Bacteria possessing ACC deaminase activity reduce the level of stress ethylene conferring resistance and stimulating growth of plants under various biotic and abiotic stresses. Therefore, this study was carried out at National Agriculture Research Centre Islamabad to screen rhizobacteria containing ACC deaminase for inducing salt tolerance and improving rice plant growth and enhancement in paddy production under salt-stressed conditions. (ECe=9.65 dS m-1) during June, 2015 to November, 2016. Rice variety Basmati-385 seeds were inoculated with rhizobacterial strains which were: SBCC (M9), RPR (32), RPR (33), WPS (8) PBS, SBCC (M8) and RPR (41). Salinity (9.65dS m-1) was artificially developed using salts. This study resulted that rice crop improved growth and yield under salt stressed conditions with the induction of salt tolerance through ACC deaminaze PGPR and this was accomplished with the reduction in ethylene production. Reduction in sodium uptake by the utilization of different rhizobial strains having ACC deaminaze activity under saline environment is a encouraging sign to induce salt tolerance naturally and reduce the toxic effects of utilization of chemicals for reclamation of salt – affected lands.

1. Screening Rhizobacteria containing Acc-Deaminase for Growth and Yield of Rice (Oryza sativa) under Salt Stress Conditions
IJPBCS
Screening Rhizobacteria containing Acc-Deaminase for
Growth and Yield of Rice (Oryza sativa) under Salt Stress
Conditions
Muhammad Arshadullah1, Syed Ishtiaq Hyder2, Raheel Baber3 and Tariq Sultan4
1,2,3,4Land Resources Research Institute, National Agricultural Research Centre, Park Road, Islamabad-45500, Pakistan
Bacteria possessing ACC deaminase activity reduce the level of stress ethylene conferring resistance
and stimulating growth of plants under various biotic and abiotic stresses. Therefore, this study was
carried out at National Agriculture Research Centre Islamabad to screen rhizobacteria containing ACC
deaminase for inducing salt tolerance and improving rice plant growth and enhancement in paddy
production under salt-stressed conditions. (ECe=9.65 dS m-1) during June, 2015 to November, 2016.
Rice variety Basmati-385 seeds were inoculated with rhizobacterial strains which were: SBCC (M9),
RPR (32), RPR (33), WPS (8) PBS, SBCC (M8) and RPR (41). Salinity (9.65dS m-1) was artificially
developed using salts. This study resulted that rice crop improved growth and yield under salt stressed
conditions with the induction of salt tolerance through ACC deaminaze PGPR and this was
accomplished with the reduction in ethylene production. Reduction in sodium uptake by the utilization
of different rhizobial strains having ACC deaminaze activity under saline environment is a encouraging
sign to induce salt tolerance naturally and reduce the toxic effects of utilization of chemicals for
reclamation of salt – affected lands.
KEY WORDS: Rice growth and yield, Salinity, Ethylene, Rhizobial strains, Salt tolerance, PGPR ACC Deaminaze
INTRODUCTION
Soil salinization from the agricultural standpoint is one of
the most urgent problems in many areas worldwide,
especially in agricultural countries. Salinization can be
caused by salt water invasion, long and severe drought,
excessive use of chemical fertilizers. As a result, it can
impact agricultural production, water quality, ecological
health of streams and biodiversity. According to Qadir et
al, (2014) every day for the last two decades, about 2000
hectares of irrigated land in arid and semi-arid areas
across 75 countries have been degraded by salt.
Plant growth-promoting rhizobacteria (PGPR), free living
soil bacteria thriving in the plant rhizosphere, have been
studied as plant growth promoters for increasing
agricultural productivity (Lucy et al. 2004). Many PGPRs
can also increase plant resistance to biotic and abiotic
stress factors. Presence of 1-aminocyclopropane-1-
carboxylate (ACC) Deaminase activity in several
rhizospheric bacteria and regulation of ACC, a precursor
to plant ethylene levels, is one of the principal mechanisms
by which bacteria exert beneficial effects on plants under
abiotic stress (Glick et al. 2007a,b; Glick 2004, 2005;
Saleem et al. 2007).
