Salinity is one of the most important abiotic stresses, limiting crop production in arid and semi-arid regions, where soil salt content is naturally high. According to the FAO land and nutrition management service (2008), over 16 percent of the world’s land is affected by either salinity or sodicity which accounts for more than 800 million ha of land (CSSIR, 2016). The common cations associated with salinity are Na+, SO+34 Ca2+ and Mg2+, while the common anions are Cl- and HCO3-. Salinity occurs through natural or human induced processes that result in the accumulation of dissolved salts in the soil water to an extent that inhibits plant growth. There is competition for fresh water among the municipal, industrial and agricultural sectors in several regions. The consequence has been a decreased allocation of fresh water to agriculture. For this reason there is increasing pressure to irrigate with water of certain salt content like ground water, drainage water and treated waste water. Various causes of salinity over globe and how plants response to their suboptimal and toxic doses along with tolerance strategies has illustrated.

1. Welcome…

2. Does your
Toothpaste having
a salt…..????

3. PHYSIOLOGY
OF
SALT TOLERANCE IN
TOMATO

4. Contents
1.Introduction
2.Cause of salinity
3.Effect of salinity
4. Physiological mechanism of salt tolerance
5.Experimental studies
6.summary
7. Conclusion
8. Future Thrust

5. INTRODUCTION

7. Area (Million ha)
World >800
India 6.73
karnataka 0.13
CSSIR(2016)
Total salinity area

8. CSSIR(2016)

9. Salinity: It is caused due to high accumulation of
sodium, magnesium, and calcium and then anions
such as , SO-3
4 NO3
-
, CO3
-2
and HCO3
-
, Cl-
, etc.

10. How salinity is caused…????
• VID-20170825-WA0061.mp4

11. Different type of salinity
Type of soil pH EC ESP
Saline soil < 8.5 > 4.0 < 15
Alkaline soil < 8.5 > 4.0 > 15
Saline Alkaline > 8.5 > 4.0 > 15

12. Natural causeNatural cause Induced causeInduced cause

13. Effects of salinity

15. Eg: Pickle weed

16. Fig 1: Relationship between growth and NaCl concentration for

17. Tomato
Scientific name: Solanum esculentum Mill.
Family: solanaceae
2n : 24

18. Area Production
India 0.89 million ha 19.16 million tonnes
Karnataka 64.63 “000” ha 20.31lakh tonnes
Area and production of Tomato
NHB.(2015-16)

19. Sensitive Moderately
sensitive
Moderately
tolerant
Tolerant
almond alfaalfa red beet sugar beet
apple broccoli safflower cotton
avocado cabbage Clover date palm
bean Tomato soybean
carrot lettuce wheat
grape fruit corn rye grass
orange cucumber wheat grass
lemon grape peanut
okra potato
onion reddish
straw berry rice
sugarcane
Four salinity crop groups

20. Sensitive Moderately
sensitive
Moderately
tolerant
Tolerant
almond alfaalfa red beet sugar beet
apple broccoli safflower cotton
avocado cabbage Clover date palm
bean Tomato soybean
carrot lettuce wheat
grape fruit corn rye grass
orange cucumber wheat grass
lemon grape peanut
okra potato
onion reddish
straw berry rice
sugarcane
Four salinity crop groups

21. Physiological mechanisms of
salt tolerance and Experimental
studies.

23. Selective accumulation of ions
• Under saline conditions plant either restrict the excess salts in
vacuole or compartmentalize ions in the vacuole.
• Glycophytes limit sodium uptake, or partition sodium in older
tissues, such as leaves that serve as storage compartments which
are eventually abscised..
Iyenger and Reddy, 1996.

24. Compartmentalize ions in the vacuole
Cross section of a salt gland

25. Synthesis of compatible solutes
• These compatible solutes include mainly proline, glycine
betaine, carbohydrates and sugars which are called as
osmolytes.
Gholam et al.,2002
Functions of osmolytes:
•Osmatic adjustment
•Protection of enzymes
and membranes
•Act as reservoir of
energy for nitrogen
uptake.

26. Fig :2 Amino acid concentration in callus of
two tomato cultivars and their interspecific
hybrids
Spain Emilio et al. (1996)
Functions of osmolytes:
•Maintain internal water potential
and turgor potential
•Initiates adaption process to salt
stress
•Provides membrane stability
•Protect cell membrane from
disruption

27. The effect of salinity on growth, hormones and
mineral elements in leaf and fruit of tomato
cultivar PKM1
Babu et al., 2012, Tamil Nadu

28. Treatment Proline in leaves
( μM/g F.W)
Proline in
fruits( μM/g F.W)
Control 0.592 ± 0.028 0.513 ± 0.021
25 mM NaCl 0.865 ± 0.0055 0.743 ± 0.0414
50 mM NaCl 1.389 ± 0.0067 0.9367 ± 0.0328
100 mM NaCl 2.069 ± 0.036 1.23 ± 0.0426
150 mM NaCl 2.759 ± 0.011 1 1.453 ± 0.0569
200 mM NaCl 6.563 ± 0.029 1.8597 ± 0.0605
Table 1: Levels of proline in leaves and fruits
Babu et al., 2012, Tamil Nadu

29. Control of ion uptake by roots and transport
into leaves:
• Plants regulate ionic balance to maintain normal metabolism.
For example, uptake and translocation of toxic ions such as
Na+ is restricted, and uptake of metabolically required ions
such as K+ is maintained or increased.
 e.g. K+
in the presence of Na+
 e.g. NO3
-
in the presence of Cl-
Zhu et al., 1993.

