Study of plant growth regulators in fruit culture – structure, biosynthesis and morphogenetic effect of different plant growth promoters and growth inhibitors

1. Doctoral
Seminar on
Study of plant growth regulators in fruit culture – structure,
biosynthesis and morphogenetic effect of different plant
growth promoters and growth inhibitors.
Seminar Incharge
Dr. Prabhakar Singh
(Professor & Head) Dept. of Fruit
Science
Presented By
Ajay Singh
DEPARTMENT OF FRUIT SCIENCE,
INDIRA GANDHI KRISHI VISHWAVIDYALAYA, RAIPUR (C.G.)

2. CONTENT OF SEMINAR
Introduction
Auxins
Classification of PGRs
Gibberellins
Cytokinins
Abscisic acid
New generation hormones
Ethylene
Conclusion
Reference
Case Study
PGR formulation & ppm calculation

3. Introduction of PGR / Plant Hormone
The term Hormone is derived from a Greek word “hormao” which
means “ to stimulate” ( Beylis and Starling, 1902).
According to Thimann (1948), suggested using the term
“phytohormone” for hormone of plant. PGR is defined as “organic
substance produced naturally in the higher plants, controlling
growth or other physiological functions at a site remote from its
place of production and active in minute amounts.”
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

4. Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Classification of PGRs
On the basis of origin On the basis of function
Natural PGR Postulated
PGR
Growth
promoting
1. Auxin
2. Gibberellins
3. Cytokinin
Growth
Inhibiting
Naturally
occuring
inhibitors
Synthetic Retardant
Kumari et al., 2018
1. Auxin
2. Gibberellins
3. Cytokinin
4. ABA
5. Ethylene
1. Florigen
2. Vernalin
1. Morphactin
2. AMO-1618
3. Phosphon-D
4. CCC
5. Malic Hydrazide
6. PBZ
1. ABA
2. Ethylene
Bisht et al., 2017

5. Auxins
History-
1. Auxin is a greek word derived from “Auxien” means “ to grow ”.
2. The discovery of auxins of the 19th century Charles Darwin was
studying tropisms in plants.
3. F.W. Went (1926) successfully discovered and isolated this
growth substance from Avena sativa (Oat) coleoptiles tips.
4. Kogl and Haagen –Sumit (1931) given term “Auxin”.
5. Thimann (1935) identified auxin previously IAA and termed as
“Heteroauxin”
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

6. A. Naturally occuring auxins
 IAA ( Indole 3- Acetic Acid)
 IAALD ( Indole 3- Acetaldehyde)
 IPyA ( Indole 3- Pyruvic Acid )
 IAN ( Indole 3- Acetonitril )
 IMA (Indole 3-Methyl Acetate)
B. Synthetic Auxins
 IBA ( Indole 3- Butyric Acid )
 NAA ( Naphthalene Acetic Acid )
 2,4-D ( 2,4- Dichloro Phenoxy Acetic acid )
 2,4,5-T ( 2,4,5- Trichloro Phenoxy Acetic
Acid )
 4-CPA (Chloro Phenoxy Acetic acid)
 BOA ( Benzathiozol 2-Oxyacetic Acid )
 2,4,6-T (2,4,6- Tri chloro Benzoic Acid )
 2,4,5-TP ( 2,4,5- Trichloro Phenoxy
Propionic )
Auxin Groups
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

7. Structure of Auxins
Michael et al., 2013
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

8. BIOSYNTHESIS OF AUXIN
• IAA is structurally related to the amino acid tryptophan, and early
studies on auxin biosynthesis focused on tryptophan as the
precursor.
Multiple Pathways Exist for the Biosynthesis of IAA
• The IPA pathway. The indole-3-pyruvic acid (IPA)
• The TAM pathway. The tryptamine (TAM)
• The IAN pathway. In the indole-3-acetonitrile (IAN)
• Bacterial pathway
Taiz and Zeiger, (2003)
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

9. Taiz and Zeiger ( 2003 )
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

10.  AUXIN TRANSPORT
IAA moves mainly from the apical to the basal end (basipetally) in excised
oat coleoptile sections. This type of unidirectional transport is termed polar
transport.
Polar transport of auxin is inhibited by 2, 3, 5 Triiodobenzoic acid (TIBA)
and Naphthyl thalamic acid (NPA). The substances are called as anti auxins.
Taiz and Zeiger (2003)
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Fig.- Polar transport of Auxin in plant

