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Antagonism between Morphactin and Cytokinins in the Seedling Growth of Lactuca sativa Var . New York
, Ii::
_2
T , 1
t Biochem. Physiol. Pflanzen (BPP), Bd. 162, S. 462 - 466 (1971) Botany Department, University of Jodhpur, Jodhpur, India
Short Communication
Antagonism between Morphactin and Cytokinins in the Seedling Growth of Lactuca sativa V AR. New York By D. D.
CHAWAN
and D. N.
SEN
(Received February 8, 1971)
Summary The antagonism between morphactin and the cytokinins (kinetin, SD 8339 and 2ip) on the seedling growth of Laduca sativa VAR. New York, has been shown in the present study. The effectiveness of antagonistic action was more in SD 8339 and 2ip as compared to kinetin.
Introduction
Derivatives of flourene-9-carboxylic acid (morphactins) in some form are probably implicated in all phases of plant growth and in a number of known and unknown physiological as well as biochemical systems in the plants (SCHNEIDER, 1970). Morphactin controls seed germination (SANKHLA and SANKHLA, 1968a, 1968b) and seedling growth (KHAN, 1967; NANDA et al., 1968). Promotion of seed germination and seedling growth by cytokinins in several types of seeds has definitely been established (MILLER, 1967; SKINNER et al., 1957; CHAWAN et al., 1971). An apparent antagonism between morphactin and kinetin during lettuce seed germination has been shown by SANKHLA and SANKHLA (1967). The present experiments were undertaken to observe the antagonistic action between morphactin and cytokinins as well as to evaluate the comparative potentialities of three different cytokinins in reversing the effect of morphactin in the seedling growth of Lactuca sativa VAR. New York. Material and Methods The seeds of L. sativa were germinated at 26 ° + 1 °C under 1000 lux in 12 cm diameter petri dishes lined with a single layer of Whatman No.1 filter paper moistened with 10 ml of distilled water (control) or an equal amount of test solutions or their mixtures in equal ratios. The cytokinins used were G-furfurylamino purine (kinetin), 6-benzylamino-9-(tetrahydropyran-2-yl)9 H purine (SD 8339), and 6-(y,y,dimethylallylamino) purine (2ip). All the measurements were
463
Antagonism between Morphactin etc.
done five days after setting the experiments. The mean average lengths (in mm) of radicle and hypocotyl with statistieal interpretation and percent.inhibition (-) or promotion (+) have been shown in Tables 1 and 2. Table 1
I
I
Effect of different concentrations of cytokinins on the growth of radicle and hypocotyl (in mm) and their'percent inhibition (-) or promotion (+) in five days old seedlings of Lactuca ~ativ(iVAR. New York,
Chemical
Control Kinetin Kinetin SD 8339 SD 8339 2ip 2ip
Conc. in mg/I.
' 10-4 10-2 ,10- 4 10-2 ,10- 4 10- 2
Radicle
40.2 ± 44.7 ± 46.5 ± 43.0 ± 53.5 ± 47.0 ± 55.5 ±
Hypocotyl
3.1 3.7 4.6 3.3 6.2 1.6 4.6
23.0 ± 28:1 ± 29.6 ± 25.6 ± 29.9 ± 25.1 ± 28.2 ±
5.5 4.6 4.2 3.4 2.4 3.1 2.2
Percentage inhibition (- ) or promotion ( + ) Radicle Hypocotyl +11.1 +15.6 + 4.4 +33.0 ±16.9 +37.9
+22.1 +28.6 +11.3 +30.0 + 9.1 +22.6
Table 2 Effect of morphactin alone and in combination with the three cytokinins on the growth of radicle and hypocotyl (in mm) and their percent inhibition ( -) or promotion (+) in five days old seedlings of Lactuca sativa VAR. New York
i,
Chemical
Cone. in mg/l
Radicle
Hypocotyl
Morphactin Morphactin + Kinetin Morphactin + Kinetin Morphactin + SD 8339 Morphactin + SD 8339 Morphactin + 2ip Morphactin + 2ip
25, 25
7.0 ± 1.3
5.0 ± 2.0
-83.0
-78.2
10-4 25
20.6 ± 3.7
10.0 ± 1.8
-46.3
-56.5
10- 2 25
20.6 ± 3.2
8.5 ± 2.2
-46.3
-63.0
10-4 25
19.8 ± 3.3
14.3 ± 2.7
-50.7
-37.7
10- 2 25
26.4 ± 3.0
13.0 ± 2.2
-34.3
-43.4
10- 4 25
23.1 ± 3.4
14.7 ± 1.5
10-2
17.2 ± 2.4
13.1 ± 3.0
Percent inhibition ( - ) or promotion ( +) Radicle Hypocotyl
-42.5
-57.2
-36.0
-43.0
i
s:
lay
t ,.j
464
D. D.
CHAWAN
and D. N.
