This document discusses several types of plant growth regulators including morphactins, anti-transpirants, anti-auxins, anti-oxidants, and growth retardants. Morphactins are substances that modulate plant morphogenesis and include derivatives of fluorine compounds. Anti-transpirants help reduce water loss from plants and include stomatal closing agents like phenyl mercuric acetate as well as film-forming and reflective materials. Anti-auxins inhibit the effects of auxins and examples provided are TIBA, NPA, and clofibric acid. Anti-oxidants protect plant cells from free radical damage and include vitamins A, C, and E. Growth retardants like CCC reduce shoot growth

1. Morphactins, Anti-transpirants, Anti-
auxins and Anti-oxidants
Ningappa Kirasur
2014-12-129
Dept. of Olericulture
COH, Vellanikkara
1

2. Morphactins
 Morphactins are a group of substances which act on
morphogenesis and modulate the expression of
plants
 Chemically, they are the derivates of fluorine
compounds
 Fluorine - inactive, but the addition of COOH group
in the 9th position makes it active
2

3. Examples
 Chloroflurenol
 Flurenol
 Methyl benzilate
 Methyl chloroflurenol
 Methyl dichloroflurenol
3

4. Effects of morphactins
 Exhibit both synergistic and antagonistic effects-
depends upon the relative concentrations
 They inhibit seed germination, sprouting, growth of
seedling and internode elongation
 They depolarize cell division which probably leads to
distorted morphogenesis
4

5. Contd….
 Very effective in inducing lateral bud development, so
tillering will be profuse
 Some morphactins stimulate flowering in certain short
day plants
 Resemble ABA in inducing seed dormancy, bud
dormancy and suppressing stem elongation
 Most of their effects can be reversed by GA3 treatment
5

6. Applications
 Morphactins + 2,4-D - controls weed growth
 Morphactins + MH - suppress growth of grass in
lawns
 Flurenol and chlorflurenol inhibits the opening of
stomata
 Reduces transpiration in spinach and broad bean
(Rustagi, 2004)
6

7. Okra
 Pre-harvest application of 2.5 mg /lit chlorfluorenol-
methyl ester (CME ) induces anatomical changes
 Including lower stomatal index and more long
trichomes
 All of which could contribute to help water conservation
by the pods
 Wax emulsion + 2.5 mg /lit. morphactin can prolonged
the shelf-life of pods
7

8. Capsicum
 A spray of morphactin at 1 ppm also significantly
increased fruit weight/plant, percentage dry weight
and titrable acidity
 But reduced Calcium content in Capsicum annuum
cv. California Wonder
8
(Asdoudi, 1993)

9. 2. Anti-auxins
 These are chemicals which inhibit the action of auxins
 They closely resembles auxin but lacks at least one
requirement for activity
 Inhibit the effects of auxin
 Synthetic chemical derived from α-p-choloro phenoxy
iso-butyric acid (PCIB)
9

10. Examples
 2, 3, 5 tri iodo benzoic acid (TIBA)
 Napthyl thalamic acid (NPA)
 Clofibric acid
 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA)
 Naphthyl-methyl-thio propionic acid
 m-tolyl phthalamic acid
10

11. Contd….
 Application of anti-auxins few days before harvesting
for leaf shedding in cotton
 The anti-auxins TIBA, naphthyl-methyl-thiopropionic
acid and m-tolylpthalamic acid induce flower bud
formation in case of cauliflower
(Margara, 1977)
11

12. Contd…
 Application of HFCA (9-hydroxyfluorene-9-carboxylic acid)
and NPA (1-N-naphthylphthalamic acid) leads to
elongation of internodes in wild type of peas
 Significantly reduced the endogenous levels of GA1
 Below the application site IAA levels were also reduce
12

13. 3. Anti-transpirants
 The term anti-transpirant is used to designate
 Any material applied to plants for the purpose of
retarding transpiration
 Useful for reducing transplantation shock of nursery
plants (Horticultural plants)
 Applied to transpiring plant surfaces for reducing water
loss from the plant
13

14. Types of anti transpirants
1. Stomatal closing type :
 Fungicides like phenyl mercuric acetate (PMA) and
herbicides like Atrazine in lower concentration serve as anti
transpirants by inducing stomatal closing
 These reduce the photosynthesis
 PMA was found to decrease transpiration than
photosynthesis
 ABA induces closure of stomata
14

15. 2. Film forming type
 Plastic and waxy material which form a thin film on the
leaf surface
 Results in reduction of transpiration rate and
photosynthesis
Examples: Silicone oils
Ethyl alcohol
Polyvinyl chloride
Polyethylene, polypropylene
15

16. 3.Reflectance type
 White materials which form a coating on the leaves and
increase the leaf reflectance (albedo)
 Examples: Kaoline @ 5% spray reduces transpiration loss
Diatomaceous earth (Celite)
Hydrated lime,
Calcium carbonate,
Magnesium carbonate,
Zinc sulphate
16

17. Features of anti-transpirants
 Non toxic
 Non permanent damage to stomata mechanism
 Specific effects on guard cells but not to other cells
 Effect on stomata should persist at least for one week
 Chemical or material should be cheap and readily
available
17

18.  Phenyl mercuric acetate at 35 ppm, kaolinite at 5% were
sprayed on onion seedlings(Arka Pragathi, Arka Niketan, Arka
Kalyan and Pusa Red) 30, 50, 70 or 90 days after
transplanting and Irrigation was with held a week before
spraying
 Anti-transpirants cause 27 to 40% stomatal closure and
reduction varied from 22 to 56% depend on cultivars
 kaolinite treatment was most effective in reducing water
stress and stomatal closure
(Rao and Bhatt, 1990)
18
Contd…

19. 4. Anti-oxidants
 Antioxidants are nutrients in food that protect our cells
from damage by free radicals
 Free radicals are unstable molecules that can damage
our cells
 This cell damage may increase the risk of cancer, heart
disease, diabetes and infections
 Free radicals may also affect brain function
19

20. Types of Anti-oxidants
 Vitamin A
 Vitamin C
 Vitamin E
 Anthocyanins
 Beta carotene
 Catechins
 Ellagic acid
 Lutein
 Lycopene
20

21. Which Foods Have Antioxidants?
21
pumpkin, winter squash Beta carotene
Beans Catechins, vitamin E
Beets Anthocyanins
Bell peppers Beta carotene, vitamin C
Broccoli, greens, spinach Beta carotene, lutein, vitamin C
Carrots Beta carotene
Tomatoes (canned) Lycopene, vitamin C
Sweet potatoes Beta carotene, vitamin C

22. Contd….
 Ascorbic acid @ 50ml/L sprayed on brinjal had
significantly higher root weight, fruit yield, fruit free
total phenols, shoot and fruit potassium and calcium
contents under saline condition
 Spraying of ascorbate is effective in alleviating adverse
effects of salinity
22
(Shaban, 2007)

23. 5. Growth retardants
 Chemicals which reduces shoot growth and increases
root growth
 Enable the plants to resist drought conditions through
stomatal closure
 CCC- Cycocel is useful for improving water status of
the plant
23

24. 24