The exogenous amelioration roles of growth regulators on crop plants grow under different osmotic potential
Автор: Abd el-samad Hamdia M., Shaddad M.A.K.
Журнал: Журнал стресс-физиологии и биохимии @jspb
Статья в выпуске: 1 т.10, 2014 года.
Бесплатный доступ
The production of fresh and dry matter of maize, wheat, cotton, broad and parsley plants show a variable response to the elevation of salinity stress. The production of fresh and dry matter of shoots and roots in wheat and broad bean plants tended to decrease with increasing NaCl concentration, salt stress progressively decrease in fresh and dry matter yield of maize plants. The increase in salinization levels induced a general insignificant change in production of fresh and dry matter of both organs of parsley plants. However, salinity induced a marked increase in the values of fresh and dry matter yields of cotton plants grown at the lowest level (-0.3 MPa NaCl) and a reduction at higher salinization levels. Leaf area of unsprayed plants was excesivly decreased with the rise of osmotic stress levels especially at higher salinity levels of maize, wheat, cotton, and broad bean and parsley plants. the total pigments concentration decreased with rise of salinization levels in maize and cotton, these contents remained more or less un affected up to the level of 0.6 MPa NaCl in wheat and up to 0.9 MPa in parsley plants, there above, they were significantly reduced with increasing salinity levels. In broad bean plants the total pigments contents showed a non-significant alterations at all salinity stress. Spraying the vegetative parts of the five tested plants with 200 ppm of either GA3 or kinetin completely ameliorated the deleterious effect of salinity in fresh, dry matter, leaf area and pigment contents.
Growth regulators, osmotic potential
Короткий адрес: https://sciup.org/14323831
IDR: 14323831
Текст научной статьи The exogenous amelioration roles of growth regulators on crop plants grow under different osmotic potential
There have been numerous studies of the effects of salinity on plants (Jamil et al ., 2007; Duan et al ., 2008, Hamdia and Shaddad, 2010). Recently, investigations have focused more on the mechanisms of salt tolerance in plants (Dajic, 2006; Munns and Tester, 2008). Some researchers have used PGRs for reducing or eradicating the negative effects of salinity (Kabar, 1987; Mutlu and Bozcuk, 2000 and Hamdia and Shaddad, 2010).
Phytohormones suggested playing important roles in stress responses and adaptation (Sharma et al., 2005; Shaterian et al., 2005). It is thought that the repressive effect of salinity on seed germination and plant growth could be related to a decline in endogenous levels of phytohormones (Zholkevich and Pustovoytova, 1993; Jackson, 1997; Debez et al., 2001). Wang et al. (2001) clearly defined that ABA and JA will be increased in response to salinity, whereas indole-3-acetic acid (IAA) and salicylic acid (SA) are declined. For example, the exogenous application of PGRs, auxins (Khan et al., 2004), gibberellins (Afzal et al., 2005), cytokinins (Gul et al., 2000) produces some benefit in alleviating the adverse effects of salt stress and also improves germination, growth, development and seed yields and yield quality
Javid et al (2011) explain that phytohormones are chemical messengers produced in one part of plant and translocated to the other parts, where they play critical roles in regulating plant responses to stress at extremely low concentration. Phytohormones are natural products and they called plant growth regulators, when they are synthesized chemically. Plants are usually subjected to environmental factors such as drought or high soil and water salinity. The reduction in plant growth exposed to saline environments could be due to either the effects of specific ions on metabolism or adverse water relations. Different strategies are being employed to maximize plant growth under saline conditions. One of them is to produce salt tolerant genotypes of different crops. Attempts to improve tolerance to salinity through conventional plant breeding methods are time consuming, laborious and depended on existing genetic variability. In addition, many attempts have been made to overcome this disorder, including proper management and exogenous application of plant growth regulators.
Thus the present work was to throw the light on the different response of crop plants to salinity stress and the amelioration roles of growth regulators on the growth and metabolic components of some crop plants.
