Abstract

Several chemical changes in soil are associated with plant growth-promoting rhizobacteria. An endosporeforming bacterium, strain XTBG34, was isolated from a Xishuangbanna Tropical Botanical Garden soil sample and identified as Bacillus megaterium. The strain’s volatiles had remarkable plant growth promotion activity in Arabidopsis thaliana plants; after 15 days treatment, the fresh weight of plants inoculated with XTBG34 was almost 2-fold compared with those inoculated with DH5α. Head space volatile compounds produced by XTBG34, trapped with headspace solid phase microextraction and identified by gas chromatography–mass spectrometry, included aldehydes, alkanes, ketones and aroma components. Of the 11 compounds assayed for plant growth promotion activity in divided Petri plates, only 2-pentylfuran increased plant growth. We have therefore identified a new plant growth promotion volatile of B. megaterium XTBG34, which deserves further study in the mechanisms of interaction between plant growth-promoting rhizobacteria and plants.

• Keywords: 2-pentylfuran; A. thaliana; B. megaterium; gas chromatography-mass spectrometry (GC/MS); plant growth-promoting rhizobacteria (PGPR); solid phase microextraction (SPME)