolism6-Plant_Cell_Energy_transductions2-

Photosynthesis.htm

http://www.healthybusiness.co.za/GNLD%20Products%20Guide/nutrition-1/n16.html

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Who are the intended targets? Larger

(mammalian) herbivores/ omnivores

Chemicals are highly irritating, and

discourage most creatures from coming back for seconds lachrymatory factor is small and light – an

airborn molecule that is perceived by the nose, the eyes, the tongue, and the skin.

Prolonged contact will blister/burn the skin.

Contact (or eating) causes chemicals to pass right through the skin and into the blood. Not very toxic to most larger pests

Damage the red blood cells of dogs and cats.

© Project SOUND

http://images.northrup.org/picture/xl/skunk/baby-

skunk%20(27).jpg

Chemicals meant to

deter larger pests

by direct contact

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What about humans? Aren’t we targets?

The human connections with Alliums likely go back a long way – we’ve learned how to deal with them

Allium chemicals are short-lived ; heat and exposure to other chemicals speeds up the process.

Most humans process Alliums before eating; this converts the irritating chemicals into something more palatable:

Boiling chopped garlic results in the formation of various sulfides.

Sautéing in oil produces the vinyl dithiins and ajoene

© Project SOUND

http://images.teamsugar.com/files/upl1/1/12981/27_2008/wet-saute.jpg

http://onioneffects.blogspot.com/2010/01/while-crying-when-cutting-onions.html

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Some insect herbivores appear to be repelled

by Alliums – or worse

Chemical location studies: In mature Alliums, alliin precursors are

concentrated in the bulbs

In premature plants, most may be found in the leaves and stems.

Several compounds shown to be toxic to beetles and other insects in stored food products - superior to methyl bromide (widely used fumigant)

Not all insects deterred: Various Allium species are used as larval food plants by some Lepidoptera, including some common moths.

© Project SOUND

http://www.ukflymines.co.uk/Images/gallery/Acrolep

iopsis_assectella/Acrolepiopsis_assectella_1.jpg

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The effect of thiosulfinates on microbes has

been puzzling Thiosulfinates have different degrees

of antibacterial and antifungal inhibition

Antibacterial activities against a variety of Gram-negative and Gram-positive bacteria – but not in all studies

Appear to amplify the effects of known antifungal/ anti-bacterial compounds

Direct affect of thiosulfinates has been difficult to understand: ? Direct effect on microbial enzymes

? Decreased production of microbial enzymes

? Kill microbial cells directly

© Project SOUND

http://img.mit.edu/newsoffice/images/article_images/201009

30171318-0.jpg

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Thiosulfinates act at the cellular level due

to their sulfur-containing properties

Allicin easily penetrates biological membranes

Reacts rapidly with other sulfur-containing molecules within cells, changing their physical structure by changing/dissolving key bonds - affects their functions as enzymes and structural proteins

Allicin affects the basic structure and functions of cells: decreases effects of enzymes and interferes with microtubule assembly by modifying SH groups in tubulin

© Project SOUND

tubulin

http://www.ipbs.fr/local/cache-vignettes/L315xH500/structure_cristallographique_proteine_gcp4_-c6d6c.jpg

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© Project SOUND

http://ars.els-cdn.com/content/image/1-s2.0-S0167779998011895-gr2.jpg

Injury/invasion sets off a chain

reaction

Early defense mechanisms: constitutive/preformed phytoanticipins

Local defense mechanisms: induced products/chemicals (phytoalexins)

Systemic defense: Long term ‘immunity’ (induced)

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Thiosulfinates act at the

cellular level due to their

sulfur-containing properties

Likely explains all of allicin effects on microbes

Modify key microbial enzymes needed for invasion

Immobilize/disrupt cell functions, then other compounds can come in for the kill – explains why allicin increases the effects of known fungicides and bacteriocides

Stops cell reproduction/replication

Ultimately causes microbe cell death

May also explain: Plant cell mortality in affected area - limits the area of infection

Stimulating long-term induced resistance mechanisms

© Project SOUND

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Types of plant invaders/competitors

Other plants (compete for water, light, nutrients)

Large herbivores

Insect herbivores

Other herbivores: mollusks

Microbial pathogens

Fungal

Bacterial

Viral

© Project SOUND

http://king.portlandschools.org/files/houses/y2/animalmaineia/files/species/wfrogkm/foodweb/food%20web.html

http://www.redorbit.com/media/gallery/national-science-foundation-

gallery/medium/183_2e89a9412c11ae4335fb2d3595389454.jpg

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Defenses cost – money or energy

Self-toxicity/injury

Resources lost for other uses

Effects on other pathogens/ insects

Effects on beneficial organisms

© Project SOUND

http://www.washingtonpost.com/blogs/wonkblog/wp/2013/01/07/everything-

chuck-hagel-needs-to-know-about-the-defense-budget-in-charts/

http://www.sciencedirect.com/science/article/pii/S0065229609510154

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Plant allocation of energy to defense

Concentrate resources on defending most vulnerable parts Young tissues

Reproductive organs

Seeds

Protect against self-toxicity/harm

Have both broad-range and specific defenses

Produce pre-formed defenses only against the most common types of pests/pathogens

Spend enough – but not so much that it effects other functions (growth; development; reproduction)

© Project SOUND

http://www.furryelephant.com/lib/swf/radioactivity/preview/re6Ms178.jpg

http://blog.optimizecode.com/wp-content/uploads/2010/07/cost.jpg

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The next time you visit a peaceful garden…

© Project SOUND

http://images2.wikia.nocookie.net/__cb20071004195640/starwars/images/3/3e/SPHAT-concentratedfire.jpg

Remember, it’s a war out there!