Rice (Oryza sativa) is a semi-aquatic plant and its
ecosystem is classified into irrigated, rain fed lowland,
upland, and flood-prone hydrology. Rice growing under
these field conditions is exposed to various types of biotic
and abiotic stresses at various developmental stages
during its life cycle. Soil salinity is one of the important
factors affecting soil microbial activities and crop
productivity in most of the humid and sub-humid
conventional rice growing areas of coastal Asia (Ismail et
al. 2009).
*Corresponding Author: Muhammad Arshadullah, Land
Resources Research Institute, National Agricultural Research
Centre, Park Road, Islamabad-45500, Pakistan. Email:
arshad_pak786@yahoo.com
International Journal of Plant Breeding and Crop Science
Vol. 4(2), pp. 251-255, July, 2017. © www.premierpublishers.org. ISSN: XXXX-XXXX
Research Article

2. Screening Rhizobacteria containing Acc-Deaminase for Growth and Yield of Rice (Oryza sativa) under Salt Stress Conditions
Arshadullah et al 252
Table 1. Physiochemical analysis of soil used in the experiment
Characteristics Unit Values
pH - 7.02
Electrical conductivity (dS m-1
) 9.65
Organic Matter (%) 0.54
Na (AB-DTPA ppm 148
K (AB-DTPA) ppm 198
P (AB-DTPA) ppm 0.92
Ca+Mg (meq/L) 30
Carbonate (meq/L) 1.1
Bicarbonate (meq/L) 0.22
SAR meq/L) 10.42
Soil texture - Sandy Loam
When exposed to salt stress conditions, plant tissues
synthesize ethylene from its immediate precursor 1-
aminocyclopropane-1-carboxylate (ACC). High levels of
ethylene in plant tissues could inhibit the growth of root and
shoot (Bleecker and Kende, 2000 and Huang et al.,2003)
as well as suppress leaf expansion (Penrose and Glick,
2003). Such plant growth promoting bacteria(PGPR)
belong to the genera such as Alcaligenes, Variovorax,
Rhodococcus, Ochrobactrum and Bacillus (Bal et al. 2013
and Belimov et al. 2005).
Previous research has shown that inoculation with PGPR
can alleviate the salt stress effects in different plant
species. Enhancement of growth and salt tolerance in
PGPR (Plant Growth Promoting Rhizobacteria) inoculated
red pepper (Siddikee et al. 2011), tomato (Mayak et al.
2004) and Groundnut (Saravanakumar and Samiyappan
2007) have been reported. Plant Growth Promoting
Rhizobacteria is found in association with plants grown
under chronically stressful conditions, including high
salinity, may have been adapted to the stress conditions,
and could provide a significant benefit to the
plants(Saravanakumar and Samiyappan 2007).
There are many reasons for the low yield but salinity stress
is the most important (Rasheed et al., 2003).
Approximately,7% of the world’s land area, 20% of the
world’s cultivated land and nearly half of the irrigated land
are significantly affected by salt contents (Zhu, 2001).
A substantial decline in root and shoot elongation and in
root and shoot fresh and dry weights under saline
conditions have been well documented in the published
literature (Farhoudi et al., 2012; Hussain et al., 2012,
2013). The presence of ACC deaminase has previously
been reported in Gram negative bacteria (Belimov et al.,
2001; Wang e tal., 2001; Babalola et al., 2003), Gram
positive bacteria (Belimov et al., 2001).
