Floral Scent mechanism and synthesis

2. UNIVERSITY OF HORTICULTURAL SCIENCES, BAGALKOT
COLLEGE OF HORTICULTURE, BENGALURU
SEMINAR- III
NAME : NATARAJ S.K.
ID NO : UHS15PGD153
CLASS :III Ph.D.(Hort.)
Dynamics of floral
scents in ornamentals

3. Topic division
Introduction
Properties and Functions of floral scent
Classification of floral scent
Biosynthesis
Regulation of FS by Temperature, Light, Cultivar
Conclusion
1

4. Dynamics of floral scents in ornamentals
“Floral fragrance is typically a complex mixture of
low molecular weight volatile compounds which
gives the flower its unique, characteristic
fragrance”
2

5. Introduction
The ability of flowering plants- strategies to lure pollinators – (>1/4 million
sps.)
 This has led to the creation of elaborate perianth forms, splendid colour
patterns, and a broad spectrum of fragrances
 Plant volatile carry information regarding physiological status and stresses
 200,000 secondary metabolites in flowers, 1700 floral volatile organic
compounds have been identified in 1000 seed plants of 90 families.
3
(Dixon and Strack, 2003)

6. Introduction
 More than 8000 tons of linalool is consumed annually worldwide for flavor
and fragrances composites (body lotion, shampoos, shower gels, soaps,
hairsprays, creams, and synthesis of Vit-E and A).
 Linalool - monoterpene is having major share to the tune of 70 % in nature and play
vital role in attracting to broad spectrum of pollinators , herbivores and parasitoids.
 Bulgaria, Turkey, southern France and Morocco are the major producing
regions of scent.
 1 kg of jasmine oil cost $9000 and used in preparation of cosmotics and
health based products (antidepressent,antiseptic, antispasmodic, sedative
and uterine)
Aprotoslare et al., 2014
4

7. Introduction
 They are used in perfumes, cosmetics, and flavorings
 Pharmaceutical applications-Anti depressant, Antiseptic, sedative, aphrodisiac, Diuretic

Aprotoslare et al., 2014
4

8. Introduction
 Grasse and Kannuj
 Rose attar is the most expensive and popular, costing about Rs 1,200
(US$21) for 10 milliliters.
 Kannauj perfume has local and international markets and about 20 companies
export to foreign countries such as UK, USA, UAE, Saudi Arabia, Iran,
Iraq, Singapore, France, Oman,
 Europe is the largest market 2016 ->$1.0 billion and it is growing @ 5.8%
Aprotoslare et al. 2014
5

9. 6

10. Break up for Indian fragrance
7

12. Properties of Floral scent
 Lipophilic liquids
 High vapor pressures -
 High boiling point (150 o C to 350 o C)
 Cross membranes freely
 They are released into atmosphere/soil media with
out any diffusion media
8

13. How the floral fragrance move in plant
 Phloem
 Golgi aperture
 Vesicular transport
 Protein mediated movement
Plasma membrane may involve exocytosis or specific
transporter
Rahmanim et al. (2007)

14. Functions of VC
Dudareva et al. 2006
9
Terpenoid,
alcohal
and aldehyde
1,8,cineole
Caryophyllene

15. Floral Scent and Pollination
 They not only attract pollinator but also they attract
carnivores and repel herbivores.
 Petal based FS attract pollinator while leaf/root emitted VC
are mainly used for defense
 Fruit emit VC- attract Seed disperse and root emitted VC
contribute to below ground defense
 Many flowers emit diverse blends of FC apart from tactice
cues-Datura
Dudareva et al. 2006
11

16. Floral bouquet -100 volatiles but most of the species 20-
60 compounds are common ranging from picogram to 30 micro g/h.
 Flowers emit species specific signals
 Insect posses Chemo receptors/ olfactory receptors
 Bees and moth use odor cues over longer distance
 Clarkia breweri- Moth
 C. concinna - bee
Floral Scent and Pollination
12
Dudareva et al. 2006

17.  Floral scent are anti microbial and antifungal in nature.
 FS from pistils and rectories of Clarkia sps. had
linalool and linalool oxide.
 Nitrogen compound and sulphur compounds usually attract
birds especially bat.
Floral Scent and Pollination
13
Dudareva et al. 2006

18. Fatty acid
derivatives
and carotenoids
Phenylpropanoid /
Benzenoids
Terpenoids
75%
producing the individual scent
molecules have been identified, but
there are still many steps unknown.
Composition floral volatile compounds
VOC
Muhlemann et al. 2014
14

19. Monoterpenes
2. limonene
3. myrcene.
1. farnesene
2. nerolidol
3. caryophyllene
Classification of VC
Terpenes
Sesquiterpenes
1. linalool
4. trans-b-ocimene
They are often found in vegetative
tissues (cystol)and serve mostly as
defense compounds.
They are synthesized in plastid
compartment and attract
pollinatior
15 Muhlemann et al. 2014