MATERIALS AND METHODS
Five plant species Maize (Zea mays), Wheat
Triticum aestivum ) , Broad bean Vicia faba ), Cotton Gossypium herbaceum ) and Parsley plants Petroselinum crispum ) were grown in plastic pots in the soil without NaCl (control) and under salinization levels corresponding to osmotic potential of NaCl solution of, -0.3, -0.6, -0.9, and -1.2MPa. Saline solutions were added to the soil in such a way that the soil solution acquired the assigned salinization levels at field capacity. Treatments of plants with saline solutions began when seedlings were two weeks old. The salinized and non-salinized plants were irrigated every other day with 1/10 Pfeffer’s nutrient solution for two weeks. Then GA 3 and kinetin (100 ppm) solutions were sprayed three times (5 intervals) by spraying the shoot system of the growing plants (each pot with 10 Cm3 of GA 3 or kinetin solutions). The control plants were sprayed with distilled water. A week after the plants were used for analysis. Dry matter was determined after drying plants in an aerated oven at 70 C to constant mass. The leaf area was determined by using (Norman and Campbell 1994 ) and pigments contents by using the spectrophotometer method of Metzner et al . (1965)
RESULTS
Fresh and dry matter
The production of fresh and dry matter of maize, wheat, cotton, broad and parsley plants show a variable response to the elevation of salinity stress. In maize plants they were progressively reduced especially at higher Stalinization levels (table 1). The production of fresh and dry matter of shoots and roots in wheat plants tended to decrease with increasing NaCl concentration, however in shoots these values were prominently higher than those of control plants up to the level -0.6 MPa NaCl (table 2). However , salinity induced a marked increase in the values of fresh and dry matter yields of cotton plants grown at the lowest level (-0.3 MPa NaCl) (table 3). This stimulatory effect was much more pronounced in shoots than in roots, thereafter these values were significantly reduced with the rise of salinization levels. In shoot and root of broad bean plants the fresh and dry matter smoothly decrease with elevation of salinity levels especially at higher salinity levels (table 4). The increase in salinization levels induced a general insignificant change in production of fresh and dry matter of both organs of parsley plants, except in case of roots, where dry matter yields mostly showed a significant decrease at the different salinity levels (table 5). It is worthy to note that the percent of reduction of fresh, dry matter of shoot and root and pigments content at 1.2 MPa was 74.7, 72.7, 60, 64.7 for maize, 80.3, 84.6, 73.9, 67.1, 47.0 for wheat, 77.7, 67.0, 46.4, 71.4, 90.0 for cotton, 87.8, 80.6, 54.1, 71.4, 85.3 for cotton and 91.1, 84.6, 89.5, 71.8, 81.2 for parsley plants.
Exogenous application of GA3 or kinetin resulted in most cases in a considerable increase in the production of fresh and dry matter yields in shoots and roots and pigments content of salt stressed maize, wheat and cotton plants as compared with control plants. This stimulatory effect was more pronounced at lower and moderate salinization levels. However, spraying with any of the two hormones (GA3 or kinetin) resulted in a more or less comparable values with those of control in shoots especially 6Mpa and 9 MPa salinity levels. In roots these treatments considerably increased the production of fresh and dry matter up to the highest salinity levels, reach than 2-folds of control plants. In parsley plants treatment with GA3 mostly resulted insignificant changes in fresh and dry matter at all salinity levels of shoots and roots, except of this trend, in case of roots a stimulatory effect was observed in the production of dry matter. Kinetin treatment induced a marked and regressive increase in fresh and dry matter in shoots and roots of parsley plants. This increase was higher than those of control (0.0 NaCl) especially at lower and moderate salinity levels.
Leaf area
The values of leaf area of the tested plants as by either salinization or salinization with phytohormones treatment (GA 3 or kinetin) were represented in tables 1, 2, 3, 4 and 5. The leaf area, of unsprayed plants was excessively decreased with rise of salinization levels especially at higher salinity levels. The percent of reduction in leaf area at -1.2MPa was 71.8, 64.5, 76.8, 61.7 and 68.3 for maize, wheat, cotton, and broad bean and parsley plants.
Spraying these salinized plants with any of the phytohormones (GA 3 or kinetin) mostly resulted in a marked increase in leaf area and the inhibitory effect of salinity stress was completely ameliorated especially at the relatively low and moderate salinity levels. It is worthy to mention that the values of leaf area was higher than control untreated plants in wheat plant treated with either GA 3 or kinetin at 0.9 MPa, in cotton plants GA 3 at 6 MPa and treated with kinetin at 9 &12 MPa. In broad bean plants leaf area values was higher than control plants at 1.9 with GA 3 treatments and at 0.6 MPa with kinetin treatments.