Penrose et al. (2001) performed an experiment to study
the effect of bacteria containing an ACC-deaminase
enzyme that reduced ethylene production and increased
the root length of canola. These authors concluded that the
canola roots were elongated and the ACC level was
reduced. The findings of some in vitro studies have
elucidated the efficacy of ACC-deaminase-containing
bacteria in promoting the root and shoot growth of maize
plants under saline conditions (Nadeem et al., 2006,
2007); however, their ability to improve rice root and shoot
growth under saline-sodic field conditions has yet to be
explored. Therefore, this field trial was conducted based
on the hypothesis that application of ACC-deaminase-
containing bacteria to improve the root and shoot growth
of rice seedlings in saline-sodic soil. Keeping in view the
fact, this study was carried out to screen rhizobacteria
containing ACC deaminase for inducing salt tolerance and
thus improving the growth and yield of rice under artificially
developed salt-stressed conditions
MATERIALS AND METHODS
The study was carried at National Agriculture Research
Centre Islamabad to screen rhizobacteria containing ACC
deaminase for inducing salt tolerance and thus improving
rice plant growth and enhancement in paddy production
under salt-stressed conditions. (ECe=9.65 dS m-1) as
indicated in table-1 during June, 2015 to November, 2015.
Salinity was developed by adding salts. The soil for this
purpose was taken from NARC (National Agriculture
Research Center). The design was completely
randomized with three repeats. Keeping in view the fact,
this study was carried out to screen rhizobacteria
containing ACC deaminase for inducing salt tolerance and
improving the growth and yield of rice under artificially
developed salt-stressed conditions Rice variety Basmati-
385 seeds were inoculated with rhizobacterial strains
which were: SBCC (M9), RPR (32), RPR (33), WPS (8)
PBS, SBCC (M8) and RPR (41). Salinity (9.65dS m-1) was
artificially developed using salts. A soil sample (0-20 cm
depth) was collected from experimental soil before sowing
of crop and fertilizers application. All agronomic practices
were kept same except treatment application. Plant
samples were collected to investigate the effect of different
rhizobial strains on the availability of nutrients to plants.
Soil samples were analyzed for various physicochemical
properties using standard methods (Ryan et al., 2001 and
Sparks et al, 1996) and soil texture by Bouyoucous
Hydrometer Method Practical Agri. Chemistry Kanwar and
Chopra (1959). The data obtained were subjected to

3. Screening Rhizobacteria containing Acc-Deaminase for Growth and Yield of Rice (Oryza sativa) under Salt Stress Conditions
Int. J. Plant Breed. Crop Sci. 253
Table 2: Effect of AC C deaminase on growth and yield of rice
Treatments Plant Height (cm Plant-1
) No. of tillers plant-1
Straw yield (g m-2
) Grain yield (g m-2
)
Control 71. 7d 6c 67. 7d 30. 7d
SBCC(M9) 88.0a 3de 72. 7d 33.0d
RPR(32) 75. 7cd 6c 92. 7c 42.0c
RPR(33) 82.3ab 6c 102. 3b 62. 7b
WPS(8) PBS 84.0ab 8a 106. 3b 74. 7a
SBCC(M8) 88.0a 7b 113. 3a 73.0a
RPR(41) 78.0bc 8a 106.0b 64.0ab
LSD (0.5%) 6. 3 1 6.9 6.3
Values followed by same letter(s) are statistically similar at P=0.05 level of significance
Table 3: Effect of ACC deaminase on the uptake of nutrients of rice plants
Treatments P% K% Na%
Control 0.087c 2.10gh 2.68a
SBCC(M9) 0.137b 3.10a 2.25b
RPR(32) 0.130b 2.90c 2.02c
RPR(33) 0.133b 2.80d 2.40 a
WPS(8) PBS 0.180a 2.70e 1.89bc
SBCC(M8) 0.077cd 2.47f 1.75 d
RPR(41) 0.123b 2.62e 1.82c
LSD (0.5%) 0.040 0.10 0.29
Values followed by same letter(s) are statistically similar at P=0.05 level of significance
statistical analysis using the STATISTIX statistical
software (Version 8.1) and the mean values were
compared using least significant difference (LSD) multiple
range test (Steel and Torrie, 1997).
