Abstract
We previously isolated a rhizobacterium (Bacillus subtilis IJ-31) and demonstrated that its associated allelochemicals could indicate plant growth retardation. However, little is known about how the growth of plants is regulated by B. subtilis IJ-31 and its allelochemicals. In this study, we investigated whether plant growth retardation in this relationship occurred through the inhibition of gibberellin (GA) biosynthesis. GA 3β-hydroxylase activity was found to be inhibited by B. subtilis IJ-31 and hydrocinnamic acid (HCA), which is one of the allelochemicals produced by B. subtilis IJ-31. Additionally, thin layer chromatography (TLC) demonstrated that B. subtilis IJ-31 culture broth and HCA both inhibit GA 3β-hydroxylase (MBP-GA4) activity. The retardation of plants by HCA was then confirmed in vivo and in vitro using a Ryegrass and Arabidopsis growth retardation assay. Furthermore, treatment with either B. subtilis IJ-31 culture extract or its allelochemicals resulted in significant down-regulation of XTR9 gene expression in Arabidopsis. Overall, we identified the functional mechanism of plant growth retardation by B. subtilis IJ-31 and its allelochemicals.
| Original language | English |
|---|---|
| Pages (from-to) | 1375-1380 |
| Number of pages | 6 |
| Journal | Journal of Microbiology and Biotechnology |
| Volume | 22 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2012 |
Keywords
- Allelochemicals
- Bacillus subtilis
- Gibberellin 3β-hydroxylase
- Hydrocinnamic acid
- Xyloglucan endotransglycosylases