Strain-specific variation in plant growth promoting volatile organic compounds production by five different Pseudomonas spp. as confirmed by response of Vigna radiata seedlings

Analysis of a blend of volatile organic compounds (VOCs) released by Pseudomonas spp. with growth‐promoting effect in Vigna radiata seedlings. Plant growth‐promoting activity of VOCs produced by five different Pseudomonas spp. was investigated by I‐plate technique. VOCs produced by different organisms were extracted by various solvents (methanol, ethyl acetate, hexane and butanol) and were identified by gas chromatography‐mass spectrometric analysis. The major VOCs identified were undecane, nonadecane, hexacosane, tetradecane, heptacosane, pentadecane, dodecane and tetratetracontane. The cultural conditions for the production of VOCs with plant growth enhancement effect were optimized and further confirmed using pure pentadecane as a candidate VOC. The study provides insight into plant beneficial effect of VOCs produced by Pseudomonas spp. Remarkable modulation in the production of VOCs with plant growth‐promoting effect by rhizobacteria was found to be dependent on the bacterial strain and its concentration. The study describes the requirement to consider bacterial VOC production also for preparing plant probiotic formulations. As VOCs are least considered for preparation of commercial plant growth‐promoting rhizobacterial strain formulation, the results of the study is highly significant.