11.  Physiological effects of auxin
1. Cell division and elongation
2. Apical dominance
3. Root Initiation
4. Prevention of abscission
5. Formation of Parthenocarpy fruits
6. Respiration
7. Callus formation
8. Eradication of weeds
9. Flowering and sex expression
Taiz and Zeiger (2003)
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Bisht et al., 2017

12. Gibberellins
History-
1. Gibberellin first isolated from the fungus ‘Gibberella fujikuroi’
in 1926 by Japanese scientist E. Kurosawa.
2. G. fujikuroi causes “ bakanae” (foolish seedling of rice) disease
in rice.
3. Yabuta and Hayashi (1935) first time isolated gibberellins.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

13. Structure of Gibberellin
Taiz and Zeiger (2003)
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

14.  BIOSYNTHESIS OF GIBBERELLIN
1. The precursor of gibberellins is
terpenoid and ent-kaurene.
2. GGPP is converted by two
cyclization reaction through
copalyl pyrophosphate into ent-
kaurene by the enzyme cyclase in
proplastids and ent-kaurene
converting to GA12 aldehyde.
3. GA12 aldehyde is oxidised to give
GA12 which is precursor to all
other GAs in plant.
4. All other step in biosynthesis of
GAs from GA12 or GA53 are
carried out in cytosol by soluble
enzymes dioxygenases.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Taiz and Zeiger (2003)

15.  GIBBERELLINS TRANSPORT IN PLANT
1. Gibberellins are translocated through both xylem and phloem.
2. Non polar transport of gibberellin is inhibited by Paclobutrazol
(PBZ) . The substances are called as antigibberellins.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Taiz and Zeiger (2003)

16.  Physiological effects of Gibberellin
1. To Promote Fruit Set
2. Seed Germination
3. Breaking of seed & bud dormancy
4. Produce parthenocarpy fruits
5. Stimulate the stem growth
6. Cell division
7. Tolerance to chilling
8. Stimulates bolting in rosette in plants
9. Improve fruit size
Bisht et al., 2017; Peter and Valeie ( 2015) ; Taiz and Zeiger (2003) ; Singh et al., (2021)
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

17. Cytokinins
History-
1. The discovery of kinetin by Skoog and miller (1950) from the
tobacco pith callus. The chemical substance was identified as 6-
furfuyl amino purin. Because of its specific effect on cell
division it was called as cytokinins.
2. The term cytokinin was proposed by Letham (1963).
3. Eventually coconut milk was show to contain the cytokinins
zeatin, but this finding was not obtained until several years after
the discovery of the cytokinins by (Letham 1974).
4. The first cytokinins to be discovered was the synthetic analog
kinetin.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Taiz and Zeiger (2003)

18.  Types of Cytokinins
Natural cytokinin :- Isopentenyl adenine (IPA) and zeatin (Z)
Synthetic cytokinin :- Kinetin , BA ( Benzyle adenine)
Structure of Cytokinins
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

19.  BIOSYNTHESIS OF CYTOKININS
1. Site of production root tips and
zeatin is mobile in zylem .
2. The precourser of Cytokinins is
adenosine monophosphate (AMP)
and 6-aminopurine.
3. The plant & bacterial enzyme
isopentanyl transferase (IPT)
through utilized to ATP, ADP &
AMP the presence of dimethyle
ally phosphate.
4. The products of these reactions
(iPMP, iPDP, or iPTP) are
converted to zeatin by an
unidentified hydroxylase.
5. The various phosphorylated forms
can be interconverted to free trans-
Zeatin and cis-Zeatin.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Taiz and Zeiger (2003)

20.  Physiological effects of Cytokinin
1. Regulate Cell Division in Shoots and Roots
2. Delay Leaf Senescence
3. Regulate Cell Division in Shoots and Roots
4. Regulate Specific Components of the Cell Cycle
5. Regulates Morphogenesis in Cultured Tissues
6. Promote Chloroplast Development
7. Regulate Growth of Stems and Roots
8. Promote Lateral Bud Growth
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Bisht et al., 2017 Taiz and Zeiger (2003)

