This document summarizes a seminar presentation on improving fruit quality through the use of elicitors and bio-molecules. The presentation outlines the seminar topics which include introduction to elicitors and bio-molecules, their mechanisms of action, and case studies on their use in pomegranate and citrus fruits. It also summarizes results from studies showing elicitors can increase phenolic content and bioactive compounds in fruits, thereby improving quality attributes such as color, firmness, and reducing decay during storage.

1. 1
Welcome
to
credit seminar session 2020
Speaker
Bhupendra Sagore
21292
M.Sc. 1st Year

2. 2
“Role of next-generation
elicitors and bio-molecules
for improving
fruit quality”
Topic
Division of Fruits and Horticultural Technology
ICAR-Indian Agricultural Research Institute, New Delhi-110012

3. 3
Seminar outlines
1. Introduction
2. Types of elicitors
3. Bio-molecules
4. Mechanism
5. Factors affecting elicitation
6. Case studies
7. Conclusion
8. Future thrusts

4. 4
Fruit quality
Fruits are mainly consumed for their nutritive value as
well as for the variety of shapes, colours and flavours
that make them attractive for food preparation.
When they are consumed raw or with very little
preparation, the consumer’s main concern is that they
must be free of biotic or non-biotic contaminants that
may affect health.

5. Types of bio-active compounds
Bioactive
compoundsFlavonoids
Anthocyanins
Tannins
Betalins
Carotenoids
Plant sterols
Walia et al. (2019)

6. Sources of Carotenoids
Apricot
Mango
Guava
PlumPapaya
Grapefruit Persimmon
IndianAgriculturalResearchInstitute,NewDelhi
Agnieszka Szajdek & E. J. Borowska (2008)

7. Sources of Anthocyanin
Acai berry
Black currant
Blueberry
CherryRed grapes
IndianAgriculturalResearchInstitute,NewDelhi
Agnieszka Szajdek & E. J. Borowska (2008)

8. ICMR recommendation
Dietary guidelines for Indians -a manual by ICMR, 2011

9. WHO, 2014

10. 10
• To improve the phenolic content of fruits, a novel
field of interest is based on results obtained using
elicitors, agrochemicals which were primarily
designed to improve resistance to plant
pathogens.
• Elicitors do not kill pathogens, they trigger plant
defense mechanisms, one of which is to increase
the levels of phenolic compounds.
• Therefore, their application not only allows us to
control plant disease but also to increase the
phenolic content of plant foodstuffs.
Quality improvement tool

11. 11
Elicitors
Elicitors are generally defined as molecules that can
stimulate the defense responses of plants, including the
formation of phytoalexins.
Source: Bioprocessing for Value-Added Products from Renewable Resources, 2007
OR
An elicitor is defined as a compound that, in small
concentrations, can activate different plant responses, such
as endogenous protection responses, including the
production of different secondary metabolites .
(Namdeo, 2007)
The first biotic elicitors were described in the early 1970s.

12. 12
Types of elicitors
Biotic Abiotic

13. 13
Source-Journal of Applied Research on Medicinal and Aromatic
Plants,2013 Review article

14. 14Jesus et al. 2018

15. 15
Effects of the application of different elicitors on polyphenol
content
Source- Ruiz et al. Review 2013

16. 16

17. 17
Source- Molecules 2014, ISSN 1420-3049 (Review)
Elicitation: A Tool for Enriching the Bioactive Composition of Foods

18. 18
Bio-molecules
Bio-molecules are also called biological
molecules, any of numerous substances that are
produced by cells and living organisms. Bio-molecules
have a wide range of sizes and structures and perform
a vast array of functions. The four major types of
biomolecules are
1. Carbohydrate
2. Lipids
3. Proteins
4. Nucleic Acids

19. Postharvest pathogens/diseases of horticultural
produce and their control by chitosan
19
Source-Sharma and Pongener / Stewart Postharvest review,2010

20. 20

21. 21

22. 22
Elicitations
1. Pre harvest elicitations
Preharvest elicitation could be done as seed
priming, soaking seeds in a water solution with the
elicitor, or after seedling, applying exogenous
spraying treatment over the leaves or in a
hydroponic system.
2. Post harvest elicitations-
The post harvest application of low or high
temperature treatments, ultraviolet (UV) or gas
combinations, phytohormones applied to tissues
will increase phenolic concentration.

