Klebsiella sp. confers enhanced tolerance to salinity and plant growth promotion in oat seedlings (Avena sativa)

Abstract

Plant growth and yield is adversely affected by soil salinity. Salt tolerant plant growth-promoting rhizobacteria (PGPR) strain IG 3 was isolated from rhizosphere of wheat plants. The isolate IG 3 was able to grow in presence of NaCl ranging from 0 to 20% in Luria Bertani medium. The present study was planned to evaluate the role of inoculation of PGPR strain IG 3 and its efficacy in augmenting salt tolerance in oat (Avena sativa) under NaCl stress (100mM). The physiological parameter such as shoot length, root length, shoot dry weight, root dry weight and relative water content (RWC) were remarkably higher in IG 3 inoculated plants in comparison to un-inoculated plants under NaCl stress. Similarly, the biochemical parameters such as proline content, electrolyte leakage and malondialdehyde (MDA) content and activities of antioxidant enzymes were analyzed and found to be notably lesser in IG 3 inoculated oat plants in contrast to un-inoculated plants under salt stress. Inoculation of IG 3 strain to oat seedlings under salt stress positively modulated the expression profile of rbcL and WRKY1 genes. Root colonization of root surface and interior was demonstrated using scanning electron microscopy and tetrazolium staining, respectively. Due these outcomes, it could be implicated that inoculation of PGPR strain IG 3 enhanced plant growth under salt stress condition. This study demonstrates that PGPR play an imperative function in stimulating salt tolerance in plants and can be used as biofertilizer to enhance growth of crops in saline areas.

Increase in phenolic compounds of Coriandrum sativum L. after the application of a Bacillus halotolerans biofertilizer

“…However, biofertilization with SCCPVE07 enhances chlorophyll concentration even under saline conditions. Other studies have also reported a significant increased production of photosynthetic pigments in horticultural inoculated plants under salt stress …”

Pseudomonas knackmussiiMLR6, a rhizospheric strain isolated from halophyte, enhances salt tolerance inArabidopsis thaliana

“…; Singh and Jha ; Sapre et al . ). An important factor to be considered when looking for new isolates is to screen them from environmental conditions for which they would be used (Príncipe et al .…”

“…; Sapre et al . ). The great reduction reported in the chlorophyll content in control plants under the salt stress is in line with previous studies (Mahmood et al .…”

“…; Sapre et al . ) and their implication in the plant growth. In our study, plant height and shoot fresh weight decreased in control plants under NaCl stress but A. thaliana inoculation with MLR6 increased significantly the plant growth parameters under normal as well as under saline stress conditions.…”

“…; Sapre et al . ). In this way, micro‐organisms present in the saline area or in the rhizosphere of halophytic plants may provide a valuable resource to improve crop tolerance to salinity (Vaishnav et al .…”