RESEARCH ARTICLE Growth promoting properties of Mycobacterium and Bacillus on rice plants under induced drought Joydip Karmakar 1 , Sayani Goswami 1 , Krishnendu Pramanik 3 , Tushar Kanti Maiti 2 , Rup Kumar Kar 3 & Narottam Dey 1* 1 Rice Biotechnology laboratory, Department of Biotechnology, Visva–Bharati, Santiniketan 731 235, West Bengal, India 2 Department of Botany, The University of Burdwan, Burdwan 713 104, West Bengal, India 3 Department of Botany, Visva-Bharati, Santiniketan 731 235, West Bengal, India *Email: narottam.dey@visva-bharati.ac.in ARTIC LE HISTORY Received: 18 September 2020 Accepted: 26 November 2020 Published: 01 January 2021 KEYWORDS Rice Drought PGPR 16S rDNA Mycobacterium sp. Bacillu s sp. ABSTRACT Management of drought stress through applicaton of plant growth promotng rhizobacteria (PGPR) is now considered as an efectve strategy in the present scenario of altered environmental conditons of the world. The aims and objectves of the present investgaton was isolaton, characterizaton and identfcaton of some potental microbial resources (PGPR) from drought-afected upland rice felds of South Bengal followed by experimentaton on the efect of isolated PGPR on drought induced rice seedlings. Selected isolates were isolated from rice feld rhizospheric soils and tested for their PGPR actvity, through phosphate solubilizaton, nitrogen fxaton, IAA producton and ACC deaminase actvity. Then, the selected isolates were identfed through 16S rDNA sequencing and phylogenetc analysis. Among the screened isolates two (isolate 1 and isolate 6) showing plant growth promotng traits, was applied on studied germplasm (IR64) to fnd out the infuence of the applied organisms on rice growth and development under induced drought. Both organisms showed a positve infuence (through increase in germinaton percentage, root growth, shoot growth, fresh weight and dry weight) on the studied rice growth and development under induced drought. Isolate 1 and 6 identfed as species of Mycobacterium sp. and Bacillus sp. respectvely through molecular taxonomy. Hence, these two isolates are expected to alleviate drought stress in the rice feld for their nature of plant growth promoton under drought stress. Introducton Among the different abiotic factors, drought is one of the major constraints that adversely affect rice plant’s growth and productivity worldwide and it is expected that drought will hamper rice production in more than 50% of the arable lands by 2050 (1). Also increase in population, decrease in arable lands due to urbanization and constant increasing global warming makes the situation more adverse (2). Plants response to drought in several ways including reduction in cellular water potential, closure of stomata, decrease in the rate of photosynthesis, nitrate assimilation and generation of a number of antioxidative enzymes like Super oxide dismutase (SOD), Catalase (CAT), Peroxidase etc. (3). A variety of strategies has been used to improve the drought tolerance of rice like conventional stress management, different breeding approaches, genetic engineering etc. (4, 5). Though the most successful strategy for management of drought tolerance is the use of drought tolerant potent rice genotypes and introgression of drought tolerance in higher yield background but the strategy is very complex and long time consuming (6). So researchers are looking for different and easy techniques to achieve their goal. Use of PGPR in relation to stress management is one of them. It is one of the recently employed strategy © Karmakar et al (2021). This is an open-access artcle distributed under the terms of the Creatve Commons Atributon License, which permits unrestricted use, distributon and reproducton in any medium, provided the original author and source are credited (htps://creatvecommons.org/licenses/by/4.0/). To cite this artcle: Karmakar J, Goswami S, Pramanik K, Mait T K, Kar R K, Dey N. Growth promotng propertes of Mycobacterium and Bacillus on rice plants under induced drought. Plant Science Today. 2021;8(1):49–57. htps://doi.org/10.14719/pst.2021.8.1.965 Abbreviatons: PGPR: Plant growth promotng rhizobacteria; BOD: Biological oxygen demand; IAA: Indole acetc acid; ACC: 1-aminocyclopropane-1-carboxylic acid; LB: Luria-Bertani; PKV: Pikovskaya’s; PSI: Phosphate solubilizaton index; DM: Davis and Mingioli; DF: Dworkin and Foster; PBS: Phosphate bufer saline; ANOVA: Analysis of variance. Plant Science Today, published by Horizon e-Publishing Group, is covered by Scopus, Web of Science, BIOSIS Previews, Clarivate Analytcs, etc. Full list at htp://www.plantsciencetoday.online PLANT SCIENCE TODAY, 2021 Vol 8(1): 49–57 https://doi.org/10.14719/pst.2021.8.1.965 ISSN 2348-1900 (online) HORIZON e-Publishing Group