Location: Plant, Soil and Nutrition ResearchTitle: Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening
|Chialva, Mateo - University Of Turin|
|Zouari, Ines - University Of Turin|
|Salvioli, Allesandro - University Of Turin|
|Novero, Mara - University Of Turin|
|Cao, Zulv - Sichuan University|
|Vrebalov, Julia - Boyce Thompson Institute|
|Bonfante, Paola - University Of Turin|
Submitted to: Planta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2016
Publication Date: 7/2/2016
Citation: Chialva, M., Zouari, I., Salvioli, A., Novero, M., Cao, Z., Vrebalov, J., Giovannoni, J.J., Bonfante, P. 2016. Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening. Planta. 244(1):155-165.
Interpretive Summary: The availability of tomato ripening mutants has unraveled many aspects of the genetics behind fleshy fruit ripening, plant hormones and light signal reception. Previous analyses revealed that arbuscular mycorrhizal (AM) symbiosis influences tomato ripening, we tested the hypothesis that an interplay might occur between the root symbiosis and ripening. Two mutants affected in different ripening processes were selected and the systemic response to fungal inoculation of each genotype was investigated in roots versus fruits by applying phenological, molecular, and biochemical approaches. Green ripe (Gr), deficient in fruit ethylene perception and hp-1 (high-pigment-1), displaying enhanced light signal perception throughout the plant, including the fruit, were inoculated with the AM fungus Funneliformis mosseae. As a further step we considered the expression of three genes previously selected as potential systemic markers of mycorrhization in tomato, LHY, ALN and LePT7. Our results show that both mutants, notwithstanding a normal root mycorrhizal phenotype, have altered expression of the three AM-induced transcripts in fruit. In such mutants the mycorrhization does not lead elevated fruit phosphate concentration as in WT controls. These results suggest that ripening mutations interfere with AM inducing systemic changes in plant phenology and gene expression in fruits. We hypothesize cross-talk between AM and ripening processes to mediate activities that are important to the ripening of fleshy fruits.
Technical Abstract: The roots of plants interact with soil mycorrhizal fungi to facilitate soil nutrient acquisition by the plant and carbon transfer to the fungus. Here we use tomato fruit ripening mutations to demonstrate that this root interaction communicates with and supports genetic mechanisms associated with the accumulation of necessary nutrients and maturation of the developing fruit. Tomato fruits with and without arbuscular mycorrhiza displayed differential gene expression profiles that ultimately led to differential nutrient accumulation profiles of the fruit. These results suggest that the microbiome influences fruit quality and may serve as a target for manipulation of fruit crop traits of human relevance.