The Variability of the Predominant Culturable Plant Growth-Promoting Rhizobacterial Diversity in the Acidic Tea Rhizosphere Soils in the Eastern Black Sea Region

Abstract

The purpose of this study was to investigate the diversity of cultivable nitrogen fixing, phosphate solubilising and total bacteria originated from 580 rhizospheric acidic soils samples of tea plants grown at 62 locations. Based on FAME profiles of over 1428 rhizoplane bacteria, 63 bacterial genera were identified with a similarity index > 0.3, but 56.4% of the identified isolates belonged to six genera: Bacillus (37.02%), Pseudomonas (12.67%), Stenotrophomonas (5.71%), Paenibacillus (6.58%), Arthrobacter (4.35%) and Brevibacillus (3.98%). Most of the total, N₂-fixing and P-solubilizing bacteria isolated were Gram positive (59.9, 58.8 and 56.3%) and Gram negative constituted only 40.1, 41.2 and 43.7%. Among different groups, Firmicutes, Gammaproteobacteria and Actinobacteria comprised the largest groups contributing to about 50.3 and 46.6%, 30.8 and 32.5%, and 8.3 and 9.6% of the total N₂-fixing and P-solubilizing isolates, respectively. B. cereus, P. fluorescens, B. megaterium, S. maltophilia, P. putida, B. licheniformis, B. pumilus, B. subtilis and P. polymyxa were the most frequent N₂-fixing and P-solubilizing species in the acidic tea rhizosohere soils. In these studies were evaluated to represent the dominant culturable diversity of diazotrophs and phosphobacteria, and thus potentially beneficial to the growth and survival of tea plants in that specific acidic ecosystem of eastern Black Sea region.

Keywords

• Acid tolerant strains,acidic soils,biodiversity,Camellia sinensis,FAME analysis,phosphate solubilizing bacteria,nitrogen fixing bacteria

References

1. Asghar, H.N., Zahir, Z.A., Arshad, M. and Khaliq, A. 2002. Relationship between in vitro production of auxins by rhizobacteria and their growth-promoting activi¬ties in Brassica juncea L. Biology and Fertility of Soils 35:231-237.
2. Beneduzi, A., Peres, D., da Costa, P.B., Bodanese Zanettini, M.H. and Passaglia, L.M.P., 2008. Genetic and phenotypic diversity of plant-growth-promoting bacilli isolated from wheat fields in southern Brazil. Research in Microbiology 159: 244-250.
3. Borsodi, A.K., Makk, J., Rusznyák, A., Vajna, B., Taba, G., and Márialigeti, K., 2007. Phenotypic characterization and molecular taxonomic studies on Bacillus and related isolates from Phragmites australis periphyton. Aquatic Botany 86: 243-252.
4. Çakmakçi, R., Dönmez, F., Aydin, A., and Sahin, F., 2006. Growth promotion of plants by plant growth-promoting rhizobacteria under greenhouse and two different field soil conditions. Soil Biology & Biochemistry 38: 1482-1487.
5. Çakmakçı, R., Erat, M., Erdoğan, Ü., and Dönmez, F., 2007. The influence of plant growth-promoting rhizobacteria on growth and enzyme activities in wheat and spinach plants. Journal of Plant Nutrition and Soil Science 170: 288-295.
6. Çakmakçı, R., Dönmez, M.F., Ertürk,Y., Erat, M., Haznedar, A., and Sekban, R., 2010. Diversity and metabolic potential of culturable bacteria from the rhizosphere of Turkish tea grown in acidic soils. Plant and Soil 332: 299-318.
7. Chen, Y.P., Rekha, P.D., Arun, A.B., Shen, F.T., Lai, W.-A., and Young, C.C., 2006. Phosphate solubilizing bacteria from subtropical soil and their tricalcium phosphate solubilizing abilities. Applied Soil Ecology 34: 33-41.
8. Costa, R., Götz, M., Mrotzek, N., Lottmann, J., Berg, G., and Smalla, K., 2006. Effects of site and plant species on rhizosphere community structure as revealed by molecular analysis of microbial guilds. FEMS Microbiology Ecology 56: 236–249.