RESULTS AND DISCUSSION
Growth of rice plants was significantly influenced by
different rhizobial strains containing ACC Deaminase
activity under artificially developed saline conditions
(ECe= 9.65 dS m-1) mentioned in table-2. The highest plant
height (88cm) was gained by inoculating SBCC (M8) which
was statistically at par with SBCC (M9) and lowest height
in plant (71.7 cm) was observed in control i.e. without
inoculation. Inoculation of rice seed with rhizobial strains
showed better performance in plant height justifying the
toxic impacts of saline conditions (ECe=9.65 dS m-1) two
months after sowing. Number of tillers plant-1 showed
statistically significant results in data of rice plants
inoculated with strains under saline environment as
indicated in table-2. Maximum number of tillers plant-1(8)
was attained by WPS (8) which was statistically at par with
RPR (41) strain. Remaining strains showed more number
of tillers plant-1comparing with control under saline
conditions at ECe=9.65 dS m-1. Straw yield (g m-2) of rice
plants depicted statistically significant results in data of rice
seeds inoculated with strains under saline environment as
indicated in table-2. The highest straw yield (113.3g m-2)
was attained by SBCC (M8) the lowest straw yield (67.7g
m-2) with control under saline conditions at ECe=9.65 dS
m-1. Grain yield is the most economical parameter of the
experiment. Significant findings were collected as depicted
in table-2. SBCC (M8) ACC deaminaze containing PGPR
strain attained the highest value (74.7g m-2). The lowest
value (30.77g m-2) attained in control treatment. Recently,
researchers have found that several ACC deaminase
producing bacteria can promote the growth of plants under
salt stress conditions (Akhgar et al. 2014 and Huang et al.
2013). Similar findings have been reported by Zahir et al.
(2011) and Zafar-ul-Hye et al. (2013) in other crops.
Rice seed inoculated with different strains of bacteria
having ACC deaminase effect on plant growth and yield
under saline conditions (ECe= 9.65 dS m-1). Ionic
concentration of P (%) in rice plants showed significant
differences among treatments (Table-3). Uptake of P (%)
was the highest (0.18%) by WPS (8) PBS and control
showed the lowest (0.087%). Uptake of K (%) was the
highest (3.1%) in plants treated with SBCC (M8)and lowest
(2.1%) was determined in control (Table-3). Sodium ionic
concentration showed significant results among
treatments (Table-3). However Na uptake in plants (%)
was the highest in control and lowest by the rice plant
tissues inoculation by SBCC (M8). This means that
reduction in sodium ions in rice plants using inoculation
with rhizobial strains having ACC Deaminaze activity
alleviates the salinity and grows rice plants in conducive
conditions to induce salt tolerance with the reduction of
ethylene production under saline environment. Salinity-
induced losses in plant growth are due to osmotic effects,
ion-specific effects, imbalanced nutrition (particularly due

4. Screening Rhizobacteria containing Acc-Deaminase for Growth and Yield of Rice (Oryza sativa) under Salt Stress Conditions
Arshadullah et al 254
to higher uptake of Na+ at the expense of K+) and oxidative
stress (Pitman and Lauchli, 2002; Hussain et al., 2012).
CONCLUSION
This experiment revealed that growth of rice crop was
improved and paddy yield was enhanced under salt
stressed conditions through ACC deaminaze PGPR to
induce salt tolerance due to reduction in ethylene
production. Reduction in sodium ion uptake by rice plants
tissues with application of different rhizobial strains having
ACC deaminaze activity under saline environment is an
encouraging sign to induce salt tolerance naturally and
reduce the toxic effects of utilization of chemicals for
reclamation of salt – affected lands.
REFERENCES
Akhgar AR, M Arzanlou, PAHM Bakker, M Hamidpour
(2014) Characterization of 1-aminocyclopropane-1-
carboxylate (ACC) deaminase-containing
Pseudomonas spp. in the rhizosphere of salt stressed
canola. Pedosphere 24: 461-468.
