toby bruce applications of understanding insect chemical ecology -2017
TRANSCRIPT
Rothamsted Researchwhere knowledge grows
Applications of understanding insect chemical ecology
PROF TOBY BRUCE
Chemical Ecology
Chemicals that insects use to communicate with each other, and
sense the world around them…
OCOC3H7
OCOC3H7
Collection of volatiles
(Headspace sampling)
Bioassay (naturals)
GC linked electrophysiology
GC-MS identification of biologically relevant compounds
Field testing (trapping experiments or plot trials)
Bioassay (synthetics)
Chemical Ecology
VOLATILE COLLECTION
Collection of volatiles
(Headspace sampling)
Bioassay (naturals)
GC linked electrophysiology
GC-MS identification of biologically relevant compounds
Field testing (trapping experiments or plot trials)
Bioassay (synthetics)
Chemical Ecology
BIOASSAY
insect released in the centre
Record time spent in different parts
Record flight / settlement on target
Olfactometer
Wind-tunnel
Collection of volatiles
(Headspace sampling)
Bioassay (naturals)
GC linked electrophysiology
GC-MS identification of biologically relevant compounds
Field testing (trapping experiments or plot trials)
Bioassay (synthetics)
Chemical Ecology
GC-EAG RECORDING
Collection of volatiles
(Headspace sampling)
Bioassay (naturals)
GC linked electrophysiology
GC-MS identification of biologically relevant compounds
Field testing (trapping experiments or plot trials)
Bioassay (synthetics)
Chemical Ecology
How can we use this?
“High yielding varieties”
NEW SOLUTIONS ARE NEEDED!
MONITORING SYSTEMS
Orange wheat blossom midge
Bruce et al. (2007) Pest Man. Sci. 63: 49
OCOC3H7
OCOC3H7
2,7-nonanediyl dibutyrate
Using the smell of sex!
Decision support system for OWBM
Bruce & Smart (2009) Outlooks Pest Management 20: 89-92
PUSH-PULL
maize yields up from 1 t/ha up to 3.5 t/ha
achieved with minimal inputs to date adopted > 90,000 smallholder farmers in East Africa
“Push-Pull”
1= (E)-ß-ocimene; 2= α-terpinolene; 3= β-caryophyllene; 4= humulene; 5= (E)-4,8-dimethyl-1,3,7-nonatriene; 6= α-cedrene; 7= hexanal; 8= (E)-2-hexenal; 9= (Z)-3-hexen-1-ol; 10= (Z)-3-hexen-1-yl acetate ; 11= 5,7,2 ,4 -tetrahydroxy-6-(3-methylbut-2-′ ′
enyl)isoflavanone (uncinanone A); 12= 4 ,5 -dihydro-5,2 ,4 -trihydroxy-5 -′′ ′′ ′ ′ ′′
isopropenylfurano-(2 ,3 ;7,6)-isoflavanone ′′ ′′(uncinanone B);
13= 4 ,5 -dihydro-2 -methoxy-5,4 -dihydroxy-5′′ ′′ ′ ′ ′-isopropenylfurano-(2 ,3 ;7,6)-isoflavanone ′ ′′ ′′
(uncinanone C), and 14= di-C-glycosylflavone 6-C-α-L-
arabinopyranosyl-8-C-β-D-glucopyranosylapigenin.