SEN
Results
a) Action of cytokinins on seedling growth The effects of different cytokinins on seedling growth of lettuce clearly indicate a favourable effect in various concentrations used. The cytokinins accelerated the seedling growth in both the concentrations used. The promoting effect was more in 10-2 mg/l solution both on radicle as well as on hypocotyl, when compared with 10-4 mg/l solution. Out of the three cytokinins, 2ip appeared to be most effective in enhancing the hypocotyl elongation and that SD "8339 for radicle (Table 1). b) Antagonism between morphactin and cytokinins on seedling growth It would be evident from Table 2 that morphactin inhibited the seedling growth considerably. The inhibitory effect was more on the hypocotyl elongation as compared to that of radicle. The morphactin induced inhibition of seedling growth was reversed by the cytokinins and the results relating to antagonism of morphactin and cytokinins on seedling growth were extremely interesting (Table 2).
Discussion
SCHNEIDER (1970) stated that the mechanism of action of morphactins on the germination process and the seedling growth apparently seem to be different. TOGNONI et al., (1967) and KRELLE and LIBBERT (1967) showed that morphactin might affect auxin metabolism. The localization of cytokinins in nucleic acids has been well established by various workers. The mechanism of cytokinins action in tobacco callus growth has been shown that they might in some way be involved with nucleic acids (SKOOG and AMSTRONG, 1970). Das et al., (1956) and PATAU et al., (1957) showed that DNA synthesis was stimulated in dividing tobacco tissue when kinetin was present in the medium. Morphactin considerably hastened the seedling growth in L. sativa. The cytokin ins strongly reversed the morphactin caused inhibition of seedling growth. These observations were found parallel with our previous experiments on Ruellia tuberosa (CHAWAN et al., 1971). The effectiveness of reversal of seedling growth was more in SD 8339 and 2ip as compared to kinetin. It might be postulated from the present investigations that some sort of physiological antagonism exists between morphactin and cytokinins in L. sativa seedling growth and this inhibition did not appear to be due to toxic effect of morphactin but probably it might affect the auxin metabolism.
\
Antagonism between l\lorphactin etc.
465
Acknowledgements The authors are thankful for the generous gifts from Prof. K. YOKOYAMA, USA (kinetin), Dr. R. W. A. LEACH, UK, (SD 8339), Dr. TH, GASPER, Belgium, (2ip), and E. MERCK, Darmstadt, (morphactin - IT 3456). The facilities provided by the Botany Department of this university are gratefully acknowledged.
Literatnre
I.
CHAWAN, D. D., SEN, D. N., and SHARMA, K. D., Curr. Sci. 40, 93 (1971). DAs, N. K., PATAU, K., and SKOOG, F., Physiol. Plant. 9, 640 (1956). KHAN, A. A., Physiol. Plant. 20, 306 (1967). KRELLE, E. and LIBBERT, E., Plant a 76, 179 (1967). MILLER, C. 0., Science Hi7, 1055 (1967). NANDA, K. K., PUROHIT, A. N., and PRABHA, A., Indian J. Plant Physiol. 11,20 (1968). PATAU, K., DAS, N. K., and SKOOG, F., Physiol. Plant. 10, 949 (1957). SANKHLA, N., and SANKHLA, D., Planta 76, 47 (1967). SANKHLA, D., and SANKHU, N., Arabid. Inf. Servo ii, 19 (1968a). SANKHLA, N., and SANKHLA, D., BioI. Plant 10,37 (1968b). SCHNEIDER, G., Ann. Rev. Plant Physiol. 21, 499 (1970). SKINNER, C. G., CLAYBOOK, J. R., TOLBERT, F. and SHIVE, W., Plant Physiol. 32, 117 (1957). SKOOG, F., and AMSTRONG, D. J., Ann. Rev. Plant. Physiol. 21, 359 (1970). TOGNONI, F., DEHERTOGH, A. A. and WITTWER, S. H., Plant and Cell Physiol. 8, 231 (1967). Author's address: Dr. D. D. CHAWAN and Dr. D. N. SEN, Botany Department, University of Jodhpur, Jodhpur (India).