9. Döbereiner, J., 1989. Isolation and identification of root associated diazotrophs, in: F.A. Skinner (Ed.), Nitrogen Fixation with Non-Legumes, Kluwer Academic Publishers, Dordrecht, Boston, London, pp. 103-108.
10. Donate-Correa, J., León-Barrios, M., and Pérez-Galdona, R., 2004. Screening for plant growth-promoting rhizobacteria in Chamaecytisus proliferus (tagasaste), a forage tree-shrub legume endemic to the Canary Islands. Plant and Soil 266: 261-272
11. Fierer, N., Jackson, R.B., 2006. The diversity and biogeography of soil bacterial communities. Proceedings of the National Academy of Sciences 103: 626–631.
12. Hariprasad, P., and Niranjana, S.R., 2009. Isolation and characterization of phosphate solubilizing rhizobacteria to improve plant health of tomato. Plant and Soil 316: 13-24
13. Karagöz, K., Ateş, F., Karagöz, H., Kotan, R., and Çakmakçı, R., 2012. Characterization of plant growth-promoting traits of bacteria isolated from the rhizosphere of grapevine grown in alkaline and acidic soils. European Journal of Soil Biology 50:144-150.
14. Oka, N., Hartel, P.G., Finlay-Moore, O., Gagliardi, J., Zuberer, D.A., Fuhrmann, J.J., Angle, J.S., and Skipper, H.D., 2000. Misidentification of soil bacteria by fatty acid methyl ester (FAME) and BIOLOG analyses. Biology and Fertility of Soils 32: 256–258.
15. Pikovskaya RE (1948) Mobilization of phosphates in soil in connection with vital activities of some microbial species. Microbiologia 17:362-370.
16. Piromyou, P., Buranabanyat, B., Tantasawat, P., Tittabutr, P., Boonkerd, N., and Teaumroong, N., 2011. Effect of plant growth promoting rhizobacteria (PGPR) inoculation on microbial community structure in rhizosphere of forage corn cultivated in Thailand. European Journal of Soil Biology 47: 44-54.
17. Poonguzhali, S., Madhaiyan, M., and Sa T., 2006. Cultivation-dependent characterization of rhizobacterial communities from field grown Chinese cabbage Brassica campestris ssp pekinensis and screening of traits for potential plant growth promotion. Plant and Soil 286:167-180.
18. Rau, N., Mishra, V., Sharma, M., Das, M.K., Ahaluwalia, K., and Sharma, R.S., 2009. Evaluation of functional diversity in rhizobacterial taxa of a wild grass (Saccharum ravennae) colonizing abandoned fly ash dumps in Delhi urban ecosystem. Soil Biology & Biochemistry 41: 813-821.
19. Şahin, F., Çakmakçi, R., Kantar, F., 2004. Sugar beet and barley yields in relation to inoculation with N2-fixing and phosphate solubilizing bacteria. Plant and Soil 265:123-129.
20. Varmazyari, A., and Çakmakçı, R., 2018. Diversity and metabolic potential of the dominant culturable N2-fixing and P-solubilising bacteria from tea (Camellia sinensis L.) rizosphere. Frontiers in Environmental Microbiology 4(2): 45-54.
21. Xie, G.H., Cai, M.Y., Tao, G.C., and Steinberger, Y., 2003. Cultivable heterotrophic N2-fixing bacterial diversity in rice fields in the Yangtze River Plain, Biology and Fertility of Soils 37:29-38.
22. Xue, D., Yao, H.Y., Ge, D.Y., Huang, C.Y., 2008. Soil microbial community structure in diverse land use systems: A comparative study using Biolog, DGGE, and PLFA analyses. Pedosphere 18: 653-663.
23. Xue, D., Yao, H., and Huang, C. Y., 2006. Microbial biomass, N mineralization and nitrification, enzyme activities, and microbial community diversity in tea orchard soils. Plant and Soil 288:319-331.