20. 2. Iso eugenol
3.Methyl cinnamate.
1. Beta-ionone
2. dihydroactinidiolide
Classification of VC
Phenylproponoids/Benznoides
1. Eugenol
4.Methyl eugenol
They are often found in vegetative
tissues (cystol)and serve mostly as
defense compounds.
They are synthesized in plastid
compartment.
Carotenoid derivatives
16
Muhlemann et al. 2014

21. 2. 3-hexen-l-ol
Classification of VC
Fattyacid derivatives
1. 3-hexenol
They are synthesized in plastid
compartment.
17
Muhlemann et al. 2014

22. Schematic representation of the floral scent responsible
biosynthesis pathways.
Pathways of VOC: Mevalonic acid (MVA), the methylerythritol phosphate
(MEP), lipoxygenase (LOX) and shikimate/phenylalanine pathways
Ramya et al.2017
18
PTS
PAL
TPS
AOS
3 deoxy d
arbhinoh
eptuloson
ate

23. Biosynthesis of Terpenoids
Terpenoids are the dominant and most VOC
Monoterpenes, diterpenes and
sesquiterpenes
IPP, DMAPP source
Location:- cytosol (MVA)and plastids(MEP),
Enzyme :- prenyltransferases, produce the
precursors GPP and GGPP
Farnesyl diphosphatease (FPPs)
Sesquiterpenes
Clarkia breweri S -linalool synthase
Rose (Guterman et al., 2002), and Snapdragon
(Dudareva et al., 2003; Nagegowda et al., 2008)
Ramya et al.2017
19

24. Biosynthesis of Phenolpropanoids/Benzenoids
Phenylpropanoids and benzenoids are the second largest group of
volatile compounds
Originated from: aromatic amino acid phenylala- nine
Pathway: shikimate pathway and arogenate pathway
Plastids
phenylalanine formed the cinnamic acid by the enzyme
phenylalanine ammonia lyase (PAL)
Cinnamic acid
Finally eugenol and isoeugenol formed through conversion of coniferyl
acetate.
Ramya et al.2017
20

25. Biosynthesis of Fatty acid derivatives
Methyl jasmonate
Antirrhinum majus flowers, 20 fatty acid
derivatives have been identified
(Suchet et al., 2011).
The orchid genus Ophrys synthesizes fatty
acid volatiles; among them alkenes, are used
to attract pollinators.
21

26. Chemical constituents of floral scent
Ramya et al.201722

27. List of few fragrant flowers of India
Ramya et al.2017
23

28. Molecular basis of FS
TransTranscription factors are sequence specific DNA-binding proteins that interact with
the regulatory regions of the target genes, and modulate the rate of transcriptional
initiation by RNA polymerase.
MYB play key role in primary metabolism and regulation of Secondary metabolites
MYB factors have conserved domine with 52 aa
MYB proteins- have two distinct regions, a N-terminal conserved MYB DNA-binding domain
and a diverse C-terminal modulator region which are responsible for the regulatory activity of
the protein.
MYB family can be divided into four classes, 1R-, R2R3-, 3R- and 4RMYB .
R2R3-MYB proteins are specific to plants and are also the most abundant type found in
plants, with more than 100 R2R3-MYB members in the genomes of dicots and monocots.
MYB Transcription factors
25

29. Fig.1 MYB transcription structure in plants and (B) the role of R2R3 in plant metabolism.
(A)Dubos et al. 2010 (B) He et al. (2016)
MYB Transcription Structure
26

30. ODORANT1(ODO1) was the first identified,anR2R3-typeMYB transcription factor in Petunia
hybrida (Verdonk et al., 2005)
Scent emission is higher levels at evening. Phenylpropanoids and benzenoids
RNAi of ODO1 suppression drastically reduced the transcript levels of many key FVBP
genes including DAHPS, EPSPS, PAL, CM, and SAMS.
Suppression of ODO1 does not effect on flower anthocyanins.
EMISSION OF BENZENOIDS I and II (EOBI and EOBII), have also been recently identified.
Suppression of EOBII significantly decreased the emission of most floral volatiles.
Up-regulation and down-regulation of EOBII transcription increases and decreases the enzyme.
Ramya et al.2017
MYB Transcription regulation in Petunia
27

31. RhAAT (Alcohol Acetyl Transferase) gene responsible for geranyl acetate
Scent emission is higher levels at day. Terpenes
 RhGDS (germacrene D Synthase) is the gene responsible for germacrene D
Shalit et al.2017
MYB Transcription regulation in Rose
28