Babalola OO, Osir EO, Sanni AI et al. (2003) Amplification
of 1-aminocyclopropane-1-carboxylic (ACC) deaminase
from plant growth promoting rhizobacteria in Striga-
infested soils. African J Biotechnol 2:157-160.
Bal HB, L Nayak, S Das, TK Adhya (2013) Isolation of ACC
deaminase producing PGPR from rice rhizosphere and
evaluating their plant growth promoting activity under
salt stress. Plant and Soil 366: 93-105.
Belimov AA, Hontzeas N, Safronova VI, Demchinskaya
SV, Piluzza G, et al. (2005) Cadmium-tolerant plant
growth-promoting rhizobacteria associated with the
roots of Indian mustard (Brassica juncea L. Czern). Soil
Biol Biochem 37: 241-250.
Belimov AA, Safronova VI, Sergeyeva TA et al. (2001)
Characterization of plant growth promoting rhizobacteria
isolated from polluted soils and containing 1-
aminocyclopropane- 1-carboxylate deaminase. Can J
Microbiol 47:242-252.
Bleecker AB, Kende H (2000) Ethylene: a gaseous signal
molecule in plants. Annu Rev Cell Dev Biol 16: 1-18.
Farhoudi R, Hussain M, Lee D-J (2012) Modulation of
enzymatic antioxidants improves the salinity resistance
in canola (Brassica napus). Int J Agric Biol 14:465-468.
Glick BR (2004) Bacterial ACC deaminase and the
alleviation of plant stress. Adv Appl Microbiol 56:291–
312
Glick BR (2005) Modulation of plant ethylene levels bythe
enzyme ACC deaminase. FEMS Microbiol Lett 251:1–7
Glick BR, Cheng Z, Czarny J, Duan J (2007a) Promotion
of plant growth by ACC deaminase-containing soil
bacteria. Eur J Plant Pathol 119:329–339
Glick BR, Todorovic B, Czarny J, Cheng Z, Duan J,
McConkey B (2007b) Promotion of plant growth by
bacterial ACC deaminase. Crit Rev Plant Sci 26:227–
242
Huang H, M, Huang G Gan, X Liu, J Wang, (2013) Isolation
and characterization of 1-aminocyclopropane-1-
carboxylate (ACC) deaminase-containing plant growth-
promoting rhizobacteria from carnation soil and roots.
Afr J Microbiol Res 7: 5664-5668.
Hussain M, Jang KH, Farooq M et al. (2012) Morphological
and physiological evaluation of Korean rice genotypes
for salt resistance. Int J Agric Biol 14:970-974.
Hussain M, Park H-W, Farooq M et al. (2013a)
Morphological and physiological basis of salt resistance
in different rice genotypes. Int J Agric Biol 15:113-118.
Ismail AM, Thapa B, Egdane J (2009) Salinity tolerance in
rice: physiological bases and implications on
management strategies for better crop establishment. In:
Improving productivity and livelihood for fragile
environments IRRI technical bull. 13. International Rice
Research Institute, Los Banos, pp 8–13
Kanwar, T. S. and S. L. Chopra. 1959. Practical
Agricultural Chemistry. S. Chand and Co., Delhi.
Lucy M, Reed E, Glick BR (2004) Applications of free living
plant growth-promoting rhizobacteria. Antonie van
Leeuwenhoek 86:1–25
Mayak S, Tirosh T, Glick BR (2004) Plant growth-
promoting bacteria confer resistance in tomato plants to
salt stress. Plant Physiol Biochem 42:565–572
Nadeem SM, Zahir AZ, Naveed M et al. (2006) Variation
in growth and ion uptake of maize due to inoculation with
plant growth promoting rhizobacteria under salt stress.
Soil Environ 25:78-84.
