Plant Chemical Ecology The chemistry suppor ng plant anatomy
April 6, 2016 Lecture #21 Will Barnes
1 ecologyandevolu on.cornell.edu Want to save the world using sustainable agriculture? Apply to perform undergraduate research in the Anderson Lab!
a plant cell making cellulose cellulose in a stem sec on - we use microscopy to understand how plants build their cell walls
Brachypodium plants a er drought
If not research, how about TAing Bio127?
- we study how plants can tolerate the nega ve effects of climate change, like severe heat and drought
- we do and talk about cool science together!
Interested? Send an email to Dr. Anderson: [email protected] Objec ves
• Learn about how plants communicate in an ecological se ng – Role of plant secondary metabolites in defense responses – Signaling – Reproduc on • Discuss applica ons of chemical ecology Don’t worry so much about notes, just enjoy the ride 2 What is Chemical Ecology? • Chemical ecology is the study of chemicals involved in the interac on of living organisms – Defense – Reproduc on Source – Quorum sensing – Nutri on
– Adapta on Product – Co---evolu on – Symbiosis Receiver Environment Everything is context dependent!!! 3 Plants interact through unique chemistry • These are o en vola le organic compounds (VOCs), soluble compounds that are exuded into the soil or are retained in the plant
When and why are these compounds produced?
4 www.extension.umn.edu Objec ves
• Learn about how plants communicate in an ecological se ng – Role of plant secondary metabolites in defense responses – Signaling – Reproduc on • Discuss applica ons of chemical ecology
5 Defense
--- In general, the main types of defensive compounds are: --- Direct defense compounds (toxins) --- Deterrants --- A ractants --- An -herbivory compounds (an -diges ve, or an -nutri ve) --- Hormonal
6 Dicke et al., 2009 Direct defense compounds
• Saxitoxin is a cyanobacteria / algae---derived neurotoxin that affects numerous tropic levels as a result of sequestra on Paraly c Shellfish Poisoning 1000X more toxic than sarin
www.mbari.org
equatox.net
h p://en.wikipedia.org/wiki/Saxitoxin
“Keystone Species” www.foodsafetywatch.org 7 Deterrants
• O en stored as glycosides in vacuoles, un l damage occurs and they interact with cytosolic enzymes that cleave the sugar away, releasing a toxin/deterrant
Cyanogenic glucosides present in cherry/ Glucosinolates present in mustard family apple/co on seeds, sorghum roots, almonds plants (Brassicales)
users.aber.ac.uk
myrosinase
isothiocyanate
vaccineresistancemovement.org www.dachshund---owner--- guide.com h p://en.wikipedia.org/wiki/Glucosinolate#/media/File:Glucosinol8ate--- skeletal.png The Grapefruit Effect
Furanocoumarins interacts with CYP450 (CYP3A4 specifically known) in the intes nes and can affect the ac vity and metabolism of at least 85 studied drugs (Bailey et al. 2013 CMAJ).
9 If linear, can also crosslink DNA under high UV botaderma.com www.medicinescomplete.com A ractants Fatouros et al., 2008 An ---herbivory compounds • An ---diges ve (e.g. tannins, most abundant plant secondary metabolite; Protease Inhibitors) Protein Precipita on (astringency) Or Oxida ve Stress Low pH of vacuole
High pH
what---when--- how.com www.theworldwidewine.com
Both types can interact!
Barbehenn & Constabel (2011) Phytochemistry 11 An ---herbivory compounds
• An ---nutri ve compounds reduce the nutri onal value of a plant for an herbivore, leading to malnutri on despite an ample food source. – Canavanine in legumes Rosenthal & Dahlman (1986) PNAS
– Ground cherry amino acid metabolism limits the nutri onal quality of phloem contents for aphids (Karley et al., 2002, JEB).
12 Hormonal Pest Control Sláma and Carroll Williams (1965) discovered that paper towels made from the wood of the balsam fir (Abies balsamea) released VOCs that elicited a potent effect on balsam bark beetles, made no ceable by a lack of beetle mol ng.
(+)---juvabione was first isolated as an ac ve component from the balsam fir
h p://en.wikipedia.org/wiki/Juvabione#/media/File:JH3,_Juvabione,_Todo.png
www.forestrydistribu ng.com
Hodin, J. (2009). "On the Origins of Insect Hormone Signaling. 13 Phenotypic Plas city of Insects". Science Pubslishers: 817–839. Objec ves
• Learn about how plants communicate in an ecological se ng – Role of plant secondary metabolites in defense responses – Signaling – Reproduc on • Discuss applica ons of chemical ecology
14 Plant Signaling • Intra---plant signaling • Inter---plant signaling • Insect signaling • Pathogen signaling
www.biol.unt.edu
www.united--- academics.org 15 Chemical interac ons can be subdivided into affects:
A semiochemical is a chemical produced by a living organism, exer ng a physiological effect on the individuals of another species when released into the environment.