32. Metabolic,physiological process and factors affecting
Genes Enzymes Floral volatiles (Liquid form)
Epidermal layers
Endogenous diurnal
rhythm
Age of flower
Pollination status
Temperature
Light
Moisture
Physiologicalprocess
Floral scent
Metabolic+ Vaporization = emission
Metabolic process
Dudareva et al.2004

33. Headspace technique of collecting VOC from plant intact
Bag(Todller)
Air supply 500 ml/min in
filtered in activated charchol
Tenax-TA Traps to collect VOC
 Extraction-Pentane /ether
 Dried-Anhydrous sodum sulfate
Dudareva et al.2007
29

34. SPME
Static sampling
 Polarity/affinity poly fiber
 ppb
 ad/abosorbent fiber
subjected to desorption in GC
Pragadheesh et al.2017
29

35. GC MS

36. Pragadheesh et al.2017
Objectives
1.The enantiomeric analysis and differentiation of linalool at
various developmental stages.
2) correlation of linalool enantiomer emission and expression of
linalool synthase in J. grandiflorum.
(i)-Mature bud (6 p.m.), (ii)-Blooming bud stage 1 (7 p.m.), (iii)-
Blooming bud stage 2 (8 p.m.), (iv)- Flower stage 1 (9 p.m.),
(v)-Flower stage 2 (10 p.m.), (vi)-Flower stage 3(11 p.m.); Day 2:
(vii)-Mature flower stage 1 (12 a.m.), (viii)-Mature flowers stage 2
(5 a.m.), (ix)-Mature flower stage 3 (11 a.m.), (x)-Flower shedding
stage (5 p.m.)
30

37. Fig.2 Biosynthesis of linalool enantiomers,
Biosynthesis of linalool enantiomers
Pragadheesh et al.2017
31

38. Fig. 3 Rhythmic emission of floral volatile compounds in J.
grandiflorum flowers (Error bars showing the standard deviation
of relative %).
Rhythamic emission at different stages
Pragadheesh et al.2017
31

39. Table 1.Enantiomeric ratio of linalool racemate in floral volatiles of J. grandiflorum analyzed
by SPME-enantioselective gas chromatography.
Pragadheesh et al.2017
32

40. Effect of pH on FC
Fig. 4 Change in pH of the flowers with respect to different
anthesis time
Pragadheesh et al.2017
32
Allelic hydroxyl

41. Amplification of linalool synthase gene using degenerate primers
Fig. 6. Gel image of (a) various combinations of primer sets at three annealing temperatures and (b) the primer combination F3R2 with
marker. (a) Lane 1: F1R1, lane 2: F2R2, lane 3: F3R1, lane 4: F3R2, lane 5: F4R1, lane 6: F4R2 annealing temperature of 50 C; lane 7: 1 kb DNA
ladder; lane 8: F1R1, lane 9: F2R2, lane 10: F3R1, lane 11: F3R2, lane 12: F4R1, lane 13: F4R2 annealing temperature of 55 C; lane14: F1R1, lane
15: F2R2, lane 16: F3R1, lane 17: F3R2, lane 18: F4R1, lane 19: F4R2 annealing temperature of 60 C. (b) 1: 1 kb DNA ladder; 2: PCR
amplification product of primer combination of F3R2 at annealing temperature of 55 C.
34

42. Fig. 5 Partial nucleotide sequence and deduced protein sequence of linalool synthase
gene from J. grandiflorum 33

43. Comparison of (R)-linalool synthase and (S) linalool synthase with Jasminum grandiflorum
linalool synthase
Fig. 5a. Similarity of partial sequence of linalool synthase from J. grandiflorum flowers with the full length sequence
of plants used to design degenerate primers. 33

44. Fig.7 Emission of (R)-()-linalool (a); (S)-(þ)-linalool (6) at different stages of flower
development. Expression of linalool synthase in the flowers of J. grandiflorum at different
stages of flower development (c).
Pragadheesh et al.201735

45. Objectives:
whether the control of scent emission is due to the temperature effect on metabolic rate or vaporization, or
both.
Why petunia ???
Material and methods
Plants are cultivated in growth chambers at 20,25,30 and 35 o C
Headspace techniques is employed to collect FS between 23.00 to 24.00 hrs.
 subjected to GC MS and
Endogeneous VC are also assessed .
Sagae et al.200836

46. Effect of temperature on size of Petunia auxallaris
20 o C 25 o C 30 o C 35 o C
Flower weight (g) 0:33+_ 0:01a 0:29+_ 0:01 0:24+_ 0:01 0:16 +_ 0:01
Petal diameter (mm) 50+_ 1:9 50+_ 0:9 49+_ 1:2 37+_ 0:9
Table 1. Mature Flower Size of P. axillaris at Different Growth Temperatures
aMean SE (n =3)
Sagae et al.2008
37

