Studies on Plant Growth Promoting Properties of Fruit-Associated Bacteria from Elettaria cardamomum and Molecular Analysis of ACC Deaminase Gene
- 411 Downloads
Endophytic microorganisms have been reported to have diverse plant growth promoting mechanisms including phosphate solubilization, N2 fixation, production of phyto-hormones and ACC (1-aminocyclopropane-1-carboxylate) deaminase and antiphyto-pathogenic properties. Among these, ACC deaminase production is very important because of its regulatory effect on ethylene which is a stress hormone with precise role in the control of fruit development and ripening. However, distribution of these properties among various endophytic bacteria associated with fruit tissue and its genetic basis is least investigated. In the current study, 11 endophytic bacteria were isolated and identified from the fruit tissue of Elettaria cardamomum and were studied in detail for various plant growth promoting properties especially ACC deaminase activity using both culture-based and PCR-based methods. PCR-based screening identified the isolates EcB 2 (Pantoea sp.), EcB 7 (Polaromonas sp.), EcB 9 (Pseudomonas sp.), EcB 10 (Pseudomonas sp.) and EcB 11 (Ralstonia sp.) as positive for ACC deaminase. The PCR products were further subjected to sequence analysis which proved the similarity of the sequences identified in the study with ACC deaminase sequences reported from other sources. The detailed bioinformatic analysis of the sequence including homology-based modelling and molecular docking confirmed the sequences to have ACC deaminase activity. The docking of the modelled proteins was done using patch dock, and the detailed scrutiny of the protein ligand interaction revealed conservation of key amino acids like Lys51, Ser78, Tyr268 and Tyr294 which play important role in the enzyme activity. These suggest the possible regulatory effect of these isolates on fruit physiology.
KeywordsEndophyte Plant growth promotion ACC deaminase Elettaria cardamomum In silico modelling and docking
This study was supported by the Department of Biotechnology (DBT), Government of India under DBT-RGYI and DBT-MSUB schemes and Kerala State Council for Science, Technology & Environment (KSCSTE), Government of Kerala under KSCSTE-SARD support programme.
We have not used any animal models for the experiments and thus do not require ethical committee clearance.
Conflict of Interest
The authors declare no conflict of interest.
- 8.Abeles, F. B. (1973). Ethylene in plant biology. New York: Academic Press.Google Scholar
- 10.Fujino, A., Ose, T., Yao, M., Tokiwano, T., Honma, M., Watanabe, N., & Tanaka, I. (2004). Structural and enzymatic properties of 1-aminocyclopropane-1-carboxylate deaminase homologue from Pyrococcus horikoshii. Journal of Molecular Biology, 341, 999–1013. doi: 10.1016/j.jmb.2004.06.062.CrossRefGoogle Scholar
- 12.Jia, Y. J., Kakuta, Y., Sugawara, M., Igarashi, T., Oki, N., Kisaki, M., Shoji, T., Kanetuna, Y., Horita, T., Matsui, H., & Honma, M. (1999). Synthesis and degradation of 1-aminocyclopropane- 1-carboxylic acid by Penicillium citrinum. Bioscience Biotechnology and Biochemistry, 63, 542–549.CrossRefGoogle Scholar
- 14.Sheehy, R. E., Honma, M., Yamada, M., Sasaki, T., Martineau, B., & Hiatt, W. R. (1991). Isolation, sequence, and expression in Escherichia-coli of the Pseudomonas sp strain ACP gene encoding 1-aminocyclopropane-1-carboxylate deaminase. Journal of Bacteriology, 173, 5260–5265.Google Scholar
- 17.Minami, R., Uchiyama, K., Murakami, T., Kawai, J., Mikami, K., Yamada, T., Yokoi, D., Ito, H., Matsui, H., & Honma, M. (1998). Properties, sequence, and synthesis in Escherichia coli of 1- aminocyclopropane-1-carboxylate deaminase from Hansenula saturnus. Journal of Biochemistry, 123, 1112–1118.CrossRefGoogle Scholar
- 21.Jimtha, J. C., Smitha, P. V., Anisha, C., Deepthi, T., Meekha, G., Radhakrishnan, E. K., Gayatri, G. P., & Remakanthan, A. (2014). Studies on endophytic bacteria obtained as culturable during development of embryogenic suspension culture of banana. Plant Cell Tissue and Organ Culture, 118, 57–66.CrossRefGoogle Scholar
- 24.Hall, T. A. (1999). BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series, 41, 95–98.Google Scholar
- 29.Finkmann, W., Altendorf, K., Stackebrandt, E., & Lipski, A. (2000). Characterization of N2O producing Xanthomonas-like isolates from biofilters as Stenotrophomonas nitritireducens sp. nov., Luteimonas mephitis gen. nov., sp. nov. and Pseudoxanthomonas broegbernensis gen. nov., sp. nov. International Journal of Systematic and Evolutionary Microbiology, 50, 273–282.CrossRefGoogle Scholar
- 31.Gravel, V., Antoun, H., & Tweddell, R. J. (2007). Growth stimulation and fruit yield improvement of greenhouse tomato plants by inoculation with Pseudomonas putida or Trichoderma atroviride: possible role of indole acetic acid (IAA). Soil Biology and Biochemistry, 39, 1968–1977.CrossRefGoogle Scholar
- 34.Richardson, A. E. (2001). Prospects for using soil microorganism to improve the acquisition of phosphorus by plants. Australian Journal of Plant Physiology, 28, 897–906.Google Scholar
- 36.Thakuria, D., Talukdar, N. C., Goswami, C., Hazarika, S., Boro, R. C., & Khan, M. R. (2004). Characterization and screening of bacteria from rhizosphere of rice grown in acidic soils of Assam. Current Science, 86, 978–985.Google Scholar
- 40.Glick, B. R., Jacobson, C. B., Schwarze, M. M. K., & Pasternak, J. J. (1994). 1-Aminocyclo propane-1-carboxylic acid deaminase mutants of the plant growth promoting rhizobacterium Pseudomonas putida GR12-2 do not stimulate canola root elongation. Canadian Journal of Microbiology, 40, 911–915.CrossRefGoogle Scholar
- 42.Onofre-Lemus, J., Hernández-Lucas, I., Girard, L., & Caballero-Mellado, J. (2009). ACC (1-Aminocyclopropane-1-Carboxylate) deaminase activity, a widespread trait in Burkholderia species, and its growth-promoting effect on tomato plants. Applied and Environmental Microbiology, 70, 6581–6590.CrossRefGoogle Scholar