Penrose D. M., and Glick B. R., (2003). Methods for
isolating and characterizing ACC deaminase-containing
plant growth-promoting rhizobacteria. Physiologia
Plantarum, 118: 10-15.
Pitman MG, Lauchli A (2002) Global impact of salinity and
agricultural ecosystems. In: A. Lauchli and U. Luttge
(eds) Salinity: Environment-Plants-Molecules. Kluwer
Academic Publishers, Dordrecht pp 3-20.
Qadir M, Quillérou E, Nangia V, Murtaza G, Singh M, et al.
(2014) Economics of salt-induced land degradation and
restoration. Natural Resources Forum 38: 282-295.
Rasheed M, Mahmood T, Nazir MS (2003) Response of
hybrid maize to different planting methods and nutrient
management. Pak J AgriSci 4:73-76.
Ryan, J., G. Estefan and A. Rashid. 2001. Soil and Plant
Analysis Laboratory Manual. International Center for
Agricultural Research in the Dry Areas (ICARDA),
Islamabad, Pakistan. 172p
Saleem M, Arshad M, Hussain S, Bhatti AS (2007)
Perspective of plant growth promoting rhizobacteria
(PGPR) containing ACC deaminase in stress
agriculture. J Ind Microbiol Biotechnol 34:635–648
Saravanakumar D, Samiyappan R (2007) ACC deaminase
from Pseudomonas fluorescens mediated saline
resistance in groundnut (Arachis hypogea) plants. J Appl
Microbiol 102:1283–1292

5. Screening Rhizobacteria containing Acc-Deaminase for Growth and Yield of Rice (Oryza sativa) under Salt Stress Conditions
Int. J. Plant Breed. Crop Sci. 255
Siddikee MA, Glick BR, Chauhan PS, Yim W, Sa T (2011)
Enhancement of growth and salt tolerance of red pepper
seedlings (Capsicum annuum L.) by regulating stress
ethylene synthesis with halotolerant bacteria containing
1-aminocyclopropane-1-carboxylic acid deaminase
activity. Plant Physiol Biochem 49:427–434
Sparks, D.L., T.H. Carski, S.E. Fendorf, and C.V. IV.
Toner, 1996. Kinetic methods and measurements. p.
1275-1307. In D.L. Sparks (ed.) Methods of soil analysis:
Chemical methods. Soil Science Society of America,
Madison, WI.
Steel, R.G.D. and J.H. Torrie, 1997. Principles and
Procedure of Statistics. McGraw Hill Book Co., Inc.
Singapore, pp: 173–177.
Wang C, Ramette A, Punjasamarnwong P et al. (2001)
Cosmopolitan distribution of phlD-containing
dicotyledonous crop associated biological control
Pseudomonads of worldwide origin. FEMS Microbiol
Ecol 37:105-116.
Zafar-ul-Hye M, Ahmad M, Shahzad SM (2013)
Synergistic effect of rhizobia and plant growth promoting
rhizobacteria on the growth and nodulation of lentil
seedlings under axenic conditions. Soil Environ 32:79-
86.
Zahir ZA, Zafar-ul-Hye M, Sajjad S et al. (2011)
Comparative effectiveness of Pseudomonas and
Serratiasp. Containing ACC-deaminase for co-
inoculation with Rhizobium leguminosarumto improve
growth, nodulation and yield oflentil. BiolFertil Soils
47:457-465
Zhu JK (2001) Plant salt tolerance: regulatory pathway,
genetic improvement and model systems. Trends Plant
Sci 6:66-71
Accepted 4 July, 2017
Citation: Arshadullah M, Hyder SI, Baber R, Sultan T.
Screening Rhizobacteria containing Acc-Deaminase for
Growth and Yield of Rice (Oryza sativa) under Salt Stress
Conditions. International Journal of Plant Breeding and
Crop Science 4(2): 243-247.
Copyright: © 2017 Arshadullah et al. This is an open-
access article distributed under the terms of the Creative
Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium,
provided the original author and source are cited.