Pigment contents
The results presented in tables 1,2,3,4,5 demonstrated that the total pigments concentration decreased with rise of salinization levels in maize and cotton, these contents remained more or less un affected up to the level of 0.6 MPa
NaCl in wheat and up to 0.9 MPa in parsley plants, there above, they were significantly reduced with increasing salinity levels. In broad bean plants the total pigments contents showed a non-significant alterations at all salinity stress. The percent of reduction at 1.2 MPa was 64.7, 47.0, 90.0, 85.3 and 81.2.
Hormonal treatment mostly increases the concentration of total pigment contents in maize especially in kinetin treatment. In wheat GA3 treatments induced non-significant changes while a marked and progressive increase in case of kinetin treatments, cotton, broad bean and parsley plants. Salinity with hormonal treatments resulted a stimulatory effect in the biosynthetic pigments over those of control plants (0.0) of both broad bean and parsley plants, and in GA3 especially in broad bean plants.
Table 1 : Effect of salinization levels and treatment with GA 3 or Kinetin (200 mg kg-1) on fresh, dry matter [g plant-1] of shoot and root , leaf area and total pigments maize plants.
|
Treatment |
NaCl mM |
Shoot |
Root |
Leaf area |
||
|
f.m. |
d.m. |
f.m. |
d.m. |
|||
|
0 |
0.0 |
29.3 |
4.4 |
4.5 |
1.2 |
223.8 |
|
0.3 |
28.2 |
3.9 |
3.7 |
0.92 |
221.1 |
|
|
0.6 |
23.9 |
3.7 |
4.0 |
0.93 |
188 |
|
|
0.9 |
21.4 |
3.9 |
3.9 |
0.94 |
166.9 |
|
|
1.2 |
21.9 |
3.2 |
2.4 |
0.72 |
160.7 |
|
|
GA 3 |
0.0 |
35.6 |
5.2 |
4.9 |
1.3 |
230.8 |
|
0.3 |
31.6 |
8.5 |
6.2 |
1.5 |
230.9 |
|
|
0.6 |
29.0 |
6.1 |
7.9 |
1.7 |
210.0 |
|
|
0.9 |
29.6 |
4.5 |
5.9 |
1.6 |
170.9 |
|
|
1.2 |
25.5 |
4.4 |
4.2 |
1.2 |
170.5 |
|
|
Kinetin |
0.0 |
39.6 |
8.4 |
5.2 |
1.7 |
248.1 |
|
0.3 |
36.3 |
7.5 |
5.6 |
1.4 |
230.6 |
|
|
0.6 |
36.2 |
7.3 |
5.2 |
0.97 |
200.5 |
|
|
0.9 |
36.1 |
7.1 |
4.8 |
0.94 |
184.1 |
|
|
1.2 |
29.2 |
5.9 |
3.7 |
0.92 |
180.2 |
|
|
L.S.D. 5% |
2.3 |
0.84 |
0.88 |
0.13 |
4.9 |
|
Table 2 : Effect of salinization levels and treatment with GA 3 or Kinetin (200 mg kg-1) on fresh, dry matter [g plant-1] of shoot and root, leaf area and total pigments wheat plants.
