Halotolerant bacteria with ACC deaminase activity alleviate salt stress effect in canola seed germination

Amelioration of salt stress effect on canola seed germination was investigated using 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing plant growth promoting halotolerant bacteria. NaCl at 120 mM concentration reduced canola seed germination by 50 %. The inoculation of ACC deaminase-producing halotolerant Brevibacterium epidermidis RS15 and Bacillus aryabhattai RS341 at 120 mM NaCl significantly increased the seed germination with decreased seed ACC content. Notably, the hydrolytic enzymes activities like amylase, invertase, and protease also increased due to inoculation of RS15 and RS341 compared to uninoculated salt stress imposed germinating canola seeds. Ethylene emission of salt stress exposed eight-day-old canola seedlings was reduced by 35.4 and 41.1 % compared to uninoculated salt stressed control due to respective inoculation of RS341 and RS15. The amelioration of salt stress inhibitory effect on the canola seed germination was attributed to the inoculation of ACC deaminase-producing halotolerant bacteria modulating ethylene emission and inducing hydrolytic enzymes.