Fruit ripening mutants yield insight into ripening control

Authors: Giovannoni, James

Submitted to: Current Opinion in Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2007
Publication Date: 6/12/2007
Citation: Giovannoni, J.J. 2007. Fruit ripening mutants yield insight into ripening control. Current Opinion in Plant Biology. 10:283-284.

Interpretive Summary: Physiologically characterized single gene tomato ripening mutants that have in some cases been available for decades have recently become accessible at the molecular level as genomics infrastructure for tomato has expanded. These advances have been facilitated by increasingly efficient positional cloning in tomato, the development of a model for ethylene signal transduction from Arabidopsis (which could be tested in tomato) and improved metabolic profiling technologies, respectively. The result has been the opening of a new frontier in ripening molecular biology focused on primary genetic control in addition to characterization of hormonal and environmental signaling mechanisms. The first deep screen of mature mutagenized tomato plants combined with extensive fruit metabolic quantitative trait mapping holds the promise of numerous additional functionally defined loci that will become increasingly accessible via expanding genomics resources and the emerging tomato genome sequence.

Technical Abstract: Fruit ripening is a developmental process exclusive to plants whereby mature seed-bearing organs undergo physiological and metabolic changes promoting seed dispersal. Molecular investigations into ripening control mechanisms have been aided by the recent cloning of tomato ripening genes known previously only through mutation. Advances in the genomics of tomato have provided genetic and molecular tools that have facilitated positional and candidate gene based cloning of several key ripening genes. These discoveries have created new inroads into understanding of both primary ripening control mechanisms including transcription factors such as those encoded by the RIN MADS-box and CNR SPB-box genes which are necessary for the progression of virtually all ripening processes and elucidation of downstream signal transduction components impacting hormonal and environmental stimuli which coordinate and modulate ripening phenotypes.