|
Treatment |
NaCl mM |
Shoot |
Root |
Leaf area |
||
|
f.m. |
d.m. |
f.m. |
d.m. |
|||
|
0 |
0.0 |
7.6 |
1.3 |
2.3 |
0.450 |
99.3 |
|
0.3 |
9.6 |
1.8 |
1.8 |
0.436 |
93.9 |
|
|
0.6 |
8.8 |
1.5 |
1.8 |
0.401 |
88.5 |
|
|
0.9 |
5.5 |
1.1 |
1.6 |
0.371 |
67.2 |
|
|
1.2 |
6.1 |
1.1 |
1.6 |
0.302 |
63.9 |
|
|
GA 3 |
0.0 |
15.3 |
3.2 |
2.8 |
0.558 |
150.1 |
|
0.3 |
13.2 |
2.5 |
2.3 |
0.555 |
130.1 |
|
|
0.6 |
10.5 |
2.0 |
2.1 |
0.590 |
114.2 |
|
|
0.9 |
11.3 |
2.8 |
3.2 |
0.618 |
115. 0 |
|
|
1.2 |
11.7 |
2.3 |
2.9 |
0.668 |
116.9 |
|
|
Kinetin |
0.0 |
12.1 |
2.9 |
3.3 |
0.811 |
110.6 |
|
0.3 |
12.4 |
2.6 |
3.2 |
0.776 |
112.0 |
|
|
0.6 |
11.4 |
2.0 |
2.3 |
0.523 |
131.7 |
|
|
0.9 |
8.5 |
1.6 |
2.3 |
0.523 |
115.7 |
|
|
1.2 |
8.3 |
1.2 |
2.3 |
0.470 |
73.5 |
|
|
L.S.D. 5% |
1.55 |
0.115 |
0.793 |
0.014 |
2.3 |
|
Table 3 : Effect of salinization levels and treatment with GA 3 or Kinetin (200 mg kg-1) on fresh, dry matter [g plant-1] of shoot and root , leaf area and total pigments cotton plants.
|
Treatment |
NaCl mM |
Shoot |
Root |
Leaf area |
||
|
f.m. |
d.m. |
f.m. |
d.m. |
|||
|
0 |
0.0 |
31.9 |
8.8 |
6.7 |
2.1 |
130.4 |
|
0.3 |
37.7 |
13.4 |
6. 9 |
2.8 |
124.6 |
|
|
0.6 |
28.4 |
6.7 |
5.9 |
2.0 |
118.4 |
|
|
0.9 |
26.6 |
6.4 |
3.6 |
1.6 |
100.2 |
|
|
1.2 |
24.8 |
5.9 |
3.2 |
1.5 |
100.1 |
|
|
GA 3 |
0.0 |
35.9 |
10.7 |
7.9 |
2.6 |
114.7 |
|
0.3 |
39.7 |
12.7 |
7.8 |
2.4 |
140.7 |
|
|
0.6 |
42.9 |
13.5 |
7.7 |
2.8 |
136.4 |
|
|
0.9 |
30.6 |
11.1 |
7.8 |
2.8 |
120.2 |
|
|
1.2 |
28.9 |
11.5 |
7.7 |
2.7 |
118.9 |
|
|
Kinetin |
0.0 |
37.3 |
12.6 |
7.1 |
3.3 |
136.3 |
|
0.3 |
35.5 |
10.4 |
7.8 |
3.1 |
131.4 |
|
|
0.6 |
34.9 |
10.4 |
7.8 |
3.1 |
127.9 |
|
|
0.9 |
34.7 |
11.3 |
7.1 |
2.5 |
135.4 |
|
|
1.2 |
30.9 |
10.2 |
6.1 |
2.4 |
138.9 |
|
|
L.S.D. 5% |
2.5 |
1.5 |
0.68 |
0.369 |
5.3 |
|
Table 4 : Effect of salinization levels and treatment with GA 3 or Kinetin (200 mg kg-1) on fresh, dry matter [g plant-1] of shoot and root , leaf area and total pigments broad bean plants.
|
Treatment |
NaCl mM |
Shoot |
Root |
Leaf area |
||
|
f.m. |
d.m. |
f.m. |
d.m. |
|||
|
0 |
0.0 |
29.2 |
3.6 |
3.7 |
0.429 |
140.4 |
|
0.3 |
28.4 |
3.5 |
3.8 |
0.433 |
116.5 |
|
|
0.6 |
27.6 |
3.1 |
3.2 |
0.393 |
103.9 |
|
|
0.9 |
24.7 |
3.0 |
3.0 |
0.369 |
96.6 |
|
|
1.2 |
25.6 |
2.9 |
2.0 |
0.369 |
86.6 |
|
|
GA 3 |
0.0 |
29.7 |
3.6 |
6.6 |
0.533 |
149.6 |
|
0.3 |
29.2 |
3.5 |
6.7 |
0.628 |
149.8 |
|
|
0.6 |
32.8 |
4.9 |
8.3 |
0.746 |
157.8 |
|
|
0.9 |
28.9 |
3.9 |
8.8 |
0.794 |
165.7 |
|
|
1.2 |
25.7 |
3.2 |
6.4 |
0.654 |
130.2 |
|
|
Kinetin |
0.0 |
30.0 |
3.2 |
6.8 |
0.710 |
147.3 |
|
0.3 |
30.0 |
3.5 |
6.7 |
0.719 |
147.2 |
|
|
0.6 |
29.3 |
3.9 |
6.7 |
0.617 |
150.1 |
|
|
0.9 |
25.4 |
3.2 |
5.6 |
0.632 |
132.4 |
|
|
1.2 |
25.3 |
3.1 |
5.9 |
0.579 |
130.2 |
|
|
L.S.D. 5% |
1.6 |
0.254 |
1.4 |
0.017 |
6.9 |
|
Table 5 : Effect of salinization levels and treatment with GA 3 or Kinetin (200 mg kg-1) on fresh, dry matter [g plant-1] of shoot and root, leaf area and total pigments of parsely plants.