30. Changes in photosynthetic capacity under
salinity:
• The reduction in photosynthetic rates in plants under salt
stress is mainly due to the reduction in water potential.
• The aim of slat tolerance is, therefore, to increase water use
efficiency under salinity. To this effect, some plants such as
facultative halophyte shift their C3 mode of photosynthesis
to CAM.
Cushman et al.,1989

31. Impact of salt stress on morpho-physiological and
biochemical parameters of Solanum lycopersicum cv.
Microtom leaves
Bacha et al.,2016,
Tunisia

32. Fig. 4. Modification of instantaneouswater use efficiency (WUEinstantaneous, A) at 2 dates of
leaf sampling (after 1 week and after 2weeks of stress application). T1: control, 0 mM NaCl; T2:
50mM NaCl; and T3: 150mMNaCl. The results are expressed as means ±S.D. (n=3). Different
letters indicate significantly different values at p ≤ 0.05 according to Duncan test.
Bacha et al.,2016,
Tunisia

33. Induction of antioxidative enzymes under salt
stress:
• Salinity lead to the production of reactive oxygen species (ROS) that
cause oxidative damage.
Smirnoff.,1993

34. •Some of these enzymes: enzymes as catalase (CAT), glutathione reductase
(GR), superoxide dismutase (SOD) and glutathione-S-transferase (GST).
Smirnoff.,1993

35. Salinity and induction of plant hormones:
• Abscisic acid (ABA) causes alteration in the expression of
stress-induced genes which are predicted to play an
important role in the mechanism of salt tolerance
Vidyanathan et al.,1999
Functions of abscisic acid:
•Increase calcium uptake
•Reduces ethylene release
•Reduces leaf abscission

36. Babu et al., 2012, Tamil Nadu

37. Treatment Abscisic acid ( mM/g F.W) Indole acetic acid ( mM/g F.W)
Control 0.484 ± 0.0025 0.587 ± 0.0025
25 mM NaCl 0.529 ± 0.0025 0.599 ± 0.0035
50 mM NaCl 1.0479 ± 0.0026 0.981 ± 0.0032
100 mM NaCl 2.065 ± 0.0036 2.203 ± 0.004
150 mM NaCl 8.17 ± 0.031 2.32 ± 0.0049
200 mM NaCl 24.7 ± 0.02 3.168 ± 0.0062
Table 2: Levels of Abscisic acid and Indole acetic acid in leaves of tomato
Babu et al., 2012, Tamil Nadu

38. Impact of salt stress on morpho-physiological and
biochemical parameters of Solanum lycopersicum cv.
Microtom leaves
Bacha et al.,2016,
Tunisia

39. Parameters sampling dates
(after stress
application)
Concentration of salts treatments
T1 (0mM) T2 (50mM) T3 (150mM)
Total
chlorophyll
(mg/g )
After 1 week 1.13 ± 0.02a 1.07 ± 0.03a 1.04 ± 0.03b
After 2 week 1.16 ± 0.03a 0.92 ± 0.04b 0.64 ± 0.02c
Total phenols
(mg/g)
After 1 week 0.78 ± 0.12b 0.81 ± 0.11b 1.87 ± 0.21a
After 2 week 0.80 ± 0.1c 2.64 ± 0.20b 4.54 ± 0.19a
TABLE 3: Variation In foliar contents of chlorophyll and total
phenols following increasing concentration of salinity and period of
salt treatments.
Results are expressed as means ± SD (n=3)
A,b,c,d : Values in same row with different letters showed statically significant
difference (P <0.05) according to Duncun test.
Bacha et al.,2016,
Tunisia

40. Physiological response of tomato to saline
irrigation in long-term salinized soils
Maggio et al., 2003, Italy

41. Salinity Leaf Root
Total
potential
Osmatic
potential
Turgor
potential
Total
potential
Osmatic
potential
Turgor
potential
S0 -0.99a -1.37a 0.38a -0.44a -0.72a 0.28a
S1 -1.08b -1.41b 0.33b -0.57b -0.81b 0.24ab
S2 -1.27c -1.54d 0.27c -0.74c -0.95c 0.21b
S3 -1.46d -1.67d 0.21d -0.92d -1.07d 0.15c
Table 4: Leaf and root water potentials in response to saline irrigation
S0: non-salinized control; S1: 0.25% salt; S2: 0.5% salt and S3: 1.0%
salt. Different letters indicate significant differences at P = 0.05.
Maggio et al., 2003, Italy