\
_2
T , 1
t Biochem. Physiol. Pflanzen (BPP), Bd. 162, S. 462 - 466 (1971) Botany Department, University of Jodhpur, Jodhpur, India
Short Communication
Antagonism between Morphactin and Cytokinins in the Seedling Growth of Lactuca sativa V AR. New York By D. D.
CHAWAN
and D. N.
SEN
(Received February 8, 1971)
Summary The antagonism between morphactin and the cytokinins (kinetin, SD 8339 and 2ip) on the seedling growth of Laduca sativa VAR. New York, has been shown in the present study. The effectiveness of antagonistic action was more in SD 8339 and 2ip as compared to kinetin.
Introduction
Derivatives of flourene-9-carboxylic acid (morphactins) in some form are probably implicated in all phases of plant growth and in a number of known and unknown physiological as well as biochemical systems in the plants (SCHNEIDER, 1970). Morphactin controls seed germination (SANKHLA and SANKHLA, 1968a, 1968b) and seedling growth (KHAN, 1967; NANDA et al., 1968). Promotion of seed germination and seedling growth by cytokinins in several types of seeds has definitely been established (MILLER, 1967; SKINNER et al., 1957; CHAWAN et al., 1971). An apparent antagonism between morphactin and kinetin during lettuce seed germination has been shown by SANKHLA and SANKHLA (1967). The present experiments were undertaken to observe the antagonistic action between morphactin and cytokinins as well as to evaluate the comparative potentialities of three different cytokinins in reversing the effect of morphactin in the seedling growth of Lactuca sativa VAR. New York. Material and Methods The seeds of L. sativa were germinated at 26 ° + 1 °C under 1000 lux in 12 cm diameter petri dishes lined with a single layer of Whatman No.1 filter paper moistened with 10 ml of distilled water (control) or an equal amount of test solutions or their mixtures in equal ratios. The cytokinins used were G-furfurylamino purine (kinetin), 6-benzylamino-9-(tetrahydropyran-2-yl)9 H purine (SD 8339), and 6-(y,y,dimethylallylamino) purine (2ip). All the measurements were
463
Antagonism between Morphactin etc.
done five days after setting the experiments. The mean average lengths (in mm) of radicle and hypocotyl with statistieal interpretation and percent.inhibition (-) or promotion (+) have been shown in Tables 1 and 2. Table 1
I
I
Effect of different concentrations of cytokinins on the growth of radicle and hypocotyl (in mm) and their'percent inhibition (-) or promotion (+) in five days old seedlings of Lactuca ~ativ(iVAR. New York,
Chemical
Control Kinetin Kinetin SD 8339 SD 8339 2ip 2ip
Conc. in mg/I.
' 10-4 10-2 ,10- 4 10-2 ,10- 4 10- 2
Radicle
40.2 ± 44.7 ± 46.5 ± 43.0 ± 53.5 ± 47.0 ± 55.5 ±
Hypocotyl
3.1 3.7 4.6 3.3 6.2 1.6 4.6
23.0 ± 28:1 ± 29.6 ± 25.6 ± 29.9 ± 25.1 ± 28.2 ±
5.5 4.6 4.2 3.4 2.4 3.1 2.2
Percentage inhibition (- ) or promotion ( + ) Radicle Hypocotyl +11.1 +15.6 + 4.4 +33.0 ±16.9 +37.9
+22.1 +28.6 +11.3 +30.0 + 9.1 +22.6
Table 2 Effect of morphactin alone and in combination with the three cytokinins on the growth of radicle and hypocotyl (in mm) and their percent inhibition ( -) or promotion (+) in five days old seedlings of Lactuca sativa VAR. New York
i,
Chemical
Cone. in mg/l
Radicle
Hypocotyl
Morphactin Morphactin + Kinetin Morphactin + Kinetin Morphactin + SD 8339 Morphactin + SD 8339 Morphactin + 2ip Morphactin + 2ip
25, 25
7.0 ± 1.3
5.0 ± 2.0
-83.0
-78.2
10-4 25
20.6 ± 3.7
10.0 ± 1.8
-46.3
-56.5
10- 2 25
20.6 ± 3.2
8.5 ± 2.2
-46.3
-63.0
10-4 25
19.8 ± 3.3
14.3 ± 2.7
-50.7
-37.7
10- 2 25
26.4 ± 3.0
13.0 ± 2.2
-34.3
-43.4
10- 4 25
23.1 ± 3.4
14.7 ± 1.5
10-2
17.2 ± 2.4
13.1 ± 3.0
Percent inhibition ( - ) or promotion ( +) Radicle Hypocotyl
-42.5
-57.2
-36.0
-43.0
i
s:
lay
t ,.j
464
D. D.
CHAWAN
and D. N.
