AUXIN INVENTION AND BIOFERTILIZATION OF TRITICUM AESTIVUM L. BY HALOTOLERANT RHIZOBACTERIA

Author (s) : Dr. G. SAKTHIVEL, Dr.V.K. EVANJALENE

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Abstract :
Salt-tolerant strains of Enterobacter asburiae, Bacillus thuringiensis, Moraxella pluranimalium and Pseudomonas stutzeri were evaluated for their ability to alleviate salt stress of wheat (Triticum aestivum L.) seedlings. 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of P. stutzeri S-80 and B. thuringiensis S-26 was 190 and 183 nmolh-I, respectively. Maximum levels of auxin were recorded with P. stutzeri S-80 (107 µg ml-I) and E. asburiae S-24 (143 µg ml-I) under normal and salt-stressed conditions (0.25M NaCl), respectively with 500 µg ml-I L-tryptophan. Auxin response mediated by rhizobacteria was also demonstrated by microscopically assaying the transgenic auxin-responsive reporter DR5::GUS expression tomato (Solanum lycopersicum L. cv. MicroTom). In pot trials, seedlings fresh and dry biomass witnessed highly significant improvements of 1 and 2.2 folds, respectively, with M. pluranimalium S-29 (at 100 mM NaCl) and E. asburiae S-24 (150 mM NaCl), over control. At final harvest, maximum increase in number of tillers (up to 94%) and seed weight (up to 40%) were recorded with E. asburiae S-24 and M. pluranimalium S-29 at 200 mM salt stress. In conclusion, newly isolated strains of M. pluranimalium S-29, E. asburiae S-24 and P. stutzeri S-80 enhanced the growth of T. aestivum by mitigating the salt stress of plants.

Keywords : Halotolerant rhizobacteria, ACC-deaminase, bacterial auxin production, Salt stress alleviation, Plant growth promoting rhizobacteria

Conference Date : 13/11/2020

Pages : 121

Paper ID : 20121