23. 23
How
Does
It
Work

24. 24
Mode of action

25. 25
Stress-induced polyphenols synthesis in plants

26. 26
Factors affecting elicitation
Several parameters which decide the
elicitation such as:
• elicitors concentration and selectivity
• duration of elicitation
• age of culture
• cell line
• growth regulation
• nutrient composition
• quality of cell wall materials and

27. 27
Research work related to elicitors & bio-molecules
in ICAR-IARI, New Delhi
S.N. Research work Crop Name of
Division
1.
Preharvest application of methyl jasmonate for
improving post harvest quality of “Pusa Navrang”
Grape Fruits &
Horticultural
Technology
2.
Induction of resistance by synthetic elicitor
molecules against root-knot nematode
Brinjal Nematology
3. Biotic elicitor induced biochemical and molecular
manifestations of drought tolerance in contrasting
rice genotypes
Rice Biochemistry
4. Microbial priming elicits improved plant growth
promotion and nutrient uptake.
Pea Microbiology
5.
Effect of Salicylic Acid and Pseudomonas
fluorescens
Cotton Plant Pathology
6. Postharvest studies in tuberose. Tuberose Floriculture and
landscaping
7. Natural products for postharvest decay control in
horticultural produce.
Horticultur
al crops
Post Harvest
Technology
8. Genome-wide characterization and expression
patterns of chitinase genes.
Pigeon Pea National Institute
for Plant
Biotechnology

28. 28
Case studies

29. 29
CASE STUDY- I Pomegranate (Methyl jasmonate)
The effects of preharvest MeJA treatments on pomegranate ‘Mollar de
Elche’ for-
1.Crop yield,
2.Quality attributes and bioactive compounds content (at harvest or after
long-term storage).
Maria et. al - Oct, 2019
Objectives

30. 30
Experimental details
Particular Details
Name of cultivar “Mollar de Elche”
Plant age 8 years (planted at 6 m × 5 m)
Date of experiment Start from April 2016 to 2017
Place Elche, Spain
Design RBD
Type of research Pre -harvest treatment with post
harvest analysis
Elicitor used Methyl jasmonate ( MeJA)
NPK ratio 160:80:160
Treatment Total 4 (control , 1, 5 and 10 mmol L-1
MeJA)
Application at monthly intervals (94, 64, 34 and 4
days before harvesting)

31. 31
Materials and Methods
Plant material and experimental design
• For each treatment (control, 1, 5 and 10 mmol L-1 MeJA),
three blocks of two trees each one were selected.
• Each block or replicate for the four treatments was set in
a row, leaving an untreated tree between each block and
an untreated row between each treated row in order to
avoid treatment cross effects.
• In addition, at least one tree without treatment was left in
each row to avoid edge effect.
• Treatments were performed by applying 3 L of freshly
prepared MeJA at 1, 5 or 10 mmol L-1, containing 1 mL
L−1 Tween-20, to each tree at monthly intervals (94, 64,
34 and 4 days before harvesting). sprayed with distilled

32. 32
Controlled T-1(1) T-2 (5) T-3 (10)v
Untreated Controlled Treated

33. 33
Result
Fruit Yield

34. 34
Result
Respiration Rate , Firmness, Weight loss & Hue angle

35. 35
Result
Sugar & Organic acids

36. 36
Result
Phenols & anthocyanins content
Total phenols and total anthocyanins content in pomegranate arils in
control and methyl jasmonate (MeJA, 1, 5 and 10 mmol L-1) treated trees
at harvest and during postharvest storage at 10 ∘C.

37. 37
Inference
• Preharvest treatments with MeJA at 1, 5, and 10 mmol L-1 increased
crop yield. In addition, the on-tree fruit ripening process was
accelerated by 1 and 5 mmol L-1 doses.
• Quality parameters after 30 and 60 days of storage at 10 ∘C were
maintained at higher levels in MeJA treated fruit, manifested by
reduced weight loss, respiration rate and losses of firmness and
titratable acidity.
• MeJA treatments improved arils colour and their content in bioactive
compounds (phenolics, anthocyanins and ascorbic acid) and these
effects being maintained during storage.
• Among the assayed doses, the highest effects were found with MeJA at
5 mmol L-1.
• Thus, MeJA has potential application in pre-harvest treatment as a
useful tool for the induction of health benefitting chemicals in the
plant diet.

