These authors contributed equally to this work.
Unraveling the regulatory network of the MADS box transcription factor RIN in fruit ripening
Article first published online: 19 DEC 2011
© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd
The Plant Journal
Volume 70, Issue 2, pages 243–255, April 2012
How to Cite
Qin, G., Wang, Y., Cao, B., Wang, W. and Tian, S. (2012), Unraveling the regulatory network of the MADS box transcription factor RIN in fruit ripening. The Plant Journal, 70: 243–255. doi: 10.1111/j.1365-313X.2011.04861.x
- Issue published online: 3 APR 2012
- Article first published online: 19 DEC 2011
- Accepted manuscript online: 18 NOV 2011 11:43PM EST
- Received 8 October 2011; accepted 17 November 2011; published online 19 December 2011.
- chromatin immunoprecipitation;
- fruit ripening;
- transcription factor;
The MADS box transcription factor RIN is a global regulator of fruit ripening. However, the direct targets modulated by RIN and the mechanisms underlying the transcriptional regulation remain largely unknown. Here we identified 41 protein spots representing 35 individual genes as potential targets of RIN by comparative proteomic analysis of a rin mutant in tomato fruits. Gene expression analysis showed that the mRNA level of 26 genes correlated well with the protein level. After examining the promoter regions of the candidate genes, a variable number of RIN binding sites were found. Five genes (E8, TomloxC, PNAE, PGK and ADH2) were identified as novel direct targets of RIN by chromatin immunoprecipitation. The results of a gel mobility shift assay confirmed the direct binding of RIN to the promoters of these genes. Of the direct target genes, TomloxC and ADH2, which encode lipoxygenase (LOX) and alcohol dehydrogenase, respectively, are critical for the production of characteristic tomato aromas derived from LOX pathway. Further study indicated that RIN also directly regulates the expression of HPL, which encodes hydroperoxide lyase, another rate-limiting enzyme in the LOX pathway. Loss of function of RIN causes de-regulation of the LOX pathway, leading to a specific defect in the generation of aroma compounds derived from this pathway. These results indicate that RIN modulates aroma formation by direct and rigorous regulation of expression of genes in the LOX pathway. Taken together, our findings suggest that the regulatory effect of RIN on fruit ripening is achieved by targeting specific molecular pathways.