SEN
Results
a) Action of cytokinins on seedling growth The effects of different cytokinins on seedling growth of lettuce clearly indicate a favourable effect in various concentrations used. The cytokinins accelerated the seedling growth in both the concentrations used. The promoting effect was more in 10-2 mg/l solution both on radicle as well as on hypocotyl, when compared with 10-4 mg/l solution. Out of the three cytokinins, 2ip appeared to be most effective in enhancing the hypocotyl elongation and that SD "8339 for radicle (Table 1). b) Antagonism between morphactin and cytokinins on seedling growth It would be evident from Table 2 that morphactin inhibited the seedling growth considerably. The inhibitory effect was more on the hypocotyl elongation as compared to that of radicle. The morphactin induced inhibition of seedling growth was reversed by the cytokinins and the results relating to antagonism of morphactin and cytokinins on seedling growth were extremely interesting (Table 2).
Discussion
SCHNEIDER (1970) stated that the mechanism of action of morphactins on the germination process and the seedling growth apparently seem to be different. TOGNONI et al., (1967) and KRELLE and LIBBERT (1967) showed that morphactin might affect auxin metabolism. The localization of cytokinins in nucleic acids has been well established by various workers. The mechanism of cytokinins action in tobacco callus growth has been shown that they might in some way be involved with nucleic acids (SKOOG and AMSTRONG, 1970). Das et al., (1956) and PATAU et al., (1957) showed that DNA synthesis was stimulated in dividing tobacco tissue when kinetin was present in the medium. Morphactin considerably hastened the seedling growth in L. sativa. The cytokin ins strongly reversed the morphactin caused inhibition of seedling growth. These observations were found parallel with our previous experiments on Ruellia tuberosa (CHAWAN et al., 1971). The effectiveness of reversal of seedling growth was more in SD 8339 and 2ip as compared to kinetin. It might be postulated from the present investigations that some sort of physiological antagonism exists between morphactin and cytokinins in L. sativa seedling growth and this inhibition did not appear to be due to toxic effect of morphactin but probably it might affect the auxin metabolism.
\
Antagonism between l\lorphactin etc.
465
Acknowledgements The authors are thankful for the generous gifts from Prof. K. YOKOYAMA, USA (kinetin), Dr. R. W. A. LEACH, UK, (SD 8339), Dr. TH, GASPER, Belgium, (2ip), and E. MERCK, Darmstadt, (morphactin - IT 3456). The facilities provided by the Botany Department of this university are gratefully acknowledged.
Literatnre
I.
CHAWAN, D. D., SEN, D. N., and SHARMA, K. D., Curr. Sci. 40, 93 (1971). DAs, N. K., PATAU, K., and SKOOG, F., Physiol. Plant. 9, 640 (1956). KHAN, A. A., Physiol. Plant. 20, 306 (1967). KRELLE, E. and LIBBERT, E., Plant a 76, 179 (1967). MILLER, C. 0., Science Hi7, 1055 (1967). NANDA, K. K., PUROHIT, A. N., and PRABHA, A., Indian J. Plant Physiol. 11,20 (1968). PATAU, K., DAS, N. K., and SKOOG, F., Physiol. Plant. 10, 949 (1957). SANKHLA, N., and SANKHLA, D., Planta 76, 47 (1967). SANKHLA, D., and SANKHU, N., Arabid. Inf. Servo ii, 19 (1968a). SANKHLA, N., and SANKHLA, D., BioI. Plant 10,37 (1968b). SCHNEIDER, G., Ann. Rev. Plant Physiol. 21, 499 (1970). SKINNER, C. G., CLAYBOOK, J. R., TOLBERT, F. and SHIVE, W., Plant Physiol. 32, 117 (1957). SKOOG, F., and AMSTRONG, D. J., Ann. Rev. Plant. Physiol. 21, 359 (1970). TOGNONI, F., DEHERTOGH, A. A. and WITTWER, S. H., Plant and Cell Physiol. 8, 231 (1967). Author's address: Dr. D. D. CHAWAN and Dr. D. N. SEN, Botany Department, University of Jodhpur, Jodhpur (India).
\