21. Abscisic acid (ABA)
History-
 In 1963, a substance strongly antagonistic to growth was isolated
by Addicott from young cotton fruits and named Abscisin II.
Later on, this name was changed to Abscisic acid.
 Warning et al. (1963, 64) pointed out the presence of a substance
in birch leaves (Betula pubescens, a deciduous plant) which
inhibited growth and induced dormancy of buds and, therefore,
named it ‘dormin’. But, very soon as a result of the work of
Cornforth et al. (1965), it was found to be identical with abscisic
acid.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Taiz and Zeiger (2003)

22. Structure of Abscisic Acid
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

23.  BIOSYNTHESIS OF ABA
1. The initial step of ABA biosynthesis take
place in chloroplast, plastid and cytosol.
2. Biosynthesis 1st in chloroplast the
precursor of mevalonic acid.
3. And 2nd in plastid the precoursor
Isopentanyl diphosphate.
- Isopentanyl diphosphat lead to the
formation of zeaxanthin then the trans-
violaxanthin then the 9-cis neoxanthin
and finally xanthoxin. The 9-cis-
neoxanthin is then convert to form a 15C
compound called xanthoxine (Yu &
Assmann, 2014).
4. The xanthoxin is then oxidized at the
cytosol to ABA- aldehyde, and then
this aldehyde is converted to ABA by the
enzyme ABA-aldehyde oxidase (Awan et
al., 2017).
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Fig- Pathway of biosynthesis of abscisic acid

24.  PHYSIOLOGICAL EFFECTS OF ABA
 Plant Stress hormone
Promotes stomatal closing
Induces bud and seed dormancy
Inhibits precocious germination
Promotes root growth and inhibits shoot growth in water stress
condition.
Leaf and fruit Senescence
Disease resistance
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Bisht et al., 2017 Taiz and Zeiger (2003)

25. Ethylene
Introduction ;-
1. The first indication that ethylene is a natural product of plant
tissues was published by H. H. Cousins in 1910.
2. Others identified ethylene chemically as a natural product of plant
metabolism by (R. Gane, 1934) .
3. Ethylene was rediscovered and its physiological significance as a
plant growth regulator was recognized (Burg and Thimann 1959).
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

26. Structure of Ethylene
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

27.  BIOSYNTHESIS OF ETHYLENE
1. The precursor of ethylene is
methionine .
2. Methionine is transferred to S-
Adenosyl methionine (SAM) this
reaction is catalysed by the
enzyme SAM-synthetase.
3. S-Adenosyl methionine (SAM) is
transferred to form 1-
Aminocyclopropane-l-Carboxylic
Acid (ACC) by the enzyme ACC
synthease (Mao et al., 2015).
4. The conversion of the ACC is
carried out by the enzyme ACC
oxidas (ACO) to form ethylene
(Yoo, Cho & Sheen, 2009).
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Awan et al., 2017

28.  PHYSIOLOGICAL EFFECTS OF ETHYLENE
 Fruit Ripening
Triple Response
(i) inhibition of stem elongation, (ii) stimulation of radial swelling of
stems and (iii) horizontal growth of stems with respect to gravity
(Neljubow 1901).
 Formation of Adventitious Roots and Root Hairs
 Inhibition of Root Growth
 Flowering
 Senescence
 Abscission of leaves
 Dormancy breaking of Seeds and Buds
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Bisht et al., 2017 Taiz and Zeiger (2003)

29. New Generation Hormone
Brassinosteroids
Salicylic acid
Polyamines
Jasmonic Acid
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

30. New Generation Hormone
 Brassinosteroids
1. Firstly discovered in the Brassica spp. in Pollen (Mitchell et al.,
1979).
2. Found mainly in pollen and immature seeds.
3. Promoter of plant growth.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
 PHYSIOLOGICAL EFFECTS OF BRASSINOSTROIDS
1. Vegetative role- Enhance germination, cell and shoot elongation,
photosynthesis.
2. Reproductive role- Flower and fruit development, improved yield.
Bhattacharjee et al., 2017

31. Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
 Jasmonic Acid
1. Isolated from Jasminum grandiflrom in 1971.
2. Regulated plant growth and senescence, flower development and
leaf abscission also helps in tuber formation in potatoes, yams, and
onions.
 Salicylic acid
1. First isolated from the bark of Willow tree (Salix alba).
2. German scientist Johann A. Buchner purified salicylic in 1828.
3. Regulated disease resistance, germination, crop yield.
4. Protection to various environmental stress.
 Polyamines
 Regulated cell division, embryo development, regulate fruit
ripening, flower development, defense mechanism against abiotic
stress.
Bhattacharjee et al., 2017