Allelochemical Producer Recipient Example Effect Effect allomone Defensive + --- compounds kairomone Cabbage o + insect nes ng pollinator synonome + + a rac on with nectar
16 A ractants and Tri---Trophic Interac ons
• Tri---trophic a rac on to HIPVs has been shown across 5 orders of natural herbivore enemies (Hilker and Meiners, 2006)
• Alborn et al. (1997) cite fa y acid---amino acid 15mL of BAW OS conjugate, volici n, as the chemical elicitor of the plant response in maize via beet armyworm herbivory. Similar story with caeliferins (Alborn et al., 2007) and grasshopper feeding. 15mL volici n
15mL buffer www.pherobase.com
Undamaged
17 en.rian.ru Intra---Plant Signaling Vaccinium corymbosum •Rodriguez---Saona and Frost (2009) explain No damage how blueberries, among other taxonomically diverse plants such as poplar, sagebrush, and lima beans, depend on HIPV intra---plant signaling. Gypsy moth caterpillars •JA is converted to the vola le form MeJA to facilitate rapid signaling (Rodriguez---Saona and Frost, 2009).
Ar ficial damage
+ MeJA
Disconnected Connected Heil and Ton, 2008 Rodriguez---Saona and Frost (2009) Side Note: add ½ pill of aspirin to water for longer--- las ng bouquets
www. d.com www.dailymail.co.uk
Salicylic Acid Aspirin 19 commons.wikimedia.org chemistry.about.com Communica on with Conspecific Plants (Tri---trophic interac ons) •Karban and Shirojiri (2009) sagebrush (Artemisia tridentate) clipping and subsequent vola le emission caused gene cally iden cal cu ngs to have priming response (inclusive fitness) •Ton et al. (2007) maize priming of both direct and indirect defenses. •terpenoids and aroma cs a racted a greater number of parasi c wasps (Cotesia marginiventris) •reduced Spodoptera li?oralis caterpillar feeding and development.
www.bentolunch.net
www.flickr.com www.discoverlife.org
clipart--- finder.com Communica on with Heterospecific Plants
•Sagebrush ( Artemisia tridentate) HIPVs and mechanical damage cause tobacco (Nico ana a?enuata) priming (Karban et al., 2003) •Tobacco plants increase produc on of polyphenol oxidases (PPOs) and protease inhibitors (PIs) under similar condi ons (Kessler et al., 2006). •Lower herbivory was observed and a greater number of seed capsules were produced
Baldwin et al., 2006
Intra---Plant Signaling
• Localized anatomical defenses
– Bruchins
Neoplas c ssue growth
Pea response
to
oviposi on
by a pea
weevil 22 Inter---plant communica on • Dodder and parasi sm of tomato
Dodder and Tomato- - - Dr. De Moraes Penn State
web.stanford.edu
23
www.thedrunkgnome.com Pathogen VOC interac ons Fungi Bacteria
h ps://swissplantscienceweb.ch/typo3temp/pics/Chromobacterium_96fd1091ea.jpg Paul & Park, Sensors, 2013 Dirk Blom 24
The germina on rate of the conidia, can be reduced by exposure to the C6 aldehydes cons tu ng GLVs (Brown et al., 1995) Objec ves
• Learn about how plants communicate in an ecological se ng – Role of plant secondary metabolites in defense responses – Signaling – Reproduc on • Discuss applica ons of chemical ecology
25 Roles of Chemical Ecology in Plant Reproduc on
• A rac on / Repulsion of pollinators (Kessler et al., Science 2008)
www.mpg.de www.tech mes.com
“Both repellent and a ractant were required to maximize capsule produc on and seed siring in emasculated flowers and flower visita on by na ve pollinators, whereas nico ne reduced florivory and nectar robbing.” 26 Floral Filters--- choosing the appropriate pollinator
Chemical (Aposema sm) www.nps.gov
Structural / Anatomical
UV Bee’s sight
Bee Orchid
en.wikipedia.org 27
Nygb.org h p://www.nhm.ac.uk/nature---online/life/plants---fungi/bee--- blogs.discovermagazine.com orchids/ Objec ves
• Learn about how plants communicate in an ecological se ng – Role of plant secondary metabolites in defense responses – Signaling – Reproduc on • Discuss applica ons of chemical ecology
28 Push---Pull (Organic) Agriculture
www.push---pull.net
Nitrogen, Isoflavones
www.push--- rstb.royalsocietypublishing.org 29 pull.net Manipula ng Plant Yield
Just a li le early---season feeding can trigger the mobiliza on of resources to the roots, and can be advantageous for agricultural yields.
30 CLICKER
What role(s) do Desmodium plants have in the push---pull agriculture system? A)Fill up space to reduce weed growth and maintain soil moisture B)Fix Nitrogen that can be used by the primary crop C)Induce Striga suicidal germina on D)Repel primary crop pests E)All of the above
31 THM
•Plant chemistry is highly diverse and provides addi onal resources for the plant outside of sessile structures •Plant anatomy serves a role in separa ng and dispersing secondary metabolites crucial for plant defense and reproduc on •Plant responses to the environment display high plas city •Chemical ecology is context dependent
32 33 www.reedprojects.no