38. 38
CASE STUDY- II Citrus
( Oligochitosan, Salicylic acid, Pichia membranaefaciens )
1. To study the effects of oligochitosan, salicylic acid (SA), and Pichia
membranaefaciens on inducing disease resistance against Geotrichum
candidum in citrus fruit by using iTRAQ proteomic and physicochemical
analysis.
Wang et. al 2020
Objective

39. 39
Genesis of the research
• During transporation of citrus fruits severe quality losses
are commonly occurred mainly due to the fungal disease
like Sour rot (Geotrichum candidum)
• The most effective way to control these fungi is the
application of synthetic fungicides, such as 2,4-D, imazalil,
thiabendazole, pyrimethanil, prochloraz, fludioxonil, etc.
• Salicylic acid (SA), Pichia membranaefaciens and
oligochitosan have been reported to be able to induce
multiple defensive reactions against particular biotic and
abiotic stresses in some postharvest fruits, including citrus,
apple, peach, pear, sweet cherry, etc.

40. 40
Materials and methods
• Harvested Citrus sinensis (L.) Osbeck cv.
Jincheng fruits were selected based on
their uniformity in color, size and
lack of physical injury or infection.
The fruits were superficially
disinfected for 2 min via dipping in
2% (v/v) sodium hypochlorite,
followed by washing with water, and
air-dried at room temperature (25
°C).
• The antagonistic yeast maintained on
yeast extract peptone dextrose
medium at 4 °C in lab.
Citrus Sinesis cv.
Jincheng

41. 41
• The solution of SA and oligochitosan was prepared
with SDW to the final concentrations of 2.5 mmol
L−1 and 15 g L−1 , respectively.
• The pathogen G. candidum maintained in the
laboratory was isolated from decayed citrus fruit
showing symptoms of the disease and identified on
the basis of morphology and internal transcribed
spacer (ITS) sequence region of the rDNA analysis
(Zhao et al., 2017).

42. 42
Induction of resistance treatment and sample preparation
Two wounds (3 mm diameter × 3 mm deep) per fruit were
created on the opposite sides of fruit equator using a sterile
needle. Each wound was then inoculated with 30 μL of:
(1) SDW as the control
(2) SA (2.5 mmol L−1 )
(3) P. membranaefaciens (1 × 108 cells mL−1 )
(4) Oligochitosan (15 g L−1 ).

43. 43
Result
Effects of SA, P. membranaefaciens and oligochitosan on disease incidence
and lesion diameter of citrus fruit caused by G. candidum when treatment
solutions and pathogens were inoculated on the same (A and B) and
different wounds (C and D).

44. 44
Effects of SA, P. membranaefaciens and oligochitosan on the relative contents of sugars:
glucose (A), fructose (B), sucrose (C), inositol (D), glucopyranose (E), arabinose (F),
galactose (G), mannose (H), ribose (I) and xylose (J) contents in citrus peel

45. 45
Effects of SA, P. membranaefaciens and oligochitosan on the relative contents of organic
acids: citrate acid (A), α-ketoglutarate acid (B), succinic acid (C), malic acid (D), fumaric (E),
2-keto-D-glucosaccharic acid (F), gulonic acid (G) and oxalic acid (H) contents in citrus peel .

46. 46
Inference
1.These three elicitors significantly improved disease resistance against
G. candidum in citrus, by regulating the DEPs involved in pathways of
starch and sucrose metabolism, carbon metabolism and amino acid
metabolism.
2. Besides, the three elicitors induced accumulation of soluble sugars,
key organic acids in TCA circle and amino acids, which resulted in
reprogramming the energy and resources relevant to the disease
resistance system, via different modes of action directly or indirectly
enhanced the resistance reaction of the citrus fruit.
3. The primary metabolism played a vital role in the disease resistance of
citrus induced by oligochitosan, SA and P. membranaefaciens.

47. 47
1. The use of elicitors may be regarded as a simple and useful
technique to increase the phenolic content of fruit, protecting,
at the same time, both plants and fruits from biotic and abiotic
stresses, without the disadvantage of the environment.
e
2. Major advantage of the post harvest elicitations is cell cultures
includes synthesis of bioactive secondary metabolites,
independently of environmental and soil conditions.
3. However, more research is needed to better understand
the effect of these elicitors in the different phytochemical
synthesis pathways in order to be able to increase the health
related properties of fruit products without decreasing the
sensory properties of these products..
Conclusion

48. 48
Future thrusts
 Utilization of next-generation elicitors and bio-molecules
for improving fruit quality and disease management in fruit
crops.
 Elicitor treatments could be an alternative to genetically
modified (GM) plants for better attraction of natural enemies
of pest organisms on cultivated plants.
 Elicitor-treated plants bear lower ecological risks than GM
plants.
 Improved quality fruit with high phenolic and anti-oxidant is
a basic need to fight against several disease, COVID-19 is one
of them.

49. 49
‘Quality
improvement never
ends…’
Thank You _/_