ASSESSMENT OF ENDOPHYTIC GUARD CELL BACTERIAL STRAINS KLEBSEILLA OXYTOCA AND ACINETOBACTER SP. OF RICE FOR ABIOTIC STRESS TOLERANCE

B. VIBITHA BALA¹, N.O. GOPAL²*, U. SIVAKUMAR^3
1Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, 641003, Tamil Nadu, India
²PGP College of Agricultural Sciences, Namakkal, Tamil Nadu Agricultural University, Coimbatore, 641003, Tamil Nadu, India
³Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, 641003, Tamil Nadu, India
* Corresponding Author : nogopal1964@yahoo.com

Received : 02-05-2019     Accepted : 26-05-2019     Published : 30-05-2019
Volume : 11     Issue : 5       Pages : 1580 - 1584
Int J Microbiol Res 11.5 (2019):1580-1584

Keywords : IAA, ACC deaminase, moisture stress, Antibiotic, Polyethylene glycol, solubilization
Conflict of Interest : None declared
Acknowledgements/Funding : Authors are thankful to Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, 641003, India
Author Contribution : All author equally contributed

The endophytic bacterial communities have intense importance in agriculture due to their widespread benefits to plants and the ability to ameliorate biotic and abiotic stresses. In this present study, two of the endophytic bacterial strains Klebseilla oxytoca and Acinetobacter sp. isolated from the guard cell protoplast of rice genotype in the previous study were tested for the ability to grow under moisture stress of about -10 bars (-1.0 Mpa) induced with 30% polyethylene glycol 6000. Similarly, these strains were tested for the intrinsic antibiotic resistance with the antibiotics viz., streptomycin, ampicillin, kanamycin, tetracycline and chloramphenicol at varied concentrations. Also, these strains were analyzed for growth under different cultural parameters such as pH (4.5-8.5), temperature (20º, 30º and 40ºC) and NaCl (2%, 5% and 10%) concentrations and the strains Klebseilla oxytoca and Acinetobacter sp. showed maximum cell density in the pH regime of 5..5 to 8.5, temperature of 30ºand 40ºC and the NaCl concentrations of 2% and 5% respectively. Correspondingly, these strains were able to solubilize the plant required minerals such as phosphate and zinc. The bacterial strain Acinetobacter sp. showed the maximum solubilization index. Approaching to the plant growth promoting activities, these strains produced maximum amount of Indole Acetic Acid (IAA), ACC deaminase activity and Gibberllic acid(GA3) production under induced moisture stress condition. Hence, this study confirms the plant growth and stress ameliorating activities of the selected endophytic bacterial strains and further gene regulations and stress alleviating metabolomic must be analyzed to understand the complete mechanism of these strains under stress environments. percent.

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