42. salinity
Total yield
Yield
(t ha−1)
Yield
(fruit
per plant)
Fruit mean
weight (g)
TSS
(Brix)
EC
(dSm−1)
Titrable
acidity
(% citric
acid)
S0 51.3 a 18.9 a 81.0 a 5.10 c 4.37 c 0.31 c
S1 49.0 ab 19.2 a 76.0 a 5.96 c 5.24 b 0.44 b
S2 46.7 b 20.7 a 67.3 b 6.47 b 5.57 b 0.42 b
S3 24.7 c 15.4 b 47.7 c 8.39 a 6.02 a 0.49 a
S0: non-salinized control; S1: 0.25% salt; S2: 0.5% salt; S3: 1.0% salt and TSS: total
soluble solids. Different letters indicate significant differences at P = 0.05.
Table 5: Tomato yield and fruit characteristics in response to saline
irrigation
Maggio et al., 2003, Italy

43. Salt stress response in tomato beyond the
salinity tolerance threshold
Maggio et al., 2006, Italy

44. EC (dS m−1)
Ψt (MPa) Ψ π (MPa) Ψp (MPa) OA (MPa)
2.5 −0.70 −1.49 0.79 –
4.2 −0.81 −1.58 0.77 0.07
6.0 −0.81 −1.65 0.84 0.15
7.8 −0.86 −1.67 0.81 0.18
9.6 −0.87 −1.78 0.91 0.27
11.4 −0.88 −1.82 0.92 0.31
13.2 −0.90 −1.86 0.96 0.36
15.0 −1.21 −2.28 1.07 0.70
LSD 0.11 0.17 0.07 0.15
Table 6: Total leaf water potential (Ψt), osmotic potential (Ψ),
pressure potential (Ψp) and osmotic adjustment (OA) in response to
increasing electric conductivity (EC) of the nutrient solution
LSD, least significant difference at P = 0.05.
Maggio et al., 2006, Italy

45. The effect of salinity on growth, hormones and
mineral elements in leaf and fruit of tomato
cultivar PKM1
Babu et al., 2012, Tamil Nadu

46. Treatment Leaf Area
(cm2)
Dry matter
weight %
Plant height
(cm)
No. of
fruits per
plant
Control 18.24 ± 0.31 9.943 ± 0.3252 161.88 ± 3.83 15
25 mM NaCl 16.45 ± 0.45 8.231 ± 0.130 149.72 ± 2.72 12
50 mM NaCl 15.38 ± 0.13 6.947 ± 0.0252 129.54 ± 2.63 10
100 mM NaCl 12.53 ± 0.51 5.231 ± 0.0529 116.55 ± 3.77 7
150 mM NaCl 11.28 ± 0.17 4.176 ± 0.1504 101.34 ± 2.55 6
200 mM NaCl 10.23 ± 0.29 2.786 ± 0.105 85.71 ± 4.02 4
Table 7: Leaf area, dry matter weight percentage, plant height and
no. of fruits per plant
Babu et al., 2012, Tamil Nadu

47. Physiological responses and adaptive strategies
of tomato plants to salt and alkali stresses
Wang et al., 2011, south Korea

48. Fig. 3. Effects of salt and alkali stresses on total OA (K and L) in tomato roots and leaves of plants
treated with salt (NaCl:Na2SO4 = 9:1) and alkali (NaHCO3:Na2CO3 = 9:1) stresses. The values
are means (±SE) of three replicates. Means followed by different letters in the same curve are
significantly different at P < 0.05, according to Student–Newman–Keuls (q-test)
Wang et al., 2011, south Korea

49. Management practices

50. • Salt leaching
a. Scraping
b. Flushing
c. Leaching
• Drainage
• Applying of gypsum
• Afforestation
• Magnetized water technology

51. Summary
• Tomato is moderately salt sensitive crop.
• Accumulation of NaCl is more in leaf (64%) followed by
fruit(22%)
• Germination is drastically reduced after 100 mM salt
concentration.
• Duration of salt treatment is more important than
concentration
• Quality improves with increase in salinity upto certain
limit.
• Accumulation of amino acids is more in salt sensitive
cultivar than tolerant cultivars.

52. ConclusionsConclusions
 Tomato crop is affected by a number of abiotic stresses ofTomato crop is affected by a number of abiotic stresses of
which salinity is important.which salinity is important.
 Salinity affects different stages of tomato viz., germination,Salinity affects different stages of tomato viz., germination,
early vegetative stage and developmental stages byearly vegetative stage and developmental stages by
increasing toxicity of ions and decreasing water potentialincreasing toxicity of ions and decreasing water potential
of soil.of soil.
 Quality of fruit increases due to high ionic strength andQuality of fruit increases due to high ionic strength and
thickening of cell wall.thickening of cell wall.
 Induction of salt tolerance may be achieved by ionInduction of salt tolerance may be achieved by ion
balancing, use of growth regulator and resistantbalancing, use of growth regulator and resistant
germplasm.germplasm.