|
Treatment |
NaCl mM |
Shoot |
Root |
Leaf area |
||
|
f.m. |
d.m. |
f.m. |
d.m. |
|||
|
0 |
0.0 |
6.8 |
1.3 |
1.9 |
0.685 |
61.9 |
|
0.3 |
6.6 |
1.3 |
1.8 |
0.519 |
57.1 |
|
|
0.6 |
6.5 |
1.3 |
1.8 |
0.544 |
36.2 |
|
|
0.9 |
7.3 |
1.3 |
1.8 |
0.518 |
45.2 |
|
|
1.2 |
6.2 |
1.1 |
1.7 |
0.492 |
42.3 |
|
|
GA 3 |
0.0 |
6.8 |
2.6 |
2.2 |
0.841 |
65.0 |
|
0.3 |
6.9 |
1.6 |
2.0 |
0.696 |
60.3 |
|
|
0.6 |
6.6 |
1.3 |
1.9 |
0.719 |
67.7 |
|
|
0.9 |
6.5 |
1.4 |
1.8 |
0.459 |
57.5 |
|
|
1.2 |
5.2 |
1.3 |
1.7 |
0.529 |
54.0 |
|
|
Kinetin |
0.0 |
7.6 |
1.8 |
3.6 |
1.3 |
65.8 |
|
0.3 |
7.4 |
1.6 |
3.1 |
1.0 |
52.6 |
|
|
0.6 |
8.2 |
1.8 |
2.6 |
0.804 |
50.2 |
|
|
0.9 |
7.9 |
1.3 |
2.2 |
0.800 |
50.4 |
|
|
1.2 |
7.2 |
1.3 |
2.4 |
0.732 |
38.1 |
|
|
L.S.D. 5% |
1.3 |
0.1 |
0.280 |
0.011 |
5.1 |
|
DISCUSSION
Therefore an alternative strategy of ameliorate salt stress could be by exogenous application of plant growth regulators. So, focusing on using of phytohormones such as GA 3 or kinetin, which has important effects on regulation of plant reaction to environment and control of some metabolic changes and more or less similar between the five tested plants. It has been reported that GA 3 or kinetin treatment reduces the adverse effects of salt stress of the maize, wheat, cotton, broad bean and parsley plants
Список литературы The exogenous amelioration roles of growth regulators on crop plants grow under different osmotic potential
- Afzal I, Basara S. M. A., Faooq M., Nawaz A. (2006): Alleviation of salinity stress in spring wheat by hormonal priming with ABA, salicylic acid and ascorbic acid. Int J Agric Biol. 8: 23-28
- Ali Y., Aslam Z., Ashraf M. Y. and Tahir G. R. (2004): Effect of salinity on chlorophyll concentration, leaf area, yield and yield components of rice genotypes grown under saline environment. International Journal of Environmental Science & Technology. 1: 221-225
- Anuradha S, Rao SSR (2001) Effect of brassinosteroids on salinity stress induced inhibition of seed germination and seedling growth of rice (Oryza sativa L.). Plant Growth Regul 33: 151-153
- Amuthavalli P. and Sivasankaramoorthy S. (2012): Effect of salt stress on the growth and photosynthetic pigments of pigeon pea (Cajanus cajan). Journal of Applied Pharmaceutical Science. 2: 131-133
- Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plant. Plant Sci 166: 3-16
- Chakrabarti, N. and Mukherji, S. (2003): Alleviation of NaCl stress by pre-treatment with phytohormones in Vigna radiata. Plant Biology. 46: 589-594
- Dajic Z. (2006): Salt stress. In: Madhava Rao KV, Raghavendra AS, Janardhan Reddy K (ed) Physiology and molecular biology of salt tolerance in plant. Springer, Netherlands, pp 41-99
- Debez A., Chaibi W., Bouzid S. (2001): Effect du NaCl et de regulatoeurs de croissance sur la germination d’ Atriplex halimus L. Cah Agri.c 10: 135-138
- Duan J., Li J., Guo S., Kang Y. (2008): Exogenous spermidine affects polyamine metabolism in salinity-stressed Cucumis sativus roots and enhances short-term salinity tolerance. J Plant Physiol. 165: 1620-1635
- Gul B., Khan M. A., Weber D. J. (2000): Alleviation salinity and dark enforced dormancy in Allenrolfea occidentalis seeds under various thermoperiods. Aust J Bot. 48: 745-752
