In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants

Ajit Kumar Passari; Vineet Kumar Mishra; Vijai Kumar Gupta; Mukesh Kumar Yadav; Ratul Saikia; Bhim Pratap Singh

doi:10.1371/journal.pone.0139468

In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants

PLoS One. 2015 Sep 30;10(9):e0139468. doi: 10.1371/journal.pone.0139468. eCollection 2015.

Authors

Ajit Kumar Passari¹, Vineet Kumar Mishra¹, Vijai Kumar Gupta², Mukesh Kumar Yadav³, Ratul Saikia⁴, Bhim Pratap Singh¹

Affiliations

¹ Molecular Microbiology and Systematic Laboratory, Department of Biotechnology, Aizawl, Mizoram University, Mizoram, 796004, India.
² Molecular Glyco-biotechnology Group, Department of Biochemistry, National University of Ireland Galway, Galway, Ireland.
³ Korea University college of Medicine, Korea University, Seoul, South Korea.
⁴ Biotechnology Division, CSIR-North East Institute of Science & Technology, Jorhat, 785006, Assam, India.

Abstract

Endophytic actinomycetes have shown unique plant growth promoting as well as antagonistic activity against fungal phytopathogens. In the present study forty-two endophytic actinomycetes recovered from medicinal plants were evaluated for their antagonistic potential and plant growth-promoting abilities. Twenty-two isolates which showed the inhibitory activity against at least one pathogen were subsequently tested for their plant-growth promoting activities and were compared genotypically using DNA based fingerprinting, including enterobacterial repetitive intergenic consensus (ERIC) and BOX repetitive elements. Genetic relatedness based on both ERIC and BOX-PCR generates specific patterns corresponding to particular genotypes. Exponentially grown antagonistic isolates were used to evaluate phosphate solubilization, siderophores, HCN, ammonia, chitinase, indole-3-acetic acid production, as well as antifungal activities. Out of 22 isolates, the amount of indole-3-acetic acid (IAA) ranging between 10-32 μg/ml was produced by 20 isolates and all isolates were positive for ammonia production ranging between 5.2 to 54 mg/ml. Among 22 isolates tested, the amount of hydroxamate-type siderophores were produced by 16 isolates ranging between 5.2 to 36.4 μg/ml, while catechols-type siderophores produced by 5 isolates ranging from 3.2 to 5.4 μg/ml. Fourteen isolates showed the solubilisation of inorganic phosphorous ranging from 3.2 to 32.6 mg/100ml. Chitinase and HCN production was shown by 19 and 15 different isolates, respectively. In addition, genes of indole acetic acid (iaaM) and chitinase (chiC) were successively amplified from 20 and 19 isolates respectively. The two potential strains Streptomyces sp. (BPSAC34) and Leifsonia xyli (BPSAC24) were tested in vivo and improved a range of growth parameters in chilli (Capsicum annuum L.) under greenhouse conditions. This study is the first published report that actinomycetes can be isolated as endophytes from within these plants and were shown to have antagonistic and plant growth promoting abilities. These results clearly suggest the possibility of using endophytic actinomycetes as bioinoculant for plant growth promotion, nutrient mobilization or as biocontrol agent against fungal phytopathogens for sustainable agriculture.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Actinobacteria / classification
Actinobacteria / genetics*
Actinobacteria / pathogenicity
DNA Fingerprinting
India
Plant Diseases / microbiology
Plants, Medicinal / growth & development*
Plants, Medicinal / microbiology*

Grants and funding

This work was supported by grants sanctioned to BPS from the Department of Biotechnology, Government of India, through the DBT-Twinning project (No. BT/209/NE/TBP/2011). This funding did not include any publication charges. The funding agency had no role in performing the experiments or in writing the manuscript.