Location: Plant, Soil and Nutrition ResearchTitle: The pineapple AcMADS1 promoter confers high level expression in tomato and arabidopsis flowering and fruiting tissues, but AcMADS1 does not complement the tomato LeMADS-RIN (rin) mutant Author
|Moyle, Richard - University Of Queensland|
|Koia, Jonni - University Of Queensland|
|Vrebalov, Julia - Boyce Thompson Institute|
|Botella, Jose - University Of Queensland|
Submitted to: Plant Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2014
Publication Date: 11/1/2014
Publication URL: http://DOI: 10.1007/s11103-014-0236-3
Citation: Moyle, R., Koia, J., Vrebalov, J., Giovannoni, J.J., Botella, J. 2014. The pineapple AcMADS1 promoter confers high level expression in tomato and arabidopsis flowering and fruiting tissues, but AcMADS1 does not complement the tomato LeMADS-RIN (rin) mutant. Plant Molecular Biology. 86(4-5):395-407.
Interpretive Summary: Regulatory genes known as transcription factors have been identified and characterized in tomato. A key tomato ripening regulator termed RIN is a member of the MADS-box class of transcription factors and is necessary for all ripening processes to occur. RIN operates with the ripening hormone ethylene. Unlike tomato, pineapple does not require ethylene for ripening yet has a gene similar to RIN. Here we report the characterization of the pineapple RIN gene, demonstrate that it can function to influence ripening genes in tomato (as pineapple is difficult for such experiments) yet is not capable of recovering a mutation in the tomato RIN gene. We propose that similar genes regulate ripening of fruit regardless of whether ethylene is important for a given species, suggesting RIN function is conserved through evolution.
Technical Abstract: A previous EST study identified a MADS box transcription factor coding sequence, AcMADS1, that is strongly induced during non-climacteric pineapple fruit ripening. Phylogenetic analyses place the AcMADS1 protein in the same superclade as LeMADS-RIN, a master regulator of fruit ripening upstream of ethylene in climacteric tomato. LeMADS-RIN has been proposed to be a global ripening regulator shared among climacteric and non-climacteric species, although few functional homologs of LeMADSRIN have been identified in non-climacteric species. AcMADS1 shares 67 % protein sequence similarity and a similar expression pattern in ripening fruits as LeMADSRIN. However, in this study AcMADS1 was not able to complement the tomato rin mutant phenotype, indicating AcMADS1 may not be a functionally conserved homolog of LeMADS-RIN or has sufficiently diverged to be unable to act in the context of the tomato network of interacting proteins. The AcMADS1 promoter directed strong expression of the GUS reporter gene to fruits and developing floral organs in tomato and Arabidopsis thaliana, suggesting AcMADS1 may play a role in flower development as well as fruitlet ripening. The AcMADS1 promoter provides a useful molecular tool for directing transgene expression, particularly where up-regulation in developing flowers and fruits is desirable.