- Hamdia. M. A., El-Komy, H.M. (1998): Effect of salinity, gibberllic acid and Azospirillium inoculation on growth and nitrogen uptake of Zea mays. Biol.Planta. 40: 109-120
- Hamdia, M. A. and Shaddad, M. A.K (2010): Salt tolerance of crop plants. Journal of Stress Pysiology and Biochemisrty. 6: 46-90
- Hernandez, J.A. and M.S. Almansa. (2002): Short-term effects of salt stress on antioxidant systems and leaf water relations of pea leaves. Physiol. Plant. 115: 251-257
- Hernandez, J.A., Olmos E., Corpas F.J., Sevilla F. and De1 Rio L. A. (1995): Salt-induced oxidative stress in chloroplasts of pea plants. Plant Sci. 105: 151-167
- Hernandez, J.A., Corpas F. J., M. Gamez, L.A, De1 Rio and F. Sevilla. (1993): Salt-induced oxidative stress mediated by activated oxygen species in pea leaf mitochondria. Physiol. Plant. 89: 103-110
- Iqbal M, Ashraf M (2013): Gibberellic acid mediated induction of salt tolerance in wheat plants: Growth, ionic partitioning, photosynthesis, yield and hormonal homeostasis. Environ Exp Bot. 86: 76-85
- Iqbal M., Ashraf M., Jamil A. (2006a): Seed enhancement with cytokinins: changes in growth and grain yield in salt stressed wheat plants. Plant Growth Regul. 50: 29-39
- Iqbal M., Ashraf M., Jamil A., Ur-Rehman S. (2006b): Does seed priming induce changes in the levels of some endogenous plant hormones in hexaploid wheat plants under salt stress? J Integ Plant Biol. 48: 81-189
- Jamil M, Lee K. B., Jung K.Y., Lee D. B., Han M. S., Rha E. S. (2007): Salt stress inhibits germination and early seedling growth in cabbage (Brassica oleracea capitata L.). Pakistan J Biol Sci. 10: 910-914
- Jackson M (1997) Hormones from roots as signals for the shoots of stressed plants. Trends in Plant Science 2(1): 22-28
- Javid M.G., Sorooshzadeh A., Moradi F., Sanavy S.A., Allahdadi I. (2011): The role of phytohormones in alleviating salt stress in crop plants. Australian Journal of Crop Science 5(6): 726-734
- Jeschke W. D., Peuke A. D., Pate J. S., Hartung W. (1997): Transport, synthesis and catabolism of abscisic acid (ABA) in intact plants of castor bean (Ricinus communis L.) under phosphate deficiency and moderate salinity. J Exp Bot. 48: 1737-1747
- Kabar K. (1987): Alleviation of salinity stress by plant growth regulators on seed germination. J Plant Physiol. 128: 179-183
- Khan MA, Gul B, Weber DJ (2004) Action of plant growth regulators and salinity on seed germination of Ceratoides lanata. Can J Bot 82: 37-42
- Letham D.S. (1978): Cytokinins. In: Letham DS, Goodwin PB, Higgins TJV (ed) Phytohormones and related compounds. Elsevier, Amsterdam. 1: 205-243
- Maggio A., Barbieri G., Raimondi G., De Pascale S. (2010): Contrasting Effects of GA3 Treatments on Tomato Plants Exposed to Increasing Salinity. J Plant Growth Regul. 29: 63-72
- Munns R., Tester M. (2008): Mechanisms of salinity tolerance. Annu Rev Plant Biol. 59: 651-681
- Metzner, H., Rau H., Senger, H. (1965): Untersuchungen zur Synchronisierbarkeit einzelner Pigment-Mungel Mutanten von Chlorella. Planta. 65: 186-194
