ACC deaminase-producing bacteria mediated drought and salt tolerance in <i>Capsicum annuum</i>

2017-11-27T15:02:26Z (GMT) by Ann Maxton Poonam Singh Sam A. Masih
<p>Influence of drought and salt stress on different morphological and physiological growth parameters in <i>Capsicum annuum</i> inoculated with our isolates was estimated during the present study. <i>Bulkhorderia cepacia</i> was reported to possess the maximal, whereas <i>Citrobacter feurendii</i> the least plant growth promoting efficacy under salt and drought stress. ACC Deaminase activity of purified <i>B. cepacia, C. feurendii and Serratia marcescens</i> was 12.8 ± 0.44, 12.3 ± 0.56 and 11.7 ± 0.53 μM αKB mg<sup>−1</sup> min<sup>−1</sup> respectively. Under drought stress, <i>B. cepacia</i> showed maximum tolerance as it produced 4.893 ± 0.06 mg/mg protein of exopolysaccharide followed by <i>C. feurendii</i> and <i>S. marcescens</i> that produced 4.23 ± 0.03 and 3.46 ± 0.05 mg/mg protein, respectively. Chlorophyll “<i>a</i>” concentration was recorded 5.7 gm L<sup>−1</sup> in <i>B. cepacia</i> inoculated plant (without stress) and was sustained till 2.9 gm L<sup>−1</sup> even under the highest tested drought period. Chlorophyll “<i>a</i>” concentration in the <i>B. cepacia</i> inoculated plant under the highest tested NaCl concentration was 3.2 gm L<sup>−1</sup>. Thus, bacterial inoculation mitigates the effects of salinity by the proliferation of root system, increasing plant biomass proving to be potential bioinoculum for alleviating abiotic stress.</p>