Khan et al. (1997) Nature 388: 631-632Khan et al. (2010) J. Exp. Bot. 61: 4185
“Push-Pull”
PLANTS THAT RESPOND BETTER (INDUCED DEFENCE)
0
10
20
30
40
50
60
70
-1 4 9 14 19 24
time after release (h)
% s
ettle
men
t
controlcis-jasmone
cis-jasmone
O
Bruce et al. (2003) Pest Management Science 59: 1031 – 1036
O
0
0.2
0.4
0.6
0.8
1
1.2
28-May 8-Jun 16-Jun 24-Jun 6-Jul
Mea
n N
o. A
phid
s / T
iller
*
*
control
cis-jasmone
P = 0.036
Bruce et al. (2003) Pest Management Science 59: 1031 – 1036
cis-jasmone
Arabidopsis - Myzus persicae – Aphidius ervi
Bruce et al. 2008 PNAS 105: 4553-4558
MI PS Nr. Putative function Log2(R/G) At5g22140 Putative protein -2 At2g44130 F-box protein -1.83 At2g04870 Hypothetical protein -1.61 At1g21310 Hypothetical protein -1.44 At3g28740 Cytochrome P450 -1.42 At1g55920 Serine acetyltransferase -1.4 At5g44030 Cellulose synthase catalytic subunit -like -1.4 At2g28330 Hypothetical protein -1.34 At3g05110 Hypothetical protein -1.32 At1g78380 Glutathione S-transferase, similar to -1.32 At2g29490 Putative Glutathione S-transf erase -1.29 At1g55920 Serine acetyltransferase -1.28 At5g24610 Putative protein -1.28 At5g14730 Putative protein -1.27 At4g39290 Putative protein -1.27 At5g21940 Putative protein -1.26 At1g78380 Similar to glutathione S-transf erase -1.25 At1g21310 Hypothetical protein -1.24 At1g69980 Hypothetical protein -1.23 At3g16920 Basic chitinase, putative -1.22 At4g12470 pEARL 1-like protein -1.2 At3g13750 Galactosidase putative -1.19 At1g76690 12-oxophytodienoate reductase (OPR1/ 2) -1.19 At3g25910 Unknown protein -1.18 At3g02300 Unknown protein/ chromatin modification -1.17 At1g07920 Elongation f actor 1-alpha -1.17 At4g12000 Putative protein -1.15 At1g09500 Putative cinnamyl alcohol dehydrogenase -1.12 At3g09270 Glutathione transf erase -1.11 At4g30920 Leucyl aminopeptidase like -1.11 At1g32940 Hypothetical protein -1.09 At1g21310 Hypothetical protein -1.08 At5g15630 Phytochelatine synthase, putative -1.08 At4g02520 Atpm24.1 glutathione transf erase -1.07 At1g17860 Hypothetical protein -1.06 At1g48090 Unknown protein -1.05 At4g21130 Hypothetical protein -1.04 At3g08790 Hypothetical protein -1.04 At2g18190 Putative AAA-type ATPase -1.04 At1g35580 I nvertase, putative -1.02 At3g13310 DNAJ protein, putative -1.01 At4g26050 Putative leucine rich repeat protein -1
upregulated genes: OPR1/2
Cell wall biosynthetic genes
Cytochrome P450 (CYP81D11)
F-box containing protein
Sequences unaffected by cis-jasmone:
Defence genes (PR proteins, etc)
Stress genes (HSPs, etc)
Jasmonate-regulated genes (OPR3, LOX)
cis-jasmone
Myzus persicae responses to CYP81D11 overexpressing plants
Bruce et al. 2008 PNAS 105: 4553-4558
Aphidius ervi responses to CYP81D11 overexpressing plants
Bruce et al. 2008 PNAS 105: 4553-4558
EGG ALERT
HYPOTHESIS: Landraces are MORE RESISTANT TO STRESSES such as stemborer attack…
are parasitoids more attracted to HIPVs from landraces?
±
24h
Bioassay of response to volatiles from plants WITH and WITHOUT eggs
Tamiru et al. (2011) Ecology Letters 14: 1075
Parasitoid response - landraces
ATTRACTED to plants with eggs
Volatile profiles - landraces
(a) (E)-ocimene, (b) (R)-linalool, (c) (E)-4,8-dimethyl-1,3,7, nonatriene (DMNT), (d) methyl salicylate, (e) decanal, (f) methyleugenol, (g) (E)-(1R,9S)-caryophyllene, (h) (E)-β-farnesene, (i) (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT).
Tamiru et al. (2011) Ecology Letters 14: 1075
INDUCTION with plants with eggs
IMPROVING BIOCONTROL
New Agri-tech Catalyst project: Lure-and-kill technology to manage beetle pests of field beans and peas
4-Methylheptane-3,5-dione
Beauveria bassiana spores adhering to Entostat particles
Sitona lineatus adults
♂ produced aggregation pheromone that attracts ♀s and ♂s
Flight is not an option for plants !
Labandeira (2013) Curr. Opin. Plant Biol. 16: 414
400 Million years of Coevolution
Innovation in crop protection is very much needed as conventional pesticides are lost to resistance or banned
Perhaps an understanding of chemical ecology can help ?