- Mutlu F., Bozcuk S. (2000): Tuzlu kos¸ullarda ayc¸ic¸eg˘i tohumların c¸imlenmesi ve erken bu¨yu¨me u¨zerine dıs¸sal spermin’in etkileri. Turkish J Biol 24: 635-643
- Norman, J.M. and Campbell G.S. (1994): Canopy structure. In: Pearcy R. W., Ehleringerj., Mooney H.A., Rundel P.W. (eds) Plant Physiological Ecology: 301-326 Champman &Hall, London
- Naqviss M. (1999): Plant hormones and stress phenomena. In PESSARAKLI, M. ed, Handbook of plant and crop stress, Marcel Dakker, New York, pp. 709-730
- Parasher A., Varma S.K. (1988): Effect of pre-sowing seed soaking in gibberellic acid on growth of wheat (Triticum aestivum L.) under different saline conditions. Indian J Biol Sci 26: 473-475
- Pazuki A., Sedghi, M., Aflaki F. (2013): Interaction of salinity and phytohormones on wheat photosynthetic traits and membrane stability. Agriculture (Poľnohospodárstvo). 59: 33-41
- Pospisil J. (2003): Interaction of cytokinins and abscisic acid during regulation of stomatal opening in bean leaves. Photosynthetica 41: 49-56
- Prakash L., Prathapasenan G. (1990): NaCl and gibberellic acid induced changes in the content of auxin, the activity of cellulose and pectin lyase during leaf growth in rice (Oryza sativa). Ann Bot. 365: 251-257
- Sabir P., Ashraf M., Hussain M. and Jamil A. (2009): Relationship of photosynthetic pigments and warer relations with salt tolerance of Proso Millet (Panicum Miliacum L.) accessions. Pak. J. Bot., 41: 2957-2964
- Seckin B., A.H. Sekmen, I. Turkan. (2009): An enhancing effect of exogenous mannitol on the antioxidant enzyme activities in roots of wheat under salt stress. J Plant Growth Regul 28: 12-20
- Shaddad, M.A.K. (1990): The effect of proline application on the physiology of Raphanus sativus plants grown under different salinity stress. Biol. Plant. 32: 104-112
- Sharma N., Abrams S.R., Waterer D.R. (2005): Uptake, movement, activity, and persistence of an abscisic acid analog (80 acetylene ABA methyl ester) in marigold and tomato. J Plant Growth Regul. 24: 28-35
- Shaterian J., Waterer D., De Jong H., Tanino K.K. (2005): Differential stress responses to NaCl salt application in early-and late maturing diploid potato (Solanum sp.) clones. Environ Exp Bot. 54: 202-212
- Singh, A.K. and R.S. Dubey. (1995): Changes in chlorophyll a and b contents and activities of photo systems I and II in rice seedlings induced by NaCl. Photosynthetica, 31: 489-499
- Stepien P., Klobus G. (2006): Water relations and photosynthesis in Cucumis sativus L. leaves under salt stress. Biologia Plantarum. 50: 610-616
- Tabur S, Demir K (2010): Role of some growth regulators on cytogenetic activity of barley under salt stress. Plant Growth Regul 60: 99-104
- Tuna L.A., Kaya C., Dicilitas M. and Higgs D. (2008): The combined effects of gibberellic acid and salinity on some antioxidant enzyme activities, plant growth parameters and nutritional status in maize plants. Environmental and Experimental Botany. 62: 1-9
- Wang Y., Mopper S., Hasentein K.H. (2001): Effects of salinity on endogenous ABA, IAA, JA, and SA in Iris hexagona. J Chem Ecol 27: 327-342
- Zholkevich V.N., Pustovoytova T.N. (1993): The role of Cucumis sativum L leaves and content of phytohormones under soil drought. Russ J Plant Physiol 40: 676-680