32. SL – Liquid Suspension; DP – Dust Powder
Source:
http://www.nda.agric.za/act36/AR/PGRs.htm
Dept. of Crop Physiology, TNAU, Coimbatore
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
List of marketed plant growth regulators

33. PPM Calculation
Denoted very low concentration of a solution
ppm is an abbreviation of parts per million.
ppm is a value that represents the part of whole number of units of 1/10,00,000.
So, 1ppm = 1/1000000 = 0.000001 = 1× 106
1ppm = 1mg/lit.
1gm/lit. = 1000 ppm ( Stock solution)
100 mg /lit. = 100 ppm ( Stock solution)
1% = 10,000 ppm
0.1% = 1000 ppm = 1000 mg /lit.
0.01% = 100 ppm = 100 mg /lit.
0.001% = 10 ppm = 10 mg/ lit.
DILUTION FORMULA : C1V1 = C2V2
This equation applies to all dilution problems
C1 ( initial con.) × V1 ( initial volume) = C2 ( final con.) × V2 ( final volume )
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

34. CASE STUDY

35. Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Case Study
Bons and Kaur, (2020)
PAU, Ludhiana

36. Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Case Study
Diwan et al., 2022

37. Case Study
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Singh et al., 2021
IGKV, Raipur

38. Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)
Case Study
Paikra et al., 2018
IGKV, Raipur

39. Plant growth regulators has a enormous potential to
increase yield , quality , flowering , fruit setting at low and
very low and high temperature, sex modification , post
harvest, it increase self life and resistance to biotic and
abiotic stresses in fruit crops to get better requirement of
food supplies.
But still more research is required to develop simple
economical and technical viable production system of
bioregulators. Bioregulators must be toxicologically and
environmentally safe.
CONCLUSION
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

40. REFERENCES
1. Taiz, L. and Zeiger, E., 2003. Plant physiology 3rd ed. Animal of botany company,
91:750-751.
2. Singh, P. and Ramteke, V.,2018. Comprehensive Fruit Science. New vishal
publication.
3. Muthukumar, P. and Selvakumar, R.., 2017. Glaustas of Horticulture. New vishal
publication.
4. Awan, F., Yasir, K., & Atif, M. (2017). Plant growth regulators and their role in abiotic
stress management. Int J Innovative Res Biosci, 1, 9-22.
5. Kumari, S., Bakshi, P., Sharma, A., Wali, V. K., Jasrotia, A., & Kour, S. (2018). Use of
plant growth regulators for improving fruit production in sub tropical crops ,
International Journal of Current Microbiology and Applied Sciences, 7(3),
659-668.
6. Bisht, T. S., Rawat, L., Chakraborty, B., & Yadav, V. (2018). A Recent Advances in
Use of Plant Growth Regulators (PGRs) in Fruit Crops-A Review.
7. Bhattacharjee, P., Das, U., & Meena, M. K. (2017). The New Generation of
Phytohormones and their use in Horticulture.
8. Singh, A., Sahu, G. D., Nasim, A., Diwan, S. K. (2021). Studies on the
different concentration of GA3 and media for seed germination of
Acid lime (Citrus aurantifolia Swingle) under protected structure.
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)

41. 9. Lanjhiyana, R., Sahu, G. D., Panigrahi, H. K., & Katiyar, P. (2020). Role of pre-sowing seed
treatment on germination behavior and seedling vigour of papaya (Carica papaya
L.). Journal of Pharmacognosy and Phytochemistry, 9(5), 3039-3042.
10. Diwan, S. K., Sahu, G. D., Verma, M., Chawla, J., & Singh, A. (2022). Studies on different
concentrations of IBA as powder and lanolin paste formulation on survival and growth of
air layers in guava (Psidium guajava L.).
11. Paikra, S., Panigrahi, H. K., & Chandrakar, S. (2018). Effect of NAA and GA3 spray on quality
parameters of strawberry (Fragaria x ananassa Duch.) cv. Sabrina under net tunnel. J.
Pharm. Phytochem, 7, 393-395.
12. Bons, H. K., & Kaur, M. (2020). Role of plant growth regulators in improving fruit set, quality
and yield of fruit crops: a review. The Journal of Horticultural Science and
Biotechnology, 95(2), 137-146.
13. www.slideshare.net
14. Source: http://www.nda.agric.za/act36/AR/PGRs.htm
Department of Fruit Science,
Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.)