47. Table 2:Endogenous Levels of Floral Scent Compounds in P. axillaris Flowers at Different Growth Temperatures
Sagae et al.200838

48. Table 3: Amounts of Floral Scent Compounds Emitted from P. axillaris Flowers at Different Growth Temperatures

49. Sagae et al.2008
Methyl benzoate ; , iso-eugenol; , benzyl benzoate; , others.
39
Fig.7a. Emission and Endogenous Concentration of Scent Compounds
in 1-Day-Old P. axillaris Flowers at Different Temperatures
Fig.7b. Natural Logarithm of the Emission Ratio of Each P. axillaris
Scent Compound as Determined at Different Growth Temperatures

50. Emission Ratios of Floral Scent Compounds in P. axillaris Flowers

51. Objectives:-
1.Standardising the harvesting time of tuberose
2. Performance of cultivars
Material and methods
1. Single and double cv.
2. 6.30 am and 6.30 pm, Solvent extraction(PE), Concrete(EA) and absolute
3. Popular single and double
Chaudhary and Kumar,2017
40

52. Table 4: List of tuberose (Polianthes tuberosa L.) genotype (single) with their characters
Chaudhary and Kumar,2017
42

53. Table 5 : Effect of harvesting time of flowers on concrete and absolute recovery in tuberose (Polianthes
tuberosa L.) cultivars Double.
Chaudhary and Kumar,201743

54. Fig 8: Concrete and absolute % in single petalled genotypes
of tuberose harvested in the morning and evening.
Fig 9: Concrete and absolute % in double petalled genotypes
of tuberose harvested in the morning and evening
Chaudhary and Kumar,2017
44

55. Effect of Light on emission of floral scent
Flowers which are pollinated at night have peak emission at night are called as nocturnal and
follow circadian rhythm .
Flowers which are pollinated at day have peak emission at day which are diurnal and regulated
by light.
 Endogenous circadian clock-emission recurring naturally on 24 hr cycle even absence of light.
 Snapdragan emission fallowing circadian rhythm but during day and direct light regulating
emission in nocturnal Petunia.
Rahmanim et al.2007
45

56. Objectives:-
1.Diurnal regulation of scent emission in rose
2. Impact of light on scent emitting genes
Material and methods
1. Rosa damascena cv. Fragrant Cloud (Stage 4)
2. FS geranyl acetate(RhAAT) and germacrene D(RhGDS)
3. Sucrose solution and light/dark
4. Headspace and GC MS
Rahmanim et al.2007
Diurnal regulation of scent emission in rose flowers
Keren Hendel-Rahmanim .Tania Masci
Alexander Vainstein .David Weiss
46

57. Fig 10. in sucrose solution under 12 hr light/dark Fig 11. endogenous study state level of geranyl acetate and
germacrene D
Effect of Light on emission of floral scent
Rahmanim et al.2007
47

58. Fig 12. Daily changes in the expression of RhAAT and
RhGDS in rose petals
Fig.13 Free-running oscillation of RhAAT expression under
continuous light and dark conditions
Effect of Light on expression of genes
Rahmanim et al.2007
48

59. Fig 14. Light has no direct effect on RhAAT expression
49
Effect of Light on expression of genes

60. Fig.14a.Emission of geranyl acetate does not oscillate under
continuous light
Fig.14b. Steady-state levels of geranyl acetate (a) and its
substrate geraniol (b) in rose petals do not oscillate under
continuous light
Effect of Light on geranyl and geraniol

61. Fig.14c. Rhythmic emission of germacrene D is regulated by light
Effect of Light on germacrene D

62. Best method for commercial extraction of floral scent
Objective:
Standardize best method of floral scent extraction
Material methods
Jasminum sambac
Hydro distillation
Akram et al. 2017
50

63. Table.6.Comparision of essential oil physico-chemical properties of Jasminum sambac (SCFE and HD)
Akram et al. 2017

64. Concrete and absolute oil(%) yield in SCFE and HD
Akram et al. 2017
Fig. 15.SCFE and hydro-distillation showing comparsion of concrete and absolute oil yield %
51

65. Fig 16. SCFE method showing chemical components in GC-MS
Akram et al. 2017
52

66. Fig 18. SCFE and HD showing chemical
constituents
Fig 17. HD showing chemical constituents in GC-MS Akram et al. 20175

67. Breeding for fragrance
 Rose-Inheritance did not followed definite pattern – its controlled
by many genes
and complementary genes.
 Crossing two fragrant parents = ?
 Environment, maturity and human perception
,
Heritage
Fragrant cloud
Jawahar,
Rose sherbet
Fragrant deligh
Himroz
Jwala
Arka parimala,
Arka sukanya
Honeyperfume,
Raktima ,
Fragrant plum,
Nurjan
Radiant perfume

68. Conclusion

69. 69